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Zhao M, Peng Z, Qin Y, Tamang TM, Zhang L, Tian B, Chen Y, Liu Y, Zhang J, Lin G, Zheng H, He C, Lv K, Klaus A, Marcon C, Hochholdinger F, Trick HN, Liu Y, Cho MJ, Park S, Wei H, Zheng J, White FF, Liu S. Bacterium-enabled transient gene activation by artificial transcription factors for resolving gene regulation in maize. THE PLANT CELL 2023; 35:2736-2749. [PMID: 37233025 PMCID: PMC10396389 DOI: 10.1093/plcell/koad155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 04/11/2023] [Accepted: 05/04/2023] [Indexed: 05/27/2023]
Abstract
Understanding gene regulatory networks is essential to elucidate developmental processes and environmental responses. Here, we studied regulation of a maize (Zea mays) transcription factor gene using designer transcription activator-like effectors (dTALes), which are synthetic Type III TALes of the bacterial genus Xanthomonas and serve as inducers of disease susceptibility gene transcription in host cells. The maize pathogen Xanthomonas vasicola pv. vasculorum was used to introduce 2 independent dTALes into maize cells to induced expression of the gene glossy3 (gl3), which encodes a MYB transcription factor involved in biosynthesis of cuticular wax. RNA-seq analysis of leaf samples identified, in addition to gl3, 146 genes altered in expression by the 2 dTALes. Nine of the 10 genes known to be involved in cuticular wax biosynthesis were upregulated by at least 1 of the 2 dTALes. A gene previously unknown to be associated with gl3, Zm00001d017418, which encodes aldehyde dehydrogenase, was also expressed in a dTALe-dependent manner. A chemically induced mutant and a CRISPR-Cas9 mutant of Zm00001d017418 both exhibited glossy leaf phenotypes, indicating that Zm00001d017418 is involved in biosynthesis of cuticular waxes. Bacterial protein delivery of dTALes proved to be a straightforward and practical approach for the analysis and discovery of pathway-specific genes in maize.
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Affiliation(s)
- Mingxia Zhao
- Department of Plant Pathology, Kansas State University, Manhattan, KS 66506, USA
| | - Zhao Peng
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611, USA
- College of Plant Protection, Jilin Agricultural University, Changchun, Jilin 130118, China
| | - Yang Qin
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Tej Man Tamang
- Department of Plant Pathology, Kansas State University, Manhattan, KS 66506, USA
| | - Ling Zhang
- College of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI 49931, USA
| | - Bin Tian
- Department of Plant Pathology, Kansas State University, Manhattan, KS 66506, USA
| | - Yueying Chen
- Department of Plant Pathology, Kansas State University, Manhattan, KS 66506, USA
| | - Yan Liu
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Junli Zhang
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611, USA
| | - Guifang Lin
- Department of Plant Pathology, Kansas State University, Manhattan, KS 66506, USA
| | - Huakun Zheng
- Department of Plant Pathology, Kansas State University, Manhattan, KS 66506, USA
| | - Cheng He
- Department of Plant Pathology, Kansas State University, Manhattan, KS 66506, USA
| | - Kaiwen Lv
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Heilongjiang 150040, China
| | - Alina Klaus
- INRES, Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, Bonn 53113, Germany
| | - Caroline Marcon
- INRES, Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, Bonn 53113, Germany
| | - Frank Hochholdinger
- INRES, Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, Bonn 53113, Germany
| | - Harold N Trick
- Department of Plant Pathology, Kansas State University, Manhattan, KS 66506, USA
| | - Yunjun Liu
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Myeong-Je Cho
- Innovative Genomics Institute, University of California, Berkeley, CA 94704, USA
| | - Sunghun Park
- Department of Horticulture and Natural Resources, Kansas State University, Manhattan, KS 66506, USA
| | - Hairong Wei
- College of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI 49931, USA
| | - Jun Zheng
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Frank F White
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611, USA
| | - Sanzhen Liu
- Department of Plant Pathology, Kansas State University, Manhattan, KS 66506, USA
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Das J, Kumar R, Yadav SK, Jha G. Nicotinic Acid Catabolism Modulates Bacterial Mycophagy in Burkholderia gladioli Strain NGJ1. Microbiol Spectr 2023; 11:e0445722. [PMID: 37014254 PMCID: PMC10269826 DOI: 10.1128/spectrum.04457-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 03/03/2023] [Indexed: 04/05/2023] Open
Abstract
Burkholderia gladioli strain NGJ1 exhibits mycophagous activity on a broad range of fungi, including Rhizoctonia solani, a devastating plant pathogen. Here, we demonstrate that the nicotinic acid (NA) catabolic pathway in NGJ1 is required for mycophagy. NGJ1 is auxotrophic to NA and it potentially senses R. solani as a NA source. Mutation in the nicC and nicX genes involved in NA catabolism renders defects in mycophagy and the mutant bacteria are unable to utilize R. solani extract as the sole nutrient source. As supplementation of NA, but not FA (fumaric acid, the end product of NA catabolism) restores the mycophagous ability of ΔnicC/ΔnicX mutants, we anticipate that NA is not required as a carbon source for the bacterium during mycophagy. Notably, nicR, a MarR-type of transcriptional regulator that functions as a negative regulator of the NA catabolic pathway is upregulated in ΔnicC/ΔnicX mutant and upon NA supplementation the nicR expression is reduced to the basal level in both the mutants. The ΔnicR mutant produces excessive biofilm and is completely defective in swimming motility. On the other hand, ΔnicC/ΔnicX mutants are compromised in swimming motility as well as biofilm formation, potentially due to the upregulation of nicR. Our data suggest that a defect in NA catabolism alters the NA pool in the bacterium and upregulates nicR which in turn suppresses bacterial motility as well as biofilm formation, leading to mycophagy defects. IMPORTANCE Mycophagy is an important trait through which certain bacteria forage over fungal mycelia and utilize fungal biomass as a nutrient source to thrive in hostile environments. The present study emphasizes that nicotinic acid (NA) is important for bacterial motility and biofilm formation during mycophagy by Burkholderia gladioli strain NGJ1. Defects in NA catabolism potentially alter the cellular NA pool, upregulate the expression of nicR, a negative regulator of biofilm, and therefore suppress bacterial motility as well as biofilm formation, leading to mycophagy defects.
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Affiliation(s)
- Joyati Das
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, New Delhi, India
| | - Rahul Kumar
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, New Delhi, India
| | - Sunil Kumar Yadav
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, New Delhi, India
| | - Gopaljee Jha
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, New Delhi, India
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3
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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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The MinCDE Cell Division System Participates in the Regulation of Type III Secretion System (T3SS) Genes, Bacterial Virulence, and Motility in Xanthomonas oryzae pv. oryzae. Microorganisms 2022; 10:microorganisms10081549. [PMID: 36013967 PMCID: PMC9414521 DOI: 10.3390/microorganisms10081549] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/27/2022] [Accepted: 07/28/2022] [Indexed: 11/17/2022] Open
Abstract
Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial leaf blight (BLB) in rice, which is one of the most severe bacterial diseases in rice in some Asian countries. The type III secretion system (T3SS) of Xoo encoded by the hypersensitive response and pathogenicity (hrp) genes is essential for its pathogenicity in host rice. Here, we identified the Min system (MinC, MinD, and MinE), a negative regulatory system for bacterial cell division encoded by minC, minD, and minE genes, which is involved in negative regulation of hrp genes (hrpB1 and hrpF) in Xoo. We found that the deletion of minC, minD, and minCDE resulted in enhanced hrpB1 and hrpF expression, which is dependent on two key hrp regulators HrpG and HrpX. The minC, minD, and minCDE mutants exhibited elongated cell lengths, and the classic Min system-defective cell morphology including minicells and short filamentations. Mutation of minC in Xoo resulted in significantly impaired virulence in host rice, swimming motility, and enhanced biofilm formation. Our transcriptome profiling also indicated some virulence genes were differentially expressed in the minC mutants. To our knowledge, this is the first report about the Min system participating in the regulation of T3SS expression. It sheds light on the understanding of Xoo virulence mechanisms.
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Zhang B, Han X, Yuan W, Zhang H. TALEs as double-edged swords in plant-pathogen interactions: Progress, challenges, and perspectives. PLANT COMMUNICATIONS 2022; 3:100318. [PMID: 35576155 PMCID: PMC9251431 DOI: 10.1016/j.xplc.2022.100318] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 03/08/2022] [Accepted: 03/23/2022] [Indexed: 06/15/2023]
Abstract
Xanthomonas species colonize many host plants and cause huge losses worldwide. Transcription activator-like effectors (TALEs) are secreted by Xanthomonas and translocated into host cells to manipulate the expression of target genes, especially by Xanthomonas oryzae pv. oryzae and Xanthomonas oryzae pv. oryzicola, which cause bacterial blight and bacterial leaf streak, respectively, in rice. In this review, we summarize the progress of studies on the interaction between Xanthomonas and hosts, covering both rice and other plants. TALEs are not only key factors that make plants susceptible but are also essential components of plant resistance. Characterization of TALEs and TALE-like proteins has improved our understanding of TALE evolution and promoted the development of gene editing tools. In addition, the interactions between TALEs and hosts have also provided strategies and possibilities for genetic engineering in crop improvement.
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Affiliation(s)
- Biaoming Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Xiaoyuan Han
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Wenya Yuan
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China.
| | - Haitao Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China.
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Jiang D, Zhang D, Li S, Liang Y, Zhang Q, Qin X, Gao J, Qiu J. Highly efficient genome editing in Xanthomonas oryzae pv. oryzae through repurposing the endogenous type I-C CRISPR-Cas system. MOLECULAR PLANT PATHOLOGY 2022; 23:583-594. [PMID: 34954876 PMCID: PMC8916207 DOI: 10.1111/mpp.13178] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 11/25/2021] [Accepted: 12/09/2021] [Indexed: 06/14/2023]
Abstract
Efficient and modular genome editing technologies that manipulate the genome of bacterial pathogens will facilitate the study of pathogenesis mechanisms. However, such methods are yet to be established for Xanthomonas oryzae pv. oryzae (Xoo), the causal agent of rice bacterial blight. We identified a single type I-C CRISPR-Cas system in the Xoo genome and leveraged this endogenous defence system for high-efficiency genome editing in Xoo. Specifically, we developed plasmid components carrying a mini-CRISPR array, donor DNA, and a phage-derived recombination system to enable the efficient and programmable genome editing of precise deletions, insertions, base substitutions, and gene replacements. Furthermore, the type I-C CRISPR-Cas system of Xoo cleaves target DNA unidirectionally, and this can be harnessed to generate large genomic deletions up to 212 kb efficiently. Therefore, the genome-editing strategy we have developed can serve as an excellent tool for functional genomics of Xoo, and should also be applicable to other CRISPR-harbouring bacterial plant pathogens.
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Affiliation(s)
- Dandan Jiang
- State Key Laboratory of Plant GenomicsInstitute of MicrobiologyChinese Academy of SciencesBeijingChina
- CAS Center for Excellence in Biotic InteractionsUniversity of Chinese Academy of SciencesBeijingChina
| | - Dandan Zhang
- State Key Laboratory of Plant GenomicsInstitute of MicrobiologyChinese Academy of SciencesBeijingChina
| | - Shengnan Li
- State Key Laboratory of Plant GenomicsInstitute of MicrobiologyChinese Academy of SciencesBeijingChina
| | - Yueting Liang
- State Key Laboratory of Plant GenomicsInstitute of MicrobiologyChinese Academy of SciencesBeijingChina
- CAS Center for Excellence in Biotic InteractionsUniversity of Chinese Academy of SciencesBeijingChina
| | - Qianwei Zhang
- State Key Laboratory of Plant GenomicsInstitute of MicrobiologyChinese Academy of SciencesBeijingChina
- CAS Center for Excellence in Biotic InteractionsUniversity of Chinese Academy of SciencesBeijingChina
| | - Xu Qin
- State Key Laboratory of Plant GenomicsInstitute of MicrobiologyChinese Academy of SciencesBeijingChina
- CAS Center for Excellence in Biotic InteractionsUniversity of Chinese Academy of SciencesBeijingChina
| | - Jinlan Gao
- State Key Laboratory of Plant GenomicsInstitute of MicrobiologyChinese Academy of SciencesBeijingChina
| | - Jin‐Long Qiu
- State Key Laboratory of Plant GenomicsInstitute of MicrobiologyChinese Academy of SciencesBeijingChina
- CAS Center for Excellence in Biotic InteractionsUniversity of Chinese Academy of SciencesBeijingChina
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Lachaux M, Thomas E, Bogdanove AJ, Szurek B, Hutin M. TAL Effectors with Avirulence Activity in African Strains of Xanthomonas oryzae pv. oryzae. RICE (NEW YORK, N.Y.) 2022; 15:9. [PMID: 35119567 PMCID: PMC8816977 DOI: 10.1186/s12284-022-00553-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 01/15/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial leaf blight, a devastating disease of rice. Among the type-3 effectors secreted by Xoo to support pathogen virulence, the Transcription Activator-Like Effector (TALE) family plays a critical role. Some TALEs are major virulence factors that activate susceptibility (S) genes, overexpression of which contributes to disease development. Host incompatibility can result from TALE-induced expression of so-called executor (E) genes leading to a strong and rapid resistance response that blocks disease development. In that context, the TALE functions as an avirulence (Avr) factor. To date no such avirulence factors have been identified in African strains of Xoo. RESULTS With respect to the importance of TALEs in the Rice-Xoo pathosystem, we aimed at identifying those that may act as Avr factor within African Xoo. We screened 86 rice accessions, and identified 12 that were resistant to two African strains while being susceptible to a well-studied Asian strain. In a gain of function approach based on the introduction of each of the nine tal genes of the avirulent African strain MAI1 into the virulent Asian strain PXO99A, four were found to trigger resistance on specific rice accessions. Loss-of-function mutational analysis further demonstrated the avr activity of two of them, talD and talI, on the rice varieties IR64 and CT13432 respectively. Further analysis of TalI demonstrated the requirement of its activation domain for triggering resistance in CT13432. Resistance in 9 of the 12 rice accessions that were resistant against African Xoo specifically, including CT13432, could be suppressed or largely suppressed by trans-expression of the truncTALE tal2h, similarly to resistance conferred by the Xa1 gene which recognizes TALEs generally independently of their activation domain. CONCLUSION We identified and characterized TalD and TalI as two African Xoo TALEs with avirulence activity on IR64 and CT13432 respectively. Resistance of CT13432 against African Xoo results from the combination of two mechanisms, one relying on the TalI-mediated induction of an unknown executor gene and the other on an Xa1-like gene or allele.
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Affiliation(s)
- Marlène Lachaux
- Plant Health Institute of Montpellier, Univ Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - Emilie Thomas
- Plant Health Institute of Montpellier, Univ Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - Adam J Bogdanove
- Plant Pathology and Plant Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
| | - Boris Szurek
- Plant Health Institute of Montpellier, Univ Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France.
| | - Mathilde Hutin
- Plant Health Institute of Montpellier, Univ Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France.
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Chen X, Li Q, Wang J, Zhang Y, Tang L, Huang S, Mo J, Guo T. Genome Resource of a Hypervirulent Strain C9-3 of Xanthomonas oryzae pv. oryzae Causing Bacterial Blight of Rice. PLANT DISEASE 2022; 106:741-744. [PMID: 34598657 DOI: 10.1094/pdis-07-21-1565-a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Xanthomonas oryzae pv. oryzae is the causal agent of bacterial blight, one of the most devastating diseases of rice. Here, a hypervirulent strain, C9-3, defeating Xa1, Xa10, xa13, and Xa23 resistance genes, was used to extract genomic DNA for single molecule real-time (SMRT) sequencing. After assembly, the genome consists of a single-circular chromosome with the size of 4,924,298 bp with G+C content of 63.7% and contains 4,715 genes. Annotation and analysis of the TALE genes using a suite of applications named AnnoTALE suggested that 17 transcription activator-like effectors, including 15 typical TALEs and 2 iTALEs/truncTALEs, were encoded in the genome. The approach and genome resource will contribute to the discovery of new virulence effectors and understanding on rice-X. oryzae pv. oryzae interactions.
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Affiliation(s)
- Xiaolin Chen
- Guangxi Key Laboratory of Biology for Crop Diseases and Insect Pests, Plant Protection Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, Guangxi, China
| | - Qili Li
- Guangxi Key Laboratory of Biology for Crop Diseases and Insect Pests, Plant Protection Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, Guangxi, China
| | - Jinkai Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, Guangxi, China
| | - Yu Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, Guangxi, China
| | - Lihua Tang
- Guangxi Key Laboratory of Biology for Crop Diseases and Insect Pests, Plant Protection Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, Guangxi, China
| | - Suiping Huang
- Guangxi Key Laboratory of Biology for Crop Diseases and Insect Pests, Plant Protection Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, Guangxi, China
| | - Jianyou Mo
- Guangxi Key Laboratory of Biology for Crop Diseases and Insect Pests, Plant Protection Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, Guangxi, China
| | - Tangxun Guo
- Guangxi Key Laboratory of Biology for Crop Diseases and Insect Pests, Plant Protection Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, Guangxi, China
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Xu Z, Xu X, Wang Y, Liu L, Li Y, Yang Y, Liu L, Zou L, Chen G. A varied AvrXa23-like TALE enables the bacterial blight pathogen to avoid being trapped by Xa23 resistance gene in rice. J Adv Res 2022; 42:263-272. [PMID: 36513417 PMCID: PMC9788936 DOI: 10.1016/j.jare.2022.01.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 01/12/2022] [Accepted: 01/15/2022] [Indexed: 12/27/2022] Open
Abstract
INTRODUCTION Xa23 as an executor mediates broad-spectrum resistance to Xanthomonas oryzae pv. oryzae (Xoo), which contains a matching avirulence gene avrXa23, in rice for bacterial leaf blight (BLB). avrXa23 encodes a transcription activator-like effector (TALE) protein which binds to the EBE (effector-binding element) of the Xa23 promoter. It is unclear whether the considerable pressure of Xa23 leads to an emerging Xoo strain that overcomes Xa23 resistance. OBJECTIVES This study aimed to uncover new Xoo isolate(s) that overcome Xa23-mediated resistance and to investigate how the pathogen evades the resistance. METHODS Totally 185 Xoo isolates were used to screen possibly compatible strain(s) with Xa23-containing rice CBB23 by pathogenicity test. Genome Sequencing, Southern blot, tal gene cloning, Western blot, qRT-PCR and electrophoretic mobility shift assays (EMSA) were conducted to determine the mechanism of one Xoo isolate being compatible with Xa23-containing rice. RESULTS One isolate AH28 from Anhui province is compatible with CBB23. AH28 strain contains an ortholog of avrXa23, tal7b and has 17 tal genes. The 4th RVD (repeat-variable diresidue) in Tal7b are missed and the 5th and 8th RVDs changed from NG and NS to NS and S*, respectively. These alternations made Tal7b unable to bind to the EBE of Xa23 promoter to activate the expression of Xa23 in rice. The ectopic expression of tal7b in a tal-free mutant PH of PXO99A did not alter the virulence of the strain PH, whereas avrXa23 made AH28 from compatibility to incompatibility with Xa23 rice. CONCLUSION Best to our knowledge, this is the first insight of a naturally-emerging Xoo isolate that overcomes the broad-spectrum resistance of Xa23 by the variable AvrXa23-like TALE Tal7b. The RVD alteration in AvrXa23 may be a common strategy for the pathogen evolution to avoid being "trapped" by the executor R gene.
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Affiliation(s)
- Zhengyin Xu
- Shanghai Collaborative Innovation Center of Agri-Seeds/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China,State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiameng Xu
- Shanghai Collaborative Innovation Center of Agri-Seeds/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China,State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yijie Wang
- Shanghai Collaborative Innovation Center of Agri-Seeds/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Linlin Liu
- Shanghai Collaborative Innovation Center of Agri-Seeds/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China,State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ying Li
- Shanghai Collaborative Innovation Center of Agri-Seeds/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China,State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yangyang Yang
- Shanghai Collaborative Innovation Center of Agri-Seeds/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Liang Liu
- Shanghai Collaborative Innovation Center of Agri-Seeds/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Lifang Zou
- Shanghai Collaborative Innovation Center of Agri-Seeds/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China,State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Gongyou Chen
- Shanghai Collaborative Innovation Center of Agri-Seeds/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China,State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China,Corresponding author.
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10
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Osdaghi E, Jones JB, Sharma A, Goss EM, Abrahamian P, Newberry EA, Potnis N, Carvalho R, Choudhary M, Paret ML, Timilsina S, Vallad GE. A centenary for bacterial spot of tomato and pepper. MOLECULAR PLANT PATHOLOGY 2021; 22:1500-1519. [PMID: 34472193 PMCID: PMC8578828 DOI: 10.1111/mpp.13125] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/03/2021] [Accepted: 08/05/2021] [Indexed: 05/08/2023]
Abstract
DISEASE SYMPTOMS Symptoms include water-soaked areas surrounded by chlorosis turning into necrotic spots on all aerial parts of plants. On tomato fruits, small, water-soaked, or slightly raised pale-green spots with greenish-white halos are formed, ultimately becoming dark brown and slightly sunken with a scabby or wart-like surface. HOST RANGE Main and economically important hosts include different types of tomatoes and peppers. Alternative solanaceous and nonsolanaceous hosts include Datura spp., Hyoscyamus spp., Lycium spp., Nicotiana rustica, Physalis spp., Solanum spp., Amaranthus lividus, Emilia fosbergii, Euphorbia heterophylla, Nicandra physaloides, Physalis pubescens, Sida glomerata, and Solanum americanum. TAXONOMIC STATUS OF THE PATHOGEN Domain, Bacteria; phylum, Proteobacteria; class, Gammaproteobacteria; order, Xanthomonadales; family, Xanthomonadaceae; genus, Xanthomonas; species, X. euvesicatoria, X. hortorum, X. vesicatoria. SYNONYMS (NONPREFERRED SCIENTIFIC NAMES) Bacterium exitiosum, Bacterium vesicatorium, Phytomonas exitiosa, Phytomonas vesicatoria, Pseudomonas exitiosa, Pseudomonas gardneri, Pseudomonas vesicatoria, Xanthomonas axonopodis pv. vesicatoria, Xanthomonas campestris pv. vesicatoria, Xanthomonas cynarae pv. gardneri, Xanthomonas gardneri, Xanthomonas perforans. MICROBIOLOGICAL PROPERTIES Colonies are gram-negative, oxidase-negative, and catalase-positive and have oxidative metabolism. Pale-yellow domed circular colonies of 1-2 mm in diameter grow on general culture media. DISTRIBUTION The bacteria are widespread in Africa, Brazil, Canada and the USA, Australia, eastern Europe, and south-east Asia. Occurrence in western Europe is restricted. PHYTOSANITARY CATEGORIZATION A2 no. 157, EU Annex designation II/A2. EPPO CODES XANTEU, XANTGA, XANTPF, XANTVE.
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Affiliation(s)
- Ebrahim Osdaghi
- Department of Plant ProtectionCollege of AgricultureUniversity of TehranKarajIran
| | - Jeffrey B. Jones
- Plant Pathology DepartmentUniversity of FloridaGainesvilleFloridaUSA
| | - Anuj Sharma
- Plant Pathology DepartmentUniversity of FloridaGainesvilleFloridaUSA
| | - Erica M. Goss
- Plant Pathology DepartmentUniversity of FloridaGainesvilleFloridaUSA
- Emerging Pathogens InstituteUniversity of FloridaGainesvilleFloridaUSA
| | - Peter Abrahamian
- Plant Pathology DepartmentUniversity of FloridaGainesvilleFloridaUSA
- Gulf Coast Research and Education CenterUniversity of FloridaWimaumaFloridaUSA
| | - Eric A. Newberry
- Department of Entomology and Plant PathologyAuburn UniversityAuburnAlabamaUSA
| | - Neha Potnis
- Department of Entomology and Plant PathologyAuburn UniversityAuburnAlabamaUSA
| | - Renato Carvalho
- Plant Pathology DepartmentUniversity of FloridaGainesvilleFloridaUSA
| | - Manoj Choudhary
- Plant Pathology DepartmentUniversity of FloridaGainesvilleFloridaUSA
| | - Mathews L. Paret
- Department of Plant PathologyNorth Florida Research and Education CenterUniversity of FloridaQuincyFloridaUSA
| | - Sujan Timilsina
- Plant Pathology DepartmentUniversity of FloridaGainesvilleFloridaUSA
| | - Gary E. Vallad
- Gulf Coast Research and Education CenterUniversity of FloridaWimaumaFloridaUSA
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11
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Deb S, Madhavan VN, Gokulan CG, Patel HK, Sonti RV. Arms and ammunitions: effectors at the interface of rice and it's pathogens and pests. RICE (NEW YORK, N.Y.) 2021; 14:94. [PMID: 34792681 PMCID: PMC8602583 DOI: 10.1186/s12284-021-00534-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 11/06/2021] [Indexed: 06/13/2023]
Abstract
The plant immune system has evolved to resist attack by pathogens and pests. However, successful phytopathogens deliver effector proteins into plant cells where they hijack the host cellular machinery to suppress the plant immune responses and promote infection. This manipulation of the host cellular pathways is done by the pathogen using various enzymatic activities, protein- DNA or protein- protein interactions. Rice is one the major economically important crops and its yield is affected by several pathogens and pests. In this review, we summarize the various effectors at the plant- pathogen/ pest interface for the major pathogens and pests of rice, specifically, on the mode of action and target genes of the effector proteins. We then compare this across the major rice pathogens and pests in a bid to understand probable conserved pathways which are under attack from pathogens and pests in rice. This analysis highlights conserved patterns of effector action, as well as unique host pathways targeted by the pathogens and pests.
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Affiliation(s)
- Sohini Deb
- CSIR-Centre for Cellular and Molecular Biology (CSIR-CCMB), Hyderabad, 500007 India
- Present Address: Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg C, Denmark
| | | | - C. G. Gokulan
- CSIR-Centre for Cellular and Molecular Biology (CSIR-CCMB), Hyderabad, 500007 India
| | - Hitendra K. Patel
- CSIR-Centre for Cellular and Molecular Biology (CSIR-CCMB), Hyderabad, 500007 India
| | - Ramesh V. Sonti
- CSIR-Centre for Cellular and Molecular Biology (CSIR-CCMB), Hyderabad, 500007 India
- Present Address: Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati, 517507 India
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12
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Joe A, Stewart V, Ronald PC. The HrpX Protein Activates Synthesis of the RaxX Sulfopeptide, Required for Activation of XA21-Mediated Immunity to Xanthomonas oryzae pv. oryzae. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:1307-1315. [PMID: 34731589 DOI: 10.1094/mpmi-05-21-0124-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Upon encountering a susceptible plant host, a bacterial pathogen expresses specific virulence factors. For example, in planta, the Xanthomonas HrpX protein activates transcription of roughly 150 genes encoding components of the type III secretion system or its translocated effectors, as well as other secreted proteins implicated in pathogenesis. Here, we show that X. oryzae pv. oryzae growth in planta or in HrpX-inducing XOM2 media resulted in HrpX-dependent transcription of the raxX and raxST genes that control production of the RaxX sulfopeptide, exported through a type I secretion system. The RaxX protein is required for activation of XA21-mediated immunity in Xa21+ rice lines. We identified potential plant-inducible promoter elements upstream of the likely 5' ends of the raxX and raxST transcripts. Deletions and nucleotide substitutions confirmed that these elements are required for HrpX-dependent expression of raxX and raxST. We conclude that raxX-raxST gene expression is induced by HrpX during growth in planta and, therefore, is coordinately expressed with other genes required for pathogenesis.[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)
- Anna Joe
- Department of Plant Pathology, University of California, Davis, CA 95616, U.S.A
| | - Valley Stewart
- Department of Microbiology & Molecular Genetics, University of California, Davis, CA 95616, U.S.A
| | - Pamela C Ronald
- Department of Plant Pathology, University of California, Davis, CA 95616, U.S.A
- Genome Center, University of California, Davis, CA 95616, U.S.A
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13
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Xue Y, Hu M, Chen S, Hu A, Li S, Han H, Lu G, Zeng L, Zhou J. Enterobacter asburiae and Pantoea ananatis Causing Rice Bacterial Blight in China. PLANT DISEASE 2021; 105:2078-2088. [PMID: 33342235 DOI: 10.1094/pdis-10-20-2292-re] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Rice bacterial blight is a devastating bacterial disease threatening rice yield all over the world and Xanthomonas oryzae pv. oryzae is traditionally believed to be the pathogen. In recent years, we have received diseased rice samples with symptoms of blighted leaves from Sichuan and Guangdong provinces, China. Pathogen isolation and classification identified two different enterobacteria as the causal agents, namely Enterobacter asburiae and Pantoea ananatis. Among them, E. asburiae was isolated from samples of both provinces, and P. ananatis was only isolated from the Sichuan samples. Different from rice foot rot pathogen Dickeya zeae EC1 and rice bacterial blight pathogen X. oryzae pv. oryzae PXO99A, strains SC1, RG1, and SC7 produced rare cell wall degrading enzymes (CWDEs) but more extrapolysaccharides (EPS). E. asburiae strains SC1 and RG1 produced bacteriostatic substances while P. ananatis strain SC7 produced none. Pathogenicity tests indicated that all of them infected monocotyledonous rice and banana seedlings, but not dicotyledonous potato, radish, or cabbage. Moreover, strain RG1 was most virulent, while strains SC1 and SC7 were similarly virulent on rice leaves, even though strain SC1 propagated significantly faster in rice leaf tissues than strain SC7. This study firstly discovered E. asburiae as a new pathogen of rice bacterial blight, and in some cases, P. ananatis could be a companion pathogen. Analysis on production of virulence factors suggested that both pathogens probably employ a different mechanism to infect hosts other than using cell wall degrading enzymes to break through host cell walls.
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Affiliation(s)
- Yang Xue
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China
| | - Ming Hu
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China
| | - Shanshan Chen
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China
| | - Anqun Hu
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China
| | - Shimao Li
- Agricultural Technology Service Centre of Daojiao Town, Dongguan 523170, China
| | - Haiya Han
- Dongguan Agricultural Technology Extension Management Office, Dongguan 523010, China
| | - Guangtao Lu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Lisha Zeng
- Dongguan Banana and Vegetable Research Institute, Dongguan 523061, China
| | - Jianuan Zhou
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China
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14
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Arnesen JA, Hoof JB, Kildegaard HF, Borodina I. Genome Editing of Eukarya. Metab Eng 2021. [DOI: 10.1002/9783527823468.ch10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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15
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Chen X, Liu P, Mei L, He X, Chen L, Liu H, Shen S, Ji Z, Zheng X, Zhang Y, Gao Z, Zeng D, Qian Q, Ma B. Xa7, a new executor R gene that confers durable and broad-spectrum resistance to bacterial blight disease in rice. PLANT COMMUNICATIONS 2021; 2:100143. [PMID: 34027390 PMCID: PMC8132130 DOI: 10.1016/j.xplc.2021.100143] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 01/02/2021] [Accepted: 01/07/2021] [Indexed: 05/03/2023]
Abstract
Bacterial blight (BB) is a globally devastating rice disease caused by Xanthomonas oryzae pv. oryzae (Xoo). The use of disease resistance (R) genes in rice breeding is an effective and economical strategy for the control of this disease. Nevertheless, a majority of R genes lack durable resistance for long-term use under global warming conditions. Here, we report the isolation of a novel executor R gene, Xa7, that confers extremely durable, broad-spectrum, and heat-tolerant resistance to Xoo. The expression of Xa7 was induced by incompatible Xoo strains that secreted the transcription activator-like effector (TALE) AvrXa7 or PthXo3, which recognized effector binding elements (EBEs) in the Xa7 promoter. Furthermore, Xa7 induction was faster and stronger under high temperatures. Overexpression of Xa7 or co-transformation of Xa7 with avrXa7 triggered a hypersensitive response in plants. Constitutive expression of Xa7 activated a defense response in the absence of Xoo but inhibited the growth of transgenic rice plants. In addition, analysis of over 3000 rice varieties showed that the Xa7 locus was found primarily in the indica and aus subgroups. A variation consisting of an 11-bp insertion and a base substitution (G to T) was found in EBEAvrXa7 in the tested varieties, resulting in a loss of Xa7 BB resistance. Through a decade of effort, we have identified an important BB resistance gene and characterized its distinctive interaction with Xoo strains; these findings will greatly facilitate research on the molecular mechanism of Xa7-mediated resistance and promote the use of this valuable gene in breeding.
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Affiliation(s)
- Xifeng Chen
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Pengcheng Liu
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Le Mei
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Xiaoling He
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Long Chen
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China
- China National Rice Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310006, China
| | - Hui Liu
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Shurong Shen
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Zhandong Ji
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Xixi Zheng
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Yuchen Zhang
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Zhenyu Gao
- China National Rice Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310006, China
| | - Dali Zeng
- China National Rice Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310006, China
| | - Qian Qian
- China National Rice Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310006, China
| | - Bojun Ma
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China
- Corresponding author
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16
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Luo D, Huguet-Tapia JC, Raborn RT, White FF, Brendel VP, Yang B. The Xa7 resistance gene guards the rice susceptibility gene SWEET14 against exploitation by the bacterial blight pathogen. PLANT COMMUNICATIONS 2021; 2:100164. [PMID: 34027391 PMCID: PMC8132128 DOI: 10.1016/j.xplc.2021.100164] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 01/14/2021] [Accepted: 01/15/2021] [Indexed: 05/03/2023]
Abstract
Many plant disease resistance (R) genes function specifically in reaction to the presence of cognate effectors from a pathogen. Xanthomonas oryzae pathovar oryzae (Xoo) uses transcription activator-like effectors (TALes) to target specific rice genes for expression, thereby promoting host susceptibility to bacterial blight. Here, we report the molecular characterization of Xa7, the cognate R gene to the TALes AvrXa7 and PthXo3, which target the rice major susceptibility gene SWEET14. Xa7 was mapped to a unique 74-kb region. Gene expression analysis of the region revealed a candidate gene that contained a putative AvrXa7 effector binding element (EBE) in its promoter and encoded a 113-amino-acid peptide of unknown function. Genome editing at the Xa7 locus rendered the plants susceptible to avrXa7-carrying Xoo strains. Both AvrXa7 and PthXo3 activated a GUS reporter gene fused with the EBE-containing Xa7 promoter in Nicotiana benthamiana. The EBE of Xa7 is a close mimic of the EBE of SWEET14 for TALe-induced disease susceptibility. Ectopic expression of Xa7 triggers cell death in N. benthamiana. Xa7 is prevalent in indica rice accessions from 3000 rice genomes. Xa7 appears to be an adaptation that protects against pathogen exploitation of SWEET14 and disease susceptibility.
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Affiliation(s)
- Dangping Luo
- Division of Plant Sciences, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Jose C. Huguet-Tapia
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611, USA
| | - R. Taylor Raborn
- Department of Biology, Department of Computer Science, Indiana University, Bloomington, IN 47405, USA
- Current address: Biodesign Institute Center for Mechanisms of Evolution, Arizona State University, Tempe, AZ 85281, USA
| | - Frank F. White
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611, USA
| | - Volker P. Brendel
- Department of Biology, Department of Computer Science, Indiana University, Bloomington, IN 47405, USA
| | - Bing Yang
- Division of Plant Sciences, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA
- Corresponding author
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17
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Zou L, Zhang C, Li Y, Yang X, Wang Y, Yan Y, Yang R, Huang M, Haq F, Yang C, Chen G. An improved, versatile and efficient modular plasmid assembly system for expression analyses of genes in Xanthomonas oryzae. MOLECULAR PLANT PATHOLOGY 2021; 22:480-492. [PMID: 33486879 PMCID: PMC7938625 DOI: 10.1111/mpp.13033] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 12/02/2020] [Accepted: 12/10/2020] [Indexed: 06/12/2023]
Abstract
Xanthomonas oryzae pathovars oryzae (Xoo) and oryzicola (Xoc) infect rice, causing bacterial blight and bacterial leaf streak, respectively, which are two economically important bacterial diseases in paddy fields. The interactions of Xoo and Xoc with rice can be used as models for studying fundamental aspects of bacterial pathogenesis and host tissue specificity. However, an improved vector system for gene expression analysis is desired for Xoo and Xoc because some broad host range vectors that can replicate stably in X. oryzae pathovars are low-copy number plasmids. To overcome this limitation, we developed a modular plasmid assembly system to transfer the functional DNA modules from the entry vectors into the pHM1-derived backbone vectors on a high-copy number basis. We demonstrated the feasibility of our vector system for protein detection, and quantification of virulence gene expression under laboratory conditions and in association with host rice and nonhost tobacco cells. This system also allows execution of a mutant complementation equivalent to the single-copy chromosomal integration system and tracing of pathogens in rice leaf. Based on this assembly system, we constructed a series of protein expression and promoter-probe vectors suitable for classical double restriction enzyme cloning. These vector systems enable cloning of all genes or promoters of interest from Xoo and Xoc strains. Our modular assembly system represents a versatile and highly efficient toolkit for gene expression analysis that will accelerate studies on interactions of X. oryzae with rice.
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Affiliation(s)
- Lifang Zou
- School of Agriculture and BiologyShanghai Jiao Tong UniversityShanghaiChina
- Key Laboratory of Urban Agriculture by Ministry of Agriculture of ChinaShanghai Jiao Tong UniversityShanghaiChina
- State Key Laboratory of Microbial MetabolismSchool of Life Sciences & BiotechnologyShanghai Jiao Tong UniversityShanghaiChina
| | - Cuiping Zhang
- School of Agriculture and BiologyShanghai Jiao Tong UniversityShanghaiChina
| | - Yilang Li
- School of Agriculture and BiologyShanghai Jiao Tong UniversityShanghaiChina
| | - Xiaofei Yang
- School of Agriculture and BiologyShanghai Jiao Tong UniversityShanghaiChina
| | - Yanyan Wang
- School of Agriculture and BiologyShanghai Jiao Tong UniversityShanghaiChina
| | - Yichao Yan
- School of Agriculture and BiologyShanghai Jiao Tong UniversityShanghaiChina
| | - Ruihuan Yang
- School of Agriculture and BiologyShanghai Jiao Tong UniversityShanghaiChina
| | - Mengsang Huang
- School of Agriculture and BiologyShanghai Jiao Tong UniversityShanghaiChina
| | - Fazal Haq
- School of Agriculture and BiologyShanghai Jiao Tong UniversityShanghaiChina
| | - Ching‐Hong Yang
- Department of Biological SciencesUniversity of WisconsinMilwaukeeWisconsinUSA
| | - Gongyou Chen
- School of Agriculture and BiologyShanghai Jiao Tong UniversityShanghaiChina
- Key Laboratory of Urban Agriculture by Ministry of Agriculture of ChinaShanghai Jiao Tong UniversityShanghaiChina
- State Key Laboratory of Microbial MetabolismSchool of Life Sciences & BiotechnologyShanghai Jiao Tong UniversityShanghaiChina
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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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Overexpression of OsCM alleviates BLB stress via phytohormonal accumulation and transcriptional modulation of defense-related genes in Oryza sativa. Sci Rep 2020; 10:19520. [PMID: 33177639 PMCID: PMC7658211 DOI: 10.1038/s41598-020-76675-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 10/18/2020] [Indexed: 12/14/2022] Open
Abstract
Xanthomonas oryzae is a serious pathogen causing bacterial leaf blight (BLB) disease in rice, markedly reducing its yield. In this study, the rice chorismate mutase (OsCM) gene was overexpressed in a bacterial leaf blight-susceptible rice line to investigate the functional role of OsCM in response to bacterial leaf blight stress. We reported that overexpression of OsCM altered the downstream pathway of aromatic amino acids, mitigating pathogen stress by altering stress-responsive genes and hormonal accumulation. Phenotypic evaluation showed that the lesion length in the transgenic line was significantly lesser than that in the wild-type, suggesting greater resistance in the transgenic line. Further analysis revealed that OsCM expression induced phenylalanine accumulation and suppressed tyrosine accumulation in response to bacterial leaf blight stress. Furthermore, bacterial leaf blight stress induced genes downstream of the phenylpropanoid pathway in conjunction with OsCM, suggesting that the phenylpropanoid pathway is dependent on OsCM gene expression. We reported high SA and low JA accumulation in response to bacterial leaf blight stress in the transgenic line. This higher SA accumulation suggested that SA induces immune responses by functioning as a promoter of nonexpresser pathogenesis-related genes 1 (NPR1) transcriptional regulation. Xa7 expression was induced with increase in nonexpresser pathogenesis-related genes 1, which is thought to be responsible for Xa7 expression, which is responsible for mitigating bacterial leaf blight stress.
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Shahbaz MU, Qian S, Yun F, Zhang J, Yu C, Tian F, Yang F, Chen H. Identification of the Regulatory Components Mediated by the Cyclic di-GMP Receptor Filp and Its Interactor PilZX3 and Functioning in Virulence of Xanthomonas oryzae pv. oryzae. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:1196-1208. [PMID: 32720873 DOI: 10.1094/mpmi-04-20-0088-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The degenerate GGDEF/EAL domain protein Filp was previously shown to function as a cyclic di-GMP (c-di-GMP) signal receptor through its specific interaction with an atypical PilZ domain protein PilZX3 (formerly PXO_02715) and that this interaction is involved in regulating virulence in Xanthomonas oryzae pv. oryzae. As a step toward understanding the regulatory role of Filp/PilZX3-mediated c-di-GMP signaling in the virulence of X. oryzae pv. oryzae, differentially expressed proteins (DEPs) downstream of Filp/PilZX3 were identified by isobaric tagging for relative and absolute quantitation (iTRAQ). A total of 2,346 proteins were identified, of which 157 displayed significant differential expression in different strains. Western blot and quantitative reverse transcription-PCR analyses showed that the expression of HrrP (histidine kinase-response regulator hybrid protein), PhrP (PhoPQ-regulated protein), ProP (prophage Lp2 protein 6) were increased in the ∆filp, ∆pilZX3, and ∆filp∆pilZX3 mutant strains, while expression of CheW1 (chemotaxis protein CheW1), EdpX2 (the second EAL domain protein identified in X. oryzae pv. oryzae), HGdpX2 (the second HD-GYP domain protein identified in X. oryzae pv. oryzae) was decreased in all mutant strains compared with that in the wild type, which was consistent with the iTRAQ data. Deletion of the hrrP and proP genes resulted in significant increases in virulence, whereas deletion of the cheW1, hGdpX2, or tdrX2 genes resulted in decreased virulence. Enzyme assays indicated that EdpX2 and HGdpX2 were active phosphodiesterases (PDEs). This study provides a proteomic description of putative regulatory pathway of Filp and PilZX3 and characterized novel factors that contributed to the virulence of X. oryzae pv. oryzae regulated by c-di-GMP signaling.
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Affiliation(s)
- Muhammad Umar Shahbaz
- State Key Laboratory for Biology Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- Plant Pathology Section, Plant Pathology Research Institute, AARI, Faisalabad 38850, Pakistan
| | - Shanshan Qian
- State Key Laboratory for Biology Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Fei Yun
- National Tobacco Cultivation and Physiology and Biochemistry Research Centre/Key Laboratory for Tobacco Cultivation of Tobacco Industry, Henan Agricultural University, Zhengzhou 450002, China
| | - Jie Zhang
- State Key Laboratory for Biology Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Chao Yu
- State Key Laboratory for Biology Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Fang Tian
- State Key Laboratory for Biology Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Fenghuan Yang
- State Key Laboratory for Biology Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Huamin Chen
- State Key Laboratory for Biology Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
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21
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Sahu A, Das A, Saikia K, Barah P. Temperature differentially modulates the transcriptome response in Oryza sativa to Xanthomonas oryzae pv. oryzae infection. Genomics 2020; 112:4842-4852. [PMID: 32896629 DOI: 10.1016/j.ygeno.2020.08.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 02/19/2020] [Accepted: 08/21/2020] [Indexed: 01/17/2023]
Abstract
Bacterial blight is caused by the pathogen Xanthomonas oryzae pv. oryzae (Xoo). Genome scale integrative analysis on the interaction of high and low temperatures on the molecular response signature in rice during the Xoo infection has not been conducted yet. We have analysed a unique RNA-Seq dataset generated on the susceptible rice variety IR24 under combined exposure of Xoo with low 29/21 °C (day/night) and high 35/31 °C (day/night) temperatures. Differentially regulated key genes and pathways in rice plants during both the stress conditions were identified. Differential dynamics of the regulatory network topology showed that WRKY and ERF families of transcription factors play a crucial role during signal crosstalk events in rice plants while responding to combined exposure of Xoo with low temperature vs. Xoo with high temperatures. Our study suggests that upon onset of high temperature, rice plants tend to switch its focus from defence response towards growth and reproduction.
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Affiliation(s)
- Ankur Sahu
- Department of Molecular Biology and Biotechnology, Tezpur University, Napaam, Sonitpur, Assam 784028, India
| | - Akash Das
- Department of Molecular Biology and Biotechnology, Tezpur University, Napaam, Sonitpur, Assam 784028, India
| | - Katherine Saikia
- Department of Molecular Biology and Biotechnology, Tezpur University, Napaam, Sonitpur, Assam 784028, India
| | - Pankaj Barah
- Department of Molecular Biology and Biotechnology, Tezpur University, Napaam, Sonitpur, Assam 784028, India.
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22
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Yang F, Zhang J, Zhang H, Ji G, Zeng L, Li Y, Yu C, Fernando WGD, Chen W. Bacterial Blight Induced Shifts in Endophytic Microbiome of Rice Leaves and the Enrichment of Specific Bacterial Strains With Pathogen Antagonism. FRONTIERS IN PLANT SCIENCE 2020; 11:963. [PMID: 32793250 PMCID: PMC7390967 DOI: 10.3389/fpls.2020.00963] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 06/11/2020] [Indexed: 05/25/2023]
Abstract
The endophytic microbiome plays an important role in plant health and pathogenesis. However, little is known about its relationship with bacterial blight (BB) of rice caused by Xanthomonas oryzae pv. oryzae (Xoo). The current study compared the community compositional structure of the endophytic microbiota in healthy and BB symptomatic leaves of rice through a metabarcoding approach, which revealed BB induced a decrease in the alpha-diversity of the fungal communities and an increase in the bacterial communities. BB-diseased rice leaves were enriched with saprophytic fungi that are capable of decomposing plant cell walls (e.g. Khuskia spp. and Leptosphaerulina spp.), while healthy rice leaves were found to be significantly more abundant with plant pathogens or mycotoxin-producing fungi (e.g. Fusarium, Magnaporthe, and Aspergillus). The endophytic bacterial communities of BB-diseased leaves were significantly enriched with Pantoea, Pseudomonas, and Curtobacterium, strains. Pantoea sp. isolates from BB leaves are identified as promising candidates for the biocontrol of BB for their ability to inhibit in vitro growth of Xoo, suppress the development of rice BB disease, and possess multiple PGP characteristics. Our study revealed BB-induced complexed changes in the endophytic fungal and bacterial communities of rice leaves and demonstrated that BB-associated enrichment of some endophytic bacterial taxa, e.g. Pantoea sp. isolates, may play important roles in suppressing the development of BB disease in rice.
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Affiliation(s)
- Fenghuan Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jie Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Huaying Zhang
- Ottawa Research & Development Centre, Science & Technology Branch, Agriculture and Agri-Food Canada, Ottawa, ON, Canada
| | - Guanghai Ji
- College of Plant Protection, Yunnan Agricultural University, Kunming, China
| | - Liexian Zeng
- Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Yan Li
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Chao Yu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | | | - Wen Chen
- Ottawa Research & Development Centre, Science & Technology Branch, Agriculture and Agri-Food Canada, Ottawa, ON, Canada
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23
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Yu C, Nguyen DP, Ren Z, Liu J, Yang F, Tian F, Fan S, Chen H. The RpoN2-PilRX regulatory system governs type IV pilus gene transcription and is required for bacterial motility and virulence in Xanthomonas oryzae pv. oryzae. MOLECULAR PLANT PATHOLOGY 2020; 21:652-666. [PMID: 32112711 PMCID: PMC7170775 DOI: 10.1111/mpp.12920] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 01/22/2020] [Accepted: 01/24/2020] [Indexed: 06/10/2023]
Abstract
The type IV pilus (T4P), a special class of bacterial surface filament, plays crucial roles in surface adhesion, motility, biofilm formation, and virulence in pathogenic bacteria. However, the regulatory mechanism of T4P and its relationship to bacterial virulence are still little understood in Xanthomonas oryzae pv. oryzae (Xoo), the causal pathogen of bacterial blight of rice. Our previous studies showed that the σ54 factor RpoN2 regulated bacterial virulence on rice in a flagellum-independent manner in Xoo. In this study, both yeast two-hybrid and pull-down assays revealed that RpoN2 directly and specifically interacted with PilRX, a homolog of the response regulator PilR of the two-component system PilS-PilR in the pilus gene cluster. Genomic sequence and reverse transcription PCR (RT-PCR) analysis showed 13 regulons containing 25 genes encoding T4P structural components and putative regulators. A consensus RpoN2-binding sequence GGN10 GC was identified in the promoter sequences of most T4P gene transcriptional units. Electrophoretic mobility shift assays confirmed the direct binding of RpoN2 to the promoter of the major pilin gene pilAX, the inner membrane platform protein gene pilCX, and pilRX. Promoter activity and quantitative RT-PCR assays demonstrated direct and indirect transcriptional regulation by RpoN2 of the T4P genes. In addition, individual deletions of pilAX, pilCX, and pilRX resulted in significantly reduced twitching and swimming motility, biofilm formation, and virulence in rice. Taken together, the findings from the current study suggest that the RpoN2-PilRX regulatory system controls bacterial motility and virulence by regulating T4P gene transcription in Xoo.
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Affiliation(s)
- Chao Yu
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Doan-Phuong Nguyen
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Zhaoyu Ren
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Jianan Liu
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Fenghuan Yang
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Fang Tian
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Susu Fan
- Shandong Provincial Key Laboratory of Applied MicrobiologyEcology InstituteQilu University of Technology (Shandong Academy of Sciences)Ji’nanChina
| | - Huamin Chen
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
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24
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Haq F, Xie S, Huang K, Shah SMA, Ma W, Cai L, Xu X, Xu Z, Wang S, Zou L, Zhu B, Chen G. Identification of a virulence tal gene in the cotton pathogen, Xanthomonas citri pv. malvacearum strain Xss-V 2-18. BMC Microbiol 2020; 20:91. [PMID: 32293266 PMCID: PMC7160923 DOI: 10.1186/s12866-020-01783-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 04/05/2020] [Indexed: 01/22/2023] Open
Abstract
Background Bacterial blight of cotton (BBC), which is caused by the bacterium Xanthomonas citri pv. malvacearum (Xcm), is a destructive disease in cotton. Transcription activator-like effectors (TALEs), encoded by tal-genes, play critical roles in the pathogenesis of xanthomonads. Characterized strains of cotton pathogenic Xcm harbor 8–12 different tal genes and only one of them is functionally decoded. Further identification of novel tal genes in Xcm strains with virulence contributions are prerequisite to decipher the Xcm-cotton interactions. Results In this study, we identified six tal genes in Xss-V2–18, a highly-virulent strain of Xcm from China, and assessed their role in BBC. RFLP-based Southern hybridization assays indicated that Xss-V2–18 harbors the six tal genes on a plasmid. The plasmid-encoded tal genes were isolated by cloning BamHI fragments and screening clones by colony hybridization. The tal genes were sequenced by inserting a Tn5 transposon in the DNA encoding the central repeat region (CRR) of each tal gene. Xcm TALome evolutionary relationship based on TALEs CRR revealed relatedness of Xss-V2–18 to MSCT1 and MS14003 from the United States. However, Tal2 of Xss-V2–18 differs at two repeat variable diresidues (RVDs) from Tal6 and Tal26 in MSCT1 and MS14003, respectively, inferred functional dissimilarity. The suicide vector pKMS1 was then used to construct tal deletion mutants in Xcm Xss-V2–18. The mutants were evaluated for pathogenicity in cotton based on symptomology and growth in planta. Four mutants showed attenuated virulence and all contained mutations in tal2. One tal2 mutant designated M2 was further investigated in complementation assays. When tal2 was introduced into Xcm M2 and expressed in trans, the mutant was complemented for both symptoms and growth in planta, thus indicating that tal2 functions as a virulence factor in Xcm Xss-V2–18. Conclusions Overall, the results demonstrated that Tal2 is a major pathogenicity factor in Xcm strain Xss-V2–18 that contributes significantly in BBC. This study provides a foundation for future efforts aimed at identifying susceptibility genes in cotton that are targeted by Tal2.
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Affiliation(s)
- Fazal Haq
- School of Agriculture and Biology, Shanghai Jiao Tong University/Key Laboratory of Urban Agriculture by the Ministry of Agriculture, Shanghai, 200240, China.,State Key laboratory of Microbial Metabolism, School of life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Shiwang Xie
- School of Agriculture and Biology, Shanghai Jiao Tong University/Key Laboratory of Urban Agriculture by the Ministry of Agriculture, Shanghai, 200240, China
| | - Kunxuan Huang
- School of Agriculture and Biology, Shanghai Jiao Tong University/Key Laboratory of Urban Agriculture by the Ministry of Agriculture, Shanghai, 200240, China.,State Key laboratory of Microbial Metabolism, School of life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Syed Mashab Ali Shah
- School of Agriculture and Biology, Shanghai Jiao Tong University/Key Laboratory of Urban Agriculture by the Ministry of Agriculture, Shanghai, 200240, China.,State Key laboratory of Microbial Metabolism, School of life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Wenxiu Ma
- School of Agriculture and Biology, Shanghai Jiao Tong University/Key Laboratory of Urban Agriculture by the Ministry of Agriculture, Shanghai, 200240, China.,State Key laboratory of Microbial Metabolism, School of life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Lulu Cai
- School of Agriculture and Biology, Shanghai Jiao Tong University/Key Laboratory of Urban Agriculture by the Ministry of Agriculture, Shanghai, 200240, China.,State Key laboratory of Microbial Metabolism, School of life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xiameng Xu
- School of Agriculture and Biology, Shanghai Jiao Tong University/Key Laboratory of Urban Agriculture by the Ministry of Agriculture, Shanghai, 200240, China.,State Key laboratory of Microbial Metabolism, School of life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zhengyin Xu
- School of Agriculture and Biology, Shanghai Jiao Tong University/Key Laboratory of Urban Agriculture by the Ministry of Agriculture, Shanghai, 200240, China.,State Key laboratory of Microbial Metabolism, School of life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Sai Wang
- School of Agriculture and Biology, Shanghai Jiao Tong University/Key Laboratory of Urban Agriculture by the Ministry of Agriculture, Shanghai, 200240, China
| | - Lifang Zou
- School of Agriculture and Biology, Shanghai Jiao Tong University/Key Laboratory of Urban Agriculture by the Ministry of Agriculture, Shanghai, 200240, China.,State Key laboratory of Microbial Metabolism, School of life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Bo Zhu
- School of Agriculture and Biology, Shanghai Jiao Tong University/Key Laboratory of Urban Agriculture by the Ministry of Agriculture, Shanghai, 200240, China
| | - Gongyou Chen
- School of Agriculture and Biology, Shanghai Jiao Tong University/Key Laboratory of Urban Agriculture by the Ministry of Agriculture, Shanghai, 200240, China. .,State Key laboratory of Microbial Metabolism, School of life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
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25
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Cuculis L, Zhao C, Abil Z, Zhao H, Shukla D, Schroeder CM. Divalent cations promote TALE DNA-binding specificity. Nucleic Acids Res 2020; 48:1406-1422. [PMID: 31863586 PMCID: PMC7026652 DOI: 10.1093/nar/gkz1174] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 11/18/2019] [Accepted: 12/06/2019] [Indexed: 02/06/2023] Open
Abstract
Recent advances in gene editing have been enabled by programmable nucleases such as transcription activator-like effector nucleases (TALENs) and CRISPR–Cas9. However, several open questions remain regarding the molecular machinery in these systems, including fundamental search and binding behavior as well as role of off-target binding and specificity. In order to achieve efficient and specific cleavage at target sites, a high degree of target site discrimination must be demonstrated for gene editing applications. In this work, we studied the binding affinity and specificity for a series of TALE proteins under a variety of solution conditions using in vitro fluorescence methods and molecular dynamics (MD) simulations. Remarkably, we identified that TALEs demonstrate high sequence specificity only upon addition of small amounts of certain divalent cations (Mg2+, Ca2+). However, under purely monovalent salt conditions (K+, Na+), TALEs bind to specific and non-specific DNA with nearly equal affinity. Divalent cations preferentially bind to DNA over monovalent cations, which attenuates non-specific interactions between TALEs and DNA and further stabilizes specific interactions. Overall, these results uncover new mechanistic insights into the binding action of TALEs and further provide potential avenues for engineering and application of TALE- or TALEN-based systems for genome editing and regulation.
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Affiliation(s)
| | - Chuankai Zhao
- Department of Chemical and Biomolecular Engineering, Urbana, IL 61801, USA
| | - Zhanar Abil
- Department of Biochemistry, Urbana, IL 61801, USA
| | - Huimin Zhao
- Department of Chemistry, Urbana, IL 61801, USA.,Department of Chemical and Biomolecular Engineering, Urbana, IL 61801, USA.,Department of Biochemistry, Urbana, IL 61801, USA.,Carl R. Woese Institute for Genomic Biology, Urbana, IL 61801, USA.,Center for Biophysics and Quantitative Biology, Urbana, IL 61801, USA
| | - Diwakar Shukla
- Department of Chemical and Biomolecular Engineering, Urbana, IL 61801, USA.,Center for Biophysics and Quantitative Biology, Urbana, IL 61801, USA.,National Center for Supercomputing Applications, Urbana, IL 61801, USA.,NIH Center for Macromolecular Modeling and Bioinformatics, Urbana, IL 61801, USA.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Charles M Schroeder
- Department of Chemistry, Urbana, IL 61801, USA.,Department of Chemical and Biomolecular Engineering, Urbana, IL 61801, USA.,Carl R. Woese Institute for Genomic Biology, Urbana, IL 61801, USA.,Center for Biophysics and Quantitative Biology, Urbana, IL 61801, USA.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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26
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Kumar A, Kumar R, Sengupta D, Das SN, Pandey MK, Bohra A, Sharma NK, Sinha P, Sk H, Ghazi IA, Laha GS, Sundaram RM. Deployment of Genetic and Genomic Tools Toward Gaining a Better Understanding of Rice- Xanthomonas oryzae pv. oryzae Interactions for Development of Durable Bacterial Blight Resistant Rice. FRONTIERS IN PLANT SCIENCE 2020; 11:1152. [PMID: 32849710 PMCID: PMC7417518 DOI: 10.3389/fpls.2020.01152] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 07/15/2020] [Indexed: 05/05/2023]
Abstract
Rice is the most important food crop worldwide and sustainable rice production is important for ensuring global food security. Biotic stresses limit rice production significantly and among them, bacterial blight (BB) disease caused by Xanthomonas oryzae pv. oryzae (Xoo) is very important. BB reduces rice yields severely in the highly productive irrigated and rainfed lowland ecosystems and in recent years; the disease is spreading fast to other rice growing ecosystems as well. Being a vascular pathogen, Xoo interferes with a range of physiological and biochemical exchange processes in rice. The response of rice to Xoo involves specific interactions between resistance (R) genes of rice and avirulence (Avr) genes of Xoo, covering most of the resistance genes except the recessive ones. The genetic basis of resistance to BB in rice has been studied intensively, and at least 44 genes conferring resistance to BB have been identified, and many resistant rice cultivars and hybrids have been developed and released worldwide. However, the existence and emergence of new virulent isolates of Xoo in the realm of a rapidly changing climate necessitates identification of novel broad-spectrum resistance genes and intensification of gene-deployment strategies. This review discusses about the origin and occurrence of BB in rice, interactions between Xoo and rice, the important roles of resistance genes in plant's defense response, the contribution of rice resistance genes toward development of disease resistance varieties, identification and characterization of novel, and broad-spectrum BB resistance genes from wild species of Oryza and also presents a perspective on potential strategies to achieve the goal of sustainable disease management.
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Affiliation(s)
- Anirudh Kumar
- Department of Botany, Indira Gandhi National Tribal University (IGNTU), Amarkantak, India
- *Correspondence: Raman Meenakshi Sundaram, ; Anirudh Kumar,
| | - Rakesh Kumar
- Department of Life Science, Central University of Karnataka, Kalaburagi, India
| | - Debashree Sengupta
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad (UoH), Hyderabad, India
| | - Subha Narayan Das
- Department of Botany, Indira Gandhi National Tribal University (IGNTU), Amarkantak, India
| | - Manish K. Pandey
- Department of Biotechnology, ICAR-Indian Institute of Rice Research (IIRR), Hyderabad, India
| | - Abhishek Bohra
- ICAR-Crop Improvement Division, Indian Institute of Pulses Research (IIPR), Kanpur, India
| | - Naveen K. Sharma
- Department of Botany, Indira Gandhi National Tribal University (IGNTU), Amarkantak, India
| | - Pragya Sinha
- Department of Biotechnology, ICAR-Indian Institute of Rice Research (IIRR), Hyderabad, India
| | - Hajira Sk
- Department of Biotechnology, ICAR-Indian Institute of Rice Research (IIRR), Hyderabad, India
| | - Irfan Ahmad Ghazi
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad (UoH), Hyderabad, India
| | - Gouri Sankar Laha
- Department of Biotechnology, ICAR-Indian Institute of Rice Research (IIRR), Hyderabad, India
| | - Raman Meenakshi Sundaram
- Department of Biotechnology, ICAR-Indian Institute of Rice Research (IIRR), Hyderabad, India
- *Correspondence: Raman Meenakshi Sundaram, ; Anirudh Kumar,
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27
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Xu Z, Xu X, Gong Q, Li Z, Li Y, Wang S, Yang Y, Ma W, Liu L, Zhu B, Zou L, Chen G. Engineering Broad-Spectrum Bacterial Blight Resistance by Simultaneously Disrupting Variable TALE-Binding Elements of Multiple Susceptibility Genes in Rice. MOLECULAR PLANT 2019; 12:1434-1446. [PMID: 31493565 DOI: 10.1016/j.molp.2019.08.006] [Citation(s) in RCA: 151] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 08/01/2019] [Accepted: 08/11/2019] [Indexed: 05/04/2023]
Abstract
Xanthomonas oryzae pv. oryzae (Xoo), the causal agent of bacterial blight of rice, employs the transcription activator-like effectors (TALEs) to induce the expression of the OsSWEET family of putative sugar transporter genes, which function in conferring disease susceptibility (S) in rice plants. To engineer broad-spectrum bacterial blight resistance, we used CRISPR/Cas9-mediated gene editing to disrupt the TALE-binding elements (EBEs) of two S genes, OsSWEET11 and OsSWEET14, in rice cv. Kitaake, which harbors the recessive resistance allele of Xa25/OsSWEET13. The engineered rice line MS14K exhibited broad-spectrum resistance to most Xoo strains with a few exceptions, suggesting that the compatible strains may contain new TALEs. We identified two PthXo2-like TALEs, Tal5LN18 and Tal7PXO61, as major virulence factors in the compatible Xoo strains LN18 and PXO61, respectively, and found that Xoo encodes at least five types of PthXo2-like effectors. Given that PthXo2/PthXo2.1 target OsSWEET13 for transcriptional activation, the genomes of 3000 rice varieties were analyzed for EBE variationsin the OsSWEET13 promoter, and 10 Xa25-like haplotypes were identified. We found that Tal5LN18 and Tal7PXO61 bind slightly different EBE sequences in the OsSWEET13 promoter to activate its expression. CRISPR/Cas9 technology was then used to generate InDels in the EBE of the OsSWEET13 promoter in MS14K to creat a new germplasm with three edited OsSWEET EBEs and broad-spectrum resistance against all Xoo strains tested. Collectively, our findings illustrate how to disarm TALE-S co-evolved loci to generate broad-spectrum resistance through the loss of effector-triggered susceptibility in plants.
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Affiliation(s)
- Zhengyin Xu
- School of Agriculture and Biology/State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiameng Xu
- School of Agriculture and Biology/State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qiang Gong
- School of Agriculture and Biology/State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ziyang Li
- School of Agriculture and Biology/State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ying Li
- School of Agriculture and Biology/State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Sai Wang
- School of Agriculture and Biology/State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yangyang Yang
- School of Agriculture and Biology/State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Wenxiu Ma
- School of Agriculture and Biology/State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Longyu Liu
- School of Agriculture and Biology/State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Bo Zhu
- School of Agriculture and Biology/State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Lifang Zou
- School of Agriculture and Biology/State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Gongyou Chen
- School of Agriculture and Biology/State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China.
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28
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Li C, Ji C, Huguet‐Tapia JC, White FF, Dong H, Yang B. An efficient method to clone TAL effector genes from Xanthomonas oryzae using Gibson assembly. MOLECULAR PLANT PATHOLOGY 2019; 20:1453-1462. [PMID: 31414714 PMCID: PMC6792135 DOI: 10.1111/mpp.12820] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Transcription Activator-Like effectors (TALes) represent the largest family of type III effectors among pathogenic bacteria and play a critical role in the process of infection. Strains of Xanthomonas oryzae pv. oryzae (Xoo) and some strains of other Xanthomonas pathogens contain large numbers of TALe genes. Previous techniques to clone individual or a complement of TALe genes through conventional strategies are inefficient and time-consuming due to multiple genes (up to 29 copies) in a given genome, and technically challenging due to the repetitive sequences (up to 33 nearly identical 102-nucleotide repeats) of individual TALe genes. Thus, only a limited number of TALe genes have been molecularly cloned and characterized, and the functions of most TALe genes remain unknown. Here, we present an easy and efficient cloning technique to clone TALe genes selectively through in vitro homologous recombination and single-strand annealing, and demonstrate the feasibility of this approach with four different Xoo strains. Based on the Gibson assembly strategy, two complementary vectors with scaffolds that can preferentially capture all TALe genes from a pool of genomic fragments were designed. Both vector systems enabled cloning of a full complement of TALe genes from each of four Xoo strains and functional analysis of individual TALes in rice in approximately 1 month compared to 3 months by previously used methods. The results demonstrate a robust tool to advance TALe biology and a potential for broad usage of this approach to clone multiple copies of highly competitive DNA elements in any genome of interest.
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Affiliation(s)
- Chenhao Li
- Department of Plant PathologyNanjing Agricultural UniversityNanjing210095Jiangsu ProvidenceP.R. China
- Division of Plant SciencesUniversity of MissouriColumbiaMO65211USA
| | - Chonghui Ji
- Division of Plant SciencesUniversity of MissouriColumbiaMO65211USA
| | | | - Frank F. White
- Department of Plant PathologyUniversity of FloridaGainesvilleFL32611USA
| | - Hansong Dong
- Department of Plant PathologyNanjing Agricultural UniversityNanjing210095Jiangsu ProvidenceP.R. China
| | - Bing Yang
- Division of Plant SciencesUniversity of MissouriColumbiaMO65211USA
- Donald Danforth Plant Science CenterSt. LouisMO63132USA
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Ma YN, Chen L, Si NG, Jiang WJ, Zhou ZG, Liu JL, Zhang LQ. Identification of Benzyloxy Carbonimidoyl Dicyanide Derivatives as Novel Type III Secretion System Inhibitors via High-Throughput Screening. FRONTIERS IN PLANT SCIENCE 2019; 10:1059. [PMID: 31543889 PMCID: PMC6739442 DOI: 10.3389/fpls.2019.01059] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 08/05/2019] [Indexed: 06/10/2023]
Abstract
The type III secretion system (T3SS) in many Gram-negative bacterial pathogens is regarded as the most critical virulence determinant and an attractive target for novel anti-virulence drugs. In this study, we constructed a T3SS secretion reporter containing the β-lactamase gene fused with a signal peptide sequence of the T3SS effector gene, and established a high-throughput screening system for T3SS inhibitors in the plant pathogenic bacterium Acidovorax citrulli. From a library of 12,000 chemical compounds, we identified a series of benzyloxy carbonimidoyl dicyanide (BCD) derivatives that effectively blocked T3SS-dependent β-lactamase secretion. Substitution of halogens or nitro groups at the para-position on the benzene ring contributed to an increased inhibitory activity. One representative compound, BCD03 (3,4-dichloro-benzyloxy carbonimidoyl dicyanide), dramatically reduced pathogenicity of A. citrulli on melon seedlings, and attenuated hypersensitive responses in the non-host Nicotiana tabacum caused by pathogenic bacteria A. citrulli, Xanthomonas oryzae pv. oryzae and Pseudomonas syringae pv. tomato at sub-MIC concentrations. Western blotting assay further confirmed that BCD03 inhibited effector secretion from the above bacteria via T3SS in the liquid medium. Taken together, our data suggest that BCD derivatives act as novel inhibitors of T3SS in multiple plant bacterial pathogens.
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Affiliation(s)
- Yi-Nan Ma
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing, China
| | - Liang Chen
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing, China
- State Key Laboratory of the Discovery and Development of Novel Pesticide, Shenyang Sinochem Agrochemicals R&D Co., Ltd, Shenyang, China
| | - Nai-Guo Si
- State Key Laboratory of the Discovery and Development of Novel Pesticide, Shenyang Sinochem Agrochemicals R&D Co., Ltd, Shenyang, China
| | - Wen-Jun Jiang
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing, China
| | - Zhi-Gang Zhou
- China-Norway Joint Lab on Fish Gut Microbiota, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jun-Li Liu
- State Key Laboratory of the Discovery and Development of Novel Pesticide, Shenyang Sinochem Agrochemicals R&D Co., Ltd, Shenyang, China
| | - Li-Qun Zhang
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing, China
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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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Li H, Xue D, Tian F, Yuan X, Yang F, Chen H, Hutchins W, Yang CH, He C. Xanthomonas oryzae pv. oryzae Response Regulator TriP Regulates Virulence and Exopolysaccharide Production Via Interacting With c-di-GMP Phosphodiesterase PdeR. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:729-739. [PMID: 30589364 DOI: 10.1094/mpmi-09-18-0260-r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
PdeR, a response regulator of the two-component system (TCS) with the cognate histidine kinase PdeK, has been shown to be an active phosphodiesterase (PDE) for intracellular cyclic dimeric guanosine monophosphate (c-di-GMP) turnover and positively regulates the virulence of Xanthomonas oryzae pv. oryzae, the causal pathogen of bacterial blight of rice. To further reveal the key components and pathways involved in the PdeR-mediated c-di-GMP regulation of virulence, 16 PdeR-interacting proteins were identified, using the yeast two-hybrid (Y2H) assay. Among them, PXO_04421 (named as TriP, a putative transcriptional regulator interacting with PdeR) was verified via Y2H and glutathione-S-transferase pull-down assays, and its regulatory functions in bacterial virulence and exopolysaccharide (EPS) production were assessed by biochemical and genetic analysis. The REC domain of TriP specifically interacted with the EAL domain of PdeR. TriP promoted the PDE activity of PdeR to degrade c-di-GMP in the presence of PdeK. In-frame deletion in triP abolished the polar localization of PdeR in the cell. Notably, the ∆triP mutant showed significantly reduced virulence on susceptible rice leaves and impaired EPS production compared with wild type, whereas the double mutant ∆triP∆pdeR, like ∆pdeR, caused shorter lesion lengths and produced less EPS than ∆triP. In addition, cross-complementation showed in trans expression of pdeR in ∆triP restored its EPS production to near wild-type levels but not vice versa. Taken together, our results suggest that TriP is a novel regulator that is epistatic to PdeR in positively regulating virulence expression in X. oryzae pv. oryzae.
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Affiliation(s)
- Haiyun Li
- 1 State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- 2 Jingtang Port Office of Hebei Entry-Exit Inspection and Quarantine Bureau, Tangshan 063611, China
| | - Dingrong Xue
- 1 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
- 1 State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Xiaochen Yuan
- 3 Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, U.S.A
| | - Fenghuan Yang
- 1 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
- 1 State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | | | - Ching-Hong Yang
- 3 Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, U.S.A
| | - Chenyang He
- 1 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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Biosynthesis and secretion of the microbial sulfated peptide RaxX and binding to the rice XA21 immune receptor. Proc Natl Acad Sci U S A 2019; 116:8525-8534. [PMID: 30948631 DOI: 10.1073/pnas.1818275116] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The rice immune receptor XA21 is activated by the sulfated microbial peptide required for activation of XA21-mediated immunity X (RaxX) produced by Xanthomonas oryzae pv. oryzae (Xoo). Mutational studies and targeted proteomics revealed that the RaxX precursor peptide (proRaxX) is processed and secreted by the protease/transporter RaxB, the function of which can be partially fulfilled by a noncognate peptidase-containing transporter component B (PctB). proRaxX is cleaved at a Gly-Gly motif, yielding a mature peptide that retains the necessary elements for RaxX function as an immunogen and host peptide hormone mimic. These results indicate that RaxX is a prokaryotic member of a previously unclassified and understudied group of eukaryotic tyrosine sulfated ribosomally synthesized, posttranslationally modified peptides (RiPPs). We further demonstrate that sulfated RaxX directly binds XA21 with high affinity. This work reveals a complete, previously uncharacterized biological process: bacterial RiPP biosynthesis, secretion, binding to a eukaryotic receptor, and triggering of a robust host immune response.
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Bae N, Park H, Park H, Kim M, Han S. Deciphering the functions of the outer membrane porin OprBXo involved in virulence, motility, exopolysaccharide production, biofilm formation and stress tolerance in Xanthomonas oryzae pv. oryzae. MOLECULAR PLANT PATHOLOGY 2018; 19:2527-2542. [PMID: 30073749 PMCID: PMC6638129 DOI: 10.1111/mpp.12727] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 06/25/2018] [Accepted: 07/09/2018] [Indexed: 05/24/2023]
Abstract
Xanthomonas oryzae pv. oryzae (Xoo) is a Gram-negative bacterium causing bacterial leaf blight disease in rice. Previously, proteomic analysis has shown that the outer membrane protein B in Xoo (OprBXo) is more abundant in the wildtype strain than is the outer membrane protein 1 in the Xoo (Omp1X) knockout mutant. OprBXo shows high homology with OprB, which has been well characterized as a carbohydrate-selective porin in X. citri ssp. citri and Pseudomonas species. However, the functions of OprBXo in Xoo have not yet been documented. To elucidate the functions of OprBXo, we generated the OprBXo-overexpressing mutant, Xoo(OprBXo), and the knockout mutant, XooΔoprBXo(EV). We found that the virulence and migration of Xoo(OprBXo), but not XooΔoprBXo(EV), were markedly reduced in rice. To postulate the mechanisms affected by OprBXo, comparative proteomic analysis was performed. Based on the results of proteomics, we employed diverse phenotypic assays to characterize the functions of OprBXo. Abnormal twitching motility and reduction in swarming motility were observed in Xoo(OprBXo). Moreover, Xoo(OprBXo) decreased, but XooΔoprBXo(EV) enhanced, exopolysaccharide production and biofilm formation. The chemotactic ability of XooΔoprBXo(EV) was dramatically lower than that of Xoo(EV) in the presence of glucose and xylose. Xoo(OprBXo) was resistant to sodium dodecylsulphate and hydrogen peroxide, but XooΔoprBXo(EV) was highly sensitive compared with Xoo(EV). Thus, OprBXo is not only essential for chemotaxis and stress tolerance, but also for motility, biofilm formation and exopolysaccharide production, which may contribute to the virulence of Xoo. These results will lead to new insights into the functions of a sugar-selective porin in Xoo.
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Affiliation(s)
- Nahee Bae
- Department of Integrative Plant ScienceChung‐Ang UniversityAnseong17546South Korea
| | - Hye‐Jee Park
- Department of Integrative Plant ScienceChung‐Ang UniversityAnseong17546South Korea
| | - Hanbi Park
- Department of Integrative Plant ScienceChung‐Ang UniversityAnseong17546South Korea
| | - Minyoung Kim
- Department of Integrative Plant ScienceChung‐Ang UniversityAnseong17546South Korea
| | - Sang‐Wook Han
- Department of Integrative Plant ScienceChung‐Ang UniversityAnseong17546South Korea
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Ma W, Zou L, Zhiyuan JI, Xiameng XU, Zhengyin XU, Yang Y, Alfano JR, Chen G. Xanthomonas oryzae pv. oryzae TALE proteins recruit OsTFIIAγ1 to compensate for the absence of OsTFIIAγ5 in bacterial blight in rice. MOLECULAR PLANT PATHOLOGY 2018; 19:2248-2262. [PMID: 29704467 PMCID: PMC6638009 DOI: 10.1111/mpp.12696] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 04/24/2018] [Accepted: 04/26/2018] [Indexed: 05/12/2023]
Abstract
Xanthomonas oryzae pv. oryzae (Xoo), the causal agent of bacterial blight (BB) of rice, uses transcription activator-like effectors (TALEs) to interact with the basal transcription factor gamma subunit OsTFIIAγ5 (Xa5) and activates the transcription of host genes. However, how OsTFIIAγ1, the other OsTFIIAγ protein, functions in the presence of TALEs remains unclear. In this study, we show that OsTFIIAγ1 plays a compensatory role in the absence of Xa5. The expression of OsTFIIAγ1, which is activated by TALE PthXo7, increases the expression of host genes targeted by avirulent and virulent TALEs. Defective OsTFIIAγ1 rice lines show reduced expression of the TALE-targeted susceptibility (S) genes, OsSWEET11 and OsSWEET14, which results in increased BB resistance. Selected TALEs (PthXo1, AvrXa7 and AvrXa27) were evaluated for interactions with OsTFIIAγ1, Xa5 and xa5 (naturally occurring mutant form of Xa5) using biomolecular fluorescence complementation (BiFC) and microscale thermophoresis (MST). BiFC and MST demonstrated that the three TALEs bind Xa5 and OsTFIIAγ1 with a stronger affinity than xa5. These results provide insights into the complex roles of OsTFIIAγ1 and OsTFIIAγ5 in TALE-mediated host gene transcription.
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Affiliation(s)
- Wenxiu Ma
- School of Agriculture and BiologyShanghai Jiao Tong University/Key Laboratory of Urban Agriculture by Ministry of AgricultureShanghai200240China
- State Key Laboratory of Microbial Metabolism, School of Life Science & BiotechnologyShanghai Jiao Tong UniversityShanghai200240China
| | - Lifang Zou
- School of Agriculture and BiologyShanghai Jiao Tong University/Key Laboratory of Urban Agriculture by Ministry of AgricultureShanghai200240China
- State Key Laboratory of Microbial Metabolism, School of Life Science & BiotechnologyShanghai Jiao Tong UniversityShanghai200240China
| | - JI Zhiyuan
- School of Agriculture and BiologyShanghai Jiao Tong University/Key Laboratory of Urban Agriculture by Ministry of AgricultureShanghai200240China
- State Key Laboratory of Microbial Metabolism, School of Life Science & BiotechnologyShanghai Jiao Tong UniversityShanghai200240China
- Present address:
Present address: National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Institute of Crop ScienceChinese Academy of Agriculture Sciences (CAAS)Beijing 100081China
| | - XU Xiameng
- School of Agriculture and BiologyShanghai Jiao Tong University/Key Laboratory of Urban Agriculture by Ministry of AgricultureShanghai200240China
- State Key Laboratory of Microbial Metabolism, School of Life Science & BiotechnologyShanghai Jiao Tong UniversityShanghai200240China
| | - XU Zhengyin
- School of Agriculture and BiologyShanghai Jiao Tong University/Key Laboratory of Urban Agriculture by Ministry of AgricultureShanghai200240China
- State Key Laboratory of Microbial Metabolism, School of Life Science & BiotechnologyShanghai Jiao Tong UniversityShanghai200240China
| | - Yangyang Yang
- School of Agriculture and BiologyShanghai Jiao Tong University/Key Laboratory of Urban Agriculture by Ministry of AgricultureShanghai200240China
- State Key Laboratory of Microbial Metabolism, School of Life Science & BiotechnologyShanghai Jiao Tong UniversityShanghai200240China
| | - James R. Alfano
- School of Agriculture and BiologyShanghai Jiao Tong University/Key Laboratory of Urban Agriculture by Ministry of AgricultureShanghai200240China
- The Center for Plant Science Innovation, University of NebraskaLincolnNE68588‐0660USA
| | - Gongyou Chen
- School of Agriculture and BiologyShanghai Jiao Tong University/Key Laboratory of Urban Agriculture by Ministry of AgricultureShanghai200240China
- State Key Laboratory of Microbial Metabolism, School of Life Science & BiotechnologyShanghai Jiao Tong UniversityShanghai200240China
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Gao Y, Zhang C, Han X, Wang ZY, Ma L, Yuan DP, Wu JN, Zhu XF, Liu JM, Li DP, Hu YB, Xuan YH. Inhibition of OsSWEET11 function in mesophyll cells improves resistance of rice to sheath blight disease. MOLECULAR PLANT PATHOLOGY 2018; 19:2149-2161. [PMID: 29660235 PMCID: PMC6638089 DOI: 10.1111/mpp.12689] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Revised: 04/04/2018] [Accepted: 04/08/2018] [Indexed: 05/20/2023]
Abstract
Pathogen-host interaction is a complicated process; pathogens mainly infect host plants to acquire nutrients, especially sugars. Rhizoctonia solani, the causative agent of sheath blight disease, is a major pathogen of rice. However, it is not known how this pathogen obtains sugar from rice plants. In this study, we found that the rice sugar transporter OsSWEET11 is involved in the pathogenesis of sheath blight disease. Quantitative real-time polymerase chain reaction (qRT-PCR) and β-d-glucuronidase expression analyses showed that R. solani infection significantly enhanced OsSWEET11 expression in leaves amongst the clade III SWEET members. The analyses of transgenic plants revealed that Ossweet11 mutants were less susceptible, whereas plants overexpressing OsSWEET11 were more susceptible, to sheath blight compared with wild-type controls, but the yield of OsSWEET11 mutants and overexpressors was reduced. SWEETs become active on oligomerization. Split-ubiquitin yeast two-hybrid, bimolecular fluorescence complementation and co-immunoprecipitation assays showed that mutated OsSWEET11 interacted with normal OsSWEET11. In addition, expression of conserved residue mutated AtSWEET1 inhibited normal AtSWEET1 activity. To analyse whether inhibition of OsSWEET11 function in mesophyll cells is related to defence against this disease, mutated OsSWEET11 was expressed under the control of the Rubisco promoter, which is specific for green tissues. The resistance of transgenic plants to sheath blight disease, but not other disease, was improved, whereas yield production was not obviously affected. Overall, these results suggest that R. solani might acquire sugar from rice leaves by the activation of OsSWEET11 expression. The plants can be protected from infection by manipulation of the expression of OsSWEET11 without affecting the crop yield.
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Affiliation(s)
- Yue Gao
- College of Plant ProtectionShenyang Agricultural UniversityShenyang 110866China
| | - Chong Zhang
- College of Plant ProtectionShenyang Agricultural UniversityShenyang 110866China
| | - Xiao Han
- College of Biological Science and EngineeringFuzhou UniversityFuzhou 350108China
- Biotechnology Research InstituteChinese Academy of Agricultural SciencesBeijing 100081China
| | - Zi Yuan Wang
- College of Plant ProtectionShenyang Agricultural UniversityShenyang 110866China
| | - Lai Ma
- College of Resources & Environmental SciencesNanjing Agricultural UniversityNanjing 210095China
| | - De Peng Yuan
- College of Plant ProtectionShenyang Agricultural UniversityShenyang 110866China
| | - Jing Ni Wu
- Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of SciencesShanghai 200032China
| | - Xiao Feng Zhu
- College of Plant ProtectionShenyang Agricultural UniversityShenyang 110866China
| | - Jing Miao Liu
- Department of Agricultural and Biological TechnologyWenzhou Agricultural Science Research Institute (Wenzhou Vocational College of Science & Technology)Wenzhou 325006China
| | - Dao Pin Li
- Department of Agricultural and Biological TechnologyWenzhou Agricultural Science Research Institute (Wenzhou Vocational College of Science & Technology)Wenzhou 325006China
| | - Yi Bing Hu
- College of Resources & Environmental SciencesNanjing Agricultural UniversityNanjing 210095China
| | - Yuan Hu Xuan
- College of Plant ProtectionShenyang Agricultural UniversityShenyang 110866China
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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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Yu C, Chen H, Tian F, Yang F, Yuan X, Yang C, He C. A ten gene-containing genomic island determines flagellin glycosylation: implication for its regulatory role in motility and virulence of Xanthomonas oryzae pv. oryzae. MOLECULAR PLANT PATHOLOGY 2018; 19:579-592. [PMID: 28213905 PMCID: PMC6638077 DOI: 10.1111/mpp.12543] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 02/06/2017] [Accepted: 02/13/2017] [Indexed: 05/19/2023]
Abstract
Flagellin glycosylation plays a crucial role in flagellar assembly, motility and virulence in several pathogenic bacteria. However, little is known about the genetic determinants and biological functions of flagellin glycosylation in Xanthomonas oryzae pv. oryzae (Xoo), the causal pathogen of bacterial blight of rice. Here, the structure, regulation and functions of a ten-gene cluster gigX (glycosylation island genes of Xoo), which was embedded in a flagellar regulon, were characterized. gigX1 to gigX10 encoded putative enzymes or proteins involved in glycan biosynthesis and transfer, including a nucleotide sugar transaminase, an acyl-carrier protein (ACP), a 3-oxoacyl-ACP synthase, a 3-oxoacyl-ACP reductase, a dehydrogenase, an acetyltransferase, a ring hydroxylating dioxygenase, a hypothetical protein, a methyltransferanse and a glycosyltransferase, respectively. The gigX genes were co-transcribed in an operon and up-regulated by the upstream σ54 factor RpoN2 and transcriptional activator FleQ. In-frame deletion of each gigX gene affected flagellin glycosylation modification, meaning that the unglycosylated flagellin of the mutants was smaller than the glycosylated flagellin of the wild-type. No significant changes in flagellar filament and motility were observed in the ΔgigX mutants, among which only ΔgigX6 displayed increased swimming ability. Importantly, all mutants, except ΔgigX9, showed significantly increased virulence and bacterial growth in the susceptible rice cultivar IR24, and ΔgigX1 and ΔgigX10 showed enhanced type III secretion system (T3SS)-related gene expression. Moreover, the glycosylated flagellin of the wild-type induced higher H2 O2 levels in rice leaves than did the unglycosylated flagellins of ΔgigX1 or ΔgigX10. Taken together, this study reveals that the gigX cluster determines flagellin glycosylation, and implicates the regulatory role of post-translational modification with the glycosylation, acetylation and methylation of flagellin in the regulation of motility and virulence of Xoo.
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Affiliation(s)
- Chao Yu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing100193China
| | - Huamin Chen
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing100193China
| | - Fang Tian
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing100193China
| | - Fenghuan Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing100193China
| | - Xiaochen Yuan
- Department of Biological SciencesUniversity of Wisconsin‐MilwaukeeMilwaukeeWI53211USA
| | - Ching‐Hong Yang
- Department of Biological SciencesUniversity of Wisconsin‐MilwaukeeMilwaukeeWI53211USA
| | - Chenyang He
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing100193China
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Xie S, Zang H, Wu H, Uddin Rajer F, Gao X. Antibacterial effects of volatiles produced by Bacillus strain D13 against Xanthomonas oryzae pv. oryzae. MOLECULAR PLANT PATHOLOGY 2018; 19:49-58. [PMID: 27682316 PMCID: PMC6637998 DOI: 10.1111/mpp.12494] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 08/29/2016] [Accepted: 09/24/2016] [Indexed: 05/26/2023]
Abstract
Recent investigations have demonstrated that bacteria employ the volatile compounds they produce during interactions with other organisms, such as plants, fungi, nematodes and bacteria. However, studies focused on the antibacterial activity of plant growth-promoting rhizobacteria (PGPR) volatiles against bacterial phytopathogens are still rare. In this study, Bacillus strain D13, which is antagonistic to Xanthomonas oryzae pv. oryzae (Xoo), was isolated and screened. Volatile compounds emitted from strain D13 reduced the colony diameter and cell motility of Xoo cultured in divided Petri plates. Transmission electron micrograph analysis showed concentration in cytoplasm and altered surface morphology in the majority of Xanthomonas cells after co-cultivation with strain D13. Transcriptional expression of virulence-associated genes in Xoo was repressed. Based on gas chromatography/mass spectrometry (GC/MS) analysis, 12 volatile compounds specifically produced by strain D13 were identified. Among them, decyl alcohol and 3,5,5-trimethylhexanol inhibited the growth of Xoo at minimum inhibitory amounts of 0.48 and 2.4 mg, respectively. Furthermore, transcriptional expression of virulence-associated genes was also repressed by decyl alcohol and 3,5,5-trimethylhexanol. These results are useful for a better understanding of the biocontrol mechanisms of Bacillus.
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Affiliation(s)
- Shanshan Xie
- Department of Plant Pathology, College of Plant ProtectionNanjing Agricultural University, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of EducationNanjing210095China
| | - Haoyu Zang
- Department of Plant Pathology, College of Plant ProtectionNanjing Agricultural University, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of EducationNanjing210095China
| | - Huijun Wu
- Department of Plant Pathology, College of Plant ProtectionNanjing Agricultural University, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of EducationNanjing210095China
| | - Faheem Uddin Rajer
- Department of Plant Pathology, College of Plant ProtectionNanjing Agricultural University, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of EducationNanjing210095China
| | - Xuewen Gao
- Department of Plant Pathology, College of Plant ProtectionNanjing Agricultural University, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of EducationNanjing210095China
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Long J, Song C, Yan F, Zhou J, Zhou H, Yang B. Non-TAL Effectors From Xanthomonas oryzae pv. oryzae Suppress Peptidoglycan-Triggered MAPK Activation in Rice. FRONTIERS IN PLANT SCIENCE 2018; 9:1857. [PMID: 30631333 PMCID: PMC6315156 DOI: 10.3389/fpls.2018.01857] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 11/30/2018] [Indexed: 05/12/2023]
Abstract
Xanthomonas oryzae pv. oryzae, the causal pathogen of bacterial blight of rice, depends on its type III secretion system and associated effector proteins to grow and colonize the vascular tissues of rice plants. The type III effectors include a family of closely related transcription activator-like (TAL) effectors and the rest of diverse effectors, so-called non-TAL effectors. Our understanding of non-TAL effectors for pathogenesis in rice blight is still limited. Here we report a feasible method to rapidly detect the activation of mitogen-activated protein kinase pathway in rice mesophyll protoplasts by the X. oryzae pv. oryzae derived peptidoglycan and screen for virulent effectors that can suppress the pathogen-associated molecular pattern triggered immunity (PTI) response. Amongst 17 non-TAL effectors transiently expressed in rice cells, we found that three effectors (XopZ, XopN, and XopV) were able to suppress the peptidoglycan-triggered MAPK activation. The triple mutant of the X. oryzae pv. oryzae strain PXO99A lacking XopZ, XopN, and XopV showed additively reduced virulence. Adding back either of genes restored the virulence of the triple mutant. Our results demonstrate the collective and redundant ability of defense suppression by non-TAL effectors in causing bacterial blight of rice.
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Affiliation(s)
- Juying Long
- Key Laboratory of Monitoring and Management of Plant Diseases and Insects, Ministry of Education, Nanjing Agricultural University, Nanjing, China
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA, United States
| | - Congfeng Song
- Key Laboratory of Monitoring and Management of Plant Diseases and Insects, Ministry of Education, Nanjing Agricultural University, Nanjing, China
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA, United States
| | - Fang Yan
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Junhui Zhou
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA, United States
| | - Huanbin Zhou
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- *Correspondence: Huanbin Zhou, Bing Yang,
| | - Bing Yang
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA, United States
- Division of Plant Sciences, University of Missouri, Columbia, MO, United States
- Donald Danforth Plant Science Center, St. Louis, MO, United States
- *Correspondence: Huanbin Zhou, Bing Yang,
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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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Cui H, Wang C, Qin T, Xu F, Tang Y, Gao Y, Zhao K. Promoter variants of Xa23 alleles affect bacterial blight resistance and evolutionary pattern. PLoS One 2017; 12:e0185925. [PMID: 28982185 PMCID: PMC5628896 DOI: 10.1371/journal.pone.0185925] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 09/21/2017] [Indexed: 01/18/2023] Open
Abstract
Bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo), is the most important bacterial disease in rice (Oryza sativa L.). Our previous studies have revealed that the bacterial blight resistance gene Xa23 from wild rice O. rufipogon Griff. confers the broadest-spectrum resistance against all the naturally occurring Xoo races. As a novel executor R gene, Xa23 is transcriptionally activated by the bacterial avirulence (Avr) protein AvrXa23 via binding to a 28-bp DNA element (EBEAvrXa23) in the promoter region. So far, the evolutionary mechanism of Xa23 remains to be illustrated. Here, a rice germplasm collection of 97 accessions, including 29 rice cultivars (indica and japonica) and 68 wild relatives, was used to analyze the evolution, phylogeographic relationship and association of Xa23 alleles with bacterial blight resistance. All the ~ 473 bp DNA fragments consisting of promoter and coding regions of Xa23 alleles in the germplasm accessions were PCR-amplified and sequenced, and nine single nucleotide polymorphisms (SNPs) were detected in the promoter regions (~131 bp sequence upstream from the start codon ATG) of Xa23/xa23 alleles while only two SNPs were found in the coding regions. The SNPs in the promoter regions formed 5 haplotypes (Pro-A, B, C, D, E) which showed no significant difference in geographic distribution among these 97 rice accessions. However, haplotype association analysis indicated that Pro-A is the most favored haplotype for bacterial blight resistance. Moreover, SNP changes among the 5 haplotypes mostly located in the EBE/ebe regions (EBEAvrXa23 and corresponding ebes located in promoters of xa23 alleles), confirming that the EBE region is the key factor to confer bacterial blight resistance by altering gene expression. Polymorphism analysis and neutral test implied that Xa23 had undergone a bottleneck effect, and selection process of Xa23 was not detected in cultivated rice. In addition, the Xa23 coding region was found highly conserved in the Oryza genus but absent in other plant species by searching the plant database, suggesting that Xa23 originated along with the diversification of the Oryza genus from the grass family during evolution. This research offers a potential for flexible use of novel Xa23 alleles in rice breeding programs and provide a model for evolution analysis of other executor R genes.
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Affiliation(s)
- Hua Cui
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Institute of Crop Science, Chinese Academy of Agriculture Sciences (CAAS), Beijing, China
| | - Chunlian Wang
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Institute of Crop Science, Chinese Academy of Agriculture Sciences (CAAS), Beijing, China
| | - Tengfei Qin
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Institute of Crop Science, Chinese Academy of Agriculture Sciences (CAAS), Beijing, China
| | - Feifei Xu
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Institute of Crop Science, Chinese Academy of Agriculture Sciences (CAAS), Beijing, China
| | - Yongchao Tang
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Institute of Crop Science, Chinese Academy of Agriculture Sciences (CAAS), Beijing, China
| | - Ying Gao
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Institute of Crop Science, Chinese Academy of Agriculture Sciences (CAAS), Beijing, China
| | - Kaijun Zhao
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Institute of Crop Science, Chinese Academy of Agriculture Sciences (CAAS), Beijing, China
- * E-mail:
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Synthesis and biological evaluation of pyridinium-functionalized carbazole derivatives as promising antibacterial agents. Bioorg Med Chem Lett 2017; 27:4294-4297. [PMID: 28843708 DOI: 10.1016/j.bmcl.2017.08.040] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 08/15/2017] [Accepted: 08/17/2017] [Indexed: 11/21/2022]
Abstract
Various pyridinium-functionalized carbazole derivatives were constructed by coupling the key fragments of carbazole skeleton and pyridinium nucleus in a single molecular architecture. Antibacterial bioassays revealed that some of the title compounds displayed impressive bioactivities against plant pathogens such as Xanthomonas oryzae pv. oryzae, Ralstonia solanacearum, and Xanthomonas axonopodis pv. citri with minimal EC50 values of up to 0.4, 0.3, and 0.3mg/L, respectively. These bioactivities were achieved by systematically tuning and optimizing bridging linker, alkyl length of the tailor, and substituents on the carbazole scaffold. Compared with the bioactivity of the lead compound (AP-10), antibacterial efficacy dramatically increased by approximately 13-, 104- and 21-fold. This finding suggested that these compounds can serve as new lead compounds in research on antibacterial chemotherapy.
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Yu C, Chen H, Tian F, Yang F, He C. RpoN2- and FliA-regulated fliTX is indispensible for flagellar motility and virulence in Xanthomonas oryzae pv. oryzae. BMC Microbiol 2017; 17:171. [PMID: 28793882 PMCID: PMC5550985 DOI: 10.1186/s12866-017-1083-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 08/02/2017] [Indexed: 12/26/2022] Open
Abstract
Background Bacterial blight of rice caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most important crop diseases in the world. More insights into the mechanistic regulation of bacterial pathogenesis will help us identify novel molecular targets for developing effective disease control strategies. A large flagellar gene cluster is regulated under a three-tiered hierarchy by σ54 factor RpoN2 and its activator FleQ, and σ28 factor FliA. A hypothetical protein gene fliTX is located upstream of rpoN2, however, how it is regulated and how it is related to bacterial behaviors remain to be elucidated. Results Sequence alignment analysis indicated that FliTX in Xoo is less well conserved compared with FliT proteins in Escherichia coli, Salmonella typhimurium, and Pseudomonas fluorescens. Co-transcription of fliTX with a cytosolic chaperone gene fliS and an atypical PilZ-domain gene flgZ in an operon was up-regulated by RpoN2/FleQ and FliA. Significantly shorter filament length and impaired swimming motility were observed in ∆fliTX compared with those in the wildtype strain. ∆fliTX also demonstrated reduced disease lesion length and in planta growth in rice, attenuated ability of induction of hypersensitive response (HR) in nonhost tobacco, and down-regulation of type III secretion system (T3SS)-related genes. In trans expression of fliTX gene in ∆fliTX restored these phenotypes to near wild-type levels. Conclusions This study demonstrates that RpoN2- and FliA-regulated fliTX is indispensible for flagellar motility and virulence and provides more insights into mechanistic regulation of T3SS expression in Xoo. Electronic supplementary material The online version of this article (doi:10.1186/s12866-017-1083-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- 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
| | - Fenghuan Yang
- 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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Zhang J, Huguet ‐Tapia JC, Hu Y, Jones J, Wang N, Liu S, White FF. Homologues of CsLOB1 in citrus function as disease susceptibility genes in citrus canker. MOLECULAR PLANT PATHOLOGY 2017; 18:798-810. [PMID: 27276658 PMCID: PMC6638217 DOI: 10.1111/mpp.12441] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 05/01/2016] [Accepted: 06/05/2016] [Indexed: 05/06/2023]
Abstract
The lateral organ boundary domain (LBD) genes encode a group of plant-specific proteins that function as transcription factors in the regulation of plant growth and development. Citrus sinensis lateral organ boundary 1 (CsLOB1) is a member of the LBD family and functions as a disease susceptibility gene in citrus bacterial canker (CBC). Thirty-four LBD members have been identified from the Citrus sinensis genome. We assessed the potential for additional members of LBD genes in citrus to function as surrogates for CsLOB1 in CBC, and compared host gene expression on induction of different LBD genes. Using custom-designed transcription activator-like (TAL) effectors, two members of the same clade as CsLOB1, named CsLOB2 and CsLOB3, were found to be capable of functioning similarly to CsLOB1 in CBC. RNA sequencing and quantitative reverse transcription-polymerase chain reaction analyses revealed a set of cell wall metabolic genes that are associated with CsLOB1, CsLOB2 and CsLOB3 expression and may represent downstream genes involved in CBC.
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Affiliation(s)
- Junli Zhang
- Department of Plant PathologyUniversity of FloridaGainesvilleFLUSA 32611
| | | | - Yang Hu
- Department of Plant PathologyUniversity of FloridaGainesvilleFLUSA 32611
- Present address:
Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijingChina 100101
| | - Jeffrey Jones
- Department of Plant PathologyUniversity of FloridaGainesvilleFLUSA 32611
| | - Nian Wang
- Citrus Research and Education Center/Department of Microbiology and Cell ScienceUniversity of FloridaLake AlfredFLUSA 33850
| | - Sanzhen Liu
- Department of Plant PathologyKansas State UniversityManhattanKSUSA 66506
| | - Frank F. White
- Department of Plant PathologyUniversity of FloridaGainesvilleFLUSA 32611
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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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Wang PY, Shao WB, Xue HT, Fang HS, Zhou J, Wu ZB, Song BA, Yang S. Synthesis of novel 1,3,4-oxadiazole derivatives containing diamides as promising antibacterial and antiviral agents. RESEARCH ON CHEMICAL INTERMEDIATES 2017. [DOI: 10.1007/s11164-017-2980-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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47
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Wang J, Tian D, Gu K, Yang X, Wang L, Zeng X, Yin Z. Induction of Xa10-like Genes in Rice Cultivar Nipponbare Confers Disease Resistance to Rice Bacterial Blight. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2017; 30:466-477. [PMID: 28304228 DOI: 10.1094/mpmi-11-16-0229-r] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Bacterial blight of rice, caused by Xanthomonas oryzae pv. oryzae, is one of the most destructive bacterial diseases throughout the major rice-growing regions in the world. The rice disease resistance (R) gene Xa10 confers race-specific disease resistance to X. oryzae pv. oryzae strains that deliver the corresponding transcription activator-like (TAL) effector AvrXa10. Upon bacterial infection, AvrXa10 binds specifically to the effector binding element in the promoter of the R gene and activates its expression. Xa10 encodes an executor R protein that triggers hypersensitive response and activates disease resistance. 'Nipponbare' rice carries two Xa10-like genes in its genome, of which one is the susceptible allele of the Xa23 gene, a Xa10-like TAL effector-dependent executor R gene isolated recently from 'CBB23' rice. However, the function of the two Xa10-like genes in disease resistance to X. oryzae pv. oryzae strains has not been investigated. Here, we designated the two Xa10-like genes as Xa10-Ni and Xa23-Ni and characterized their function for disease resistance to rice bacterial blight. Both Xa10-Ni and Xa23-Ni provided disease resistance to X. oryzae pv. oryzae strains that deliver the matching artificially designed TAL effectors (dTALE). Transgenic rice plants containing Xa10-Ni and Xa23-Ni under the Xa10 promoter provided specific disease resistance to X. oryzae pv. oryzae strains that deliver AvrXa10. Xa10-Ni and Xa23-Ni knock-out mutants abolished dTALE-dependent disease resistance to X. oryzae pv. oryzae. Heterologous expression of Xa10-Ni and Xa23-Ni in Nicotiana benthamiana triggered cell death. The 19-amino-acid residues at the N-terminal regions of XA10 or XA10-Ni are dispensable for their function in inducing cell death in N. benthamiana and the C-terminal regions of XA10, XA10-Ni, and XA23-Ni are interchangeable among each other without affecting their function. Like XA10, both XA10-Ni and XA23-Ni locate to the endoplasmic reticulum (ER) membrane, show self-interaction, and induce ER Ca2+ depletion in leaf cells of N. benthamiana. The results indicate that Xa10-Ni and Xa23-Ni in Nipponbare encode functional executor R proteins, which induce cell death in both monocotyledonous and dicotyledonous plants and have the potential of being engineered to provide broad-spectrum disease resistance to plant-pathogenic Xanthomonas spp.
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Affiliation(s)
- Jun Wang
- 1 Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Republic of Singapore; and
- 2 Department of Biological Sciences, 14 Science Drive, National University of Singapore, Singapore 117543, Republic of Singapore
| | - Dongsheng Tian
- 1 Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Republic of Singapore; and
| | - Keyu Gu
- 1 Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Republic of Singapore; and
| | - Xiaobei Yang
- 1 Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Republic of Singapore; and
| | - Lanlan Wang
- 1 Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Republic of Singapore; and
| | - Xuan Zeng
- 1 Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Republic of Singapore; and
| | - Zhongchao Yin
- 1 Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Republic of Singapore; and
- 2 Department of Biological Sciences, 14 Science Drive, National University of Singapore, Singapore 117543, Republic of Singapore
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48
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Cuculis L, Schroeder CM. A Single-Molecule View of Genome Editing Proteins: Biophysical Mechanisms for TALEs and CRISPR/Cas9. Annu Rev Chem Biomol Eng 2017; 8:577-597. [PMID: 28489428 DOI: 10.1146/annurev-chembioeng-060816-101603] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Exciting new advances in genome engineering have unlocked the potential to radically alter the treatment of human disease. In this review, we discuss the application of single-molecule techniques to uncover the mechanisms behind two premier classes of genome editing proteins: transcription activator-like effector nucleases (TALENs) and the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated system (Cas). These technologies have facilitated a striking number of gene editing applications in a variety of organisms; however, we are only beginning to understand the molecular mechanisms governing the DNA editing properties of these systems. Here, we discuss the DNA search and recognition process for TALEs and Cas9 that have been revealed by recent single-molecule experiments.
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Affiliation(s)
- Luke Cuculis
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801;
| | - Charles M Schroeder
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801; .,Department of Chemical & Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
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49
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Blanvillain‐Baufumé S, Reschke M, Solé M, Auguy F, Doucoure H, Szurek B, Meynard D, Portefaix M, Cunnac S, Guiderdoni E, Boch J, Koebnik R. Targeted promoter editing for rice resistance to Xanthomonas oryzae pv. oryzae reveals differential activities for SWEET14-inducing TAL effectors. PLANT BIOTECHNOLOGY JOURNAL 2017; 15:306-317. [PMID: 27539813 PMCID: PMC5316920 DOI: 10.1111/pbi.12613] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 08/12/2016] [Accepted: 08/12/2016] [Indexed: 05/04/2023]
Abstract
As a key virulence strategy to cause bacterial leaf blight, Xanthomonas oryzae pv. oryzae (Xoo) injects into the plant cell DNA-binding proteins called transcription activator-like effectors (TALEs) that bind to effector-binding elements (EBEs) in a sequence-specific manner, resulting in host gene induction. TALEs AvrXa7, PthXo3, TalC and Tal5, found in geographically distant Xoo strains, all target OsSWEET14, thus considered as a pivotal TALE target acting as major susceptibility factor during rice-Xoo interactions. Here, we report the generation of an allele library of the OsSWEET14 promoter through stable expression of TALE-nuclease (TALEN) constructs in rice. The susceptibility level of lines carrying mutations in AvrXa7, Tal5 or TalC EBEs was assessed. Plants edited in AvrXa7 or Tal5 EBEs were resistant to bacterial strains relying on the corresponding TALE. Surprisingly, although indels within TalC EBE prevented OsSWEET14 induction in response to BAI3 wild-type bacteria relying on TalC, loss of TalC responsiveness failed to confer resistance to this strain. The TalC EBE mutant line was, however, resistant to a strain expressing an artificial SWEET14-inducing TALE whose EBE was also edited in this line. This work offers the first set of alleles edited in TalC EBE and uncovers a distinct, broader range of activities for TalC compared to AvrXa7 or Tal5. We propose the existence of additional targets for TalC beyond SWEET14, suggesting that TALE-mediated plant susceptibility may result from induction of several, genetically redundant, host susceptibility genes by a single effector.
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Affiliation(s)
- Servane Blanvillain‐Baufumé
- UMR Interactions Plantes Microorganismes Environnement (IPME)IRD‐CIRAD‐UniversitéMontpellierFrance
- Present address: LabEx CeMEBUniversité de MontpellierMontpellierFrance
| | - Maik Reschke
- Institut für BiologieInstitutsbereich GenetikMartin‐Luther‐Universität Halle‐WittenbergHalle (Saale)Germany
- Present address: Institut für PflanzengenetikLeibniz Universität HannoverHannoverGermany
| | - Montserrat Solé
- Institut für BiologieInstitutsbereich GenetikMartin‐Luther‐Universität Halle‐WittenbergHalle (Saale)Germany
- Present address: Sustainable Agro Solutions S.A.Almacelles (Lleida)Spain
| | - Florence Auguy
- UMR Interactions Plantes Microorganismes Environnement (IPME)IRD‐CIRAD‐UniversitéMontpellierFrance
| | - Hinda Doucoure
- UMR Interactions Plantes Microorganismes Environnement (IPME)IRD‐CIRAD‐UniversitéMontpellierFrance
| | - Boris Szurek
- UMR Interactions Plantes Microorganismes Environnement (IPME)IRD‐CIRAD‐UniversitéMontpellierFrance
| | - Donaldo Meynard
- CIRADUMR AGAP (Amélioration génétique et Adaptation des Plantes)MontpellierFrance
| | - Murielle Portefaix
- CIRADUMR AGAP (Amélioration génétique et Adaptation des Plantes)MontpellierFrance
| | - Sébastien Cunnac
- UMR Interactions Plantes Microorganismes Environnement (IPME)IRD‐CIRAD‐UniversitéMontpellierFrance
| | - Emmanuel Guiderdoni
- CIRADUMR AGAP (Amélioration génétique et Adaptation des Plantes)MontpellierFrance
| | - Jens Boch
- Institut für BiologieInstitutsbereich GenetikMartin‐Luther‐Universität Halle‐WittenbergHalle (Saale)Germany
- Present address: Institut für PflanzengenetikLeibniz Universität HannoverHannoverGermany
| | - Ralf Koebnik
- UMR Interactions Plantes Microorganismes Environnement (IPME)IRD‐CIRAD‐UniversitéMontpellierFrance
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50
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Li L, Li RF, Ming ZH, Lu GT, Tang JL. Identification of a novel type III secretion-associated outer membrane-bound protein from Xanthomonas campestris pv. campestris. Sci Rep 2017; 7:42724. [PMID: 28198457 PMCID: PMC5309889 DOI: 10.1038/srep42724] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 01/13/2017] [Indexed: 12/31/2022] Open
Abstract
Many bacterial pathogens employ the type III secretion system (T3SS) to translocate effector proteins into eukaryotic cells to overcome host defenses. To date, most of our knowledge about the T3SS molecular architecture comes from the studies on animal pathogens. In plant pathogens, nine Hrc proteins are believed to be structural components of the T3SS, of which HrcC and HrcJ form the outer and inner rings of the T3SS, respectively. Here, we demonstrated that a novel outer membrane-bound protein (HpaM) of Xanthomonas campestris pv. campestris is critical for the type III secretion and is structurally and functionally conserved in phytopathogenic Xanthomonas spp. We showed that the C-terminus of HpaM extends into the periplasm to interact physically with HrcJ and the middle part of HpaM interacts physically with HrcC. It is clear that the outer and inner rings compose the main basal body of the T3SS apparatus in animal pathogens. Therefore, we presume that HpaM may act as a T3SS structural component, or play a role in assisting assembling or affecting the stability of the T3SS apparatus. HpaM is a highly prevalent and specific protein in Xanthomonas spp., suggesting that the T3SS of Xanthomonas is distinctive in some aspects from other pathogens.
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Affiliation(s)
- Lei Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, China
| | - Rui-Fang Li
- Guangxi Key Laboratory of Biology for Crop Diseases and Insect Pests, Plant Protection Research Institute, Guangxi Academy of Agricultural Sciences, 174 Daxue Road, Nanning, Guangxi 530007, China
| | - Zhen-Hua Ming
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, China
| | - Guang-Tao Lu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, China
| | - Ji-Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, China
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