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Richter I, Uzum Z, Wein P, Molloy EM, Moebius N, Stinear TP, Pidot SJ, Hertweck C. Transcription activator-like effectors from endosymbiotic bacteria control the reproduction of their fungal host. mBio 2023; 14:e0182423. [PMID: 37971247 PMCID: PMC10746252 DOI: 10.1128/mbio.01824-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 10/03/2023] [Indexed: 11/19/2023] Open
Abstract
IMPORTANCE Interactions between fungi and bacteria are critically important in ecology, medicine, and biotechnology. In this study, we shed light on factors that promote the persistence of a toxin-producing, phytopathogenic Rhizopus-Mycetohabitans symbiosis that causes severe crop losses in Asia. We present an unprecedented case where bacterially produced transcription activator-like (TAL) effectors are key to maintaining a stable endosymbiosis. In their absence, fungal sporulation is abrogated, leading to collapse of the phytopathogenic alliance. The Mycetohabitans TAL (MTAL)-mediated mechanism of host control illustrates a unique role of bacterial effector molecules that has broader implications, potentially serving as a model to understand how prokaryotic symbionts interact with their eukaryotic hosts.
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Affiliation(s)
- Ingrid Richter
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Zerrin Uzum
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Philipp Wein
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Evelyn M. Molloy
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Nadine Moebius
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Timothy P. Stinear
- Department of Microbiology and Immunology, Doherty Institute, Melbourne, Australia
| | - Sacha J. Pidot
- Department of Microbiology and Immunology, Doherty Institute, Melbourne, Australia
| | - Christian Hertweck
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
- Institute of Microbiology, Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany
- Cluster of Excellence Balance of the Microverse, Friedrich Schiller University Jena, Jena, Germany
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de Souza-Neto RR, Vasconcelos FNDC, Teper D, Carvalho IGB, Takita MA, Benedetti CE, Wang N, de Souza AA. The Expansin Gene CsLIEXP1 Is a Direct Target of CsLOB1 in Citrus. PHYTOPATHOLOGY 2023; 113:1266-1277. [PMID: 36825333 DOI: 10.1094/phyto-11-22-0424-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Transcription activator-like effectors are key virulence factors of Xanthomonas. They are secreted into host plant cells and mimic transcription factors inducing the expression of host susceptibility (S) genes. In citrus, CsLOB1 is a direct target of PthA4, the primary effector associated with citrus canker symptoms. CsLOB1 is a transcription factor, and its expression is required for canker symptoms induced by Xanthomonas citri subsp. citri. Several genes are up-regulated by PthA4; however, only CsLOB1 was described as an S gene induced by PthA4. Here, we investigated whether other up-regulated genes could be direct targets of PthA4 or CsLOB1. Seven up-regulated genes by PthA4 were investigated; however, an expansin-coding gene was more induced than CsLOB1. In Nicotiana benthamiana transient expression experiments, we demonstrate that the expansin-coding gene, referred here to as CsLOB1-INDUCED EXPANSIN 1 (CsLIEXP1), is not a direct target of PthA4, but CsLOB1. Interestingly, CsLIEXP1 was induced by CsLOB1 even without the predicted CsLOB1 binding site, which suggested that CsLOB1 has other unknown binding sites. We also investigated the minimum promoter regulated by CsLOB1, and this region and LOB1 domain were conserved among citrus species and relatives, which suggests that the interaction PthA4-CsLOB1-CsLIEXP1 is conserved in citrus species and relatives. This is the first study that experimentally demonstrated a CsLOB1 downstream target and lays the foundation to identify other new targets. In addition, we demonstrated that the CsLIEXP1 is a putative S gene indirectly induced by PthA4, which may serve as the target for genome editing to generate citrus canker-resistant varieties.
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Affiliation(s)
- Reinaldo Rodrigues de Souza-Neto
- Citrus Research Center "Sylvio Moreira", Agronomic Institute-IAC, Brazil
- Departament of Genetics, Evolution and Bioagents, Institute of Biology, University of Campinas, Brazil
| | | | - Doron Teper
- Department of Plant Pathology and Weed Research, Institute of Plant Protection, Agricultural Research Organization, Volcani Center, Israel
| | | | | | - Celso Eduardo Benedetti
- Brazilian Biosciences National Laboratory (LNBio), Brazilian Center for Research in Energy and Materials (CNPEM), Brazil
| | - Nian Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences (IFAS), University of Florida, U.S.A
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Richter I, Wein P, Uzum Z, Stanley CE, Krabbe J, Molloy EM, Moebius N, Ferling I, Hillmann F, Hertweck C. Transcription activator-like effector protects bacterial endosymbionts from entrapment within fungal hyphae. Curr Biol 2023:S0960-9822(23)00623-1. [PMID: 37301202 DOI: 10.1016/j.cub.2023.05.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 03/30/2023] [Accepted: 05/12/2023] [Indexed: 06/12/2023]
Abstract
As an endosymbiont of the ecologically and medically relevant fungus Rhizopus microsporus, the toxin-producing bacterium Mycetohabitans rhizoxinica faces myriad challenges, such as evading the host's defense mechanisms. However, the bacterial effector(s) that facilitate the remarkable ability of M. rhizoxinica to freely migrate within fungal hyphae have thus far remained unknown. Here, we show that a transcription activator-like (TAL) effector released by endobacteria is an essential symbiosis factor. By combining microfluidics with fluorescence microscopy, we observed enrichment of TAL-deficient M. rhizoxinica in side hyphae. High-resolution live imaging showed the formation of septa at the base of infected hyphae, leading to the entrapment of endobacteria. Using a LIVE/DEAD stain, we demonstrate that the intracellular survival of trapped TAL-deficient bacteria is significantly reduced compared with wild-type M. rhizoxinica, indicative of a protective host response in the absence of TAL proteins. Subversion of host defense in TAL-competent endobacteria represents an unprecedented function of TAL effectors. Our data illustrate an unusual survival strategy of endosymbionts in the host and provide deeper insights into the dynamic interactions between bacteria and eukaryotes.
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Affiliation(s)
- Ingrid Richter
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, HKI, Beutenbergstr. 11a, 07745 Jena, Germany
| | - Philipp Wein
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, HKI, Beutenbergstr. 11a, 07745 Jena, Germany
| | - Zerrin Uzum
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, HKI, Beutenbergstr. 11a, 07745 Jena, Germany
| | - Claire E Stanley
- Department of Bioengineering, Imperial College, South Kensington, London SW7 2AZ, UK
| | - Jana Krabbe
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, HKI, Beutenbergstr. 11a, 07745 Jena, Germany
| | - Evelyn M Molloy
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, HKI, Beutenbergstr. 11a, 07745 Jena, Germany
| | - Nadine Moebius
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, HKI, Beutenbergstr. 11a, 07745 Jena, Germany
| | - Iuliia Ferling
- Junior Research Group Evolution of Microbial Interactions, Leibniz Institute for Natural Product Research and Infection Biology, Beutenbergstr. 11a, 07745 Jena, Germany
| | - Falk Hillmann
- Junior Research Group Evolution of Microbial Interactions, Leibniz Institute for Natural Product Research and Infection Biology, Beutenbergstr. 11a, 07745 Jena, Germany
| | - Christian Hertweck
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, HKI, Beutenbergstr. 11a, 07745 Jena, Germany; Institute of Microbiology, Faculty of Biological Sciences, Friedrich Schiller University Jena, 07743 Jena, Germany.
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4
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Teper D, White FF, Wang N. The Dynamic Transcription Activator-Like Effector Family of Xanthomonas. PHYTOPATHOLOGY 2023; 113:651-666. [PMID: 36449529 DOI: 10.1094/phyto-10-22-0365-kd] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Transcription activator-like effectors (TALEs) are bacterial proteins that are injected into the eukaryotic nucleus to act as transcriptional factors and function as key virulence factors of the phytopathogen Xanthomonas. TALEs are translocated into plant host cells via the type III secretion system and induce the expression of host susceptibility (S) genes to facilitate disease. The unique modular DNA binding domains of TALEs comprise an array of nearly identical direct repeats that enable binding to DNA targets based on the recognition of a single nucleotide target per repeat. The very nature of TALE structure and function permits the proliferation of TALE genes and evolutionary adaptations in the host to counter TALE function, making the TALE-host interaction the most dynamic story in effector biology. The TALE genes appear to be a relatively young effector gene family, with a presence in all virulent members of some species and absent in others. Genome sequencing has revealed many TALE genes throughout the xanthomonads, and relatively few have been associated with a cognate S gene. Several species, including Xanthomonas oryzae pv. oryzae and X. citri pv. citri, have near absolute requirement for TALE gene function, while the genes appear to be just now entering the disease interactions with new fitness contributions to the pathogens of tomato and pepper among others. Deciphering the simple and effective DNA binding mechanism also has led to the development of DNA manipulation tools in fields of gene editing and transgenic research. In the three decades since their discovery, TALE research remains at the forefront of the study of bacterial evolution, plant-pathogen interactions, and synthetic biology. We also discuss critical questions that remain to be addressed regarding TALEs.
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Affiliation(s)
- Doron Teper
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, Volcani Institute, Rishon LeZion, Israel
| | - Frank F White
- Department of Plant Pathology, Institute of Food and Agricultural Sciences (IFAS), University of Florida, Gainesville, FL, U.S.A
| | - Nian Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, U.S.A
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Zeng D, Liu SS, Shao WB, Zhang TH, Qi PY, Liu HW, Zhou X, Liu LW, Zhang H, Yang S. New Inspiration of 1,3,4-Oxadiazole Agrochemical Candidates: Manipulation of a Type III Secretion System-Induced Bacterial Starvation Mechanism to Prevent Plant Bacterial Diseases. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:2804-2816. [PMID: 36744848 DOI: 10.1021/acs.jafc.2c07486] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Discovering new anti-virulent agents to control plant bacterial diseases by preventing bacterial pathogenesis/pathogenicity rather than affecting bacterial growth is a sensible strategy. However, the effects of compound-manipulated bacterial virulence factors on host response are still not clear. In this work, 35 new 1,3,4-oxadiazole derivatives were synthesized and systematically evaluated for their anti-phytopathogenic activities. Bioassay results revealed that compound C7 possessed outstanding antibacterial activity in vitro (half-maximal effective concentration: 0.80 μg/mL) against Xanthomonas oryzae pv. oryzae (Xoo) and acceptable bioactivity in vivo toward rice bacterial leaf blight. Furthermore, virulence factor-related biochemical assays showed that C7 was a promising anti-virulent agent. Interestingly, C7 could indirectly reduce the inducible expression of host SWEET genes and thereby alleviate nutrient supply in the infection process of phytopathogenic bacteria. Our results highlight the potential of 1,3,4-oxadiazole-based agrochemicals for manipulating type III secretion system-induced phytopathogenic bacteria starvation mechanisms to prevent plant bacterial diseases.
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Affiliation(s)
- Dan Zeng
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Shuai-Shuai Liu
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Wu-Bin Shao
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Tai-Hong Zhang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Pu-Ying Qi
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Hong-Wu Liu
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Xiang Zhou
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Li-Wei Liu
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Heng Zhang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
| | - Song Yang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
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Lin H, Wang M, Chen Y, Nomura K, Hui S, Gui J, Zhang X, Wu Y, Liu J, Li Q, Deng Y, Li L, Yuan M, Wang S, He SY, He Z. An MKP-MAPK protein phosphorylation cascade controls vascular immunity in plants. SCIENCE ADVANCES 2022; 8:eabg8723. [PMID: 35263144 PMCID: PMC8906744 DOI: 10.1126/sciadv.abg8723] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Global crop production is greatly reduced by vascular diseases. These diseases include bacterial blight of rice and crucifer black rot caused by Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas campestris pv. campestris (Xcc). The molecular mechanisms that activate vascular defense against such pathogens remains underexplored. Here, we show that an Arabidopsis MAPK phosphatase 1 (MKP1) mutant has increased host susceptibility to the adapted pathogen Xcc and is compromised in nonhost resistance to the rice pathogen Xoo. MKP1 regulates MAPK-mediated phosphorylation of the transcription factor MYB4 that negatively regulates vascular lignification through inhibiting lignin biosynthesis. Induction of lignin biosynthesis is, therefore, an important part of vascular-specific immunity. The role of MKP-MAPK-MYB signaling in lignin biosynthesis and vascular resistance to Xoo is conserved in rice, indicating that these factors form a tissue-specific defense regulatory network. Our study likely reveals a major vascular immune mechanism that underlies tissue-specific disease resistance against bacterial pathogens in plants.
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Affiliation(s)
- Hui Lin
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Muyang Wang
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Ying Chen
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Kinya Nomura
- Department of Biology, Duke University, Durham, NC, USA
| | - Shugang Hui
- National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China
| | - Jinshan Gui
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Xiawei Zhang
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Yue Wu
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Jiyun Liu
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Qun Li
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Yiwen Deng
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Laigeng Li
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Meng Yuan
- National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China
| | - Shiping Wang
- National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China
| | - Sheng Yang He
- Department of Biology, Duke University, Durham, NC, USA
- Howard Hughes Medical Institute, Duke University, Durham, NC, USA
| | - Zuhua He
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- Corresponding author.
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7
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Diversity of transcription activator-like effectors and pathogenicity in strains of Xanthomonas oryzae pv. oryzicola from Yunnan. World J Microbiol Biotechnol 2022; 38:71. [PMID: 35258706 DOI: 10.1007/s11274-022-03230-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Accepted: 01/07/2022] [Indexed: 10/18/2022]
Abstract
The present study aimed to evaluate transcriptional activator-like effector (TALE) genes in 86 Xanthomonas oryzae pv. oryzicola strains collected from 8 rice-growing regions in Yunnan, and to examine the relationship between TALE genotypes and virulence in 6 differential rice lines. Besides, the geographical areas, distribution of these genotypes were studied in detail. Genetic diversity was analyzed through the number and size of putative TALE genes based on TALE gene avrXa3 as a probe. We found that X. oryzae pv. oryzicola strains consist of variable number (13-27) of avrXa3-hybridizing fragments (putative TALE genes). Test strains were classified into 8 genotypes (G1-G8) with major genotypes G3 and G7 widely distributed in Yunnan. Pathogenicity of X. oryzae pv. oryzicola was evaluated by inoculating 6 differential rice lines with a single resistance gene into 9 pathotypes clusters (I-IX), the dominant Genotypes G3 and G7 consist of pathotypes I, II, and IV. Furthermore, we also detected the known TALE target genes expression in susceptible rice cultivar (cv. nipponbare) after inoculating 8 genotypes-representative X. oryzae pv. oryzicola strain. Correlation between the numbers of putative TALE genes of X. oryzae pv. oryzicola and relevant target genes in nipponbare confirmed up-regulation. Altogether, this study has given insights into the population structure of X. oryzae pv. oryzicola that may inform strategies to control BLS in rice.
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Ji J, Yang L, Fang Z, Zhang Y, Zhuang M, Lv H, Wang Y. Plant SWEET Family of Sugar Transporters: Structure, Evolution and Biological Functions. Biomolecules 2022; 12:biom12020205. [PMID: 35204707 PMCID: PMC8961523 DOI: 10.3390/biom12020205] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 01/17/2022] [Accepted: 01/18/2022] [Indexed: 12/20/2022] Open
Abstract
The SWEET (sugars will eventually be exported transporter) family was identified as a new class of sugar transporters that function as bidirectional uniporters/facilitators and facilitate the diffusion of sugars across cell membranes along a concentration gradient. SWEETs are found widely in plants and play central roles in many biochemical processes, including the phloem loading of sugar for long-distance transport, pollen nutrition, nectar secretion, seed filling, fruit development, plant–pathogen interactions and responses to abiotic stress. This review focuses on advances of the plant SWEETs, including details about their discovery, characteristics of protein structure, evolution and physiological functions. In addition, we discuss the applications of SWEET in plant breeding. This review provides more in-depth and comprehensive information to help elucidate the molecular basis of the function of SWEETs in plants.
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Affiliation(s)
- Jialei Ji
- Correspondence: ; Tel.: +86-10-82108756
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9
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Xuan C, Lan G, Si F, Zeng Z, Wang C, Yadav V, Wei C, Zhang X. Systematic Genome-Wide Study and Expression Analysis of SWEET Gene Family: Sugar Transporter Family Contributes to Biotic and Abiotic Stimuli in Watermelon. Int J Mol Sci 2021; 22:8407. [PMID: 34445115 PMCID: PMC8395094 DOI: 10.3390/ijms22168407] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 08/01/2021] [Accepted: 08/04/2021] [Indexed: 12/21/2022] Open
Abstract
The SWEET (Sugars Will Eventually be Exported Transporter) proteins are a novel family of sugar transporters that play key roles in sugar efflux, signal transduction, plant growth and development, plant-pathogen interactions, and stress tolerance. In this study, 22 ClaSWEET genes were identified in Citrullus lanatus (Thunb.) through homology searches and classified into four groups by phylogenetic analysis. The genes with similar structures, conserved domains, and motifs were clustered into the same groups. Further analysis of the gene promoter regions uncovered various growth, development, and biotic and abiotic stress responsive cis-regulatory elements. Tissue-specific analysis showed most of the genes were highly expressed in male flowers and the roots of cultivated varieties and wild cultivars. In addition, qRT-PCR results further imply that ClaSWEET proteins might be involved in resistance to Fusarium oxysporum infection. Moreover, a significantly higher expression level of these genes under various abiotic stresses suggests its multifaceted role in mediating plant responses to drought, salt, and low-temperature stress. The genome-wide characterization and phylogenetic analysis of ClaSWEET genes, together with the expression patterns in different tissues and stimuli, lays a solid foundation for future research into their molecular function in watermelon developmental processes and responses to biotic and abiotic stresses.
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Affiliation(s)
- Changqing Xuan
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Horticulture, Northwest A & F University, Yangling 712100, China; (C.X.); (G.L.); (F.S.); (Z.Z.); (C.W.); (V.Y.)
| | - Guangpu Lan
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Horticulture, Northwest A & F University, Yangling 712100, China; (C.X.); (G.L.); (F.S.); (Z.Z.); (C.W.); (V.Y.)
| | - Fengfei Si
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Horticulture, Northwest A & F University, Yangling 712100, China; (C.X.); (G.L.); (F.S.); (Z.Z.); (C.W.); (V.Y.)
| | - Zhilong Zeng
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Horticulture, Northwest A & F University, Yangling 712100, China; (C.X.); (G.L.); (F.S.); (Z.Z.); (C.W.); (V.Y.)
| | - Chunxia Wang
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Horticulture, Northwest A & F University, Yangling 712100, China; (C.X.); (G.L.); (F.S.); (Z.Z.); (C.W.); (V.Y.)
| | - Vivek Yadav
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Horticulture, Northwest A & F University, Yangling 712100, China; (C.X.); (G.L.); (F.S.); (Z.Z.); (C.W.); (V.Y.)
| | - Chunhua Wei
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Horticulture, Northwest A & F University, Yangling 712100, China; (C.X.); (G.L.); (F.S.); (Z.Z.); (C.W.); (V.Y.)
| | - Xian Zhang
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Horticulture, Northwest A & F University, Yangling 712100, China; (C.X.); (G.L.); (F.S.); (Z.Z.); (C.W.); (V.Y.)
- State Key Laboratory of Vegetable Germplasm Innovation, Tianjin 300384, China
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10
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Gupta PK, Balyan HS, Gautam T. SWEET genes and TAL effectors for disease resistance in plants: Present status and future prospects. MOLECULAR PLANT PATHOLOGY 2021; 22:1014-1026. [PMID: 34076324 PMCID: PMC8295518 DOI: 10.1111/mpp.13075] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 03/13/2021] [Accepted: 04/28/2021] [Indexed: 06/12/2023]
Abstract
SWEET genes encode sugar transporter proteins and often function as susceptibility (S) genes. Consequently, the recessive alleles of these SWEET genes provide resistance. This review summarizes the available literature on the molecular basis of the role of SWEET genes (as S genes) in the host and corresponding transcription activator-like effectors (TALEs) secreted by the pathogen. The review has four major sections, which follow a brief introduction: The first part gives some details about the occurrence and evolution of SWEET genes in approximately 30 plant species; the second part gives some details about systems where (a) SWEET genes with and without TALEs and (b) TALEs without SWEET genes cause different diseases; the third part summarizes the available information about TALEs along with interfering/truncated TALEs secreted by the pathogens; this section also summarizes the available information on effector-binding elements (EBEs) available in the promoters of either the SWEET genes or the Executor R genes; the code that is used for binding of TALEs to EBEs is also described in this section; the fourth part gives some details about the available approaches that are being used or can be used in the future for exploiting SWEET genes for developing disease-resistant cultivars. The review concludes with a section giving conclusions and future possibilities of using SWEET genes for developing disease-resistant cultivars using different approaches, including conventional breeding and genome editing.
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Affiliation(s)
| | | | - Tinku Gautam
- Department of Genetics and Plant BreedingCCS UniversityMeerutIndia
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11
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Vannini C, Domingo G, Fiorilli V, Seco DG, Novero M, Marsoni M, Wisniewski-Dye F, Bracale M, Moulin L, Bonfante P. Proteomic analysis reveals how pairing of a Mycorrhizal fungus with plant growth-promoting bacteria modulates growth and defense in wheat. PLANT, CELL & ENVIRONMENT 2021; 44:1946-1960. [PMID: 33675052 DOI: 10.1111/pce.14039] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 02/17/2021] [Accepted: 02/23/2021] [Indexed: 06/12/2023]
Abstract
Plants rely on their microbiota for improving the nutritional status and environmental stress tolerance. Previous studies mainly focused on bipartite interactions (a plant challenged by a single microbe), while plant responses to multiple microbes have received limited attention. Here, we investigated local and systemic changes induced in wheat by two plant growth-promoting bacteria (PGPB), Azospirillum brasilense and Paraburkholderia graminis, either alone or together with an arbuscular mycorrhizal fungus (AMF). We conducted phenotypic, proteomic, and biochemical analyses to investigate bipartite (wheat-PGPB) and tripartite (wheat-PGPB-AMF) interactions, also upon a leaf pathogen infection. Results revealed that only AMF and A. brasilense promoted plant growth by activating photosynthesis and N assimilation which led to increased glucose and amino acid content. The bioprotective effect of the PGPB-AMF interactions on infected wheat plants depended on the PGPB-AMF combinations, which caused specific phenotypic and proteomic responses (elicitation of defense related proteins, immune response and jasmonic acid biosynthesis). In the whole, wheat responses strongly depended on the inoculum composition (single vs. multiple microbes) and the investigated organs (roots vs. leaf). Our findings showed that AMF is the best-performing microbe, suggesting its presence as the crucial one for synthetic microbial community development.
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Affiliation(s)
- Candida Vannini
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, Varese, Italy
| | - Guido Domingo
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, Varese, Italy
| | - Valentina Fiorilli
- Department of Life Sciences and Systems Biology, Università degli Studi di Torino, Torino, Italy
| | | | - Mara Novero
- Department of Life Sciences and Systems Biology, Università degli Studi di Torino, Torino, Italy
| | - Milena Marsoni
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, Varese, Italy
| | - Florence Wisniewski-Dye
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, INRAE, VetAgroSup, UMR Ecologie Microbienne, Villeurbanne, France
| | - Marcella Bracale
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, Varese, Italy
| | - Lionel Moulin
- IRD, CIRAD, University of Montpellier, IPME, Montpellier, France
| | - Paola Bonfante
- Department of Life Sciences and Systems Biology, Università degli Studi di Torino, Torino, Italy
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12
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Xu L, Xiao L, Xiao Y, Peng D, Xiao X, Huang W, Gheysen G, Wang G. Plasmodesmata play pivotal role in sucrose supply to Meloidogyne graminicola-caused giant cells in rice. MOLECULAR PLANT PATHOLOGY 2021; 22:539-550. [PMID: 33723908 PMCID: PMC8035636 DOI: 10.1111/mpp.13042] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 01/24/2021] [Accepted: 01/28/2021] [Indexed: 05/20/2023]
Abstract
On infection, plant-parasitic nematodes establish feeding sites in roots from which they take up carbohydrates among other nutrients. Knowledge on how carbohydrates are supplied to the nematodes' feeding sites is limited. Here, gene expression analyses showed that RNA levels of OsSWEET11 to OsSWEET15 were extremely low in both Meloidogyne graminicola (Mg)-caused galls and noninoculated roots. All the rice sucrose transporter genes, OsSUT1 to OsSUT5, were either down-regulated in Mg-caused galls compared with noninoculated rice roots or had very low transcript abundance. OsSUT1 was the only gene up-regulated in galls, at 14 days postinoculation (dpi), after being highly down-regulated at 3 and 7 dpi. OsSUT4 was down-regulated at 3 dpi. No noticeable OsSUTs promoter activities were detected in Mg-caused galls of pOsSUT1 to -5::GUS rice lines. Loading experiments with carboxyfluorescein diacetate (CFDA) demonstrated that symplastic connections exist between phloem and Mg-caused giant cells (GCs). According to data from OsGNS5- and OsGSL2-overexpressing rice plants that had decreased and increased callose deposition, respectively, callose negatively affected Mg parasitism and sucrose supply to Mg-caused GCs. Our results suggest that plasmodesmata-mediated sucrose transport plays a pivotal role in sucrose supply from rice root phloem to Mg-caused GCs, and OsSWEET11 to -15 and OsSUTs are not major players in it, although further functional analysis is needed for OsSUT1 and OsSUT4.
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Affiliation(s)
- Li‐he Xu
- Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science & TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Li‐ying Xiao
- Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science & TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Yan‐nong Xiao
- Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science & TechnologyHuazhong Agricultural UniversityWuhanChina
| | - De‐liang Peng
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural ScienceBeijingChina
| | - Xue‐qiong Xiao
- Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science & TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Wen‐kun Huang
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural ScienceBeijingChina
| | - Godelieve Gheysen
- Department of BiotechnologyFaculty of Bioscience EngineeringGhent UniversityGhentBelgium
| | - Gao‐feng Wang
- Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science & TechnologyHuazhong Agricultural UniversityWuhanChina
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13
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Veley KM, Okwuonu I, Jensen G, Yoder M, Taylor NJ, Meyers BC, Bart RS. Gene tagging via CRISPR-mediated homology-directed repair in cassava. G3 (BETHESDA, MD.) 2021; 11:jkab028. [PMID: 33855431 PMCID: PMC8049417 DOI: 10.1093/g3journal/jkab028] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 01/21/2021] [Indexed: 12/21/2022]
Abstract
Research on a few model plant-pathogen systems has benefitted from years of tool and resource development. This is not the case for the vast majority of economically and nutritionally important plants, creating a crop improvement bottleneck. Cassava bacterial blight (CBB), caused by Xanthomonas axonopodis pv. manihotis (Xam), is an important disease in all regions where cassava (Manihot esculenta Crantz) is grown. Here, we describe the development of cassava that can be used to visualize one of the initial steps of CBB infection in vivo. Using CRISPR-mediated homology-directed repair (HDR), we generated plants containing scarless insertion of GFP at the 3' end of CBB susceptibility (S) gene MeSWEET10a. Activation of MeSWEET10a-GFP by the transcription activator-like (TAL) effector TAL20 was subsequently visualized at transcriptional and translational levels. To our knowledge, this is the first such demonstration of HDR via gene editing in cassava.
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Affiliation(s)
- Kira M Veley
- Donald Danforth Plant Science Center, Saint Louis, MO 63132, USA
| | - Ihuoma Okwuonu
- Biotechnology Research Division, National Root Crops Research Institute, Umudike, Abia State, Nigeria
| | - Greg Jensen
- Donald Danforth Plant Science Center, Saint Louis, MO 63132, USA
| | - Marisa Yoder
- Donald Danforth Plant Science Center, Saint Louis, MO 63132, USA
| | - Nigel J Taylor
- Donald Danforth Plant Science Center, Saint Louis, MO 63132, USA
| | - Blake C Meyers
- Donald Danforth Plant Science Center, Saint Louis, MO 63132, USA
- Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA
| | - Rebecca S Bart
- Donald Danforth Plant Science Center, Saint Louis, MO 63132, USA
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14
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Yao T, Zhou Y, Hu J, Xiao T, Zhou C. Genomic evolutionary relationship of SWEET genes and their responses to HLB disease and oxytetracycline treatment in Valencia sweet orange. Biologia (Bratisl) 2021. [DOI: 10.1007/s11756-021-00745-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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15
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Schreiber KJ, Lewis JD. Identification of a Putative DNA-Binding Protein in Arabidopsis That Acts as a Susceptibility Hub and Interacts With Multiple Pseudomonas syringae Effectors. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:410-425. [PMID: 33373263 DOI: 10.1094/mpmi-10-20-0291-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Phytopathogens use secreted effector proteins to suppress host immunity and promote pathogen virulence, and there is increasing evidence that the host-pathogen interactome comprises a complex network. To identify novel interactors of the Pseudomonas syringae effector HopZ1a, we performed a yeast two-hybrid screen that identified a previously uncharacterized Arabidopsis protein that we designate HopZ1a interactor 1 (ZIN1). Additional analyses in yeast and in planta revealed that ZIN1 also interacts with several other P. syringae effectors. We show that an Arabidopsis loss-of-function zin1 mutant is less susceptible to infection by certain strains of P. syringae, while overexpression of ZIN1 results in enhanced susceptibility. Functionally, ZIN1 exhibits topoisomerase-like activity in vitro. Transcriptional profiling of wild-type and zin1 Arabidopsis plants inoculated with P. syringae indicated that while ZIN1 regulates a wide range of pathogen-responsive biological processes, the list of genes more highly expressed in zin1 versus wild-type plants is particularly enriched for ribosomal protein genes. Altogether, these data illuminate ZIN1 as a potential susceptibility hub that interacts with multiple effectors to influence the outcome of plant-microbe interactions.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Karl J Schreiber
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA 94720-3102, U.S.A
| | - Jennifer D Lewis
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA 94720-3102, U.S.A
- Plant Gene Expression Center, United States Department of Agriculture, Albany, CA 94710-1105, U.S.A
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16
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Schreiber KJ, Hassan JA, Lewis JD. Arabidopsis Abscisic Acid Repressor 1 is a susceptibility hub that interacts with multiple Pseudomonas syringae effectors. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:1274-1292. [PMID: 33289145 DOI: 10.1111/tpj.15110] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 11/20/2020] [Accepted: 11/23/2020] [Indexed: 06/12/2023]
Abstract
Pathogens secrete effector proteins into host cells to suppress host immunity and promote pathogen virulence, although many features at the molecular interface of host-pathogen interactions remain to be characterized. In a yeast two-hybrid assay, we found that the Pseudomonas syringae effector HopZ1a interacts with the Arabidopsis transcriptional regulator Abscisic Acid Repressor 1 (ABR1). Further analysis revealed that ABR1 interacts with multiple P. syringae effectors, suggesting that it may be targeted as a susceptibility hub. Indeed, loss-of-function abr1 mutants exhibit reduced susceptibility to a number of P. syringae strains. The ABR1 protein comprises a conserved APETALA2 (AP2) domain flanked by long regions of predicted structural disorder. We verified the DNA-binding activity of the AP2 domain and demonstrated that the disordered domains act redundantly to enhance DNA binding and to facilitate transcriptional activation by ABR1. Finally, we compared gene expression profiles from wild-type and abr1 plants following inoculation with P. syringae, which suggested that the reduced susceptibility of abr1 mutants is due to the loss of a virulence target rather than an enhanced immune response. These data highlight ABR1 as a functionally important component at the host-pathogen interface.
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Affiliation(s)
- Karl J Schreiber
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, USA
| | - Jana A Hassan
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, USA
| | - Jennifer D Lewis
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, USA
- United States Department of Agriculture, Plant Gene Expression Center, Albany, CA, USA
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17
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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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18
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Huerta AI, Delorean EE, Bossa‐Castro AM, Tonnessen BW, Raghavan C, Corral R, Pérez‐Quintero ÁL, Leung H, Verdier V, Leach JE. Resistance and susceptibility QTL identified in a rice MAGIC population by screening with a minor-effect virulence factor from Xanthomonas oryzae pv. oryzae. PLANT BIOTECHNOLOGY JOURNAL 2021; 19:51-63. [PMID: 32594636 PMCID: PMC7769240 DOI: 10.1111/pbi.13438] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 06/02/2020] [Accepted: 06/17/2020] [Indexed: 05/07/2023]
Abstract
Effective and durable disease resistance for bacterial blight (BB) of rice is a continuous challenge due to the evolution and adaptation of the pathogen, Xanthomonas oryzae pv. oryzae (Xoo), on cultivated rice varieties. Fundamental to this pathogens' virulence is transcription activator-like (TAL) effectors that activate transcription of host genes and contribute differently to pathogen virulence, fitness or both. Host plant resistance is predicted to be more durable if directed at strategic virulence factors that impact both pathogen virulence and fitness. We characterized Tal7b, a minor-effect virulence factor that contributes incrementally to pathogen virulence in rice, is a fitness factor to the pathogen and is widely present in geographically diverse strains of Xoo. To identify sources of resistance to this conserved effector, we used a highly virulent strain carrying a plasmid borne copy of Tal7b to screen an indica multi-parent advanced generation inter-cross (MAGIC) population. Of 18 QTL revealed by genome-wide association studies and interval mapping analysis, six were specific to Tal7b (qBB-tal7b). Overall, 150 predicted Tal7b gene targets overlapped with qBB-tal7b QTL. Of these, 21 showed polymorphisms in the predicted effector binding element (EBE) site and 23 lost the EBE sequence altogether. Inoculation and bioinformatics studies suggest that the Tal7b target in one of the Tal7b-specific QTL, qBB-tal7b-8, is a disease susceptibility gene and that the resistance mechanism for this locus may be through loss of susceptibility. Our work demonstrates that minor-effect virulence factors significantly contribute to disease and provide a potential new approach to identify effective disease resistance.
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Affiliation(s)
- Alejandra I. Huerta
- Department of Agricultural BiologyColorado State UniversityFort CollinsCOUSA
- Present address:
Department of Entomology and Plant PathologyNorth Carolina State UniversityRaleighNCUSA
| | - Emily E. Delorean
- Department of Agricultural BiologyColorado State UniversityFort CollinsCOUSA
- Present address:
Department of Plant PathologyKansas State UniversityManhattanKS66506USA
| | - Ana M. Bossa‐Castro
- Department of Agricultural BiologyColorado State UniversityFort CollinsCOUSA
| | - Bradley W. Tonnessen
- Department of Agricultural BiologyColorado State UniversityFort CollinsCOUSA
- Present address:
Extension Plant SciencesNew Mexico State UniversityLas CrucesNM88003USA
| | - Chitra Raghavan
- Division Genetics and BiotechnologyInternational Rice Research InstituteManilaPhilippines
- Present address:
Queensland Department of Agriculture and FisheriesHorticulture and Forestry SciencesCairnsQLD4870Australia
| | - Rene Corral
- Department of Agricultural BiologyColorado State UniversityFort CollinsCOUSA
| | | | - Hei Leung
- Division Genetics and BiotechnologyInternational Rice Research InstituteManilaPhilippines
| | | | - Jan E. Leach
- Department of Agricultural BiologyColorado State UniversityFort CollinsCOUSA
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19
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Secrete or perish: The role of secretion systems in Xanthomonas biology. Comput Struct Biotechnol J 2020; 19:279-302. [PMID: 33425257 PMCID: PMC7777525 DOI: 10.1016/j.csbj.2020.12.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/13/2020] [Accepted: 12/13/2020] [Indexed: 12/22/2022] Open
Abstract
Bacteria of the Xanthomonas genus are mainly phytopathogens of a large variety of crops of economic importance worldwide. Xanthomonas spp. rely on an arsenal of protein effectors, toxins and adhesins to adapt to the environment, compete with other microorganisms and colonize plant hosts, often causing disease. These protein effectors are mainly delivered to their targets by the action of bacterial secretion systems, dedicated multiprotein complexes that translocate proteins to the extracellular environment or directly into eukaryotic and prokaryotic cells. Type I to type VI secretion systems have been identified in Xanthomonas genomes. Recent studies have unravelled the diverse roles played by the distinct types of secretion systems in adaptation and virulence in xanthomonads, unveiling new aspects of their biology. In addition, genome sequence information from a wide range of Xanthomonas species and pathovars have become available recently, uncovering a heterogeneous distribution of the distinct families of secretion systems within the genus. In this review, we describe the architecture and mode of action of bacterial type I to type VI secretion systems and the distribution and functions associated with these important nanoweapons within the Xanthomonas genus.
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20
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Jiang S, He M, Xiang XW, Adnan M, Cui ZN. Novel S-Thiazol-2-yl-furan-2-carbothioate Derivatives as Potential T3SS Inhibitors Against Xanthomonas oryzae on Rice. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:11867-11876. [PMID: 31584805 DOI: 10.1021/acs.jafc.9b04085] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv oryzae (Xoo) is considered as the most destructive disease of rice. The use of bactericides is among the most widely used traditional methods to control this destructive disease. The excessive and repeated use of the same bactericides is also becoming the reason behind the development of bactericide resistance. The widely used method for finding the new antimicrobial agents often involves the bacterial virulence factors as a target without affecting bacterial growth. Type III secretion system (T3SS) is a protein appendage and is considered as having essential virulence factors in most Gram-negative bacteria. Due to the conserved construct, T3SS has been regarded as an important mark for the blooming of novel antimicrobial drugs. Toward the search of new T3SS inhibitors, an alternative series of 1,3-thiazole derivatives were designed and synthesized. Their structures were characterized and confirmed by 1H NMR, 13C NMR, MS, and elemental analysis. All the title compounds inhibited the promoter activity of hpa1 gene significantly. Eight of them showed better inhibition than our previous T3SS inhibitor TS006 (o-coumaric acid, OCA). The treatment of Xoo with eight compounds significantly attenuated HR without affecting bacterial growth. The mRNA levels of some representative genes (hrp/hrc genes) were reduced up to different extents. In vivo bioassay results showed that eight T3SS inhibitors could reduce bacterial leaf blight and bacterial leaf streak symptoms on rice, significantly.
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Affiliation(s)
- Shan Jiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control , South China Agricultural University , Guangzhou 510642 , China
| | - Min He
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control , South China Agricultural University , Guangzhou 510642 , China
| | - Xu-Wen Xiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control , South China Agricultural University , Guangzhou 510642 , China
| | - Muhammad Adnan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control , South China Agricultural University , Guangzhou 510642 , China
| | - Zi-Ning Cui
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control , South China Agricultural University , Guangzhou 510642 , China
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21
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Integrative analysis reveals evolutionary patterns and potential functions of SWEET transporters in Euphorbiaceae. Int J Biol Macromol 2019; 139:1-11. [DOI: 10.1016/j.ijbiomac.2019.07.102] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 07/09/2019] [Accepted: 07/16/2019] [Indexed: 01/06/2023]
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22
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Perez-Quintero AL, Szurek B. A Decade Decoded: Spies and Hackers in the History of TAL Effectors Research. ANNUAL REVIEW OF PHYTOPATHOLOGY 2019; 57:459-481. [PMID: 31387457 DOI: 10.1146/annurev-phyto-082718-100026] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Transcription activator-like effectors (TALEs) from the genus Xanthomonas are proteins with the remarkable ability to directly bind the promoters of genes in the plant host to induce their expression, which often helps bacterial colonization. Metaphorically, TALEs act as spies that infiltrate the plant disguised as high-ranking civilians (transcription factors) to trick the plant into activating weak points that allow an invasion. Current knowledge of how TALEs operate allows researchers to predict their activity (counterespionage) and exploit their function, engineering them to do our bidding (a Manchurian agent). This has been possible thanks particularly to the discovery of their DNA binding mechanism, which obeys specific amino acid-DNA correspondences (the TALE code). Here, we review the history of how researchers discovered the way these proteins work and what has changed in the ten years since the discovery of the code. Recommended music for reading this review can be found in the Supplemental Material.
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Affiliation(s)
- Alvaro L Perez-Quintero
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, Colorado 80523-1177, USA;
- IRD, CIRAD, Université Montpellier, IPME, 34000 Montpellier, France;
| | - Boris Szurek
- IRD, CIRAD, Université Montpellier, IPME, 34000 Montpellier, France;
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23
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Lang JM, Pérez-Quintero AL, Koebnik R, DuCharme E, Sarra S, Doucoure H, Keita I, Ziegle J, Jacobs JM, Oliva R, Koita O, Szurek B, Verdier V, Leach JE. A Pathovar of Xanthomonas oryzae Infecting Wild Grasses Provides Insight Into the Evolution of Pathogenicity in Rice Agroecosystems. FRONTIERS IN PLANT SCIENCE 2019; 10:507. [PMID: 31114597 PMCID: PMC6503118 DOI: 10.3389/fpls.2019.00507] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 04/02/2019] [Indexed: 05/21/2023]
Abstract
Xanthomonas oryzae (Xo) are globally important rice pathogens. Virulent lineages from Africa and Asia and less virulent strains from the United States have been well characterized. Xanthomonas campestris pv. leersiae (Xcl), first described in 1957, causes bacterial streak on the perennial grass, Leersia hexandra, and is a close relative of Xo. L. hexandra, a member of the Poaceae, is highly similar to rice phylogenetically, is globally ubiquitous around rice paddies, and is a reservoir of pathogenic Xo. We used long read, single molecule real time (SMRT) genome sequences of five strains of Xcl from Burkina Faso, China, Mali, and Uganda to determine the genetic relatedness of this organism with Xo. Novel transcription activator-like effectors (TALEs) were discovered in all five strains of Xcl. Predicted TALE target sequences were identified in the Leersia perrieri genome and compared to rice susceptibility gene homologs. Pathogenicity screening on L. hexandra and diverse rice cultivars confirmed that Xcl are able to colonize rice and produce weak but not progressive symptoms. Overall, based on average nucleotide identity (ANI), type III (T3) effector repertoires, and disease phenotype, we propose to rename Xcl to X. oryzae pv. leersiae (Xol) and use this parallel system to improve understanding of the evolution of bacterial pathogenicity in rice agroecosystems.
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Affiliation(s)
- Jillian M. Lang
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO, United States
- IRD, Cirad, Univ. Montpellier, IPME, Montpellier, France
| | - Alvaro L. Pérez-Quintero
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO, United States
- IRD, Cirad, Univ. Montpellier, IPME, Montpellier, France
| | - Ralf Koebnik
- IRD, Cirad, Univ. Montpellier, IPME, Montpellier, France
| | - Elysa DuCharme
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO, United States
| | - Soungalo Sarra
- Centre Régional de Recherche Agronomique de Niono, Institut d’Economie Rural, Bamako, Mali
| | - Hinda Doucoure
- Laboratoire de Biologie Moléculaire Appliquée, Université des Sciences Techniques et Technologiques de Bamako, Bamako, Mali
| | - Ibrahim Keita
- Laboratoire de Biologie Moléculaire Appliquée, Université des Sciences Techniques et Technologiques de Bamako, Bamako, Mali
| | - Janet Ziegle
- Pacific Biosciences, Menlo Park, CA, United States
| | - Jonathan M. Jacobs
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO, United States
- IRD, Cirad, Univ. Montpellier, IPME, Montpellier, France
- Department of Plant Pathology, Infectious Disease Institute, Ohio State University, Columbus, OH, United States
| | - Ricardo Oliva
- International Rice Research Institute, Los Baños, Philippines
| | - Ousmane Koita
- Laboratoire de Biologie Moléculaire Appliquée, Université des Sciences Techniques et Technologiques de Bamako, Bamako, Mali
| | - Boris Szurek
- IRD, Cirad, Univ. Montpellier, IPME, Montpellier, France
| | - Valérie Verdier
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO, United States
- IRD, Cirad, Univ. Montpellier, IPME, Montpellier, France
| | - Jan E. Leach
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO, United States
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Tao H, Fan SS, Jiang S, Xiang X, Yan X, Zhang LH, Cui ZN. Small Molecule Inhibitors Specifically Targeting the Type III Secretion System of Xanthomonas oryzae on Rice. Int J Mol Sci 2019; 20:E971. [PMID: 30813400 PMCID: PMC6412923 DOI: 10.3390/ijms20040971] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 01/27/2019] [Accepted: 02/03/2019] [Indexed: 11/24/2022] Open
Abstract
The initiative strategy for the development of novel anti-microbial agents usually uses the virulence factors of bacteria as a target, without affecting their growth and survival. The type III secretion system (T3SS), one of the essential virulence factors in most Gram-negative pathogenic bacteria because of its highly conserved construct, has been regarded as an effective target that developed new anti-microbial drugs. Xanthomonas oryzae pv. oryzae (Xoo) causes leaf blight diseases and is one of the most important pathogens on rice. To find potential anti-virulence agents against this pathogen, a number of natural compounds were screened for their effects on the T3SS of Xoo. Three of 34 compounds significantly inhibited the promoter activity of the harpin gene, hpa1, and were further checked for their impact on bacterial growth and on the hypersensitive response (HR) caused by Xoo on non-host tobacco plants. The results indicated that treatment of Xoo with CZ-1, CZ-4 and CZ-9 resulted in an obviously attenuated HR without affecting bacterial growth and survival. Moreover, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis showed that the expression of the Xoo T3SS was suppressed by treatment with the three inhibitors. The mRNA levels of representative genes in the hypersensitive response and pathogenicity (hrp) cluster, as well as the regulatory genes hrpG and hrpX, were reduced. Finally, the in vivo test demonstrated that the compounds could reduce the disease symptoms of Xoo on the rice cultivar (Oryza sativa) IR24.
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Affiliation(s)
- Hui Tao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China.
| | - Su-Su Fan
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Shan Jiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China.
| | - Xuwen Xiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China.
| | - Xiaojing Yan
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Lian-Hui Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China.
| | - Zi-Ning Cui
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China.
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25
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Carpenter SCD, Mishra P, Ghoshal C, Dash PK, Wang L, Midha S, Laha GS, Lore JS, Kositratana W, Singh NK, Singh K, Patil PB, Oliva R, Patarapuwadol S, Bogdanove AJ, Rai R. A Strain of an Emerging Indian Xanthomonas oryzae pv. oryzae Pathotype Defeats the Rice Bacterial Blight Resistance Gene xa13 Without Inducing a Clade III SWEET Gene and Is Nearly Identical to a Recent Thai Isolate. Front Microbiol 2018; 9:2703. [PMID: 30483230 PMCID: PMC6243107 DOI: 10.3389/fmicb.2018.02703] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 10/23/2018] [Indexed: 01/03/2023] Open
Abstract
The rice bacterial blight pathogen Xanthomonas oryzae pv. oryzae (Xoo) injects transcription activator-like effectors (TALEs) that bind and activate host "susceptibility" (S) genes important for disease. Clade III SWEET genes are major S genes for bacterial blight. The resistance genes xa5, which reduces TALE activity generally, and xa13, a SWEET11 allele not recognized by the cognate TALE, have been effectively deployed. However, strains that defeat both resistance genes individually were recently reported in India and Thailand. To gain insight into the mechanism(s), we completely sequenced the genome of one such strain from each country and examined the encoded TALEs. Strikingly, the two strains are clones, sharing nearly identical TALE repertoires, including a TALE known to activate SWEET11 strongly enough to be effective even when diminished by xa5. We next investigated SWEET gene induction by the Indian strain. The Indian strain induced no clade III SWEET in plants harboring xa13, indicating a pathogen adaptation that relieves dependence on these genes for susceptibility. The findings open a door to mechanistic understanding of the role SWEET genes play in susceptibility and illustrate the importance of complete genome sequence-based monitoring of Xoo populations in developing varieties with effective disease resistance.
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Affiliation(s)
- Sara C. D. Carpenter
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, United States
| | - Prashant Mishra
- Plant Pathogen Interaction, National Research Centre on Plant Biotechnology (ICAR), New Delhi, India
| | - Chandrika Ghoshal
- Plant Pathogen Interaction, National Research Centre on Plant Biotechnology (ICAR), New Delhi, India
| | - Prasanta K. Dash
- Plant Pathogen Interaction, National Research Centre on Plant Biotechnology (ICAR), New Delhi, India
| | - Li Wang
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, United States
| | - Samriti Midha
- Bacterial Genomics and Evolution Laboratory, Institute of Microbial Technology (CSIR), Chandigarh, India
| | - Gouri S. Laha
- Department of Plant Pathology, Indian Institute of Rice Research (ICAR), Hyderabad, India
| | - Jagjeet S. Lore
- Department of Plant Pathology, Punjab Agricultural University, Ludhiana, India
| | - Wichai Kositratana
- Department of Plant Pathology, Faculty of Agriculture at Kamphaeng Saen, Kasetsart University, Nakhon Pathom, Thailand
| | - Nagendra K. Singh
- Plant Pathogen Interaction, National Research Centre on Plant Biotechnology (ICAR), New Delhi, India
| | - Kuldeep Singh
- National Bureau of Plant Genetic Resources (ICAR), New Delhi, India
| | - Prabhu B. Patil
- Bacterial Genomics and Evolution Laboratory, Institute of Microbial Technology (CSIR), Chandigarh, India
| | - Ricardo Oliva
- Rice Breeding Platform, International Rice Research Institute, Los Banos, Philippines
| | - Sujin Patarapuwadol
- Department of Plant Pathology, Faculty of Agriculture at Kamphaeng Saen, Kasetsart University, Nakhon Pathom, Thailand
| | - Adam J. Bogdanove
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, United States
| | - Rhitu Rai
- Plant Pathogen Interaction, National Research Centre on Plant Biotechnology (ICAR), New Delhi, India
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26
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Rice Routes of Countering Xanthomonas oryzae. Int J Mol Sci 2018; 19:ijms19103008. [PMID: 30279356 PMCID: PMC6213470 DOI: 10.3390/ijms19103008] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 09/26/2018] [Accepted: 09/29/2018] [Indexed: 12/02/2022] Open
Abstract
Bacterial blight (BB) and bacterial leaf streak (BLS), caused by Xanthomonas oryzae pv. oryzae and Xanthomonas oryzae pv. oryzicola, respectively, are two devastating diseases in rice planting areas worldwide. It has been proven that adoption of rice resistance is the most effective, economic, and environment-friendly strategy to avoid yield loss caused by BB and BLS. As a model system for plant—pathogen interaction, the rice—X. oryzae pathosystem has been intensively investigated in the past decade. Abundant studies have shown that the resistance and susceptibility of rice to X. oryzae is determined by molecular interactions between rice genes or their products and various pathogen effectors. In this review, we briefly overviewed the literature regarding the diverse interactions, focusing on recent advances in uncovering mechanisms of rice resistance and X. oryzae virulence. Our analysis and discussions will not only be helpful for getting a better understanding of coevolution of the rice innate immunity and X. oryzae virulence, but it will also provide new insights for application of plant R genes in crop breeding.
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27
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Functional analysis of African Xanthomonas oryzae pv. oryzae TALomes reveals a new susceptibility gene in bacterial leaf blight of rice. PLoS Pathog 2018; 14:e1007092. [PMID: 29864161 PMCID: PMC6037387 DOI: 10.1371/journal.ppat.1007092] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 07/09/2018] [Accepted: 05/12/2018] [Indexed: 11/19/2022] Open
Abstract
Most Xanthomonas species translocate Transcription Activator-Like (TAL) effectors into plant cells where they function like plant transcription factors via a programmable DNA-binding domain. Characterized strains of rice pathogenic X. oryzae pv. oryzae harbor 9–16 different tal effector genes, but the function of only a few of them has been decoded. Using sequencing of entire genomes, we first performed comparative analyses of the complete repertoires of TAL effectors, herein referred to as TALomes, in three Xoo strains forming an African genetic lineage different from Asian Xoo. A phylogenetic analysis of the three TALomes combined with in silico predictions of TAL effector targets showed that African Xoo TALomes are highly conserved, genetically distant from Asian ones, and closely related to TAL effectors from the bacterial leaf streak pathogen Xanthomonas oryzae pv. oryzicola (Xoc). Nine clusters of TAL effectors could be identified among the three TALomes, including three showing higher levels of variation in their repeat variable diresidues (RVDs). Detailed analyses of these groups revealed recombination events as a possible source of variation among TAL effector genes. Next, to address contribution to virulence, nine TAL effector genes from the Malian Xoo strain MAI1 and four allelic variants from the Burkinabe Xoo strain BAI3, thus representing most of the TAL effector diversity in African Xoo strains, were expressed in the TAL effector-deficient X. oryzae strain X11-5A for gain-of-function assays. Inoculation of the susceptible rice variety Azucena lead to the discovery of three TAL effectors promoting virulence, including two TAL effectors previously reported to target the susceptibility (S) gene OsSWEET14 and a novel major virulence contributor, TalB. RNA profiling experiments in rice and in silico prediction of EBEs were carried out to identify candidate targets of TalB, revealing OsTFX1, a bZIP transcription factor previously identified as a bacterial blight S gene, and OsERF#123, which encodes a subgroup IXc AP2/ERF transcription factor. Use of designer TAL effectors demonstrated that induction of either gene resulted in greater susceptibility to strain X11-5A. The induction of OsERF#123 by BAI3Δ1, a talB knockout derivative of BAI3, carrying these designer TAL effectors increased virulence of BAI3Δ1, validating OsERF#123 as a new, bacterial blight S gene. The ability of most Xanthomonas plant pathogenic bacteria to infect their hosts relies on the action of a specific family of proteins called TAL effectors, which are transcriptional activators injected into the plant by the bacteria. TAL effectors enter the plant cell nucleus and bind to the promoters of specific plant genes. Genes that when induced can benefit pathogen multiplication or disease development are called susceptibility (S) genes. Here, we perform a comparative analysis of the TAL effector repertoires of three strains of X. oryzae pv. oryzae, which causes bacterial leaf blight of rice, a major yield constraint in this staple crop. Using sequencing of entire genomes, we compared the large repertoires of TAL effectors in three African Xoo strains which form a genetic lineage distinct from Asian strains. We assessed the individual contribution to pathogen virulence of 13 TAL effector variants represented in the three strains, and identified one that makes a major contribution. By combining host transcriptome profiling and TAL effector binding sites prediction, we identified two targets of this TAL effector that function as S genes, one previously identified, and one, new S gene. We validated the new S gene by functional characterization using designer TAL effectors. Both S genes encode transcription factors and can therefore be considered as susceptibility hubs for pathogen manipulation of the host transcriptome. Our results provide new insights into the diversified strategies underlying the roles of TAL effectors in promoting plant disease.
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28
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Deb D, Mackey D, Opiyo SO, McDowell JM. Application of alignment-free bioinformatics methods to identify an oomycete protein with structural and functional similarity to the bacterial AvrE effector protein. PLoS One 2018; 13:e0195559. [PMID: 29641586 PMCID: PMC5895030 DOI: 10.1371/journal.pone.0195559] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Accepted: 03/23/2018] [Indexed: 11/23/2022] Open
Abstract
Diverse plant pathogens export effector proteins to reprogram host cells. One of the most challenging goals in the molecular plant-microbe field is to functionally characterize the complex repertoires of effectors secreted by these pathogens. For bacterial pathogens, the predominant class of effectors is delivered to host cells by Type III secretion. For oomycetes, the predominant class of effectors is defined by a signal peptide that mediates secretion from the oomycete and a conserved RxLR motif. Downy mildew pathogens and Phytophthora species maintain hundreds of candidate RxLR effector genes in their genomes. Although no primary sequence similarity is evident between bacterial Type III effectors (T3Es) and oomycete RXLR effectors, some bacterial and oomycete effectors have convergently evolved to target the same host proteins. Such effectors might have evolved domains that are functionally similar but sequence-unrelated. We reasoned that alignment-free bioinformatics approaches could be useful to identify structural similarities between bacterial and oomycete effectors. To test this approach, we used partial least squares regression, alignment-free bioinformatics methods to identify effector proteins from the genome of the oomycete Hyaloperonospora arabidopsidis that are similar to the well-studied AvrE1 effector from Pseudomonas syringae. This approach identified five RxLR proteins with putative structural similarity to AvrE1. We focused on one, HaRxL23, because it is an experimentally validated effector and it is conserved between distantly related oomycetes. Several experiments indicate that HaRxL23 is functionally similar to AvrE1, including the ability to partially rescue an AvrE1 loss-of-function mutant. This study provides an example of how an alignment-free bioinformatics approach can identify functionally similar effector proteins in the absence of primary sequence similarity. This approach could be useful to identify effectors that have convergently evolved regardless of whether the shared host target is known.
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Affiliation(s)
- Devdutta Deb
- Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, Virginia, United States of America
| | - David Mackey
- Departments of Horticulture and Crop Science and Molecular Genetics, Ohio State University, Columbus, Ohio, United States of America
| | - Stephen O. Opiyo
- Molecular and Cellular Imaging Center-Columbus, Ohio Agricultural Research and Development Center, Ohio State University, Columbus, Ohio, United States of America
- * E-mail: (SOO); (JMM)
| | - John M. McDowell
- Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, Virginia, United States of America
- * E-mail: (SOO); (JMM)
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29
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Zhen Q, Fang T, Peng Q, Liao L, Zhao L, Owiti A, Han Y. Developing gene-tagged molecular markers for evaluation of genetic association of apple SWEET genes with fruit sugar accumulation. HORTICULTURE RESEARCH 2018; 5:14. [PMID: 29581882 PMCID: PMC5859117 DOI: 10.1038/s41438-018-0024-3] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 01/23/2018] [Accepted: 01/25/2018] [Indexed: 05/09/2023]
Abstract
Sugar content is an important component of fruit quality. Although sugar transporters are known to be crucial for sugar accumulation, the role of genes encoding SWEET sugar transporters in fruit sugar accumulation remains elusive. Here we report the effect of the SWEET genes on fruit sugar accumulation in apple. A total of 25 MdSWEET genes were identified in the apple genome, and 9 were highly expressed throughout fruit development. Molecular markers of these 9 MdSWEET genes were developed and used for genotyping of 188 apple cultivars. The association of polymorphic MdSWEET genes with soluble sugar content in mature fruit was analyzed. Three genes, MdSWEET2e, MdSWEET9b, and MdSWEET15a, were significantly associated with fruit sugar content, with MdSWEET15a and MdSWEET9b accounting for a relatively large proportion of phenotypic variation in sugar content. Moreover, both MdSWEET9b and MdSWEET15a are located on chromosomal regions harboring QTLs for sugar content. Hence, MdSWEET9b and MdSWEET15a are likely candidates regulating fruit sugar accumulation in apple. Our study not only presents an efficient way of implementing gene functional study but also provides molecular tools for genetic improvement of fruit quality in apple-breeding programs.
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Affiliation(s)
- Qiaoling Zhen
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden of the Chinese Academy of Sciences, Wuhan, 430074 China
- Graduate University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing, 100049 China
| | - Ting Fang
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden of the Chinese Academy of Sciences, Wuhan, 430074 China
- Graduate University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing, 100049 China
| | - Qian Peng
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden of the Chinese Academy of Sciences, Wuhan, 430074 China
- Graduate University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing, 100049 China
| | - Liao Liao
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden of the Chinese Academy of Sciences, Wuhan, 430074 China
| | - Li Zhao
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden of the Chinese Academy of Sciences, Wuhan, 430074 China
| | - Albert Owiti
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden of the Chinese Academy of Sciences, Wuhan, 430074 China
- Graduate University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing, 100049 China
| | - Yuepeng Han
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden of the Chinese Academy of Sciences, Wuhan, 430074 China
- Sino-African Joint Research Center, Chinese Academy of Sciences, Wuhan, 430074 China
- College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong 271018 China
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30
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Cohen SP, Liu H, Argueso CT, Pereira A, Vera Cruz C, Verdier V, Leach JE. RNA-Seq analysis reveals insight into enhanced rice Xa7-mediated bacterial blight resistance at high temperature. PLoS One 2017; 12:e0187625. [PMID: 29107972 PMCID: PMC5673197 DOI: 10.1371/journal.pone.0187625] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 10/06/2017] [Indexed: 12/17/2022] Open
Abstract
Plant disease is a major challenge to agriculture worldwide, and it is exacerbated by abiotic environmental factors. During some plant-pathogen interactions, heat stress allows pathogens to overcome host resistance, a phenomenon which could severely impact crop productivity considering the global warming trends associated with climate change. Despite the importance of this phenomenon, little is known about the underlying molecular mechanisms. To better understand host plant responses during simultaneous heat and pathogen stress, we conducted a transcriptomics experiment for rice plants (cultivar IRBB61) containing Xa7, a bacterial blight disease resistance (R) gene, that were infected with Xanthomonas oryzae, the bacterial blight pathogen of rice, during high temperature stress. Xa7-mediated resistance is unusual relative to resistance mediated by other R genes in that it functions better at high temperatures. Using RNA-Seq technology, we identified 8,499 differentially expressed genes as temperature responsive in rice cultivar IRBB61 experiencing susceptible and resistant interactions across three time points. Notably, genes in the plant hormone abscisic acid biosynthesis and response pathways were up-regulated by high temperature in both mock-treated plants and plants experiencing a susceptible interaction and were suppressed by high temperature in plants exhibiting Xa7-mediated resistance. Genes responsive to salicylic acid, an important plant hormone for disease resistance, were down-regulated by high temperature during both the susceptible and resistant interactions, suggesting that enhanced Xa7-mediated resistance at high temperature is not dependent on salicylic acid signaling. A DNA sequence motif similar to known abscisic acid-responsive cis-regulatory elements was identified in the promoter region upstream of genes up-regulated in susceptible but down-regulated in resistant interactions. The results of our study suggest that the plant hormone abscisic acid is an important node for cross-talk between plant transcriptional response pathways to high temperature stress and pathogen attack. Genes in this pathway represent an important focus for future study to determine how plants evolved to deal with simultaneous abiotic and biotic stresses.
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Affiliation(s)
- Stephen P. Cohen
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, Colorado, United States of America
- Cell and Molecular Biology Graduate Program, Colorado State University, Fort Collins, Colorado, United States of America
| | - Hongxia Liu
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, Colorado, United States of America
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Cristiana T. Argueso
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, Colorado, United States of America
| | - Andy Pereira
- Department of Crop, Soil and Environmental Sciences, University of Arkansas, Fayetteville, Arkansas, United States of America
| | - Casiana Vera Cruz
- Plant Breeding, Genetics and Biotechnology Division, International Rice Research Institute, Los Baños, Philippines
| | - Valerie Verdier
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, Colorado, United States of America
- IRD, Cirad, Univ Montpellier, IPME, Montpellier, France
| | - Jan E. Leach
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, Colorado, United States of America
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Phillips AZ, Berry JC, Wilson MC, Vijayaraghavan A, Burke J, Bunn JI, Allen TW, Wheeler T, Bart RS. Genomics-enabled analysis of the emergent disease cotton bacterial blight. PLoS Genet 2017; 13:e1007003. [PMID: 28910288 PMCID: PMC5614658 DOI: 10.1371/journal.pgen.1007003] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 09/26/2017] [Accepted: 08/31/2017] [Indexed: 01/09/2023] Open
Abstract
Cotton bacterial blight (CBB), an important disease of (Gossypium hirsutum) in the early 20th century, had been controlled by resistant germplasm for over half a century. Recently, CBB re-emerged as an agronomic problem in the United States. Here, we report analysis of cotton variety planting statistics that indicate a steady increase in the percentage of susceptible cotton varieties grown each year since 2009. Phylogenetic analysis revealed that strains from the current outbreak cluster with race 18 Xanthomonas citri pv. malvacearum (Xcm) strains. Illumina based draft genomes were generated for thirteen Xcm isolates and analyzed along with 4 previously published Xcm genomes. These genomes encode 24 conserved and nine variable type three effectors. Strains in the race 18 clade contain 3 to 5 more effectors than other Xcm strains. SMRT sequencing of two geographically and temporally diverse strains of Xcm yielded circular chromosomes and accompanying plasmids. These genomes encode eight and thirteen distinct transcription activator-like effector genes. RNA-sequencing revealed 52 genes induced within two cotton cultivars by both tested Xcm strains. This gene list includes a homeologous pair of genes, with homology to the known susceptibility gene, MLO. In contrast, the two strains of Xcm induce different clade III SWEET sugar transporters. Subsequent genome wide analysis revealed patterns in the overall expression of homeologous gene pairs in cotton after inoculation by Xcm. These data reveal important insights into the Xcm-G. hirsutum disease complex and strategies for future development of resistant cultivars. Cotton bacterial blight (CBB), caused by Xanthomonas citri pv. malvacearum (Xcm), significantly limited cotton yields in the early 20th century but has been controlled by classical resistance genes for more than 50 years. In 2011, the pathogen re-emerged with a vengeance. In this study, we compare diverse pathogen isolates and cotton varieties to further understand the virulence mechanisms employed by Xcm and to identify promising resistance strategies. We generate fully contiguous genome assemblies for two diverse Xcm strains and identify pathogen proteins used to modulate host transcription and promote susceptibility. RNA-Sequencing of infected cotton reveals novel putative gene targets for the development of durable Xcm resistance. Together, the data presented reveal contributing factors for CBB re-emergence in the U.S. and highlight several promising routes towards the development of durable resistance including classical resistance genes and potential manipulation of susceptibility targets.
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Affiliation(s)
- Anne Z. Phillips
- Donald Danforth Plant Science Center, St. Louis, MO, United States of America
- Department of Biology, Washington University in Saint Louis, St. Louis, MO, United States of America
| | - Jeffrey C. Berry
- Donald Danforth Plant Science Center, St. Louis, MO, United States of America
| | - Mark C. Wilson
- Donald Danforth Plant Science Center, St. Louis, MO, United States of America
| | | | - Jillian Burke
- Donald Danforth Plant Science Center, St. Louis, MO, United States of America
| | - J. Imani Bunn
- Donald Danforth Plant Science Center, St. Louis, MO, United States of America
| | - Tom W. Allen
- Delta Research and Extension Center, Mississippi State University, Stoneville, MS, United States of America
| | - Terry Wheeler
- Texas AgriLife Research, Texas AgriLife Extension Service, Lubbock, TX, United States of America
| | - Rebecca S. Bart
- Donald Danforth Plant Science Center, St. Louis, MO, United States of America
- * E-mail:
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32
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A Transcription Activator-Like Effector Tal7 of Xanthomonas oryzae pv. oryzicola Activates Rice Gene Os09g29100 to Suppress Rice Immunity. Sci Rep 2017; 7:5089. [PMID: 28698641 PMCID: PMC5505973 DOI: 10.1038/s41598-017-04800-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 05/23/2017] [Indexed: 11/09/2022] Open
Abstract
Xanthomonas oryzae pv. oryzicola (Xoc) and X. oryzae pv. oryzae (Xoo) cause bacterial leaf streak (BLS) and bacterial leaf blight (BLB) in rice, respectively. Unlike Xoo, endogenous avirulence-resistance (avr-R) gene interactions have not been identified in the Xoc-rice pathosystem; however, both pathogens possess transcription activator-like effectors (TALEs) that are known to modulate R or S genes in rice. The transfer of individual tal genes from Xoc RS105 (hypervirulent) into Xoc YNB0-17 (hypovirulent) led to the identification of tal7, which suppressed avrXa7-Xa7 mediated defense in rice containing an Xa7 R gene. Mobility shift and microscale thermophoresis assays showed that Tal7 bound two EBE sites in the promoters of two rice genes, Os09g29100 and Os12g42970, which encode predicted Cyclin-D4-1 and GATA zinc finger family protein, respectively. Assays using designer TALEs and a TALE-free strain of Xoo revealed that Os09g29100 was the biologically relevant target of Tal7. Tal7 activates the expression of rice gene Os09g29100 that suppresses avrXa7-Xa7 mediated defense in Rice. TALEN editing of the Tal7-binding site in the Os09g29100 gene promoter further enhanced resistance to the pathogen Xoc RS105. The suppression of effector-trigger immunity (ETI) is a phenomenon that may contribute to the scarcity of BLS resistant cultivars.
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Pacher M, Puchta H. From classical mutagenesis to nuclease-based breeding - directing natural DNA repair for a natural end-product. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 90:819-833. [PMID: 28027431 DOI: 10.1111/tpj.13469] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Revised: 12/22/2016] [Accepted: 12/22/2016] [Indexed: 05/18/2023]
Abstract
Production of mutants of crop plants by the use of chemical or physical genotoxins has a long tradition. These factors induce the natural DNA repair machinery to repair damage in an error-prone way. In the case of radiation, multiple double-strand breaks (DSBs) are induced randomly in the genome, leading in very rare cases to a desirable phenotype. In recent years the use of synthetic, site-directed nucleases (SDNs) - also referred to as sequence-specific nucleases - like the CRISPR/Cas system has enabled scientists to use exactly the same naturally occurring DNA repair mechanisms for the controlled induction of genomic changes at pre-defined sites in plant genomes. As these changes are not necessarily associated with the permanent integration of foreign DNA, the obtained organisms per se cannot be regarded as genetically modified as there is no way to distinguish them from natural variants. This applies to changes induced by DSBs as well as single-strand breaks, and involves repair by non-homologous end-joining and homologous recombination. The recent development of SDN-based 'DNA-free' approaches makes mutagenesis strategies in classical breeding indistinguishable from SDN-derived targeted genome modifications, even in regard to current regulatory rules. With the advent of new SDN technologies, much faster and more precise genome editing becomes available at reasonable cost, and potentially without requiring time-consuming deregulation of newly created phenotypes. This review will focus on classical mutagenesis breeding and the application of newly developed SDNs in order to emphasize similarities in the context of the regulatory situation for genetically modified crop plants.
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Affiliation(s)
- Michael Pacher
- Botanical Institute, Molecular Biology and Biochemistry, Karlsruhe Institute of Technology, PO 6980, 76049, Karlsruhe, Germany
| | - Holger Puchta
- Botanical Institute, Molecular Biology and Biochemistry, Karlsruhe Institute of Technology, PO 6980, 76049, Karlsruhe, Germany
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Fan S, Tian F, Li J, Hutchins W, Chen H, Yang F, Yuan X, Cui Z, Yang C, He C. Identification of phenolic compounds that suppress the virulence of Xanthomonas oryzae on rice via the type III secretion system. MOLECULAR PLANT PATHOLOGY 2017; 18:555-568. [PMID: 27084974 PMCID: PMC6638228 DOI: 10.1111/mpp.12415] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The targeting of bacterial type III secretion systems (T3SSs), which are critical virulence factors in most Gram-negative pathogens, is regarded as an alternative strategy for the development of novel anti-microbial drugs. Xanthomonas oryzae pv. oryzae (Xoo) and X. oryzae pv. oryzicola (Xoc) are two of the most important bacterial pathogens on rice, which cause leaf blight and leaf streak diseases, respectively. To identify potential anti-virulence drugs against these two pathogens, we screened a library of plant phenolic compounds and derivatives for their effects on the Xoo T3SS. Ten of 56 compounds significantly inhibited the promoter activity of a harpin gene, hpa1. These inhibitors were further tested for their impact on the hypersensitive response (HR) caused by Xoo on non-host tobacco plants. The results showed that pretreatment of Xoo with TS006 (o-coumaric acid, OCA), TS010, TS015 and TS018 resulted in significantly attenuated HR without affecting bacterial growth or survival. In addition, Cya translocation assays demonstrated that the translocation of two T3 effectors was suppressed by the four inhibitors. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis showed that mRNA levels of representative genes in the hrp (hypersensitive response and pathogenicity) cluster, as well as the regulatory genes hrpG and hrpX, were reduced by treatment with the four inhibitors, suggesting that expression of the Xoo T3SS was suppressed. The expression of other virulence factors was not suppressed, which indicated possible T3SS-specific inhibition. Finally, we demonstrated that these inhibitors reduced the disease symptoms of Xoo and Xoc on the rice cultivar (Oryza sativa) IR24 to varying extents.
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Affiliation(s)
- Susu Fan
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural SciencesBeijing100193China
| | - Fang Tian
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural SciencesBeijing100193China
| | - Jianyu Li
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural SciencesBeijing100193China
| | - William Hutchins
- Department of Biological SciencesUniversity of Wisconsin‐MilwaukeeMilwaukeeWI 53211USA
| | - Huamin Chen
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural SciencesBeijing100193China
| | - Fenghuan Yang
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural SciencesBeijing100193China
| | - Xiaochen Yuan
- Department of Biological SciencesUniversity of Wisconsin‐MilwaukeeMilwaukeeWI 53211USA
| | - Zining Cui
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Department of Plant PathologySouth China Agricultural UniversityGuangzhou510642China
| | - Ching‐Hong Yang
- Department of Biological SciencesUniversity of Wisconsin‐MilwaukeeMilwaukeeWI 53211USA
| | - Chenyang He
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural SciencesBeijing100193China
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Li J, Qin M, Qiao X, Cheng Y, Li X, Zhang H, Wu J. A New Insight into the Evolution and Functional Divergence of SWEET Transporters in Chinese White Pear (Pyrus bretschneideri). PLANT & CELL PHYSIOLOGY 2017; 58:839-850. [PMID: 28339862 DOI: 10.1093/pcp/pcx025] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 02/04/2017] [Indexed: 05/09/2023]
Abstract
SWEET genes are a recently identified plant gene family that play an indispensable role in sugar efflux. However, no systematic study has been performed in pear. In this research, 18 SWEET transporters identified in pear, almost twice the number found in woodland strawberry and Japanese apricot, were divided into four clades. Conserved motifs and six exons of the SWEET transporters were found in six species. SWEET transporters contained seven transmembrane segments (TMSs) that evolved from an internal duplication of an ancestral three-TMSs unit, connected by TMS4. This is the first direct evidence identifying internal repeats through bioinformatics analysis. Whole-genome duplication (WGD) or segmental duplication and dispersed duplication represent the main driving forces for SWEET family evolution in six species, with former duplications more important in pear. Gene expression results suggested that PbSWEET15 and PbSWEET17 have no expression in any tissues because of critical lost residues and that 62.5% of PbSWEET duplicate gene pairs have functional divergence. Additionally, PbSWEET6, PbSWEET7 and PbSWEET14 were found to play important roles in sucrose efflux from leaves, and the high expression of PbSWEET1 and PbSWEET2 might contribute to unloading sucrose from the phloem in the stem. Finally, PbSWEET5, PbSWEET9 and PbSWEET10 might contribute to pollen development. Overall, our study provides important insights into the evolution of the SWEET gene family in pear and four other Rosaceae, and the important candidate PbSWEET genes involved in the development of different tissues were identified in pear.
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Affiliation(s)
- Jiaming Li
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenhe District, Shenyang, Liaoning, China
| | - Mengfan Qin
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F UniversityYangling, China
| | - Xin Qiao
- Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China
| | - Yinsheng Cheng
- Key laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute, Chinese Academy of Agricultural Science, Wuhan, China
| | - Xiaolong Li
- Laboratory of Fruit Quality Biology, Zhejiang University, Zijingang Campus, Hangzhou, China
| | - Huping Zhang
- Henan Sesame Research Center, Henan Academy of Agricultural SciencesZhengzhou, China
- Henan Provincial Key Laboratory for Oil Crops ImprovementZhengzhou, China
| | - Jun Wu
- Key Laboratory of Soybean Cultivation of Ministry of Agriculture China, Soybean Research Institute, Heilongjiang Academy of Agricultural SciencesHarbin, China
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Triplett LR, Cohen SP, Heffelfinger C, Schmidt CL, Huerta A, Tekete C, Verdier V, Bogdanove AJ, Leach JE. A resistance locus in the American heirloom rice variety Carolina Gold Select is triggered by TAL effectors with diverse predicted targets and is effective against African strains of Xanthomonas oryzae pv. oryzicola. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 87:472-83. [PMID: 27197779 PMCID: PMC5030141 DOI: 10.1111/tpj.13212] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Revised: 05/11/2016] [Accepted: 05/17/2016] [Indexed: 05/19/2023]
Abstract
The rice pathogens Xanthomonas oryzae pathovar (pv.) oryzae and pv. oryzicola produce numerous transcription activator-like (TAL) effectors that increase bacterial virulence by activating expression of host susceptibility genes. Rice resistance mechanisms against TAL effectors include polymorphisms that prevent effector binding to susceptibility gene promoters, or that allow effector activation of resistance genes. This study identifies, in the heirloom variety Carolina Gold Select, a third mechanism of rice resistance involving TAL effectors. This resistance manifests through strong suppression of disease development in response to diverse TAL effectors from both X. oryzae pathovars. The resistance can be triggered by an effector with only 3.5 central repeats, is independent of the composition of the repeat variable di-residues that determine TAL effector binding specificity, and is independent of the transcriptional activation domain. We determined that the resistance is conferred by a single dominant locus, designated Xo1, that maps to a 1.09 Mbp fragment on chromosome 4. The Xo1 interval also confers complete resistance to the strains in the African clade of X. oryzae pv. oryzicola, representing the first dominant resistance locus against bacterial leaf streak in rice. The strong phenotypic similarity between the TAL effector-triggered resistance conferred by Xo1 and that conferred by the tomato resistance gene Bs4 suggests that monocots and dicots share an ancient or convergently evolved mechanism to recognize analogous TAL effector epitopes.
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Affiliation(s)
- Lindsay R. Triplett
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, CT 06511
- Department of Bioagricultural Sciences and Pest Management and Program in Plant Molecular Biology, Colorado State University, Fort Collins, CO 80523-1177
| | - Stephen P. Cohen
- Department of Bioagricultural Sciences and Pest Management and Program in Plant Molecular Biology, Colorado State University, Fort Collins, CO 80523-1177
| | - Christopher Heffelfinger
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520
| | - Clarice L. Schmidt
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA 50011
| | - Alejandra Huerta
- Department of Bioagricultural Sciences and Pest Management and Program in Plant Molecular Biology, Colorado State University, Fort Collins, CO 80523-1177
| | - Cheick Tekete
- Université des Sciences Techniques et Technologiques, Faculté des Sciences et Techniques, LBMA, Bamako, Mali
| | - Valerie Verdier
- IRD, Cirad, Univ. Montpellier, Interactions Plantes Microorganismes Environnement (IPME), 34394 Montpellier, France
| | - Adam J. Bogdanove
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA 50011
- Plant Pathology and Plant Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853
| | - Jan E. Leach
- Department of Bioagricultural Sciences and Pest Management and Program in Plant Molecular Biology, Colorado State University, Fort Collins, CO 80523-1177
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Jacques MA, Arlat M, Boulanger A, Boureau T, Carrère S, Cesbron S, Chen NWG, Cociancich S, Darrasse A, Denancé N, Fischer-Le Saux M, Gagnevin L, Koebnik R, Lauber E, Noël LD, Pieretti I, Portier P, Pruvost O, Rieux A, Robène I, Royer M, Szurek B, Verdier V, Vernière C. Using Ecology, Physiology, and Genomics to Understand Host Specificity in Xanthomonas. ANNUAL REVIEW OF PHYTOPATHOLOGY 2016; 54:163-87. [PMID: 27296145 DOI: 10.1146/annurev-phyto-080615-100147] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
How pathogens coevolve with and adapt to their hosts are critical to understanding how host jumps and/or acquisition of novel traits can lead to new disease emergences. The Xanthomonas genus includes Gram-negative plant-pathogenic bacteria that collectively infect a broad range of crops and wild plant species. However, individual Xanthomonas strains usually cause disease on only a few plant species and are highly adapted to their hosts, making them pertinent models to study host specificity. This review summarizes our current understanding of the molecular basis of host specificity in the Xanthomonas genus, with a particular focus on the ecology, physiology, and pathogenicity of the bacterium. Despite our limited understanding of the basis of host specificity, type III effectors, microbe-associated molecular patterns, lipopolysaccharides, transcriptional regulators, and chemotactic sensors emerge as key determinants for shaping host specificity.
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Affiliation(s)
- Marie-Agnès Jacques
- INRA, UMR 1345 Institut de Recherche en Horticulture et Semences (IRHS), F-49071 Beaucouzé, France; , , , , ,
| | - Matthieu Arlat
- INRA, UMR 441 Laboratoire des Interactions Plantes Micro-organismes (LIPM), F-31326 Castanet-Tolosan, France; , , , ,
- CNRS, UMR 2594 Laboratoire des Interactions Plantes Micro-organismes (LIPM), F-31326 Castanet-Tolosan, France
- Université de Toulouse, Université Paul Sabatier, F-31062 Toulouse, France
| | - Alice Boulanger
- INRA, UMR 441 Laboratoire des Interactions Plantes Micro-organismes (LIPM), F-31326 Castanet-Tolosan, France; , , , ,
- CNRS, UMR 2594 Laboratoire des Interactions Plantes Micro-organismes (LIPM), F-31326 Castanet-Tolosan, France
- Université de Toulouse, Université Paul Sabatier, F-31062 Toulouse, France
| | - Tristan Boureau
- Université Angers, UMR 1345 Institut de Recherche en Horticulture et Semences (IRHS), F-49071 Beaucouzé, France;
| | - Sébastien Carrère
- INRA, UMR 441 Laboratoire des Interactions Plantes Micro-organismes (LIPM), F-31326 Castanet-Tolosan, France; , , , ,
| | - Sophie Cesbron
- INRA, UMR 1345 Institut de Recherche en Horticulture et Semences (IRHS), F-49071 Beaucouzé, France; , , , , ,
| | - Nicolas W G Chen
- Agrocampus Ouest, UMR 1345 Institut de Recherche en Horticulture et Semences (IRHS), F-49071 Beaucouzé, France;
| | - Stéphane Cociancich
- CIRAD, UMR Biologie et Génétique des Interactions Plante-Parasite (BGPI), F-34398 Montpellier, France; , , ,
| | - Armelle Darrasse
- INRA, UMR 1345 Institut de Recherche en Horticulture et Semences (IRHS), F-49071 Beaucouzé, France; , , , , ,
| | - Nicolas Denancé
- INRA, UMR 1345 Institut de Recherche en Horticulture et Semences (IRHS), F-49071 Beaucouzé, France; , , , , ,
| | - Marion Fischer-Le Saux
- INRA, UMR 1345 Institut de Recherche en Horticulture et Semences (IRHS), F-49071 Beaucouzé, France; , , , , ,
| | - Lionel Gagnevin
- IRD, CIRAD, University of Montpellier, Interactions Plantes Micro-organismes Environnement (IPME), F-34394 Montpellier, France; , , ,
| | - Ralf Koebnik
- IRD, CIRAD, University of Montpellier, Interactions Plantes Micro-organismes Environnement (IPME), F-34394 Montpellier, France; , , ,
| | - Emmanuelle Lauber
- INRA, UMR 441 Laboratoire des Interactions Plantes Micro-organismes (LIPM), F-31326 Castanet-Tolosan, France; , , , ,
- CNRS, UMR 2594 Laboratoire des Interactions Plantes Micro-organismes (LIPM), F-31326 Castanet-Tolosan, France
| | - Laurent D Noël
- INRA, UMR 441 Laboratoire des Interactions Plantes Micro-organismes (LIPM), F-31326 Castanet-Tolosan, France; , , , ,
- CNRS, UMR 2594 Laboratoire des Interactions Plantes Micro-organismes (LIPM), F-31326 Castanet-Tolosan, France
| | - Isabelle Pieretti
- CIRAD, UMR Biologie et Génétique des Interactions Plante-Parasite (BGPI), F-34398 Montpellier, France; , , ,
| | - Perrine Portier
- INRA, UMR 1345 Institut de Recherche en Horticulture et Semences (IRHS), F-49071 Beaucouzé, France; , , , , ,
| | - Olivier Pruvost
- CIRAD, UMR Peuplements Végétaux et Bioagresseurs en Milieu Tropical (PVBMT), F-97410 Saint-Pierre, La Réunion, France; , ,
| | - Adrien Rieux
- CIRAD, UMR Peuplements Végétaux et Bioagresseurs en Milieu Tropical (PVBMT), F-97410 Saint-Pierre, La Réunion, France; , ,
| | - Isabelle Robène
- CIRAD, UMR Peuplements Végétaux et Bioagresseurs en Milieu Tropical (PVBMT), F-97410 Saint-Pierre, La Réunion, France; , ,
| | - Monique Royer
- CIRAD, UMR Biologie et Génétique des Interactions Plante-Parasite (BGPI), F-34398 Montpellier, France; , , ,
| | - Boris Szurek
- IRD, CIRAD, University of Montpellier, Interactions Plantes Micro-organismes Environnement (IPME), F-34394 Montpellier, France; , , ,
| | - Valérie Verdier
- IRD, CIRAD, University of Montpellier, Interactions Plantes Micro-organismes Environnement (IPME), F-34394 Montpellier, France; , , ,
| | - Christian Vernière
- CIRAD, UMR Biologie et Génétique des Interactions Plante-Parasite (BGPI), F-34398 Montpellier, France; , , ,
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Chen H, Li C, Liu L, Zhao J, Cheng X, Jiang G, Zhai W. The Fd-GOGAT1 mutant gene lc7 confers resistance to Xanthomonas oryzae pv. Oryzae in rice. Sci Rep 2016; 6:26411. [PMID: 27211925 PMCID: PMC4876388 DOI: 10.1038/srep26411] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 05/03/2016] [Indexed: 01/01/2023] Open
Abstract
Disease resistance is an important goal of crop improvement. The molecular mechanism of resistance requires further study. Here, we report the identification of a rice leaf color mutant, lc7, which is defective in chlorophyll synthesis and photosynthesis but confers resistance to Xanthomonas oryzae pv. Oryzae (Xoo). Map-based cloning revealed that lc7 encodes a mutant ferredoxin-dependent glutamate synthase1 (Fd-GOGAT1). Fd-GOGAT1 has been proposed to have great potential for improving nitrogen-use efficiency, but its function in bacterial resistance has not been reported. The lc7 mutant accumulates excessive levels of ROS (reactive oxygen species) in the leaves, causing the leaf color to become yellow after the four-leaf stage. Compared to the wild type, lc7 mutants have a broad-spectrum high resistance to seven Xoo strains. Differentially expressed genes (DEGs) and qRT-PCR analysis indicate that many defense pathways that are involved in this broad-spectrum resistance are activated in the lc7 mutant. These results suggest that Fd-GOGAT1 plays an important role in broad-spectrum bacterial blight resistance, in addition to modulating nitrogen assimilation and chloroplast development.
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Affiliation(s)
- Honglin Chen
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.,National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Chunrong Li
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Liping Liu
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Jiying Zhao
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xuzhen Cheng
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Guanghuai Jiang
- 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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Chanclud E, Kisiala A, Emery NRJ, Chalvon V, Ducasse A, Romiti-Michel C, Gravot A, Kroj T, Morel JB. Cytokinin Production by the Rice Blast Fungus Is a Pivotal Requirement for Full Virulence. PLoS Pathog 2016; 12:e1005457. [PMID: 26900703 PMCID: PMC4765853 DOI: 10.1371/journal.ppat.1005457] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 01/25/2016] [Indexed: 12/22/2022] Open
Abstract
Plants produce cytokinin (CK) hormones for controlling key developmental processes like source/sink distribution, cell division or programmed cell-death. Some plant pathogens have been shown to produce CKs but the function of this mimicry production by non-tumor inducing pathogens, has yet to be established. Here we identify a gene required for CK biosynthesis, CKS1, in the rice blast fungus Magnaporthe oryzae. The fungal-secreted CKs are likely perceived by the plant during infection since the transcriptional regulation of rice CK-responsive genes is altered in plants infected by the mutants in which CKS1 gene was deleted. Although cks1 mutants showed normal in vitro growth and development, they were severely affected for in planta growth and virulence. Moreover, we showed that the cks1 mutant triggered enhanced induction of plant defenses as manifested by an elevated oxidative burst and expression of defense-related markers. In addition, the contents of sugars and key amino acids for fungal growth were altered in and around the infection site by the cks1 mutant in a different manner than by the control strain. These results suggest that fungal-derived CKs are key effectors required for dampening host defenses and affecting sugar and amino acid distribution in and around the infection site.
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Affiliation(s)
- Emilie Chanclud
- Université Montpellier, UMR BGPI INRA/CIRAD/SupAgro, Montpellier, France
| | - Anna Kisiala
- Biology Department, Trent University, Peterborough, Ontario, Canada
- Department of Plant Genetics, Physiology and Biotechnology, University of Technology and Life Sciences, Bydgoszcz, Poland
| | - Neil R. J Emery
- Biology Department, Trent University, Peterborough, Ontario, Canada
| | | | | | | | | | - Thomas Kroj
- INRA, UMR BGPI INRA/CIRAD/SupAgro, Montpellier, France
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Teper D, Sunitha S, Martin GB, Sessa G. Five Xanthomonas type III effectors suppress cell death induced by components of immunity-associated MAP kinase cascades. PLANT SIGNALING & BEHAVIOR 2015; 10:e1064573. [PMID: 26237448 PMCID: PMC4883825 DOI: 10.1080/15592324.2015.1064573] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 06/15/2015] [Accepted: 06/15/2015] [Indexed: 05/13/2023]
Abstract
Mitogen-activated protein kinase (MAPK) cascades play a fundamental role in signaling of plant immunity and mediate elicitation of cell death. Xanthomonas spp. manipulate plant signaling by using a type III secretion system to deliver effector proteins into host cells. We examined the ability of 33 Xanthomonas effectors to inhibit cell death induced by overexpression of components of MAPK cascades in Nicotiana benthamiana plants. Five effectors inhibited cell death induced by overexpression of MAPKKKα and MEK2, but not of MAP3Kε. In addition, expression of AvrBs1 in yeast suppressed activation of the high osmolarity glycerol MAPK pathway, suggesting that the target of this effector is conserved in eukaryotic organisms. These results indicate that Xanthomonas employs several type III effectors to suppress immunity-associated cell death mediated by MAPK cascades.
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Affiliation(s)
- Doron Teper
- Department of Molecular Biology and Ecology of Plants; Tel-Aviv University; Tel-Aviv, Israel
| | - Sukumaran Sunitha
- Department of Molecular Biology and Ecology of Plants; Tel-Aviv University; Tel-Aviv, Israel
| | - Gregory B Martin
- Boyce Thompson Institute for Plant Research; Ithaca, NY USA
- Department of Plant Pathology and Plant-Microbe Biology; Cornell University; Ithaca, NY USA
| | - Guido Sessa
- Department of Molecular Biology and Ecology of Plants; Tel-Aviv University; Tel-Aviv, Israel
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41
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Chandran D. Co-option of developmentally regulated plant SWEET transporters for pathogen nutrition and abiotic stress tolerance. IUBMB Life 2015; 67:461-71. [PMID: 26179993 DOI: 10.1002/iub.1394] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 06/15/2015] [Indexed: 11/07/2022]
Abstract
Plant sugar will eventually be exported transporter (SWEET) sugar transporters have been implicated in various developmental processes where sugar efflux is essential, including sucrose loading of phloem for long-distance sugar transport, nectar secretion, embryo and pollen nutrition, and maintenance of sugar homeostasis in plant organs. Notably, these transporters are selectively targeted by pathogens to gain access to host sugars. In most cases, when SWEET function is blocked, the growth and virulence of the pathogen is also reduced. There is growing evidence to suggest that the lifestyle of the pathogen may dictate which SWEET or set of SWEET genes are recruited for pathogen growth and proliferation. Furthermore, SWEET transporters may also play a role in abiotic stress tolerance by enabling plant growth under unfavorable environmental conditions. This review provides an overview of the diverse functions of SWEET proteins in plant development, pathogen nutrition, and abiotic stress tolerance. In addition, utility of the model legume Medicago truncatula as a tool to elucidate SWEET function in diverse host-microbe interactions is discussed.
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Affiliation(s)
- Divya Chandran
- Regional Center for Biotechnology, NCR Biotech Science Cluster, Faridabad, Haryana, India
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42
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Li H, Yu C, Chen H, Tian F, He C. PXO_00987, a putative acetyltransferase, is required for flagellin glycosylation, and regulates flagellar motility, exopolysaccharide production, and biofilm formation in Xanthomonas oryzae pv. oryzae. Microb Pathog 2015; 85:50-7. [PMID: 26065383 DOI: 10.1016/j.micpath.2015.06.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 05/27/2015] [Accepted: 06/05/2015] [Indexed: 10/23/2022]
Abstract
Acetyltransferases catalyze an important process for sugar or protein modification. In the genome of Xanthomonas oryzae pv. oryzae (Xoo), the causal agent of bacterial blight of rice, there are 32 acetyltransferase-encoding genes belonging to different families. In this work, we focused on PXO_00987, which encodes a putative acetyltransferase in the flagellar regulon. We found that mutation of PXO_00987 gene abolished the glycosylation of wild-type flagellin protein of Xoo. In addition, the PXO_00987 mutant showed enhanced swimming motility, and decreased exopolysaccharide production and biofilm formation. Virulence assays demonstrated that the PXO_00987 mutant caused shorter disease length on rice leaves, suggesting that the function of PXO_00987 contributes to the pathogenesis of Xoo.
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Affiliation(s)
- Haiyun Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Chao Yu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Huamin Chen
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Fang Tian
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Chenyang He
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
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Poulin L, Grygiel P, Magne M, Gagnevin L, Rodriguez-R LM, Forero Serna N, Zhao S, El Rafii M, Dao S, Tekete C, Wonni I, Koita O, Pruvost O, Verdier V, Vernière C, Koebnik R. New multilocus variable-number tandem-repeat analysis tool for surveillance and local epidemiology of bacterial leaf blight and bacterial leaf streak of rice caused by Xanthomonas oryzae. Appl Environ Microbiol 2015; 81:688-98. [PMID: 25398857 PMCID: PMC4277570 DOI: 10.1128/aem.02768-14] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 11/04/2014] [Indexed: 12/12/2022] Open
Abstract
Multilocus variable-number tandem-repeat analysis (MLVA) is efficient for routine typing and for investigating the genetic structures of natural microbial populations. Two distinct pathovars of Xanthomonas oryzae can cause significant crop losses in tropical and temperate rice-growing countries. Bacterial leaf streak is caused by X. oryzae pv. oryzicola, and bacterial leaf blight is caused by X. oryzae pv. oryzae. For the latter, two genetic lineages have been described in the literature. We developed a universal MLVA typing tool both for the identification of the three X. oryzae genetic lineages and for epidemiological analyses. Sixteen candidate variable-number tandem-repeat (VNTR) loci were selected according to their presence and polymorphism in 10 draft or complete genome sequences of the three X. oryzae lineages and by VNTR sequencing of a subset of loci of interest in 20 strains per lineage. The MLVA-16 scheme was then applied to 338 strains of X. oryzae representing different pathovars and geographical locations. Linkage disequilibrium between MLVA loci was calculated by index association on different scales, and the 16 loci showed linear Mantel correlation with MLSA data on 56 X. oryzae strains, suggesting that they provide a good phylogenetic signal. Furthermore, analyses of sets of strains for different lineages indicated the possibility of using the scheme for deeper epidemiological investigation on small spatial scales.
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Affiliation(s)
- L Poulin
- UMR 186 Résistance des Plantes aux Bio-Agresseurs, Institut de Recherche pour le Développement, Montpellier, France
| | - P Grygiel
- UMR PVBMT, Centre de Coopération Internationale en Recherche Agronomique pour le Développement, Saint-Pierre, La Réunion, France
| | - M Magne
- UMR PVBMT, Centre de Coopération Internationale en Recherche Agronomique pour le Développement, Saint-Pierre, La Réunion, France
| | - L Gagnevin
- UMR PVBMT, Centre de Coopération Internationale en Recherche Agronomique pour le Développement, Saint-Pierre, La Réunion, France
| | - L M Rodriguez-R
- UMR 186 Résistance des Plantes aux Bio-Agresseurs, Institut de Recherche pour le Développement, Montpellier, France
| | - N Forero Serna
- UMR 186 Résistance des Plantes aux Bio-Agresseurs, Institut de Recherche pour le Développement, Montpellier, France
| | - S Zhao
- UMR 186 Résistance des Plantes aux Bio-Agresseurs, Institut de Recherche pour le Développement, Montpellier, France
| | - M El Rafii
- UMR 186 Résistance des Plantes aux Bio-Agresseurs, Institut de Recherche pour le Développement, Montpellier, France
| | - S Dao
- Laboratoire de Biologie Moléculaire Appliquée, Faculté des Sciences et Techniques (FAST), Université des Sciences Techniques et Technologie, Bamako, Mali
| | - C Tekete
- Laboratoire de Biologie Moléculaire Appliquée, Faculté des Sciences et Techniques (FAST), Université des Sciences Techniques et Technologie, Bamako, Mali
| | - I Wonni
- UMR 186 Résistance des Plantes aux Bio-Agresseurs, Institut de Recherche pour le Développement, Montpellier, France Institut de l'Environnement et de Recherches Agricoles, Bobo Dioulasso, Burkina Faso
| | - O Koita
- Laboratoire de Biologie Moléculaire Appliquée, Faculté des Sciences et Techniques (FAST), Université des Sciences Techniques et Technologie, Bamako, Mali
| | - O Pruvost
- UMR PVBMT, Centre de Coopération Internationale en Recherche Agronomique pour le Développement, Saint-Pierre, La Réunion, France
| | - V Verdier
- UMR 186 Résistance des Plantes aux Bio-Agresseurs, Institut de Recherche pour le Développement, Montpellier, France
| | - C Vernière
- UMR PVBMT, Centre de Coopération Internationale en Recherche Agronomique pour le Développement, Saint-Pierre, La Réunion, France
| | - R Koebnik
- UMR 186 Résistance des Plantes aux Bio-Agresseurs, Institut de Recherche pour le Développement, Montpellier, France
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Hutin M, Pérez-Quintero AL, Lopez C, Szurek B. MorTAL Kombat: the story of defense against TAL effectors through loss-of-susceptibility. FRONTIERS IN PLANT SCIENCE 2015. [PMID: 26236326 DOI: 10.3389/fpls.2015.0053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Many plant-pathogenic xanthomonads rely on Transcription Activator-Like (TAL) effectors to colonize their host. This particular family of type III effectors functions as specific plant transcription factors via a programmable DNA-binding domain. Upon binding to the promoters of plant disease susceptibility genes in a sequence-specific manner, the expression of these host genes is induced. However, plants have evolved specific strategies to counter the action of TAL effectors and confer resistance. One mechanism is to avoid the binding of TAL effectors by mutations of their DNA binding sites, resulting in resistance by loss-of-susceptibility. This article reviews our current knowledge of the susceptibility hubs targeted by Xanthomonas TAL effectors, possible evolutionary scenarios for plants to combat the pathogen with loss-of-function alleles, and how this knowledge can be used overall to develop new pathogen-informed breeding strategies and improve crop resistance.
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Affiliation(s)
- Mathilde Hutin
- UMR IPME, Institut de Recherche Pour le Développement, IRD-CIRAD-Université Montpellier 2 Montpellier, France
| | - Alvaro L Pérez-Quintero
- UMR IPME, Institut de Recherche Pour le Développement, IRD-CIRAD-Université Montpellier 2 Montpellier, France
| | - Camilo Lopez
- UMR IPME, Institut de Recherche Pour le Développement, IRD-CIRAD-Université Montpellier 2 Montpellier, France ; Biology Department, Universidad Nacional de Colombia Bogota, Colombia
| | - Boris Szurek
- UMR IPME, Institut de Recherche Pour le Développement, IRD-CIRAD-Université Montpellier 2 Montpellier, France
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Hutin M, Pérez-Quintero AL, Lopez C, Szurek B. MorTAL Kombat: the story of defense against TAL effectors through loss-of-susceptibility. FRONTIERS IN PLANT SCIENCE 2015; 6:535. [PMID: 26236326 PMCID: PMC4500901 DOI: 10.3389/fpls.2015.00535] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 06/30/2015] [Indexed: 05/21/2023]
Abstract
Many plant-pathogenic xanthomonads rely on Transcription Activator-Like (TAL) effectors to colonize their host. This particular family of type III effectors functions as specific plant transcription factors via a programmable DNA-binding domain. Upon binding to the promoters of plant disease susceptibility genes in a sequence-specific manner, the expression of these host genes is induced. However, plants have evolved specific strategies to counter the action of TAL effectors and confer resistance. One mechanism is to avoid the binding of TAL effectors by mutations of their DNA binding sites, resulting in resistance by loss-of-susceptibility. This article reviews our current knowledge of the susceptibility hubs targeted by Xanthomonas TAL effectors, possible evolutionary scenarios for plants to combat the pathogen with loss-of-function alleles, and how this knowledge can be used overall to develop new pathogen-informed breeding strategies and improve crop resistance.
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Affiliation(s)
- Mathilde Hutin
- UMR IPME, Institut de Recherche Pour le Développement, IRD-CIRAD-Université Montpellier 2Montpellier, France
| | - Alvaro L. Pérez-Quintero
- UMR IPME, Institut de Recherche Pour le Développement, IRD-CIRAD-Université Montpellier 2Montpellier, France
| | - Camilo Lopez
- UMR IPME, Institut de Recherche Pour le Développement, IRD-CIRAD-Université Montpellier 2Montpellier, France
- Biology Department, Universidad Nacional de ColombiaBogota, Colombia
| | - Boris Szurek
- UMR IPME, Institut de Recherche Pour le Développement, IRD-CIRAD-Université Montpellier 2Montpellier, France
- *Correspondence: Boris Szurek, UMR IPME, Institut de Recherche Pour le Développement, IRD-CIRAD-Université Montpellier 2, 911 Avenue Agropolis BP 64501, 34394 Montpellier Cedex 5, France,
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46
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Cohn M, Bart RS, Shybut M, Dahlbeck D, Gomez M, Morbitzer R, Hou BH, Frommer WB, Lahaye T, Staskawicz BJ. Xanthomonas axonopodis virulence is promoted by a transcription activator-like effector-mediated induction of a SWEET sugar transporter in cassava. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2014; 27:1186-98. [PMID: 25083909 DOI: 10.1094/mpmi-06-14-0161-r] [Citation(s) in RCA: 149] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The gene-for-gene concept has historically been applied to describe a specific resistance interaction wherein single genes from the host and the pathogen dictate the outcome. These interactions have been observed across the plant kingdom and all known plant microbial pathogens. In recent years, this concept has been extended to susceptibility phenotypes in the context of transcription activator-like (TAL) effectors that target SWEET sugar transporters. However, because this interaction has only been observed in rice, it was not clear whether the gene-for-gene susceptibility was unique to that system. Here, we show, through a combined systematic analysis of the TAL effector complement of Xanthomonas axonopodis pv. manihotis and RNA sequencing to identify targets in cassava, that TAL20Xam668 specifically induces the sugar transporter MeSWEET10a to promote virulence. Designer TAL effectors (dTALE) complement TAL20Xam668 mutant phenotypes, demonstrating that MeSWEET10a is a susceptibility gene in cassava. Sucrose uptake-deficient X. axonopodis pv. manihotis bacteria do not lose virulence, indicating that sucrose may be cleaved extracellularly and taken up as hexoses into X. axonopodis pv. manihotis. Together, our data suggest that pathogen hijacking of plant nutrients is not unique to rice blight but also plays a role in bacterial blight of the dicot cassava.
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Lang JM, Langlois P, Nguyen MHR, Triplett LR, Purdie L, Holton TA, Djikeng A, Vera Cruz CM, Verdier V, Leach JE. Sensitive detection of Xanthomonas oryzae Pathovars oryzae and oryzicola by loop-mediated isothermal amplification. Appl Environ Microbiol 2014; 80:4519-30. [PMID: 24837384 PMCID: PMC4148787 DOI: 10.1128/aem.00274-14] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 05/06/2014] [Indexed: 11/20/2022] Open
Abstract
Molecular diagnostics for crop diseases can enhance food security by enabling the rapid identification of threatening pathogens and providing critical information for the deployment of disease management strategies. Loop-mediated isothermal amplification (LAMP) is a PCR-based tool that allows the rapid, highly specific amplification of target DNA sequences at a single temperature and is thus ideal for field-level diagnosis of plant diseases. We developed primers highly specific for two globally important rice pathogens, Xanthomonas oryzae pv. oryzae, the causal agent of bacterial blight (BB) disease, and X. oryzae pv. oryzicola, the causal agent of bacterial leaf streak disease (BLS), for use in reliable, sensitive LAMP assays. In addition to pathovar distinction, two assays that differentiate X. oryzae pv. oryzae by African or Asian lineage were developed. Using these LAMP primer sets, the presence of each pathogen was detected from DNA and bacterial cells, as well as leaf and seed samples. Thresholds of detection for all assays were consistently 10(4) to 10(5) CFU ml(-1), while genomic DNA thresholds were between 1 pg and 10 fg. Use of the unique sequences combined with the LAMP assay provides a sensitive, accurate, rapid, simple, and inexpensive protocol to detect both BB and BLS pathogens.
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Affiliation(s)
- Jillian M. Lang
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, Colorado, USA
| | - Paul Langlois
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, Colorado, USA
| | | | - Lindsay R. Triplett
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, Colorado, USA
| | - Laura Purdie
- Biosciences eastern and central Africa, Nairobi, Kenya
| | | | | | | | - Valérie Verdier
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, Colorado, USA
- Institut de Recherche pour le Développement, UMR Résistance des Plantes aux Bioagresseurs, IRD-CIRAD-UM2, Montpellier, France
| | - Jan E. Leach
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, Colorado, USA
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Ji ZY, Zakria M, Zou LF, Xiong L, Li Z, Ji GH, Chen GY. Genetic diversity of transcriptional activator-like effector genes in Chinese isolates of Xanthomonas oryzae pv. oryzicola. PHYTOPATHOLOGY 2014; 104:672-82. [PMID: 24423401 DOI: 10.1094/phyto-08-13-0232-r] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Xanthomonas oryzae pv. oryzicola causes bacterial leaf streak (BLS), a devastating disease of rice in Asia countries. X. oryzae pv. oryzicola utilizes repertoires of transcriptional activator-like effectors (TALEs) to manipulate host resistance or susceptibility; thus, TALEs can determine the outcome of BLS. In this report, we studied genetic diversity in putative tale genes of 65 X. oryzae pv. oryzicola strains that originated from nine provinces of southern China. Genomic DNAs from the 65 strains were digested with BamHI and hybridized with an internal fragment of avrXa3, a tale gene originating from the related pathogen, X. oryzae pv. oryzae, which causes bacterial leaf blight (BLB). Southern blot analysis indicated that the strains contained a variable number (9 to 22) of avrXa3-hybridizing fragments (e.g., putative tale genes). Based on the number and size of hybridizing bands, strains were classified into 14 genotypes (designated 1 to 14), and genotypes 3 and 10 represented 29.23 and 24.64% of the total, respectively. A high molecular weight BamHI fragment (HMWB; ≈6.0 kb) was present in 12 of the 14 genotypes, and sequence analysis of the HMWB revealed the presence of a C-terminally truncated tale, an insertion element related to IS1403, and genes encoding phosphoglycerate mutase and endonuclease V. Primers were developed from the 6.0-kb HMWB fragment and showed potential in genotyping X. oryzae pv. oryzicola strains by polymerase chain reaction. Virulence of X. oryzae pv. oryzicola strains was assessed on 23 rice cultivars containing different resistance genes for BLB. The X. oryzae pv. oryzicola strains could be grouped into 14 pathotypes (I to XIV), and the grouping of strains was almost identical to the categories determined by genotypic analysis. In general, strains containing higher numbers of putative tale genes were more virulent on rice than strains containing fewer tales. The results also indicate that there are no gene-for-gene relationships between the tested rice lines and X. oryzae pv. oryzicola strains. To our knowledge, this is the first description of genetic diversity of X. oryzae pv. oryzicola strains based on tale gene analysis.
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Wonni I, Cottyn B, Detemmerman L, Dao S, Ouedraogo L, Sarra S, Tekete C, Poussier S, Corral R, Triplett L, Koita O, Koebnik R, Leach J, Szurek B, Maes M, Verdier V. Analysis of Xanthomonas oryzae pv. oryzicola population in Mali and Burkina Faso reveals a high level of genetic and pathogenic diversity. PHYTOPATHOLOGY 2014; 104:520-31. [PMID: 24199713 DOI: 10.1094/phyto-07-13-0213-r] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Bacterial leaf streak (BLS) caused by Xanthomonas oryzae pv. oryzicola was first reported in Africa in the 1980s. Recently, a substantial reemergence of this disease was observed in West Africa. Samples were collected at various sites in five and three different rice-growing regions of Burkina Faso and Mali, respectively. Sixty-seven X. oryzae pv. oryzicola strains were isolated from cultivated and wild rice varieties and from weeds showing BLS symptoms. X. oryzae pv. oryzicola strains were evaluated for virulence on rice and showed high variation in lesion length on a susceptible cultivar. X. oryzae pv. oryzicola strains were further characterized by multilocus sequence analysis (MLSA) using six housekeeping genes. Inferred dendrograms clearly indicated different groups among X. oryzae pv. oryzicola strains. Restriction fragment length polymorphism analysis using the transcriptional activator like effector avrXa7 as probe resulted in the identification of 18 haplotypes. Polymerase chain reaction-based analyses of two conserved type III effector (T3E) genes (xopAJ and xopW) differentiated the strains into distinct groups, with xopAJ not detected in most African X. oryzae pv. oryzicola strains. XopAJ functionality was confirmed by leaf infiltration on 'Kitaake' rice Rxo1 lines. Sequence analysis of xopW revealed four groups among X. oryzae pv. oryzicola strains. Distribution of 43 T3E genes shows variation in a subset of X. oryzae pv. oryzicola strains. Together, our results show that African X. oryzae pv. oryzicola strains are diverse and rapidly evolving, with a group endemic to Africa and another one that may have evolved from an Asian strain.
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Kuhn H, Panstruga R. Introduction to a Virtual Special Issue on phytopathogen effector proteins. THE NEW PHYTOLOGIST 2014; 202:727-730. [PMID: 24716512 DOI: 10.1111/nph.12804] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Affiliation(s)
- Hannah Kuhn
- Institute for Biology I, Unit of Plant Molecular Cell Biology, RWTH Aachen University, Aachen, Germany
| | - Ralph Panstruga
- Institute for Biology I, Unit of Plant Molecular Cell Biology, RWTH Aachen University, Aachen, Germany
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