Zhongguo Xiong
- Associate Professor, Plant Sciences
- Associate Professor, BIO5 Institute
- Member of the Graduate Faculty
Contact
- (520) 621-9916
- Marley, Rm. 741D
- Tucson, AZ 85721
- zxiong@arizona.edu
Biography
Huazhong Agric. Univ, China | 1978-1981 | B.S., 1981 | Plant Protection |
University of Florida | 1983-1984 | M.S., 1985 | Plant Pathology |
Kansas State University | 1985-1988 | Ph.D., 1988 | Plant Pathology |
Degrees
- Ph.D. Plant Pathology
- Kansas State University, Manhattan, Kansas, United States
- M.S. Plant Pathology
- University of Florida, Gainesville, Florida, United States
- B.S. Plant Protection
- Huazhong Agricultural University, Wuhan, China
Work Experience
- University of Arizona, Tucson, Arizona (1997 - Ongoing)
- University of Arizona, Tucson, Arizona (1991 - 1997)
- North Carolina State University (1989 - 1991)
Awards
- 2022 Biochemistry Outstanding Freshman
- Chemistry & Biochemistry Department, University of Arizona, Spring 2022
- Invited Seminar
- Chinese Society of Plant Pathology, Summer 2015
- Institute of Plant and Environmental Protection, Chinese Academy of Tropical Agricultural Sciences, Summer 2015
- Chair-Elect
- APS Virology Committee, Fall 2013
- Recognition as panel member for discussion on "Importance of plant disease and pest management"
- University of Occidente, Fall 2011
- Recognition for giving a keynote address in the National Biology Conference
- Consortium of Mexican Universities, Fall 2011
- Invited to speak at the Mastering Leadership Conference for creative adaptation of mastering technology in microbiology instruction
- Pearson Education, Pearson, Spring 2011
Interests
Research
Plant viruses as vectors to display foreign proteins/peptide as vaccine candidates, gene expression and replication of RNA and DNA viruses, mechanisms of plant resistance to viral infections and resistance-breaking by RNA viruses, recombination and evolution of RNA viruses, virus identification and discovery using high-throughput sequencing technologies, editing of host genes to generate engineered immunity against viruses, and roles of extracellular DNA in plant defense against microbial pathogens.
Teaching
Virology, Microbiology
Courses
2024-25 Courses
-
Dept of Plant Sci Smnr
PLP 596A (Fall 2024) -
Dept of Plant Sci Smnr
PLS 596A (Fall 2024) -
General Microbiology
MIC 205A (Fall 2024) -
Independent Study
PCOL 499 (Fall 2024)
2023-24 Courses
-
Independent Study
ACBS 499 (Summer I 2024) -
General Virology
PLS 333 (Spring 2024) -
Independent Study
MIC 399 (Spring 2024) -
Independent Study
PCOL 399 (Spring 2024) -
General Microbiology
MIC 205A (Fall 2023) -
Senior Capstone
BIOC 498 (Fall 2023)
2022-23 Courses
-
Honors Independent Study
BIOC 299H (Spring 2023) -
Senior Capstone
BIOC 498 (Spring 2023) -
Directed Research
ACBS 492 (Fall 2022) -
Directed Research
BIOC 492 (Fall 2022) -
Directed Research
PLP 592 (Fall 2022) -
General Microbiology
MIC 205A (Fall 2022) -
Honors Independent Study
BIOC 299H (Fall 2022) -
Independent Study
MIC 499 (Fall 2022) -
Senior Capstone
BIOC 498 (Fall 2022)
2021-22 Courses
-
Independent Study
ECOL 399 (Summer I 2022) -
Directed Research
ACBS 492 (Spring 2022) -
Independent Study
MIC 499 (Spring 2022) -
Research
PLP 900 (Spring 2022) -
Directed Research
BIOC 492 (Fall 2021) -
General Microbiology
MIC 205A (Fall 2021) -
Research
PLP 900 (Fall 2021)
2020-21 Courses
-
Dept of Plant Sci Smnr
PLP 596A (Spring 2021) -
Dept of Plant Sci Smnr
PLS 596A (Spring 2021) -
Independent Study
MIC 399 (Spring 2021) -
Research
PLP 900 (Spring 2021) -
Dept of Plant Sci Smnr
PLP 596A (Fall 2020) -
Dept of Plant Sci Smnr
PLS 596A (Fall 2020) -
General Microbiology
MIC 205A (Fall 2020) -
Independent Study
ACBS 499 (Fall 2020) -
Independent Study
PSIO 399 (Fall 2020) -
Research
PLP 900 (Fall 2020)
2019-20 Courses
-
Independent Study
PSIO 399 (Spring 2020) -
General Microbiology
MIC 205A (Fall 2019)
2018-19 Courses
-
Directed Research
PSIO 492 (Spring 2019) -
Independent Study
ECOL 399 (Spring 2019) -
General Microbiology
MIC 205A (Fall 2018)
2017-18 Courses
-
General Microbiology
MIC 205A (Fall 2017) -
Preceptorship
PLS 491 (Fall 2017)
2016-17 Courses
-
Independent Study
MCB 399 (Spring 2017) -
General Microbiology
MIC 205A (Fall 2016) -
Preceptorship
PLP 491 (Fall 2016) -
Preceptorship
PLS 491 (Fall 2016)
Scholarly Contributions
Journals/Publications
- Yu, N., Zeng, W., Xiong, Z., & Liu, Z. (2022). A high efficacy DNA vaccine against Tilapia lake virus in Nile tilapia (Oreochromis niloticus). Aquaculture Reports, 24, 101166.
- Gao, S., He, P., Lin, T., Liu, H., Guo, B., Lin, H., Hu, Y., Chen, Q., Xiang, P., Zou, L., Li, X., Xiong, Z., & Lin, J. (2021). Consecutive soybean (Glycine max) planting and covering improve acidified tea garden soil. PloS one, 16(7), e0254502.More infoPlanting soybeans (Glycine max (L.) Merr.) in tea gardens decreased soil pH in theory but increased it in practice. This controversy was addressed in this study by treating the tea garden soil consecutively with different parts of a soybean cover crop: aboveground soybean (ASB) parts, underground soybean (USB) root residues, and the whole soybean (WSB) plants. In comparison with the control, the soil pH increased significantly after the third ASB and WSB treatments, but there was no significant change in the soil pH in the USB treatment. Concordantly, the soil exchangeable acidity decreased significantly and the soil exchangeable bases increased significantly in the ASB and WSB treatments. The exchangeable acidity increased in the USB treatment, but the amount of the increased acidity was less than that of the increased bases in the ASB treatment, resulting in a net increase in the exchangeable bases in the WSB treatment. Soybean planting and covering also increased the microbial richness and abundance significantly, which led to significantly more soil organic matters. Exchangeable K+ and Mg2+, and soil organic matters played significantly positive roles and exchangeable Al3+ played negative roles in improving soil pH. Our data suggest that consecutive plantings of soybean cover crop increase the pH of the acidified tea garden soil.
- Machuka, E. M., Xiong, Z., Stomeo, F., Nyende, A. B., Njuguna, J., Mwatuni, F. M., & Machuka, E. (2020). Occurrence, genetic diversity, and recombination of maize lethal necrosis disease-causing viruses in Kenya.. Virus research, 286, 198081. doi:10.1016/j.virusres.2020.198081More infoMaize is the most important food crop in Kenya accounting for more than 51 % of all staples grown in the country. Out of Kenya's 5.3 million ha total crops area, more than 2.1 million ha is occupied by maize which translates to 40 % of all crops area. However, with the emergence of maize lethal necrosis (MLN) disease in 2011, the average yields plummeted to all-time lows with severely affected counties recording 90-100% yield loss in 2013 and 2014. The disease is mainly caused by Maize chlorotic mottle virus (MCMV) in combination with Sugarcane mosaic virus (SCMV) or other potyviruses. In this study, a country-wide survey was carried out to assess the MLN causing viruses in Kenya, their distribution, genetic diversity, and recombination. The causative viruses of MLN were determined by RT-PCR using virus-specific primers and DAS-ELISA. Next-generation sequencing (NGS) data was generated, viral sequences identified, genetic diversity of MLN viruses was determined, and recombination was evaluated. MCMV and SCMV were detected in all the maize growing regions at varying levels of incidence, and severity while MaYMV, a polerovirus was detected in some samples through NGS. However, there were some samples in this study where only MCMV was detected with severe MLN symptoms. SCMV Sequences were highly diverse while MCMV sequences exhibited low variability. Potential recombination events were detected only in SCMV explaining the elevated level of diversity and associated risk of this virus in Kenya and the eastern Africa region.
- Yu, N. T., Yang, Y., Xiong, Z., Liu, Z., & Cai, Z. Y. (2020). Complete genomic sequence of Noni mosaic virus (NoMV) associated with a mosaic disease in Morinda citrifolia L.. European Journal of Plant Pathology, 156(4), 1005-1014. doi:10.1007/s10658-020-01948-4More infoAn outbreak of a virus-like disease has caused severe damage to noni plants (Morinda citrifolia L.) in Xishuangbanna area of Yunnan province in southwest China since 2015. The diseased plants displayed typical mosaic symptom with light and dark green patches on leaves. Flexuous filamentous virus particles of about 800 nm in length were observed from the leaf saps by transmission electron microscope. Illuemina transcriptomic sequencing further revealed the presence of a potyvirus and its near complete genome was obtained from de novo assembly. The complete genome of 9659 nts was obtained by Sanger sequencing of eight amplicons generate by RT-PCR and 5′ and 3’ RACE. BLASTp analysis of the polyprotein sequence showed that the virus was most closely related to Tobacco vein banding mosaic virus (TVBMV), but these two viruses only shared 50.7% amino acid sequence similarity. Both phylogenetic analyses of the polyprotein and CP amino acid sequences indicated that this virus is a member of genus Potyvirus. However, the low sequence homology with all known potyviruses established this virus as a new species in the genus, tentatively named as Noni mosaic virus (NoMV). Our field surveys showed that 100% of the symptomatic samples and 28.57% of the asymptomatic samples were infected with this novel potyvirus. Aphids collected from diseased leaves were also detected carrying the virus and aphid transmission test confirmed it can transmit the NoMV. In summary, our data indicated that a novel species of potyvirus, NoMV, is prevalent in Yunnan, China and is associated with an emerging mosaic disease on M. citrifolia.
- Park, H. J., Wang, W., Curlango-Rivera, G., Xiong, Z., Lin, Z., Huskey, D. A., Hawes, M. C., VanEtten, H. D., & Turgeon, B. G. (2019). A DNase from a Fungal Phytopathogen Is a Virulence Factor Likely Deployed as Counter Defense against Host-Secreted Extracellular DNA. mBio, 10(2).More infoHistone-linked extracellular DNA (exDNA) is a component of neutrophil extracellular traps (NETs). NETs have been shown to play a role in immune response to bacteria, fungi, viruses, and protozoan parasites. Mutation of genes encoding group A extracellular DNases (exDNases) results in reduced virulence in animals, a finding that implies that exDNases are deployed as counter defense against host DNA-containing NETs. Is the exDNA/exDNase mechanism also relevant to plants and their pathogens? It has been demonstrated previously that exDNA is a component of a matrix secreted from plant root caps and that plants also carry out an extracellular trapping process. Treatment with DNase I destroys root tip resistance to infection by fungi, the most abundant plant pathogens. We show that the absence of a single gene encoding a candidate exDNase results in significantly reduced virulence of a fungal plant pathogen to its host on leaves, the known infection site, and on roots. Mg-dependent exDNase activity was demonstrated in fungal culture filtrates and induced when host leaf material was present. It is speculated that the enzyme functions to degrade plant-secreted DNA, a component of a complex matrix akin to neutrophil extracellular traps of animals. We document that the absence of a single gene encoding a DNase in a fungal plant pathogen results in significantly reduced virulence to a plant host. We compared a wild-type strain of the maize pathogen and an isogenic mutant lacking a candidate secreted DNase-encoding gene and demonstrated that the mutant is reduced in virulence on leaves and on roots. There are no previous reports of deletion of such a gene from either an animal or plant fungal pathogen accompanied by comparative assays of mutants and wild type for alterations in virulence. We observed DNase activity, in fungal culture filtrates, that is Mg dependent and induced when plant host leaf material is present. Our findings demonstrate not only that fungi use extracellular DNases (exDNases) for virulence, but also that the relevant molecules are deployed in above-ground leaves as well as below-ground plant tissues. Overall, these data provide support for a common defense/counter defense virulence mechanism used by animals, plants, and their fungal and bacterial pathogens and suggest that components of the mechanism might be novel targets for the control of plant disease.
- Xiong, Z., Xiong, Z., Huskey, D. A., Huskey, D. A., Hawes, M. C., Hawes, M. C., Turgeon, B. G., Turgeon, B. G., VanEtten, H. D., VanEtten, H. D., Lin, Z., Lin, Z., Curlango-Rivera, G., Curlango-Rivera, G., Wang, W., Wang, W., Park, H. C., & Park, H. C. (2019). A DNase from a Fungal Phytopathogen Is a Virulence Factor Likely Deployed as Counter Defense against Host-Secreted Extracellular DNA. MBio. doi:10.1128/mbio.02805-18
- Yu, N. T., Xie, H. M., Zhang, Y. L., Wang, J. H., Xiong, Z., & Liu, Z. X. (2019). Independent modulation of individual genomic component transcription and a cis-acting element related to high transcriptional activity in a multipartite DNA virus. BMC genomics, 20(1), 573.More infoThe genome of Banana bunchy top virus (BBTV) consists of at least six circular, single-stranded DNA components of ~ 1 kb in length. Some BBTV isolates may also carry satellite DNA molecules that are not essential for BBTV infection. The relation between multipartite DNA virus replication and their transcriptional levels and the underlying mechanism remain unclear.
- Yu, N., Cai, Z., Xiong, Z., Yang, Y., & Liu, Z. (2019). A novel species of potyvirus, Noni mosaic virus (NoMV), was identified in Morinda citrifolia L.. Preprints. doi:10.20944/preprints201910.0156.v1More infoSubmitted Nov. 2018
- Yu, N., Cai, Z., Xiong, Z., Yang, Y., Liu, Z., Liu, Z., & Yu, N. (2019). Complete Genomic Sequence of Noni mosaic virus (NoMV), a Novel Potyvirus Associated with a Mosaic Disease in Morinda citrifolia L.. PrinPrints.org. doi:10.20944/PREPRINTS201910.0156.V1
- Yu, N., Zhang, Y., Xiong, Z., Qu, L., & Liu, Z. (2019). A simplified method for the simultaneous detection of nervous necrosis virus and iridovirus in grouper Epinephelus spp.. ACTA VIROLOGICA, 63(1), 80-87.
- Yokomi, R., Selvaraj, V., Maheshwari, Y., Chiumenti, M., Saponari, M., Giampetruzzi, A., Weng, Z., Xiong, Z., & Hajeri, S. (2018). Molecular and biological characterization of a novel mild strain of citrus tristeza virus in California. Archives of virology, 163(7), 1795-1804.More infoStrain differentiating marker profiles of citrus tristeza virus (CTV) isolates from California have shown the presence of multiple genotypes. To better define the genetic diversity involved, full-length genome sequences from four California CTV isolates were determined by small-interfering RNA sequencing. Phylogenetic analysis and nucleotide sequence comparisons differentiated these isolates into the genotypes VT (CA-VT-AT39), T30 (CA-T30-AT4), and a new strain called S1 (CA-S1-L and CA-S1-L65). S1 isolates had three common recombination events within portions of genes from VT, T36 and RB strains and were transmissible by Aphis gossypii. Virus indexing showed that CA-VT-AT39 could be classified as a severe strain, whereas CA-T30-AT4, CA-S1-L and CA-S1-L65 were mild. CA-VT-AT39, CA-S1-L, and CA-S1-L65 reacted with monoclonal antibody MCA13, whereas CA-T30-AT4 did not. RT-PCR and RT-qPCR detection assays for the S1 strain were developed and used to screen MCA13-reactive isolates in a CTV collection from central California collected from 1968 to 2011. Forty-two isolates were found to contain the S1 strain, alone or in combinations with other genotypes. BLAST and phylogenetic analysis of the S1 p25 gene region with other extant CTV sequences from the NCBI database suggested that putative S1-like isolates might occur elsewhere (e.g., China, South Korea, Turkey, Bosnia and Croatia). This information is important for CTV evolution, detection of specific strains, and cross-protection.
- Yu, N., Cochran, A., Trinh, S., Wen, F., VanEtten, H., Hawes, M. C., & Xiong, Z. (2018). Battles in the outer space: Extracellular DNases secreted by Pectobacterium carotovorum and its host plants. PHYTOPATHOLOGY, 108(10), 11-11.
- Shi, S., Zhang, X., Mandel, M. A., Zhang, P., Zhang, Y., Ferguson, M., Amuge, T., Rounsley, S., Liu, Z., & Xiong, Z. (2017). Variations of five eIF4E genes across cassava accessions exhibiting tolerant and susceptible responses to cassava brown streak disease. PLOS ONE, 12(8).
- Wen, F., Curlango-Rivera, G., Huskey, D. A., Xiong, Z., & Hawes, M. C. (2017). Visualization of extracellular DNA released during border cell separation from the root cap. AMERICAN JOURNAL OF BOTANY, 104(7), 970-978.
- Curlango-Rivera, G., Gunawardena, U., Wen, F., Zhao, X., Xiong, Z., & Hawes, M. C. (2016). Roots: Contribution to the Rhizosphere. eLS, 1-7. doi:DOI: 10.1002/9780470015902.a0002335.pub3
- Hawes, M., Allen, C., Turgeon, B. G., Curlango-Rivera, G., Tran, T. M., Huskey, D. A., & Xiong, Z. (2016). Root Border Cells and Their Role in Plant Defense. ANNUAL REVIEW OF PHYTOPATHOLOGY, VOL 54, 54, 143-161.More info(Invited Review)
- Cui, B., Zheng, Y., Xiang, B., & Xiong, Z. (2015). Profiling virus infection using small RNA sequencing data: A case study of virome from a small-holder farm. PHYTOPATHOLOGY, 105(11), 32-32.
- Shi, S., Mandel, M. A., & Xiong, Z. (2015). Two amino acids of cassava novel cap-binding proteins critical for their interaction with Cassava brown streak virus VPg. PHYTOPATHOLOGY, 105(11), 127-127.
- Curlango-Rivera, G., Flores-Lara, Y., Husky, D. A., Xiong, Z., & Hawes, M. C. (2014). Signals Controlling Extracellular Trap Formation in Plant and Animal Immune Responses. Clinical Microbiology: Open Access, 3(5), -.
- Wen, F., Brigham, L. A., Curlango-Rivera, G., Xiong, Z., & Hawes, M. C. (2014). Altered growth and root tip morphology in Pisum sativum L. in response to altered expression of a gene expressed in border cells. PLANT AND SOIL, 377(1-2), 179-187.More infoRecent studies suggest that root border cells function in defense of the root by an extracellular DNA-based trapping mechanism similar to that described in mammalian white blood cells. Genes controlling the specialized properties of border cells as they detach from the root tip therefore are of interest.
- Zhang, Y., Yu, N., Huang, Q., Yin, G., Guo, A., Wang, X., Xiong, Z., & Liu, Z. (2014). Complete genome of Hainan papaya ringspot virus using small RNA deep sequencing. VIRUS GENES, 48(3), 502-508.More infoSmall RNA deep sequencing allows for virus identification, virus genome assembly, and strain differentiation. In this study, papaya plants with virus-like symptoms collected in Hainan province were used for deep sequencing and small RNA library construction. After in silicon subtraction of the papaya sRNAs, small RNA reads were used to in the viral genome assembly using a reference-guided, iterative assembly approach. A nearly complete genome was assembled for a Hainan isolate of papaya ringspot virus (PRSV-HN-2). The complete PRSV-HN-2 genome (accession no.: KF734962) was obtained after a 15-nucleotide gap was filled by direct sequencing of the amplified genomic region. Direct sequencing of several random genomic regions of the PRSV isolate did not find any sequence discrepancy with the sRNA-assembled genome. The newly sequenced PRSV-HN-2 genome shared a nucleotide identity of 96 and 94 % to that of the PRSV-HN (EF183499) and PRSV-HN-1 (HQ424465) isolates, and together with these two isolates formed a new PRSV clade. These data demonstrate that the small RNA deep sequencing technology provides a viable and rapid mean to assemble complete viral genomes in plants.
- Acosta-Leal, R., & Xiong, Z. (2013). Intrahost mechanisms governing emergence of resistance-breaking variants of Potato virus Y. Virology, 437(1), 39-47.More infoPMID: 23332684;Abstract: The emergence of resistance breaking (RB) variants starting from the avirulent Potato virus Y NN strain (PVYNN) was analyzed after imposing different selective host constraints. Tobacco resistance to PVYNN is conferred by va in both NC745 and VAM genotypes, but VAM carries an extra resistance gene, va2. RB-variants emerged only in NC745 and unexpectedly accumulated higher in the original host, tobacco B21, than the parental PVYNN. However, the recovery of RB-variants was interfered by PVYNN in mixed infections. Further analysis indicated that RB-variants also arose in tobacco VAM, but they were limited to subliminal local infections. Their inability to breakout was associated with absence of a mutational adaptation in the viral VPg gene, which implied a loss of fitness in tobacco B21. Altogether, the emergence of RB-variants was conditioned by inherited host constraints, interference by co-infecting avirulent virus genotypes, and fitness tradeoff of virus adaptations. © 2012 Elsevier Inc..
- Acosta-Leal, R., & Xiong, Z. -. (2013). Intrahost mechanisms governing emergence of resistance-breaking variants of Potato virus Y. Virology, 437(1), 39-47.More infoThe emergence of resistance breaking (RB) variants starting from the avirulent Potato virus Y NN strain (PVY(NN)) was analyzed after imposing different selective host constraints. Tobacco resistance to PVY(NN) is conferred by va in both NC745 and VAM genotypes, but VAM carries an extra resistance gene, va2. RB-variants emerged only in NC745 and unexpectedly accumulated higher in the original host, tobacco B21, than the parental PVY(NN). However, the recovery of RB-variants was interfered by PVY(NN) in mixed infections. Further analysis indicated that RB-variants also arose in tobacco VAM, but they were limited to subliminal local infections. Their inability to breakout was associated with absence of a mutational adaptation in the viral VPg gene, which implied a loss of fitness in tobacco B21. Altogether, the emergence of RB-variants was conditioned by inherited host constraints, interference by co-infecting avirulent virus genotypes, and fitness tradeoff of virus adaptations.
- Curlango-Rivera, G., Huskey, D. A., Mostafa, A., Kessler, J. O., Xiong, Z., & Hawes, M. C. (2013). INTRASPECIES VARIATION IN COTTON BORDER CELL PRODUCTION: RHIZOSPHERE MICROBIOME IMPLICATIONS. AMERICAN JOURNAL OF BOTANY, 100(9), 1706-1712.
- Curlango-Rivera, G., Huskey, D. A., Mostafa, A., Kessler, J. O., Xiong, Z., & Hawes, M. C. (2013). Intraspecies variation in cotton border cell production: rhizosphere microbiome implications. American journal of botany, 100(9), 1706-12.
- Curlango-Rivera, G., Pew, T., VanEtten, H., Xiong, Z., Yu, N., & Hawes, M. (2013). Measuring Root Disease Suppression in Response to a Compost Water Extract. Phytopathology, 103(3), 255-260.
- Mcrae, A. G., Cochran, A. M., Trinh, S. A., Felix-Gastelum, R., Herrera-Rodriguez, G., Yu, N., & Xiong, Z. (2013). A torradovirus complex in Sinaloa, Mexico. PHYTOPATHOLOGY, 103(6, 2), 94.
- Fan, Z., & Xiong, Z. (2012). Centennial Symposium in Memory of Professor Wei-Fan Chiu. Phytopathology News, 46, 61.
- Felix, R., Cochran, A. M., Yu, N., Rodriguez, G. H., Trinh, S. A., & Xiong, Z. (2012). Genetic diversity and whitefly transmission of Tomato apex necrosis virus. PHYTOPATHOLOGY, 102(7), 37-37.
- Hawes, M., Curlango-Rivera, G., Xiong, Z., & Kessler, J. (2012). The plant extracellular DNA component of root exudates: Functional impact and implications for carbon cycling, disease, and sustainable agriculture. Plant and Soil, 355, 1-15.
- Hawes, M., Curlango-Rivera, G., Xiong, Z., & Kessler, J. (2012). The plant extracellular DNA component of root exudates: Functional impact and implications for carbon cycling, disease, and sustainable agriculture. Plant and Soil.
- Wang, J. -., Zhang, S. -., Gong, D., Wu, Y. -., Zhang, Y. -., Yu, N. -., Liu, Z. -., & Xiong, Z. (2012). First Report of Chilli ringspot virus on Chili Pepper in China. PLANT DISEASE, 96(3), 462-463.
- Wang, J., Zhang, S., Gong, D., Wu, Y., Zhang, Y., Yu, N., Liu, Z., & Xiong, Z. (2012). First report of Chilli ringspot virus in China. Plant Diease.More infodx.doi.org/10.1094/PDIS-11-11-0922
- Xiong, Z., Wong, B. C., Yu, N., Cantua, J., Allee, E. F., Cochran, A. M., & Trinh, S. A. (2012). Biological and molecular characterization of Tomato chlorotic dwarf viroid in Arizona. PHYTOPATHOLOGY, 102(7), 139-139.
- Yu, N., Zhang, Y., Feng, T., Wang, J., Kulye, M., Yang, W., Lin, Z., Xiong, Z., & Liu, Z. (2012). Cloning and sequence analysis of two banana bunchy top virus genomes in Hainan. Virus Gene.More info10.1007/s11262-012-0718-9
- Yu, N., Zhang, Y., Feng, T., Wang, J., Kulye, M., Yang, W., Lin, Z., Xiong, Z., & Liu, Z. (2012). Cloning and sequence analysis of two banana bunchy top virus genomes in Hainan. Virus Genes, 44(3), 488-494.More infoPMID: 22286609;Abstract: The genome of Banana bunchy top virus (BBTV) consists of six segments of single-stranded DNA of approximately 1 kb in length. We identified and sequenced the complete genomes of two BBTV isolates, one with and one without satellite DNA, from Haikou, Hainan, China. The Haikou-2 isolate contains six genomic segments and an additional satellite DNA while the Haikou-4 isolate contains only six genomic segments. Typical of other babuviruses, each genomic segment encodes a single open reading frame and contains the highly conserved stem-loop and major common regions. Phylogenetic analysis of the two Haikou isolates together with existing sequence records in GenBank confirmed the grouping of BBTV into two large groups and further refined the geographical distribution of each group. To accommodate the changes in the BBTV geographical distribution, the two groups are proposed as the Southeast Asian group and the Pacific-Indian Oceans group. Both the Haikou-2 and Haikou-4 isolates belong to the newly proposed Southeast Asian group. © Springer Science+Business Media, LLC 2012.
- Acosta-Leal, R., Duffy, S., Xiong, Z., Hammond, R. W., & Elena, S. F. (2011). Advances in Plant Virus Evolution: Translating Evolutionary Insights into Better Disease Management. PHYTOPATHOLOGY, 101(10), 1136-1148.
- Acosta-Leal, R., Duffy, S., Xiong, Z., Hammond, R. W., & Elena, S. F. (2011). Advances in plant virus evolution: Translating evolutionary insights into better disease management. Phytopathology, 101(10), 1136-1148.More infoPMID: 21554186;Abstract: Recent studies in plant virus evolution are revealing that genetic structure and behavior of virus and viroid populations can explain important pathogenic properties of these agents, such as host resistance breakdown, disease severity, and host shifting, among others. Genetic variation is essential for the survival of organisms. The exploration of how these subcellular parasites generate and maintain a certain frequency of mutations at the intra-and inter-host levels is revealing novel molecular virus-plant interactions. They emphasize the role of host environment in the dynamic genetic composition of virus populations. Functional genomics has identified host factors that are transcriptionally altered after virus infections. The analyses of these data by means of systems biology approaches are uncovering critical plant genes specifically targeted by viruses during host adaptation. Also, a next-generation resequencing approach of a whole virus genome is opening new avenues to study virus recombination and the relationships between intra-host virus composition and pathogenesis. Altogether, the analyzed data indicate that systematic disruption of some specific parameters of evolving virus populations could lead to more efficient ways of disease prevention, eradication, or tolerable virus-plant coexistence. © 2011 The American Phytopathological Society.
- Acosta-Leal, R., Duffy, S., Xiong, Z., Hammond, R., & Elena, S. (2011). Advances in plant virus evolution: Translating evolutionary insights into better disease management. Phytopathology, 101, 1136-1148.More info10.1094/PHYTO-01-11-0017
- Curlango-Rivera, G., Xiong, Z., Kessler, J. O., & Hawes, M. C. (2011). Extracellular trapping of bacteria in plant defense responses: Dynamics and specificity. PHYTOPATHOLOGY, 101(6), S40-S40.
- Gong, D., Wang, J., Lin, Z., Zhang, S., Zhang, Y., Yu, N., Xiong, Z., & Liu, Z. (2011). Genomic sequencing and analysis of Chilli ringspot virus, a novel potyvirus. Virus Gene, 43, 439-444.
- Gong, D., Wang, J., Lin, Z., Zhang, S., Zhang, Y., Yu, N., Xiong, Z., & Liu, Z. (2011). Genomic sequencing and analysis of Chilli ringspot virus, a novel potyvirus. Virus Genes, 43(3), 439-444.More infoPMID: 21847573;Abstract: Chilli ringspot virus (ChiRSV), a novel potyvirus, was recently found in Hainan, China with high prevalence. The genomic sequence of the ChiRSV-HN/14 isolate was determined by sequencing overlapping cDNA segments generated by reverse transcription polymerase chain reaction with degenerate and/or specific primers. ChiRSV genome (GenBank Acc. no. JN008909) comprised of 9,571 nucleotides (nt) excluding the 30-terminal poly (A) tail and contained a large open reading frame of 9,240 nt encoding a large polyprotein of 3,079 amino acids with predicted Mr of 349.1 kDa. A small, overlapping PIPO coding region was also found to span from nt 2,913 to 3,095, with a capacity to encode a peptide of 60 amino acids. ChiRSV shares sequence identities of only 48.5-65.4 and 42.9-68.7% with closely related potyviruses at the nucleotide and the amino acid levels, respectively. Phylogenetic analysis of the genomic sequences provided further evidence that ChiRSV is a distinct species of the Potyvirus genus. ChiRSV-HN/14 is most closely related to Tobacco vein banding mosaic virus and two other pepper-infecting potyviruses. © Springer Science+Business Media, LLC 2011.
- Hawes, M., Curlango-Rivera, G., Wen, F., White, G., VanEtten, H., & Xiong, Z. (2011). Extracellular DNA: the tip of root defenses. Plant Science, 106, 741-745.
- Xiong, Z., & Acosta-Leal, R. (2011). Dissect the evolutionary process of Potato virus Y to overcome host resistance during single-host passages. PHYTOPATHOLOGY, 101(6), S194-S195.
- Xiong, Z., Elena, S. F., Hammond, R. W., Duffy, S., & Acosta-Leal, R. (2011). Advances in Plant Virus Evolution: Translating Evolutionary Insights into Better Disease Management. Phytopathology. doi:10.1094/phyto-01-11-0017
- Xiong, Z., Hawes, M. C., Curlango-Rivera, G., Wen, F., White, G. J., Vanetten, H. D., & Xiong, Z. -. (2011). Extracellular DNA: the tip of root defenses?. Plant science : an international journal of experimental plant biology, 180(6).More infoThis review discusses how extracellular DNA (exDNA) might function in plant defense, and at what level(s) of innate immunity this process might operate. A new role for extracellular factors in mammalian defense has been described in a series of studies. These studies reveal that cells including neutrophils, eosinophils, and mast cells produce 'extracellular traps' (ETs) consisting of histone-linked exDNA. When pathogens are attracted to such ETs, they are trapped and killed. When the exDNA component of ETs is degraded, trapping is impaired and resistance against invasion is reduced. Conversely, mutation of microbial genes encoding exDNases that degrade exDNA results in loss of virulence. This discovery that exDNases are virulence factors opens new avenues for disease control. In plants, exDNA is required for defense of the root tip. Innate immunity-related proteins are among a group of >100 proteins secreted from the root cap and root border cell populations. Direct tests revealed that exDNA also is rapidly synthesized and exported from the root tip. When this exDNA is degraded by the endonuclease DNase 1, root tip resistance to fungal infection is lost; when the polymeric structure is degraded more slowly, by the exonuclease BAL31, loss of resistance to fungal infection is delayed accordingly. The results suggest that root border cells may function in a manner analogous to that which occurs in mammalian cells.
- Yu, N., Anderson, B. L., Shen, Y., & Xiong, Z. (2011). Engineering an infectious cDNA clone of an Arizona Pepino mosaic virus isolate. PHYTOPATHOLOGY, 101(6), S199-S199.
- Xiong, Z., Weng, Z., Galbraith, D. W., & Dawson, W. O. (2010). Viral population analysis by genomic sequencing. PHYTOPATHOLOGY, 100(6), S154-S154.
- Wen, F., White, G. J., VanEtten, H. D., Xiong, Z., & Hawes, M. C. (2009). Extracellular DNA is required for root tip resistance to fungal infection. Plant physiology, 151(2), 820-9.More infoPlant defense involves a complex array of biochemical interactions, many of which occur in the extracellular environment. The apical 1- to 2-mm root tip housing apical and root cap meristems is resistant to infection by most pathogens, so growth and gravity sensing often proceed normally even when other sites on the root are invaded. The mechanism of this resistance is unknown but appears to involve a mucilaginous matrix or "slime" composed of proteins, polysaccharides, and detached living cells called "border cells." Here, we report that extracellular DNA (exDNA) is a component of root cap slime and that exDNA degradation during inoculation by a fungal pathogen results in loss of root tip resistance to infection. Most root tips (>95%) escape infection even when immersed in inoculum from the root-rotting pathogen Nectria haematococca. By contrast, 100% of inoculated root tips treated with DNase I developed necrosis. Treatment with BAL31, an exonuclease that digests DNA more slowly than DNase I, also resulted in increased root tip infection, but the onset of infection was delayed. Control root tips or fungal spores treated with nuclease alone exhibited normal morphology and growth. Pea (Pisum sativum) root tips incubated with [(32)P]dCTP during a 1-h period when no cell death occurs yielded root cap slime containing (32)P-labeled exDNA. Our results suggest that exDNA is a previously unrecognized component of plant defense, an observation that is in accordance with the recent discovery that exDNA from white blood cells plays a key role in the vertebrate immune response against microbial pathogens.
- Wen, F., White, G., Van, E., Xiong, Z., & Hawes, M. C. (2009). Another 'extracellular polysaccharide' functioning in plant defense: Role of structural DNA in border cell-mediated defense of the legume root tip. PHYTOPATHOLOGY, 99(6), S140-S141.
- Weng, Z., & Xiong, Z. (2009). Three discontinuous loop nucleotides in the 3′ terminal stem-loop are required for Red clover necrotic mosaic virus RNA-2 replication. Virology, 393(2), 346-354.More infoPMID: 19733887;Abstract: The genome of Red clover necrotic mosaic virus (RCNMV) consists of positive-sense, single-stranded RNA-1 and RNA-2. The 29 nucleotides at the 3′ termini of both RNAs are nearly identical and are predicted to form a stable stem-loop (SL) structure, which is required for RCNMV RNA replication. Here we performed a systematic mutagenesis of the RNA-2 3′ SL to identify the nucleotides critical for replication. Infectivity and RNA replication assays indicated that the secondary structure of the 3′ SL and its loop sequence UAUAA were required for RNA replication. Single-nucleotide substitution analyses of the loop further pinpointed three discontinuous nucleotides (L1U, L2A, and L4A) that were vital for RNA replication. A 3-D model of the 3′ SL predicted the existence of a pocket formed by these three nucleotides that could be involved in RNA-protein interaction. The functional groups of the bases participating in this interaction at these positions are discussed. © 2009 Elsevier Inc. All rights reserved.
- Weng, Z., Liu, X., & Xiong, Z. (2009). Uncoupling the cell-to-cell movement and RNA silencing suppressor functions of Saguaro cactus virus capsid protein. PHYTOPATHOLOGY, 99(6), S141-S141.
- Xiong, Z., Weng, Z., & Xiong, Z. -. (2009). Three discontinuous loop nucleotides in the 3' terminal stem-loop are required for Red clover necrotic mosaic virus RNA-2 replication. Virology, 393(2).More infoThe genome of Red clover necrotic mosaic virus (RCNMV) consists of positive-sense, single-stranded RNA-1 and RNA-2. The 29 nucleotides at the 3' termini of both RNAs are nearly identical and are predicted to form a stable stem-loop (SL) structure, which is required for RCNMV RNA replication. Here we performed a systematic mutagenesis of the RNA-2 3' SL to identify the nucleotides critical for replication. Infectivity and RNA replication assays indicated that the secondary structure of the 3' SL and its loop sequence UAUAA were required for RNA replication. Single-nucleotide substitution analyses of the loop further pinpointed three discontinuous nucleotides (L1U, L2A, and L4A) that were vital for RNA replication. A 3-D model of the 3' SL predicted the existence of a pocket formed by these three nucleotides that could be involved in RNA-protein interaction. The functional groups of the bases participating in this interaction at these positions are discussed.
- Acosta-Leal, R., & Xiong, Z. (2008). Complementary functions of two recessive R-genes determine resistance durability of tobacco 'Virgin A Mutant' (VAM) to Potato virus Y. Virology, 379(2), 275-283.More infoPMID: 18682305;Abstract: Tobaccos VAM and NC745 carry the recessive va gene that confers resistance to PVYNN. However, they exhibit different levels of resistance durability. Upon virus inoculation, only NC745 developed sporadic systemic symptoms caused by emerging resistance-breaking variants that easily infected both NC745 and VAM genotypes. To identify the differential host conditions associated with this phenomenon, cellular accumulation, cell-to-cell movement, vascular translocation, and foliar content of PVYNN were comparatively evaluated. Virus cell-to-cell movement was restricted and its transit through the vasculature boundaries was completely blocked in both tobacco varieties. However, an additional defense mechanism operating only in tobacco VAM drastically reduced the in situ cellular virus accumulation. Genetic analyses of hybrid plant progenies indicate that VAM-type resistance was conditioned by at least two recessive genes: va and a newly reported va2 locus. Moreover, segregant plant progenies that restricted virus movement but permitted normal virus accumulation were prone to develop resistance-breaking infections. © 2008 Elsevier Inc. All rights reserved.
- Lu, Y. W., Shen, W. T., Zhou, P., Tang, Q. J., Niu, Y. M., Peng, M., & Xiong, Z. (2008). Complete genomic sequence of a Papaya ringspot virus isolate from Hainan Island, China. ARCHIVES OF VIROLOGY, 153(5), 991-993.
- Lu, Y. W., Shen, W. T., Zhou, P., Tang, Q. J., Niu, Y. M., Peng, M., & Xiong, Z. (2008). Complete genomic sequence of a Papaya ringspot virus isolate from Hainan Island, China. Archives of Virology, 153(5), 991-993.More infoPMID: 18357409;
- Wen, F., VanEtten, H. D., Xiong, Z., & Hawes, M. C. (2008). Fighting fungal pathogen by secreting extracellular DNA at pea root tips. PHYTOPATHOLOGY, 98(6), S169-S169.
- Xiong, Z., Acosta-Leal, R., & Xiong, Z. -. (2008). Complementary functions of two recessive R-genes determine resistance durability of tobacco 'Virgin A Mutant' (VAM) to Potato virus Y. Virology, 379(2).More infoTobaccos VAM and NC745 carry the recessive va gene that confers resistance to PVY(NN). However, they exhibit different levels of resistance durability. Upon virus inoculation, only NC745 developed sporadic systemic symptoms caused by emerging resistance-breaking variants that easily infected both NC745 and VAM genotypes. To identify the differential host conditions associated with this phenomenon, cellular accumulation, cell-to-cell movement, vascular translocation, and foliar content of PVY(NN) were comparatively evaluated. Virus cell-to-cell movement was restricted and its transit through the vasculature boundaries was completely blocked in both tobacco varieties. However, an additional defense mechanism operating only in tobacco VAM drastically reduced the in situ cellular virus accumulation. Genetic analyses of hybrid plant progenies indicate that VAM-type resistance was conditioned by at least two recessive genes: va and a newly reported va2 locus. Moreover, segregant plant progenies that restricted virus movement but permitted normal virus accumulation were prone to develop resistance-breaking infections.
- Weng, Z., & Xiong, Z. (2007). Complementation of Saguaro cactus virus cell-to-cell movement by a single movement protein of Red clover necrotic mosaic virus. PHYTOPATHOLOGY, 97(7), S122-S122.
- Xiong, Z., Weng, Z., Barthelson, R., Gowda, S., Hilf, M. E., Dawson, W. O., Galbraith, D. W., & Xiong, Z. -. (2007). Persistent infection and promiscuous recombination of multiple genotypes of an RNA virus within a single host generate extensive diversity. PloS one, 2(9).More infoRecombination and reassortment of viral genomes are major processes contributing to the creation of new, emerging viruses. These processes are especially significant in long-term persistent infections where multiple viral genotypes co-replicate in a single host, generating abundant genotypic variants, some of which may possess novel host-colonizing and pathogenicity traits. In some plants, successive vegetative propagation of infected tissues and introduction of new genotypes of a virus by vector transmission allows for viral populations to increase in complexity for hundreds of years allowing co-replication and subsequent recombination of the multiple viral genotypes. Using a resequencing microarray, we examined a persistent infection by a Citrus tristeza virus (CTV) complex in citrus, a vegetatively propagated, globally important fruit crop, and found that the complex comprised three major and a number of minor genotypes. Subsequent deep sequencing analysis of the viral population confirmed the presence of the three major CTV genotypes and, in addition, revealed that the minor genotypes consisted of an extraordinarily large number of genetic variants generated by promiscuous recombination between the major genotypes. Further analysis provided evidence that some of the recombinants underwent subsequent divergence, further increasing the genotypic complexity. These data demonstrate that persistent infection of multiple viral genotypes within a host organism is sufficient to drive the large-scale production of viral genetic variants that may evolve into new and emerging viruses.
- Wang, J., Liu, Z., Niu, S., Peng, M., Wang, D., Weng, Z., & Xiong, Z. (2006). Natural occurrence of Chilli veinal mottle virus on Capsicum chinense in China.. PLANT DISEASE, 90(3), 377-377.
- Acosta-Leal, R., Blachere, F., & Xiong, Z. (2005). Dissecting evolutionary process of resistance-breaking by Potato virus Y (PVY). PHYTOPATHOLOGY, 95(6), S2-S2.
- Xiong, Z., Barthelson, R., Weng, Z., & Galbraith, D. (2005). Analysis of the Citrus tristeza virus (CTV) genome using resequencing microarrays. PHYTOPATHOLOGY, 95(6), S114-S114.
- Yang, T. W., Yang, Y. A., & Xiong, Z. (2000). Paternal inheritance of chloroplast DNA in interspecific hybrids in the genus Larrea (Zygophyllaceae). American Journal of Botany, 87(10), 1452-1458.More infoPMID: 11034920;Abstract: The mode of chloroplast DNA (cpDNA) inheritance was investigated in the genus Larrea (Zygophyllaceae) by polymerase chain reaction (PCR) amplification of cpDNA fragments using three pairs of chloroplast universal primers. A total of 20 F1s from interspecific crosses among five different taxa in the section Bifolium was examined. Twelve F1s were from six crosses between L. cuneifolia (4x) and L. divaricata (2x) (Peru or Argentina) or L. tridentata (2x or 4x). Eight F1s were from two sets of reciprocal crosses between L. divaricata (2x) (Argentina) and L. tridentata (2x). Length polymorphism was observed in all three regions of cpDNA that separated L. cuneifolia parents from L. divaricata and L. tridentata parents and in one of the three cpDNA regions that differentiated L. divaricata (Argentina) parents from L. tridentata (2x) parents. In each case, it was the paternal cpDNA marker that appeared in the F1 individuals. This was further confirmed by restriction fragment length polymorphism (RFLP) analysis of the amplified cpDNA fragments. Larrea may be the fifth genus reported in angiosperms with a paternal bias in cpDNA transmission. Possible mechanisms that may result in paternal cpDNA inheritance were briefly reviewed. Based on the observed uniparental paternal inheritance of cpDNA, restriction analysis of the three cpDNA regions and previous cytogenetic studies, L. divaricata was probably the maternal progenitor of L. cuneifolia.
- Nadeem, A., Mehmood, T., Tahir, M., Khalid, S., & Xiong, Z. (1997). First report of papaya leaf curl disease in Pakistan. Plant Disease, 81(11), 1333-.
- Nadeem, A., Mehmood, T., Tahir, M., Khalid, S., & Xiong, Z. (1997). First report of papaya leaf curl disease in Pakistan.. PLANT DISEASE, 81(11), 1333-1333.
- Weng, Z., & Xiong, Z. (1997). Genome organization and gene expression of saguaro cactus carmovirus. Journal of General Virology, 78(3), 525-534.More infoPMID: 9049400;Abstract: The complete sequence of the single-stranded, (+)-sense RNA genome of saguaro cactus carmovirus (SCV) has been determined. The 3879 nucleotide genome contains five open reading frames (ORFs). The 5'-proximal ORF encodes a 26 kDa protein (p26) and terminates with an amber codon which is readthrough into an in-frame p57 ORF to generate an 86 kDa fusion protein (p86). Two small, centrally located ORFs encode a 6 kDa protein (p6) and a 9 kDa protein (p9), respectively. The 3'-proximal ORF encodes a 37 kDa (p37) capsid protein (CP). Analysis of the nucleotide and predicted amino acid sequences supports the classification of SCV in the genus Carmovirus in the family Tombusviridae. All predicted SCV proteins are expressed in an in vitro translation system. SCV p26 and the readthrough fusion protein p86 are synthesized from the genomic RNA while p6, p9 and p37 CP ORFs at the 3' half of the genome are expressed from two subgenomic (sg) RNAs. The 5' termini of both sg RNAs have been mapped. The large 1614 nucleotide sg RNA contains the p6 and p9 ORFs as the first and the second ORFs respectively from its 5' end. It directs the synthesis of abundant p6 but a small amount of p9. While a synthetic transcript with the p9 ORF at the 5' end is a more efficient messenger for p9, no corresponding sg RNA has been identified in vivo. The smaller 1396 nucleotide sg RNA contains only the p37 ORF and directs the synthesis of SCV CP.
- Weng, Z., & Xiong, Z. (1997). Genome organization and gene expression of saguaro cactus carmovirus. The Journal of general virology, 78 ( Pt 3), 525-34.More infoThe complete sequence of the single-stranded, (+)-sense RNA genome of saguaro cactus carmovirus (SCV) has been determined. The 3879 nucleotide genome contains five open reading frames (ORFs). The 5'-proximal ORF encodes a 26 kDa protein (p26) and terminates with an amber codon which is readthrough into an in-frame p57 ORF to generate an 86 kDa fusion protein (p86). Two small, centrally located ORFs encode a 6 kDa protein (p6) and a 9 kDa protein (p9), respectively. The 3'-proximal ORF encodes a 37 kDa (p37) capsid protein (CP). Analysis of the nucleotide and predicted amino acid sequences supports the classification of SCV in the genus Carmovirus in the family Tombusviridae. All predicted SCV proteins are expressed in an in vitro translation system. SCV p26 and the readthrough fusion protein p86 are synthesized from the genomic RNA while p6, p9 and p37 CP ORFs at the 3' half of the genome are expressed from two subgenomic (sg) RNAs. The 5' termini of both sg RNAs have been mapped. The large 1614 nucleotide sg RNA contains the p6 and p9 ORFs as the first and the second ORFs respectively from its 5' end. It directs the synthesis of abundant p6 but a small amount of p9. While a synthetic transcript with the p9 ORF at the 5' end is a more efficient messenger for p9, no corresponding sg RNA has been identified in vivo. The smaller 1396 nucleotide sg RNA contains only the p37 ORF and directs the synthesis of SCV CP.
- Weng, Z., & Xiong, Z. (1996). Erratum: A Method for Accurate Determination of Terminal Sequences of Viral Genomic RNA (Genome Research 2 (202-207)). Genome Research, 6(2), 166-.
- Nadeem, A., Xiong, Z., Nelson, M. R., & Nelson, M. R. (1995). Cotton Leaf Curl Virus, A Threat to Arizona Cotton?. Cotton: A College of Agriculture Report, 363-364.More infoA serious virus disease of cotton in Pakistan is distantly related to cotton leaf crumple in Arizona. It is much more destructive on cotton than leaf crumple, and has never been found in the western hemisphere. Cotton leaf crumple in Arizona causes only modestly damaging midseason infections, while leaf curl, has had a major impact on the crop in Pakistan. Modern transportation and the increasing movement of living plants in global trade has resulted in them recent introduction of a similar disease of another crop to the western hemisphere. Cotton Leaf Curl Virus Leaf curl, a virus disease of cotton, a problem in the Sudan and other old world countries in Africa and Asia for more than fifty years, has become a critical problem during the past five years in Pakistan. During that time economic hardship and industrial dislocations have resulted from the increase in leaf curl with some estimates as high as fifty per cent loss to the crop in some areas. As a result of this disease, Pakistan, at least for now, has become a net importer rather than exporter of cotton. Cotton Leaf Crumple Virus Cotton leaf crumple virus causes a disease of cotton in the US and Central American countries. It is similar to leaf curl virus in that it is a whitefly transmitted geminivirus. Symptoms observed in Pakistan would suggest that leaf crumple may be present in Pakistan as well as leaf curl. There is no evidence that leaf curl of cotton is present in the western hemisphere. Leaf crumple infections appear in Arizona under these conditions: 1. When stubbed cotton is grown; 2. In late cotton i.e. planted after June 1; 3. when cotton is planted near a spring crop that is a vector host such as cantaloupes; In the last ten years, leaf crumple has been observed regularly in mid to late season cotton in Arizona. Such infections cause only modest losses. More severe disease has been observed sporadically under conditions outlined above. Impact of Virus Diseases on Cotton With both viruses, serious losses occur after early infections. While plants infected with cotton leaf crumple virus of the western hemisphere may have yields reduced by up to 60 percent under very early infections, the quality of the cotton produced after infection is comparable to that produced on non infected plants .When a plant is infected with leaf curl virus it produces no more useable cotton and reduced productivity may be as high as 100 percent when infections occur early.
- Weng, Z., & Xiong, Z. (1995). A method for accurate determination of terminal sequences of viral genomic RNA. Genome Research, 5(2), 202-207.More infoPMID: 9132274;Abstract: A combination of ligation-anchored PCR and anchored cDNA cloning techniques were used to clone the termini of the saguaro cactus virus (SCV) RNA genome. The terminal sequences of the viral genome were subsequently determined from the clones. The 5' terminus was cloned by ligation-anchored PCR, whereas the 3' terminus was obtained by a technique we term anchored cDNA cloning. In anchored cDNA cloning, an anchor oligonucleotide was prepared by phosphorylation at the 5' end, followed by addition of a dideoxynucleotide at the 3' end to block the free hydroxyl group. The 5' end of the anchor was subsequently ligated to the 3' end of SCV RNA. The anchor-ligated, chimerical viral RNA was then reverse-transcribed into cDNA using a primer complementary to the anchor. The cDNA containing the complete 3'-terminal sequence was converted into ds-cDNA, cloned, and sequenced. Two restriction sites, one within the viral sequence and one within the primer sequence, were used to facilitate cloning. The combination of these techniques proved to be an easy and accurate way to determine the terminal sequences of SCV RNA genome and should be applicable to any other RNA molecules with unknown terminal sequences.
- Weng, Z., & Xiong, Z. (1995). A method for accurate determination of terminal sequences of viral genomic RNA. Genome research, 5(2), 202-7.More infoA combination of ligation-anchored PCR and anchored cDNA cloning techniques were used to clone the termini of the saguaro cactus virus (SCV) RNA genome. The terminal sequences of the viral genome were subsequently determined from the clones. The 5' terminus was cloned by ligation-anchored PCR, whereas the 3' terminus was obtained by a technique we term anchored cDNA cloning. In anchored cDNA cloning, an anchor oligonucleotide was prepared by phosphorylation at the 5' end, followed by addition of a dideoxynucleotide at the 3' end to block the free hydroxyl group. The 5' end of the anchor was subsequently ligated to the 3' end of SCV RNA. The anchor-ligated, chimerical viral RNA was then reverse-transcribed into cDNA using a primer complementary to the anchor. The cDNA containing the complete 3'-terminal sequence was converted into ds-cDNA, cloned, and sequenced. Two restriction sites, one within the viral sequence and one within the primer sequence, were used to facilitate cloning. The combination of these techniques proved to be an easy and accurate way to determine the terminal sequences of SCV RNA genome and should be applicable to any other RNA molecules with unknown terminal sequences.
- SUDARSONO, ., WOLOSHUK, S. L., XIONG, Z., HELLMANN, G. M., WERNSMAN, E. A., WEISSINGER, A. K., & LOMMEL, S. A. (1993). NUCLEOTIDE-SEQUENCE OF THE CAPSID PROTEIN CISTRONS FROM 6 POTATO VIRUS-Y (PVY) ISOLATES INFECTING TOBACCO. ARCHIVES OF VIROLOGY, 132(1-2), 161-170.
- Sudarsono, ., Woloshuk, S. L., Xiong, Z., Hellmann, G. M., Wernsman, E. A., Weissinger, A. K., & Lommel, S. A. (1993). Nucleotide sequence of the capsid protein cistrons from six potato virus Y (PVY) isolates infecting tobacco. Archives of Virology, 132(1-2), 161-170.More infoPMID: 8352655;Abstract: Complementary DNA libraries representing the capsid protein cistron of the potato virus Y (PVY) isolate 'Chilean', 'Hungarian', MsNr, NsNr, O, and 'Potato US' were synthesized and used as template for polymerase chain reaction (PCR) amplification. An AUG codon for initiating a discrete capsid protein (CP) open reading frame was embedded upstream of the first codon of the CP cistrons. PCR-amplified products of the expected size of 0.8 kilo bases were cloned into the transcription vector pBS(+). The fidelity of each PCR-amplified PVY CP cistron was tested by transcribing recombinant plasmids in vitro and translating the transcripts in two cell free translation systems. Translation analysis of in vitro transcribed PVY CP cistrons consistently yielded a polypeptide co-migrating with authentic CP that was immunoprecipitated by anti PVY 'Chilean' antibodies. The nucleotide sequence of each capsid protein gene was determined by dideoxy sequence analysis. Each capsid protein gene was determined to be 801 nucleotides in length, encoding a deduced protein of 267 amino acids with calculated Mr ranging from 29 799 to 29 980. The nucleic acid sequence similarity between the six isolates ranged between 89 to 97% and the amino acid similarity between 91 to 99%. The high level of amino acid sequence similarity confirms the classification of these viruses as isolates of PVY. © 1993 Springer-Verlag.
- Xiong, Z., Kim, K. H., Giesman-Cookmeyer, D., & Lommel, S. A. (1993). The roles of the red clover necrotic mosaic virus capsid and cell-to-cell movement proteins in systemic infection. Virology, 192(1), 27-32.More infoPMID: 8517020;Abstract: The red clover necrotic mosaic dianthovirus (RCNMV) genome is split between two single-stranded RNA species termed RNA-1 and RNA-2. RNA-2 is required for infection of whole plants but is dispensable for infection and virion formation in protoplasts. We have used full-length cDNA clones of RNA- 1 and -2 from which infectious in vitro transcripts can be derived to construct a number of mutations in the RNA-1 encoded capsid protein and the RNA-2 encoded cell-to-cell movement protein genes. The capsid protein and the RNA sequence encoding the capsid protein were dispensable for infection of the inoculated leaves of Nicotiana benthamiana and N. clevelandii at both 15 and 25°. In addition, capsid protein was not necessary for systemic infection of N. benthamiana at 15°. As many as 39 amino acid residues could be deleted from the carboxyl-terminus of the RNA-2 encoded 35-kDa cell-to- cell movement protein without loss of or reduction in the rate of cell-to- cell movement or systemic infection. However, larger deletions within the cell-to-cell movement protein gene prevented cell-to-cell movement and systemic infection of N. benthamiana. These data suggest that the spread of RCNMV in a systemic host is a combination of two distinct events: cell-to- cell movement and long distance transport. We conclude that the RCNMV 35-kDa movement protein is required for cell-to-cell movement, whereas the capsid protein is not necessary for cell-to-cell movement and, depending on host genotype and environmental factors, may or may not be required for long distance transport.
- Xiong, Z., Kim, K. H., Kendall, T. L., & Lommel, S. A. (1993). Synthesis of the putative red clover necrotic mosaic virus RNA polymerase by ribosomal frameshifting in vitro. Virology, 193(1), 213-221.More infoPMID: 8438566;Abstract: The red clover necrotic mosaic virus (RCNMV) genome is split between two single-stranded RNA species termed RNA-1 and RNA-2. RNA-1 directs the synthesis of 88-kDa (p88), 57-kDa (p57), 37-kDa (p37), and 27-kDa (p27) polypeptides and RNA-2 a 35-kDa (p35) polypeptide in vitro. The coding order of the RNA-1 products was determined to be 5'-p27-p57-p37-3'. Antibodies to synthetic peptides representing the carboxyl terminal portions of p27 and p57 immunoprecipitated their respective polypeptides in addition to p88, suggesting that p88 is a fusion protein. A frameshift heptanucleotide sequence element has been identified in RCNMV RNA-1. In addition, a stable stem-loop secondary structure adjacent to the heptanucleotide sequence is predicted. Together, these sequence elements suggest that a ribosomal frameshifting event occurs which allows translational readthrough of the p27 open reading frame into the p57 open reading frame, generating the observed p88 product. An RNA-1 expression construct fusing the p57 and the CP open reading frame was engineered to investigate the ribosomal frameshifting event. CP antibodies immunoprecipitated a fusion protein of the predicted size containing the carboxyl portion of CP. Site-directed mutagenesis of the frameshift element indicates that in vitro, p88 can also be expressed alternatively by suppression of an amber termination codon. Based on these data, we propose that the putative RCNMV RNA polymerase is an 88-kDa polypeptide expressed by a ribosomal frameshifting mechanism similar to those utilized by retroviruses.
- Lommel, S. A., Kendall, T. L., Xiong, Z., & Nutter, R. C. (1991). Identification of the Maize chlorotic mottle virus capsid protein cistron and characterization of its subgenomic messenger RNA. Virology, 181(1), 382-385.More infoPMID: 1994587;Abstract: Maize chlorotic mottle virus (MCMV) is a 30-nm icosahedral plant virus composed of a single 25-kDa capsid protein component and a 4.4-kb single-stranded, positive-sense genomic RNA. Northern blot hybridization analysis detected a single 3′-terminal 1.1-kb subgenomic RNA in infected plants. Virion RNA directs the synthesis of several polypeptides in a rabbit reticulocyte lysate in vitro translation system of which only the 25-kDa polypeptide is immunoprecipitated by MCMV capsid protein antiserum. The 1.1-kb subgenomic RNA is a highly efficient messenger RNA for capsid protein synthesis. Positive polarity in vitro transcripts from 3′-proximal MCMV cDNA clones direct the synthesis of the capsid protein in in vitro translation experiments. These data suggest that the MCMV capsid protein is expressed from a subgenomic RNA in vivo, and that the 25-kDa capsid protein is encoded by the 3′-proximal open reading frame in the MCMV genome. © 1991.
- Xiong, Z., & Lommel, S. A. (1991). Red clover necrotic mosaic virus infectious transcripts synthesized in Vitro. Virology, 182(1), 388-392.More infoPMID: 2024474;Abstract: The red clover necrotic mosaic dianthovirus (RCNMV) genome is split between two essentially nonhomologous ssRNAs of 3.9 kb (RNA-1) and 1.45 kb (RNA-2) which are each capped at the 5′ terminus with m7GpppA. cDNA clones short of full length by several nucleotides at both termini have been generated to both RNAs. Oligonucleotide-directed mutagenesis was employed to generate a series of RNA-1 and -2 transcription vectors in which the bacteriophage T7 RNA polymerase promoter was fused to full-length cDNA clones. Yields of in vitro transcripts initiating with wild-type viral 5′-terminal adenosine were extremely low. Efficient transcription was achieved only when one, or alternatively two, nonviral guanosines were engineered 5′ to the authentic viral sequence at the transcription start site. m7GpppG-capped or -uncapped RCNMV RNA-1 and RNA-2 transcripts were infectious and induced symptoms identical to those of wild-type virus infection when coinoculated on the systemic hosts Nicotiana benthamiana and N. clevelandii, and on the local lesion host Chenopodium amaranticolor. Uncapped in vitro transcripts were somewhat less infectious. Progeny virus derived from infectious transcript inoculum was as infectious as wild-type virus. Primer extension analysis indicated that the 5′-terminal nonviral guanosine residues were not maintained in the progeny virus. © 1991.
- Xiong, Z., & Lommel, S. A. (1989). The complete nucleotide sequence and genome organization of red clover necrotic mosaic virus RNA-1. Virology, 171(2), 543-554.More infoPMID: 2763465;Abstract: The complete nucleotide sequence of red clover necrotic mosaic virus (RCNMV) RNA-1 has been determined. RNA-1 is 3889 nucleotides in length with a 5′ terminal m7GpppA cap. The RNA contains three large open reading frames (ORFs): the 5′ proximal ORF, encoding a 27-kDa polypeptide; the internal ORF, coding for a 57-kDa polypeptide; and the 3′ terminal ORF, encoding the 37-kDa capsid protein. The sequence results confirm in vitro translation of 27-, 50-, and 37-kDa products but do not account for the observed 90-kDa product. A translational frameshift event from the 27- to the 57-kDa ORFs is proposed to explain the synthesis of the observed 90-kDa in vitro product. The putative translational frameshift region is structurally similar to several retrovirus frameshift regions and the putative barley yellow dwarf virus (BYDV) frameshift region. Extensive amino acid homology was observed in the 57-kDa downstream ORF with the downstream domains of the carnation mottle virus (CarMV), turnip crinkle virus (TCV), maize chlorotic mottle virus (MCMV) readthrough, and BYDV fusion proteins. The 57-kDa ORF contained the conserved "GDD" motif. A significant alignment between the capsid proteins of RCNMV, CarMV, and TCV was also observed. Given the extensive amino acid sequence similarity of RCNMV, CarMV, and TCV polymerase and capsid proteins, we speculate that they are closely related, evolutionarily. © 1989.
- Lommel, S. A., Weston-Fina, M., Xiong, Z., & Lomonossoff, G. P. (1988). The nucleotide sequence and gene organization of red clover necrotic mosaic virus RNA-2. Nucleic Acids Research, 16(17), 8587-8602.More infoPMID: 3047682;PMCID: PMC338578;Abstract: Red clover necrotic mosaic virus, a member of the dianthovirus group, is characterized by a genome composed of two nonhomologous single-stranded RNAs of approximately 4.0 (RNA-1) and 1.4 kb (RNA-2). The complete nucleotide sequence of the RNA-2 has been determined. RNA-2 is 1448 nucleotides in length with a 5′ terminal m7G cap and no 3′ terminal poly-A tail or 5′ terminal VPg. An open reading frame beginning at the first initiation codon at nucleotide 80 and ending at nucleotide 1030 has been identified which can encode a polypeptide of 35 kDa. RNA-2 directs the synthesis of a 35 kDa polypeptide in vitro. SP6 and T7 transcripts from full length RNA-2 cDNA clones directed the synthesis of a polypeptide with the same electrophoretic mobility as the polypeptide directed from authentic RNA-2. Clones with various 3′ terminal deletions both outside and within the 35 kDa open reading frame were transcribed and translated in vitro to define the limits of the 35 kDa open reading frame. A second, small open reading frame capable of encoding a polypeptide of 4.9 kDa was also indicated from the sequence; however, there was no evidence for a protein product of that size. RNA-2 is presumed to be monocistronic and encode a cell-to-cell movement function. A small but significant amino acid sequence homology was observed with the brome mosaic virus RNA-3a polypeptide. © 1988 IRL Press Limited.
Proceedings Publications
- Li, C., Shi, S., Yu, N., & Xiong, Z. (2016, DEC). Displaying foreign proteins and peptides on the surface of Pepino mosaic virus virions. In PHYTOPATHOLOGY.
- Yu, N., Xie, H., Wang, J., Zhang, X., Liu, Z., & Xiong, Z. (2016, DEC). Replication and transcription are independently modulated for each Banana bunchy top virus DNA component. In PHYTOPATHOLOGY, 106, 161-161.
- Zhang, Z., Yu, N., Zhang, X., Zhang, Y., Wang, J., Liu, Z., & Xiong, Z. (2016, DEC). Two eIF4E proteins in Yellow Lantern chili pepper interact with Pepper veinal mottle virus VPg. In PHYTOPATHOLOGY, 106, 155-155.
- Cui, B., Zhen, Y., Xiang, B., & Xiong, Z. (2015, 08). Profiling virus infection using small RNA sequencing data: A case study of virome from a small-holder farm. In Phytopathology, 105, 32-32.
- Kremer, K. R., Shi, S., & Xiong, Z. (2015, 08). A reliable and highly sensitive, digital PCR-based assay for early detection of citrus Huanglongbing. In Phytopathology, 105, 76-76.
- Shi, S., Mandel, M. A., & Xiong, Z. (2015, 08). Two amino acids of cassava novel cap-binding proteins critical for their interaction with Cassava brown streak virus VPg. In Phytopathology, 105, 127-127.
- Yu, N., Zhou, P., Wang, J., Liu, Z., & Xiong, Z. (2015, 08). Diversity and recombination of DNA-U3 of Banana bunchy top virus. In Phytopathology, 105, 155-155.
Presentations
- Li, C., Kaszubinski, S., Shi, S., Zorba, D., Nair, A., & Xiong, Z. (2019, OCT). Net charges at the N-terminus of capsid protein interfere with Potexvirus systemic movement. PHYTOPATHOLOGY.
- Yu, N., Liu, F., Ji, X., Wang, J. H., Xiong, Z., & Liu, Z. (2019, OCT). Full-length infectious clones of Banana bunchy top virus. PHYTOPATHOLOGY.
- Zhang, X., Shi, S., Wu, Y., Zhang, C., Chen, B., Wang, J., Zhang, Y., Yu, N., Liu, Z., & Xiong, Z. (2019, OCT). Editing of plant eIF4E genes for potyviral resistance. PHYTOPATHOLOGY.
- Xiong, Z. -. (2013, August). Know your enemies. African Agricultural Research Connection. Nairobi, Kenya: Bill and Melinda Gates Foundation.
- Xiong, Z. -. (2013, January). Potyviral VPg: A Promising Target for Host Immunity by Genome Editing. Academy of Tropical Agricultural Sciences Seminars. Haikou, China: Academy of Tropical Agricultural Sciences.
- Xiong, Z. -. (2013, July). Viral Population Genomics: New Tools, New Revelations. Institute of Plant Protection Seminars. Beijing, China: Institute of Plant Protection, Chinese Academy of Agricultural Sciences.
- Xiong, Z. -. (2013, July). Viral population genomics: New Tools, New Revelations. BIT 4th Annual World Congress of Virus and Infection. Wuhan, China: BIT Life Sciences.
- Xiong, Z. -. (2013, July). Viruses of Tomatoes: Clear and Present Danger. Institute of Plant and Envirnomental Protection Seminars. Haikou, China: Institute of Plant and Envirnomental Protection, Chinese Academy of Tropical Agricultural Sciences.
- Xiong, Z. -. (2013, July). Viruses of Tomatoes:Clear and Present Danger. Hainan Academy of Agricutural Sciences Seminars. Haikou, China: Hainan Academy of Agricutural Sciences.
- Xiong, Z. -. (2013, March). Editing endogenous eIF4E to create immunity against cassava brown streak diseases.. GCE Agriculture & Nutrition Grantee Meeting. Seatlle, Washington: Bill and Melinda Gates Foundation.
- Xiong, Z. -. (2013, March). Harness the Power of Biotechnology to Fight against Crop Diseases. Yuma Ag Summit. Yuma, AZ: Yuma Ag Summit.
- Xiong, Z. -. (2013, May). Viral population genomics: New Tools, New Insights. Plant Pathology Seminar Series. Davis, California: Department of Plant Pathology, University of California.
- Xiong, Z. -. (2012). Change and Stability: The Balance of Life in an RNA Virus. Centennial Symposium in Memory of Prof. Wei-Fan Chiu. Beijing.
- Xiong, Z. -. (2012). Change and stability: The balance of life in an RNA virus. Current Topics in Plant Pathology Symposium. Yanglin, Shanxi, China: hosted by the Purdue-Northwest Agriculture and Forestry University Joint Center.
- Xiong, Z. -. (2012). Change and stability: The balance of life in an RNA virus. Invited Seminar.
- Xiong, Z. -. (2012). Change and stability: The balance of life in an RNA virus. Invited Seminar. Xinjiang, China: Shihezi University.
- Xiong, Z. -. (2012). RNA Vaccines against a Tomato Viroid. presented at a SCBGP conference organized by Arizona Department of Agriculture. Maricopa, AZ: Arizona Department of Agriculture.
- Xiong, Z. -. (2012). Viral Population Genomics and Extracellular DNA and DNases in Microbe-Host interactions, presented to ABBS student. ABBS student recruitment talk. Tucson, AZ.
- Xiong, Z. -. (2012). Viral Population Genomics by Resequencing and Next Generation Sequencing. Invited Seminar. China.
- Xiong, Z. -. (2011). Advances in Plant Virology. Delivered a keynote address in the National Conference on Biology organized by Consortium of Mexican Universities. Los Mochis, Sinaloa, Mexico.
- Xiong, Z. -. (2011). Developing RNA Vaccines to Manage Pepino mosaic virus. annual specialty crop block grant program report meeting. Phoenix, AZ.
- Xiong, Z. -. (2011). RNAi Suppression and RNAi-mediated Virus Resistance in Plants. Presented an invited seminar in Shihezi University, Xinjiang, China. Xingjian, China.
- Xiong, Z. -. (2011). RNAi-mediated Virus Resistance in Plants. Presented an invited seminar in Chinese Acadmy of Tropical Agricultural Sciences. Hainan, China.
- Xiong, Z. -. (2011). Viral population genomics by resequencing and high-throughput sequencing. workshop "Microarrays and ext-Generation Sequencing for Detection and Identification of Plant Viruses" sponsored by BARD. Beltsville, MD: BARD.
Poster Presentations
- Coppinger, C., Li, C., Avelar, S., Romanski, A., & Xiong, Z. (2023, April). Efficiency of self-cleavage 2A peptides in fusion proteins expressed from a plant virus vector. . The 62nd Annual Meeting of Arizona and Southern Nevada Branch of the American Society for Microbiology. Tucson. AZ: American Society for Microbiology.
- Taylor, J. C., Sadrebazzaz, A., Kriddler, M. R., Alokozai, H. A., & Xiong, Z. (2023, April). Production of Effector Proteins in E. coli for Early Detection of the HLB Complex Using Specific Antibodies.. The 62nd Annual Meeting of Arizona and Southern Nevada Branch of the American Society for Microbiology. Tucson, Arizona: American Society for Microbiology.More infoHuanglongbing (HLB), also known as citrus greening, is a destructive disease caused by the gram-negative bacterium Candidatus Liberibacter asiaticus (CLas). The disease is transmitted by the Asian citrus psyllid and has spread to all major citrus producing regions in the US except Arizona. With no cure readily available, containment is prioritized by quick eradication of infected citrus trees in an orchard. qPCR, the current standard for HLB detection, has limited utility at early stages due to low bacterial titers and sporadic distribution of CLas in newly infected citrus trees. To provide a solution to the early detection problem, we plan to develop an immunoassay that targets effector proteins secreted by CLas. These proteins can potentially circulate throughout an infected tree, making it possible to detect HLB without sampling the precise locations where the bacterium is present. We have identified five genes encoding CLas effector proteins using bioinformatics, and have cloned and expressed them in E. coli. We will purify these proteins and use them to generate highly specific antibodies, which are essential for the development a high throughput ELISA assay and a portable immunodot blot assay. These assays will enable early detection of HLB by detecting circulating effector proteins in infected trees. Our approach has the potential to improve HLB management by providing a much-needed, early detection tool.
- Yu, N., Cochran, A., Trinh, S., Wen, F., van Etten, H. D., Hawes, M. C., & Xiong, Z. (2018, August). Battles in the outer space: Extracellular DNases secreted by Pectobacterium carotovorum and its host plants. International Congress of Plant Pathology (ICPP). Boston, MA: International Society of Plant Pathology and the American Society of Phytopathology.
- Zhang, X., Shi, S., Chen, B., Xian, S., Zhang, Y., Xiong, Z., & Liu, Z. (2018, October). Editing of eIF4E Genes for Resistance to Cassava Brown Streak Disease. The 18th Triennial Symposium of the International Society for Tropical Root Crops. CIAT, Cali, Colombia: The International Society for Tropical Root Crops.
- Zhang, X., Shi, S., Wu, Y., Zhang, C., Chen, B., Wang, J., Zhang, Y., Yu, N., Liu, Z., & Xiong, Z. (2018, October). Editing of plant eIF4E genes for potyviral resistance. The 11th Annual Meeting of the Chinese Society of Plant Pathology & the 6th Sino-US Plant Pathology Symposium. Beijing, China: The Chinese Society of Plant Pathology and the American Society of Phytopathology.
- Kaszubinski1, S., Li, C., Shi, S., Zorba, D., Nair, A., & Xiong, Z. (2017, March). Small N-terminal modifications of Pepino mosaic virus capsid protein interfere with viral systemic movement. UA CALS Poster Forum. Tucson, AZ: College of Agricultural and Life Sciences.More infoPepino mosaic virus (PepMV) (family Alphaflexiviridae, genus Potexvirus) is a mechanically transmitted pathogen of the host family Solanaceae (1). The virus has a 6.4 kb single stranded, (+)-sense RNA genome, encoding for RNA-dependent RNA polymerase, triple gene block, and capsid protein (CP) (2). PepMV CP assembles into virions to protect viral genomic RNA, and is required for viral cell-to-cell movement via plasmodesmata and systemic movement via phloem. Little is known about the mechanisms of CP’s involvement in viral movements. PepMV virions are filamentous rods, usually 12.5 nm x 510 nm in dimension (1). The shape of the virions makes PepMV an ideal nanoparticle where proteins of interest can be fused to the N- terminus of the CP and expressed at the surface of the virions. In order to develop PepMV into a versatile protein display system, three restriction sites were added to 5’ terminus of PepMV CP ORF, resulting in additional seven amino acids, including three highly charged arginine residues, at the N-terminus of the CP. This small modification prevented the systemic movement of the recombinant virus but did not affect its cell-to-cell movement. Progeny viruses with restored systemic movement were recovered and found to contain compensatory mutations in the modified N-terminal region of PepMV CP, leading to overall lower positive charges. We hypothesize that the increased positive charges to the N-terminus of PepMV CP interfere with the systemic movement function of PepMV CP. Five additional mutants with various levels of charges at the N-terminus of PepMV CP were designed and tested to determine if altered charges caused the impaired systemic movement of PepMV. Determining the role of the N- terminus of the CP in systemic movement will help optimize the virus-based protein display system, and shed light on the role of PepMV CP in systemic infection
- Zhang, Y., Xiong, Z. -., Yu, N., & Liu, Z. (2013, August). Genetic diversity of viruses associated with the mosaic disease of Saccharum inter-specific hybrids in China. 10th International Congress of Plant Pathology. Beijing, China: International Society for Plant Pathology.
- Xiong, Z. -. (2012, May). Engineering Infectious cDNA Clones for Two Strains of Pepino Mosaic Virus. First annual VSM Research Poster Session. Tucson, AZ.
Others
- Xiong, Z. (2019, April). Invited seminar: Editing endogenous genes for virus resistance. Henan University of Science and technology, China.
- Xiong, Z., Shi, S., Mandel, M. A., Amuge, T., Ferguson, M., Zhang, P., & Rounsley, S. (2014, NOV). Interaction between Cassava brown streak virus VPg and cassava eIF4Es. PHYTOPATHOLOGY.
- Yu, N., Zhang, Y., Wang, J., Zhou, P., Liu, Z., & Xiong, Z. (2014, NOV). Transcriptional analysis of Banana bunchy top virus DNA-U3. PHYTOPATHOLOGY.
- Xiong, Z. -., Varady, R., van, W. F., Megdal, S., Gerlak, A., Abdalla, I. C., & House-Peters, L. (2012, February). Groundwater Policy and Governance. FAO/Global Environmental Facility, Groundwater Governance: A Global Framework for Country Action, GEF project ID: 3726 FAO project ID: 608795 FAO project symbol: GCP /GLO/277/GFF, Thematic Paper No. 5. http://www.groundwatergovernance.org/fileadmin/user_upload/groundwatergovernance/docs/Thematic_papers/GWG_Thematic5_8June2012.pdf
- Xiong, Z. -. (2010, Fall). MIC205A D2L web site development. http://d2l.arizona.edu/index.asp