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Cao P, Shi H, Zhang S, Chen J, Wang R, Liu P, Zhu Y, An Y, Zhang M. A robust high-throughput functional screening assay for plant pathogen effectors using the TMV-GFP vector. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 119:617-631. [PMID: 38647454 DOI: 10.1111/tpj.16774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 04/02/2024] [Accepted: 04/08/2024] [Indexed: 04/25/2024]
Abstract
Uncovering the function of phytopathogen effectors is crucial for understanding mechanisms of pathogen pathogenicity and for improving our ability to protect plants from diseases. An increasing number of effectors have been predicted in various plant pathogens. Functional characterization of these effectors has become a major focus in the study of plant-pathogen interactions. In this study, we designed a novel screening system that combines the TMV (tobacco mosaic virus)-GFP vector and Agrobacterium-mediated transient expression in the model plant Nicotiana benthamiana. This system enables the rapid identification of effectors that interfere with plant immunity. The biological function of these effectors can be easily evaluated by observing the GFP fluorescence signal using a UV lamp within just a few days. To evaluate the TMV-GFP system, we initially tested it with well-described virulence and avirulence type III effectors from the bacterial pathogen Ralstonia solanacearum. After proving the accuracy and efficiency of the TMV-GFP system, we successfully screened a novel virulence effector, RipS1, using this approach. Furthermore, using the TMV-GFP system, we reproduced consistent results with previously known cytoplasmic effectors from a diverse array of pathogens. Additionally, we demonstrated the effectiveness of the TMV-GFP system in identifying apoplastic effectors. The easy operation, time-saving nature, broad effectiveness, and low technical requirements of the TMV-GFP system make it a promising approach for high-throughput screening of effectors with immune interference activity from various pathogens.
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Affiliation(s)
- Peng Cao
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, China
| | - Haotian Shi
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, China
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Shuangxi Zhang
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, China
| | - Jialan Chen
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Rongbo Wang
- Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou, 350003, China
| | - Peiqing Liu
- Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou, 350003, China
| | - Yingfang Zhu
- State Key Laboratory of Crop Stress Adaptation and Improvement, Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, 475001, China
| | - Yuyan An
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, China
| | - Meixiang Zhang
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, China
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2
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Chen JR, Aguirre-Carvajal K, Xue DY, Chang HC, Arone-Maxwell L, Lin YP, Armijos-Jaramillo V, Oliva R. Exploring the genetic makeup of Xanthomonas species causing bacterial spot in Taiwan: evidence of population shift and local adaptation. Front Microbiol 2024; 15:1408885. [PMID: 38846563 PMCID: PMC11153759 DOI: 10.3389/fmicb.2024.1408885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Accepted: 05/13/2024] [Indexed: 06/09/2024] Open
Abstract
The introduction of plant pathogens can quickly reshape disease dynamics in island agro-ecologies, representing a continuous challenge for local crop management strategies. Xanthomonas pathogens causing tomato bacterial spot were probably introduced in Taiwan several decades ago, creating a unique opportunity to study the genetic makeup and adaptive response of this alien population. We examined the phenotypic and genotypic identity of 669 pathogen entries collected across different regions of Taiwan in the last three decades. The analysis detected a major population shift, where X. euvesicatoria and X. vesicatoria races T1 and T2 were replaced by new races of X. perforans. After its introduction, race T4 quickly became dominant in all tomato-growing areas of the island. The genomic analysis of 317 global genomes indicates that the Xanthomonas population in Taiwan has a narrow genetic background, most likely resulting from a small number of colonization events. However, despite the apparent genetic uniformity, X. perforans race T4 shows multiple phenotypic responses in tomato lines. Additionally, an in-depth analysis of effector composition suggests diversification in response to local adaptation. These include unique mutations on avrXv3 which might allow the pathogen to overcome Xv3/Rx4 resistance gene. The findings underscore the dynamic evolution of a pathogen when introduced in a semi-isolated environment and provide insights into the potential management strategies for this important disease of tomato.
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Affiliation(s)
- Jaw-Rong Chen
- Safe and Sustainable Value Chain, World Vegetable Center, Shanhua, Taiwan
| | - Kevin Aguirre-Carvajal
- Research Center of Information and Communication Technologies, University of A Coruña, A Coruña, Spain
- Bio-Cheminformatics Research Group, Universidad de Las Américas, Quito, Ecuador
| | - Dao-Yuan Xue
- Seed and Seedling Management Section, Taiwan Seed Improvement and Propagation Station, Ministry of Agriculture, Taichung, Taiwan
| | - Hung-Chia Chang
- Safe and Sustainable Value Chain, World Vegetable Center, Shanhua, Taiwan
| | | | - Ya-Ping Lin
- Safe and Sustainable Value Chain, World Vegetable Center, Shanhua, Taiwan
| | - Vinicio Armijos-Jaramillo
- Bio-Cheminformatics Research Group, Universidad de Las Américas, Quito, Ecuador
- Facultad de Ingeniería y Ciencias Aplicadas, Universidad de Las Américas, Quito, Ecuador
| | - Ricardo Oliva
- Safe and Sustainable Value Chain, World Vegetable Center, Shanhua, Taiwan
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Ji H, Li T, Li X, Li J, Yu J, Zhang X, Liu D. XopZ and ORP1C cooperate to regulate the virulence of Xanthomonas oryzae pv. oryzae on Nipponbare. PLANT SIGNALING & BEHAVIOR 2022; 17:2035126. [PMID: 35184695 PMCID: PMC8959505 DOI: 10.1080/15592324.2022.2035126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 01/24/2022] [Accepted: 01/24/2022] [Indexed: 06/14/2023]
Abstract
Bacterial leaf blight caused by Xanthomonas oryzae pv. oryzae (Xoo) has always been considered to be one of the most severe worldwide diseases in rice. Xoo strains usually use the highly conserved type III secretion system (T3SS) to deliver virulence effectors into rice cells and further suppress the host's immunity. Previous studies reported that different Xanthomonas outer protein (Xop) effectors include XopZ from one strain appear to share functional redundancies on suppressing rice PAMP-triggered immunity (PTI). But only xopZ, except other xop genes, could significantly impaire Xoo virulence when individually deleting in PXO99 strains. Thus, the XopZ effector should not only suppress rice PTI pathway, but also has other unknown indispensable pathological functions in PXO99-rice interactions. Here, we also found that ∆xopZ mutant strains displayed lower virulence on Nipponbare leaves compared with PXO99 strains. We identified an oxysterol-binding related protein, ORP1C, as a XopZ-interacting protein in rice. Further studies found that rice ORP1C preliminarily played a positive role in regulating the resistance to PXO99 strains, and XopZ-ORP1C interactions cooperated to regulate the compatible interactions of PXO99-Nipponbare rice. The reactive oxygen species (ROS) burst and PTI marker gene expression data indicated that ORP1C were not directly relevant to the PTI pathway in rice. The deeper mechanisms underlying XopZ-ORP1C interaction and how XopZ and ORP1C cooperate for regulating the PXO99-rice interactions require further exploration.
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Affiliation(s)
- Hongtao Ji
- Institute of Integrative Plant Biology, School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Taoran Li
- Institute of Integrative Plant Biology, School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Xiaochen Li
- Institute of Integrative Plant Biology, School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Jiangyu Li
- Institute of Integrative Plant Biology, School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Jiayi Yu
- Institute of Integrative Plant Biology, School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Xin Zhang
- Institute of Integrative Plant Biology, School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Delong Liu
- Institute of Integrative Plant Biology, School of Life Sciences, Jiangsu Normal University, Xuzhou, China
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Acidovorax citrulli Effector AopV Suppresses Plant Immunity and Interacts with Aromatic Dehydratase ADT6 in Watermelon. Int J Mol Sci 2022; 23:ijms231911719. [PMID: 36233021 PMCID: PMC9570411 DOI: 10.3390/ijms231911719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 09/25/2022] [Accepted: 09/26/2022] [Indexed: 11/17/2022] Open
Abstract
Bacterial fruit blotch (BFB) is a disease of cucurbit plants caused by Acidovorax citrulli. Although A. citrulli has great destructive potential, the molecular mechanisms of pathogenicity of A. citrulli are not clear, particularly with regard to its type III secreted effectors. In this study, we characterized the type III secreted effector protein, AopV, from A. citrulli strain Aac5. We show that AopV significantly inhibits reactive oxygen species and the expression of PTI marker genes, and helps the growth of Pseudomonas syringae D36E in Nicotiana benthamiana. In addition, we found that the aromatic dehydratase ADT6 from watermelon was a target of AopV. AopV interacts with ADT6 in vivo and in vitro. Subcellular localization indicated ADT6 and AopV were co-located at the cell membrane. Together, our results reveal that AopV suppresses plant immunity and targets ADT6 in the cell membrane. These findings provide an new characterization of the molecular interaction of A. citrulli effector protein AopV with host cells.
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Deb S, Madhavan VN, Gokulan CG, Patel HK, Sonti RV. Arms and ammunitions: effectors at the interface of rice and it's pathogens and pests. RICE (NEW YORK, N.Y.) 2021; 14:94. [PMID: 34792681 PMCID: PMC8602583 DOI: 10.1186/s12284-021-00534-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 11/06/2021] [Indexed: 06/13/2023]
Abstract
The plant immune system has evolved to resist attack by pathogens and pests. However, successful phytopathogens deliver effector proteins into plant cells where they hijack the host cellular machinery to suppress the plant immune responses and promote infection. This manipulation of the host cellular pathways is done by the pathogen using various enzymatic activities, protein- DNA or protein- protein interactions. Rice is one the major economically important crops and its yield is affected by several pathogens and pests. In this review, we summarize the various effectors at the plant- pathogen/ pest interface for the major pathogens and pests of rice, specifically, on the mode of action and target genes of the effector proteins. We then compare this across the major rice pathogens and pests in a bid to understand probable conserved pathways which are under attack from pathogens and pests in rice. This analysis highlights conserved patterns of effector action, as well as unique host pathways targeted by the pathogens and pests.
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Affiliation(s)
- Sohini Deb
- CSIR-Centre for Cellular and Molecular Biology (CSIR-CCMB), Hyderabad, 500007 India
- Present Address: Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg C, Denmark
| | | | - C. G. Gokulan
- CSIR-Centre for Cellular and Molecular Biology (CSIR-CCMB), Hyderabad, 500007 India
| | - Hitendra K. Patel
- CSIR-Centre for Cellular and Molecular Biology (CSIR-CCMB), Hyderabad, 500007 India
| | - Ramesh V. Sonti
- CSIR-Centre for Cellular and Molecular Biology (CSIR-CCMB), Hyderabad, 500007 India
- Present Address: Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati, 517507 India
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Teper D, Wang N. Consequences of adaptation of TAL effectors on host susceptibility to Xanthomonas. PLoS Genet 2021; 17:e1009310. [PMID: 33465093 PMCID: PMC7845958 DOI: 10.1371/journal.pgen.1009310] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 01/29/2021] [Accepted: 12/11/2020] [Indexed: 12/03/2022] Open
Abstract
Transcription activator-like effectors (TALEs) are virulence factors of Xanthomonas that induce the expression of host susceptibility (S) genes by specifically binding to effector binding elements (EBEs) in their promoter regions. The DNA binding specificity of TALEs is dictated by their tandem repeat regions, which are highly variable between different TALEs. Mutation of the EBEs of S genes is being utilized as a key strategy to generate resistant crops against TALE-dependent pathogens. However, TALE adaptations through rearrangement of their repeat regions is a potential obstacle for successful implementation of this strategy. We investigated the consequences of TALE adaptations in the citrus pathogen Xanthomonas citri subsp. citri (Xcc), in which PthA4 is the TALE required for pathogenicity, whereas CsLOB1 is the corresponding susceptibility gene, on host resistance. Seven TALEs, containing two-to-nine mismatching-repeats to the EBEPthA4 that were unable to induce CsLOB1 expression, were introduced into Xcc pthA4:Tn5 and adaptation was simulated by repeated inoculations into and isolations from sweet orange for a duration of 30 cycles. While initially all strains failed to promote disease, symptoms started to appear between 9–28 passages in four TALEs, which originally harbored two-to-five mismatches. Sequence analysis of adapted TALEs identified deletions and mutations within the TALE repeat regions which enhanced putative affinity to the CsLOB1 promoter. Sequence analyses suggest that TALEs adaptations result from recombinations between repeats of the TALEs. Reintroduction of these adapted TALEs into Xcc pthA4:Tn5 restored the ability to induce the expression of CsLOB1, promote disease symptoms and colonize host plants. TALEs harboring seven-to-nine mismatches were unable to adapt to overcome the incompatible interaction. Our study experimentally documented TALE adaptations to incompatible EBE and provided strategic guidance for generation of disease resistant crops against TALE-dependent pathogens. Mutation of the EBEs of susceptibility (S) genes via genome editing and utilization of naturally occurring EBE variants have been used to generate disease resistant plants. However, TALE adaptations may lead to resistance loss, limiting the long-term efficacy of the strategy. We utilized an experimental evolution approach to test TALEs adaptations in the Xanthomonas citri-citrus pathosystem using designer TALEs that cannot recognize the EBE of host targets. We identified adaptive TALE mutations and deletions that occurred during less than 30 cycles of repeated infections, which reconstituted the virulence on the host. Adaptive variants originated from TALEs that harbored a small number of mismatches (≤5) to the EBE, whereas designer TALEs that harbored larger number of mismatches (≥7) to the EBE failed to adapt in the duration of this study. Our study experimentally demonstrates adaptive rearrangements of TALEs during host adaptation and suggests that the potential durability in the resistance of modified crops should be a significant factor to be considered prior to their introduction into the field.
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Affiliation(s)
- Doron Teper
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, Florida, United States of America
| | - Nian Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, Florida, United States of America
- * E-mail:
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7
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Jiang G, Liu D, Yin D, Zhou Z, Shi Y, Li C, Zhu L, Zhai W. A Rice NBS-ARC Gene Conferring Quantitative Resistance to Bacterial Blight Is Regulated by a Pathogen Effector-Inducible miRNA. MOLECULAR PLANT 2020; 13:1752-1767. [PMID: 32966899 DOI: 10.1016/j.molp.2020.09.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 08/13/2020] [Accepted: 09/17/2020] [Indexed: 05/04/2023]
Abstract
The bacterium Xanthomonas oryzae pv. Oryzae (Xoo) causes blight in rice worldwide, resulting in significant crop loss. However, no gene underlying a quantitative trait locus (QTL) for resistance against Xoo has been cloned yet. Here, we report the map-based cloning of a QTL, in which the NBS8R gene confers quantitative resistance to Xoo. NBS8R encodes an NB-ARC protein, which is involved in pathogen/microbe-associated molecular pattern-triggered immunity and whose expression is regulated by non-TAL effector XopQ-inducible Osa-miR1876 through DNA methylation. Sequence analysis of NBS8R in wild rice species and rice cultivars suggests that the Osa-miR1876 binding sites in the 5' UTR of NBS8R are inserted by chance and have undergone variations with Osa-miR1876 throughout evolution. The interaction between NBS8R and XopQ-inducible Osa-miR1876 is partially in keeping with the zigzag model, revealing that quantitative genes may also follow this model to control the innate immune response or basal disease resistance, and may prove valuable in utilizing the existing landraces that harbor the NBS8R gene but with no Osa-miR1876 binding site in rice breeding for bacterial blight resistance.
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Affiliation(s)
- Guanghuai Jiang
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Dongfeng Liu
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Dedong Yin
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhuangzhi Zhou
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yue Shi
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Chunrong Li
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Lihuang Zhu
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
| | - Wenxue Zhai
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
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Zhang X, Zhao M, Jiang J, Yang L, Yang Y, Yang S, Walcott R, Qiu D, Zhao T. Identification and Functional Analysis of AopN, an Acidovorax Citrulli Effector that Induces Programmed Cell Death in Plants. Int J Mol Sci 2020; 21:E6050. [PMID: 32842656 PMCID: PMC7504669 DOI: 10.3390/ijms21176050] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/01/2020] [Accepted: 08/18/2020] [Indexed: 01/23/2023] Open
Abstract
Bacterial fruit blotch (BFB), caused by Acidovorax citrulli, seriously affects watermelon and other cucurbit crops, resulting in significant economic losses. However, the pathogenicity mechanism of A. citrulli is not well understood. Plant pathogenic bacteria often suppress the plant immune response by secreting effector proteins. Thus, identifying A. citrulli effector proteins and determining their functions may improve our understanding of the underlying pathogenetic mechanisms. In this study, a novel effector, AopN, which is localized on the cell membrane of Nicotiana benthamiana, was identified. The functional analysis revealed that AopN significantly inhibited the flg22-induced reactive oxygen species burst. AopN induced a programmed cell death (PCD) response. Unlike its homologous protein, the ability of AopN to induce PCD was dependent on two motifs of unknown functions (including DUP4129 and Cpta_toxin), but was not dependent on LXXLL domain. More importantly, the virulence of the aopN mutant of A. citrulli in N. benthamiana significantly decreased, indicating that it was a core effector. Further analysis revealed that AopN interacted with watermelon ClHIPP and ClLTP, which responds to A. citrulli strain Aac5 infection at the transcription level. Collectively, these findings indicate that AopN suppresses plant immunity and activates the effector-triggered immunity pathway.
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Affiliation(s)
- Xiaoxiao Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (X.Z.); (J.J.); (L.Y.); (Y.Y.); (D.Q.)
| | - Mei Zhao
- Department of Plant Pathology, University of Georgia, Athens, GA 30602, USA; (M.Z.); (R.W.)
| | - Jie Jiang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (X.Z.); (J.J.); (L.Y.); (Y.Y.); (D.Q.)
| | - Linlin Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (X.Z.); (J.J.); (L.Y.); (Y.Y.); (D.Q.)
| | - Yuwen Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (X.Z.); (J.J.); (L.Y.); (Y.Y.); (D.Q.)
| | - Shanshan Yang
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, China;
| | - Ron Walcott
- Department of Plant Pathology, University of Georgia, Athens, GA 30602, USA; (M.Z.); (R.W.)
| | - Dewen Qiu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (X.Z.); (J.J.); (L.Y.); (Y.Y.); (D.Q.)
| | - Tingchang Zhao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (X.Z.); (J.J.); (L.Y.); (Y.Y.); (D.Q.)
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9
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Zeng D, Wang MW, Xiang M, Liu LW, Wang PY, Li Z, Yang S. Design, synthesis, and antimicrobial behavior of novel oxadiazoles containing various N-containing heterocyclic pendants. PEST MANAGEMENT SCIENCE 2020; 76:2681-2692. [PMID: 32149457 DOI: 10.1002/ps.5814] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Revised: 12/18/2019] [Accepted: 03/09/2020] [Indexed: 06/10/2023]
Abstract
BACKGROUND The gradually elevated outbreak of plant bacterial diseases severely limits agricultural products and small amounts of pesticides can manage them. Our group has previously synthesized and screened the antimicrobial activity of diverse 1,3,4-oxadiazole thioether/sulfone compounds bridged by a sulfur atom at the 2-position of 1,3,4-oxadiazole. However, few studies have evaluated the effect of eliminating the sulfur atom on bioactivity. Herein, a novel type of N-containing heterocyclic pendants-tagged 1,3,4-oxadiazoles bridged by alkyl chains only was systematically synthesized and evaluated for their antimicrobial activities. RESULTS Bioassay results revealed that antibacterial efficacy increased by 551- and 314-fold against the corresponding phytopathogens Xanthomonas oryzae pv. oryzae and X. axonopodis pv. citri compared to commercial agents bismerthiazol and thiodiazole copper. In vivo trials showed that C 1 exerted remarkable curative activity against rice bacterial blight with a control effectiveness of 52.9% at 200 μg mL-1 . Antibacterial mechanism research found that C 1 could reduce the hypersensitive response behavior and pathogenicity of Xoo through targeting the type III secretion system (T3SS) at a lower drug dose. This outcome was verified by observing the significantly down-regulated proteins and representative genes from the related quantitative proteomics and qRT-PCR assays. CONCLUSION This study can inspire the design of innovative molecular frameworks targeting the T3SS of phytopathogens for controlling bacterial infections. © 2020 Society of Chemical Industry.
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Affiliation(s)
- Dan Zeng
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
| | - Ming-Wei Wang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
| | - Meng Xiang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
| | - Li-Wei Liu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
| | - Pei-Yi Wang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
| | - Zhong Li
- College of Pharmacy, East China University of Science & Technology, Shanghai, China
| | - Song Yang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
- College of Pharmacy, East China University of Science & Technology, Shanghai, China
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10
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Timilsina S, Potnis N, Newberry EA, Liyanapathiranage P, Iruegas-Bocardo F, White FF, Goss EM, Jones JB. Xanthomonas diversity, virulence and plant-pathogen interactions. Nat Rev Microbiol 2020; 18:415-427. [PMID: 32346148 DOI: 10.1038/s41579-020-0361-8] [Citation(s) in RCA: 132] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/19/2020] [Indexed: 12/19/2022]
Abstract
Xanthomonas spp. encompass a wide range of plant pathogens that use numerous virulence factors for pathogenicity and fitness in plant hosts. In this Review, we examine recent insights into host-pathogen co-evolution, diversity in Xanthomonas populations and host specificity of Xanthomonas spp. that have substantially improved our fundamental understanding of pathogen biology. We emphasize the virulence factors in xanthomonads, such as type III secreted effectors including transcription activator-like effectors, type II secretion systems, diversity resulting in host specificity, evolution of emerging strains, activation of susceptibility genes and strategies of host evasion. We summarize the genomic diversity in several Xanthomonas spp. and implications for disease outbreaks, management strategies and breeding for disease resistance.
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Affiliation(s)
- Sujan Timilsina
- Plant Pathology Department, University of Florida, Gainesville, FL, USA
| | - Neha Potnis
- Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | - Eric A Newberry
- Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | | | | | - Frank F White
- Plant Pathology Department, University of Florida, Gainesville, FL, USA
| | - Erica M Goss
- Plant Pathology Department, University of Florida, Gainesville, FL, USA. .,Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA.
| | - Jeffrey B Jones
- Plant Pathology Department, University of Florida, Gainesville, FL, USA.
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11
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Verma G, Mondal KK, Kulshreshtha A, Sharma M. XopR T3SS-effector of Xanthomonas oryzae pv. oryzae suppresses cell death-mediated plant defense response during bacterial blight development in rice. 3 Biotech 2019; 9:272. [PMID: 31245236 PMCID: PMC6582023 DOI: 10.1007/s13205-019-1802-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 06/07/2019] [Indexed: 11/26/2022] Open
Abstract
Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial blight disease that limits the rice production globally. The bacterium secretes effector proteins directly into plant cells through a type III secretion system (T3SS). Here, we examined the role of a conserved XopR T3SS-effector in the suppression of host basal defense response. Phylogenetic and sequence analysis showed that XopR is well conserved within Xoo strains but shares varying degree of similarity among the other Xanthomonas species. The expression of XopR was shown to be regulated by hrpX, a key regulator of hrp cluster. For functional analysis we employed two mutant strains of Xoo, one lacks xopR gene and other lacks hrpX gene (making the strain defective in T3SS). Programmed cell death (PCD) events was examined both in rice and tobacco leaves through trypan blue staining method. In XopR expressing tobacco leaves the PCD induction was compromised. We observed higher PCD on rice leaves inoculated with Xoo mutants lacking either xopR or functional T3SS as compared to wild type. Contrary, when xopR gene was complemented in mutated strain the PCD was suppressed which clearly suggests that XopR acts as suppressor of the PCD mediated defense response. The EYFP::XopR fusion protein was shown to be localized to the plasma membrane of Nicotiana benthamiana and onion epidermal cells. Altogether our study leads to the understanding that XopR T3SS-effector is essential for Xoo to suppress PCD, primarily to support the in planta colonization of Xoo during blight pathogenesis.
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Affiliation(s)
- Geeta Verma
- Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, Pusa Campus, New Delhi, 110012 India
| | - Kalyan K. Mondal
- Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, Pusa Campus, New Delhi, 110012 India
| | - Aditya Kulshreshtha
- Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, Pusa Campus, New Delhi, 110012 India
| | - Manju Sharma
- Amity Institute of Biotechnology, Amity University, Manesar, Gurgaon, Haryana India
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