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Zhang S, Kan J, Liu X, Wu Y, Zhang M, Ou J, Wang J, An L, Li D, Wang L, Wang X, Fang R, Jia Y. Phytopathogenic bacteria utilize host glucose as a signal to stimulate virulence through LuxR homologues. MOLECULAR PLANT PATHOLOGY 2023; 24:359-373. [PMID: 36762904 PMCID: PMC10013830 DOI: 10.1111/mpp.13302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 12/17/2022] [Accepted: 01/14/2023] [Indexed: 06/18/2023]
Abstract
Chemical signal-mediated biological communication is common within bacteria and between bacteria and their hosts. Many plant-associated bacteria respond to unknown plant compounds to regulate bacterial gene expression. However, the nature of the plant compounds that mediate such interkingdom communication and the underlying mechanisms remain poorly characterized. Xanthomonas campestris pv. campestris (Xcc) causes black rot disease on brassica vegetables. Xcc contains an orphan LuxR regulator (XccR) which senses a plant signal that was validated to be glucose by HPLC-MS. The glucose concentration increases in apoplast fluid after Xcc infection, which is caused by the enhanced activity of plant sugar transporters translocating sugar and cell-wall invertases releasing glucose from sucrose. XccR recruits glucose, but not fructose, sucrose, glucose 6-phosphate, and UDP-glucose, to activate pip expression. Deletion of the bacterial glucose transporter gene sglT impaired pathogen virulence and pip expression. Structural prediction showed that the N-terminal domain of XccR forms an alternative pocket neighbouring the AHL-binding pocket for glucose docking. Substitution of three residues affecting structural stability abolished the ability of XccR to bind to the luxXc box in the pip promoter. Several other XccR homologues from plant-associated bacteria can also form stable complexes with glucose, indicating that glucose may function as a common signal molecule for pathogen-plant interactions. The conservation of a glucose/XccR/pip-like system in plant-associated bacteria suggests that some phytopathogens have evolved the ability to utilize host compounds as virulence signals, indicating that LuxRs mediate an interkingdom signalling circuit.
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Affiliation(s)
- Siyuan Zhang
- State Key Laboratory of Plant GenomicsInstitute of Microbiology, Chinese Academy of SciencesBeijingChina
- University of Chinese Academy of SciencesBeijingChina
| | - Jinhong Kan
- State Key Laboratory of Plant GenomicsInstitute of Microbiology, Chinese Academy of SciencesBeijingChina
- University of Chinese Academy of SciencesBeijingChina
- Present address:
Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS)BeijingChina
| | - Xin Liu
- State Key Laboratory of Plant Genomics, Collaborative Innovation Center of Genetics and DevelopmentInstitute of Genetics and Developmental Biology, Chinese Academy of SciencesBeijingChina
| | - Yao Wu
- State Key Laboratory of Plant GenomicsInstitute of Microbiology, Chinese Academy of SciencesBeijingChina
| | - Mingyang Zhang
- State Key Laboratory of Plant GenomicsInstitute of Microbiology, Chinese Academy of SciencesBeijingChina
| | - Jinqing Ou
- State Key Laboratory of Plant GenomicsInstitute of Microbiology, Chinese Academy of SciencesBeijingChina
- University of Chinese Academy of SciencesBeijingChina
| | - Juan Wang
- State Key Laboratory of Plant GenomicsInstitute of Microbiology, Chinese Academy of SciencesBeijingChina
| | - Lin An
- State Key Laboratory of Plant GenomicsInstitute of Microbiology, Chinese Academy of SciencesBeijingChina
| | - Defeng Li
- State Key Laboratory of Plant GenomicsInstitute of Microbiology, Chinese Academy of SciencesBeijingChina
| | - Li Wang
- State Key Laboratory of Plant GenomicsInstitute of Microbiology, Chinese Academy of SciencesBeijingChina
| | - Xiu‐Jie Wang
- State Key Laboratory of Plant Genomics, Collaborative Innovation Center of Genetics and DevelopmentInstitute of Genetics and Developmental Biology, Chinese Academy of SciencesBeijingChina
| | - Rongxiang Fang
- State Key Laboratory of Plant GenomicsInstitute of Microbiology, Chinese Academy of SciencesBeijingChina
| | - Yantao Jia
- State Key Laboratory of Plant GenomicsInstitute of Microbiology, Chinese Academy of SciencesBeijingChina
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Tarchevsky IA, Egorova AM. Participation of Proline in Plant Adaptation to Stress Factors and Its Application in Agrobiotechnology (Review). APPL BIOCHEM MICRO+ 2022. [DOI: 10.1134/s0003683822040160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Bhakta S, Tak H, Ganapathi TR. Exploring diverse roles of micro RNAs in banana: Current status and future prospective. PHYSIOLOGIA PLANTARUM 2021; 173:1323-1334. [PMID: 33305854 DOI: 10.1111/ppl.13311] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 11/17/2020] [Accepted: 12/03/2020] [Indexed: 06/12/2023]
Abstract
Micro RNAs (miRNAs) are 20-24 nucleotides long non-coding RNA sequences identified and characterized in multiple plant and animal systems. miRNAs play multifarious roles ranging from plant development to stress tolerance by synchronizing physiological processes at the level of transcription and translation. Banana is a major horticultural crop with colossal production worldwide. Despite the recent encouraging developments, the information on functions of miRNAs in banana plants is still in its infancy. The available literature pertaining to miRNAs in banana plants hints towards their contribution as master regulators in crucial physiological processes for instance abiotic stress responses, pathogenic defence response, fruit ripening and so on. This review is focused on biogenesis of miRNAs, their identification and deciphering their respective roles in banana plants with special emphasis on abiotic stress responses, plant immune responses, fruit ripening and storage. Based on the prior reports, we identified a few miRNAs with prospective roles in stress tolerance and illustrated the potential applications of miRNAs in banana crop improvement utilizing recent biotechnological tools such as CRISPR cas9, RNAi and the nano particle based foliar spray of miRNAs. The review briefly explained the future directions in banana research with a special emphasis on miRNA regulatory networks and agronomic traits improvement. Finally, future domains in miRNA research in plants and their possible applications towards crop improvement in agriculture are described briefly.
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Affiliation(s)
- Subham Bhakta
- Plant Cell Culture Technology Section, Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai, India
| | - Himanshu Tak
- Plant Cell Culture Technology Section, Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai, India
| | - Thumballi R Ganapathi
- Plant Cell Culture Technology Section, Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai, India
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Feng L, Schaefer AL, Hu M, Chen R, Greenberg EP, Zhou J. Virulence Factor Identification in the Banana Pathogen Dickeya zeae MS2. Appl Environ Microbiol 2019; 85:e01611-19. [PMID: 31540986 PMCID: PMC6856320 DOI: 10.1128/aem.01611-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 09/16/2019] [Indexed: 11/20/2022] Open
Abstract
The phytopathogen Dickeya zeae MS2 is a particularly virulent agent of banana soft rot disease. To begin to understand this banana disease and to understand the role of quorum sensing and quorum-sensing-related regulatory elements in D. zeae MS2, we sequenced its genome and queried the sequence for genes encoding LuxR homologs. We identified a canonical LuxR-LuxI homolog pair similar to those in other members of the genus Dickeya The quorum-sensing signal for this pair was N-3-oxo-hexanoyl-homoserine lactone, and the circuit affected motility, cell clumping, and production of the pigment indigoidine, but it did not affect infections of banana seedlings in our experiments. We also identified a luxR homolog linked to a gene annotated as encoding a proline iminopeptidase. Similar linked pairs have been associated with virulence in other plant pathogens. We show that mutants with deletions in the proline iminopeptidase gene are attenuated for virulence. Surprisingly, a mutant with a deletion in the gene encoding the LuxR homolog shows normal virulence.IMPORTANCEDickeya zeae is an emerging banana soft rot pathogen in China. We used genome sequencing and annotation to create an inventory of potential virulence factors and virulence gene regulators encoded in Dickeya zeae MS2, a particularly virulent strain. We created mutations in several genes and tested these mutants in a banana seedling infection model. A strain with a mutated proline iminopeptidase gene, homologs of which are important for disease in the Xanthomonas species phytopathogens, was attenuated for soft rot symptoms in our model. Understanding how the proline iminopeptidase functions as a virulence factor may lead to insights about how to control the disease, and it is of general importance as homologs of the proline iminopeptidase occur in dozens of plant-associated bacteria.
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Affiliation(s)
- Luwen Feng
- Guangdong Province Sociomicrobiology Basic Science and Frontier Technology Research Team & Integrative Microbiology Research Center, South China Agricultural University, Guangzhou, People's Republic of China
| | - Amy L Schaefer
- Department of Microbiology, University of Washington, Seattle, Washington, USA
| | - Ming Hu
- Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, People's Republic of China
| | - Ruiyi Chen
- Guangdong Province Sociomicrobiology Basic Science and Frontier Technology Research Team & Integrative Microbiology Research Center, South China Agricultural University, Guangzhou, People's Republic of China
| | - E Peter Greenberg
- Guangdong Province Sociomicrobiology Basic Science and Frontier Technology Research Team & Integrative Microbiology Research Center, South China Agricultural University, Guangzhou, People's Republic of China
- Department of Microbiology, University of Washington, Seattle, Washington, USA
| | - Jianuan Zhou
- Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, People's Republic of China
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Zhang D, Tian C, Yin K, Wang W, Qiu JL. Postinvasive Bacterial Resistance Conferred by Open Stomata in Rice. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:255-266. [PMID: 30124364 DOI: 10.1094/mpmi-06-18-0162-r] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Stomata are leaf pores that regulate gas exchange and water transpiration in response to environmental cues. They also function in innate immunity by limiting pathogen entry through actively closing in so-called stomatal defense. However, roles of stomata in plant disease resistance are not fully elucidated, especially in monocots. Here, we report that non-race specific resistance of the rice abscisic acid-deficient mutant Osaba1 to Xanthomonas oryzae pv. oryzae is due to increased stomatal conductance. Reducing stomatal conductance in the Osaba1 mutant increases its susceptibility to X. oryzae pv. oryzae. Artificial opening of stomata in wild-type plants leads to enhanced resistance to X. oryzae pv. oryzae. The rice mutant es1-1 with constitutively higher stomatal conductance exhibits strong resistance to X. oryzae pv. oryzae. Additionally, Osaba1 and es1-1 are resistant to X. oryzae pv. oryzicola. The data support that open stomata confer postinvasive resistance against bacterial pathogens in rice, and such resistance probably results from decreased leaf water potential. Our findings reveal a novel role of stomata in plant immunity through modulation of leaf water status, which provides physiological insight into the interactions between plant, pathogen, and environment.
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Affiliation(s)
- Dandan Zhang
- 1 State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; and
- 2 University of Chinese Academy of Sciences, Beijing 100049, China
| | - Caijuan Tian
- 1 State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; and
| | - Kangquan Yin
- 1 State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; and
| | - Wenyi Wang
- 1 State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; and
| | - Jin-Long Qiu
- 1 State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; and
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A plant-responsive bacterial-signaling system senses an ethanolamine derivative. Proc Natl Acad Sci U S A 2018; 115:9785-9790. [PMID: 30190434 DOI: 10.1073/pnas.1809611115] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Certain plant-associated Proteobacteria sense their host environment by detecting an unknown plant signal recognized by a member of a LuxR subfamily of transcription factors. This interkingdom communication is important for both mutualistic and pathogenic interactions. The Populus root endophyte Pseudomonas sp. GM79 possesses such a regulator, named PipR. In a previous study we reported that PipR activates an adjacent gene (pipA) coding for a proline iminopeptidase in response to Populus leaf macerates and peptides and that this activation is dependent on a putative ABC-type transporter [Schaefer AL, et al. (2016) mBio 7:e01101-16]. In this study we identify a chemical derived from ethanolamine that induces PipR activity at picomolar concentrations, and we present evidence that this is the active inducer present in plant leaf macerates. First, a screen of more than 750 compounds indicated ethanolamine was a potent inducer for the PipR-sensing system; however, ethanolamine failed to bind to the periplasmic-binding protein (PBP) required for the signal response. This led us to discover that a specific ethanolamine derivative, N-(2-hydroxyethyl)-2-(2-hydroxyethylamino) acetamide (HEHEAA), binds to the PBP and serves as a potent PipR-dependent inducer. We also show that a compound, which coelutes with HEHEAA in HPLC and induces pipA gene expression in a PipR-dependent manner, can be found in Populus leaf macerates. This work sheds light on how plant-associated bacteria can sense their environment and on the nature of inducers for a family of plant-responsive LuxR-like transcription factors found in plant-associated bacteria.
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Zhang ZC, Zhao M, Xu LD, Niu XN, Qin HP, Li YM, Li ML, Jiang ZW, Yang X, Huang GH, Jiang W, Tang JL, He YQ. Genome-Wide Screening for Novel Candidate Virulence Related Response Regulator Genes in Xanthomonas oryzae pv. oryzicola. Front Microbiol 2018; 9:1789. [PMID: 30131784 PMCID: PMC6090019 DOI: 10.3389/fmicb.2018.01789] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 07/17/2018] [Indexed: 11/13/2022] Open
Abstract
Two-component regulatory system (TCS), a major type of cellular signal transduction system, is widely used by bacteria to adapt to different conditions and to colonize certain ecological niches in response to environmental stimuli. TCSs are of distinct functional diversity, genetic diversity, and species specificity (pathovar specificity, even strain specificity) across bacterial groups. Although TCSs have been demonstrated to be crucial to the virulence of Xanthomonas, only a few researches have been reported about the studies of TCSs in Xanthomonas oryzae pathovar oryzicola (hereafter Xoc), the pathogen of rice bacterial streak disease. In the genome of Xoc strain GX01, it has been annotated 110 TCSs genes encoding 54 response regulators (RRs), 36 orthodox histidine kinase (HKs) and 20 hybrid histidine kinase (HyHKs). To evaluate the involvement of TCSs in the stress adaptation and virulence of Xoc, we mutated 50 annotated RR genes in Xoc GX01 by homologous vector integration mutagenesis and assessed their phenotypes in given conditions and tested their virulence on host rice. 17 RR genes were identified to be likely involved in virulence of Xoc, of which 10 RR genes are novel virulence genes in Xanthomonas, including three novel virulence genes for bacteria. Of the novel candidate virulence genes, some of which may be involved in the general stress adaptation, exopolysaccharide production, extracellular protease secretion and swarming motility of Xoc. Our results will facilitate further studies on revealing the biological functions of TCS genes in this phytopathogenic bacterium.
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Affiliation(s)
- Zheng-Chun Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China.,College of Agronomy, Guangxi University, Nanning, China
| | - Min Zhao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Li-Dan Xu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Xiang-Na Niu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Hong-Ping Qin
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Yi-Ming Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Mei-Lin Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Zhong-Wei Jiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Xia Yang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Guang-Hui Huang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Wei Jiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Ji-Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Yong-Qiang He
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
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Pan Y, Liang F, Li RJ, Qian W. MarR-Family Transcription Factor HpaR Controls Expression of the vgrR-vgrS Operon of Xanthomonas campestris pv. campestris. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2018; 31:299-310. [PMID: 29077520 DOI: 10.1094/mpmi-07-17-0187-r] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
MarR (multiple antibiotic resistance regulator)-family transcription factors (TFs), which regulate the expression of virulence factors and other physiological pathways in pathogenic bacteria, are regarded as ideal molecular targets for the development of novel antimicrobial strategies. In the plant bacterial pathogen Xanthomonas campestris pv. campestris, HpaR, a typical MarR-family TF, is associated with bacterial virulence, but its mechanism of virulence regulation remains unclear. Here, we dissected the HpaR regulon using high-throughput RNA sequencing and chromatin immunoprecipitation sequencing. HpaR directly or indirectly controls the expression of approximately 448 genes; it acts both as a transcriptional activator and a repressor to control the expression of downstream genes by directly binding to their promoter regions. The consensus HpaR-binding DNA motifs contain imperfect palindromic sequences similar to [G/T]CAACAATT[C/T]TTG. In-depth analysis revealed that HpaR positively modulates transcription level of the vgrR-vgrS operon that encodes an important two-component signal transduction system to sense iron depletion and regulate bacterial virulence. Epistasis analysis demonstrated that vgrR-vgrS is a core downstream component of HpaR regulation, as overexpression of vgrR restored the phenotypic deficiencies caused by a hpaR mutation. This dissection of the HpaR regulon should facilitate future studies focused on the activating mechanism of HpaR during bacterial infection.
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Affiliation(s)
- Yue Pan
- 1 State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- 2 School of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China; and
| | - Fang Liang
- 3 Beijing Institute of Genomics, Chinese Academy of Sciences
| | - Ru-Jiao Li
- 3 Beijing Institute of Genomics, Chinese Academy of Sciences
| | - Wei Qian
- 1 State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
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Interkingdom signaling in plant-microbe interactions. SCIENCE CHINA-LIFE SCIENCES 2017; 60:785-796. [PMID: 28755299 DOI: 10.1007/s11427-017-9092-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 05/04/2017] [Indexed: 12/18/2022]
Abstract
The widespread communications between prokaryotes and eukaryotes via signaling molecules are believed to affect gene expression in both partners. During the communication process, the contacted organisms produce and release small molecules that establish communication channels between two kingdoms-this procedure is known as interkingdom signaling. Interkingdom communications are widespread between pathogenic or beneficial bacteria and their host plants, with diversified outcomes depending on the specific chemical-triggered signaling pathways. Deciphering the signals or language of this interkingdom communication and uncovering the underlying mechanisms are major current challenges in this field. It is evident that diverse signaling molecules can be produced or derived from bacteria and plants, and researchers have sought to identify these signals and explore the mechanisms of the signaling pathways. The results of such studies will lead to the development of strategies to improve plant disease resistance through controlling interkingdom signals, rather than directly killing the pathogenic bacteria. Also, the identification of signals produced by beneficial bacteria will be useful for agricultural applications. In this review, we summarize the recent progress of cross-kingdom interactions between plant and bacteria, and how LuxR-family transcription factors in plant associated bacterial quorum sensing system are involved in the interkingdom signaling.
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Chen X, Deng Z, Yu C, Yan C, Chen J. Secretome analysis of rice suspension-cultured cells infected by Xanthomonas oryzae pv.oryza (Xoo). Proteome Sci 2016; 14:2. [PMID: 26839515 PMCID: PMC4735954 DOI: 10.1186/s12953-016-0091-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 01/17/2016] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Rice bacterial blight (BB) caused by Xanthomonas oryzae pv.oryzae (Xoo) is one of the most devastating bacterial diseases in rice-growing regions worldwide. The rice-Xoo interaction is a classical model for studying the interaction between plants and pathogens. Secreted proteins play important roles in plant-bacterial interactions, but are poorly studied in the rice-Xoo system. Rice cv. Nipponbare is highly susceptible to Xoo. Here, we used two-dimensional difference gel electrophoresis (2D-DIGE) coupled with MALDI-TOF/TOF mass spectrometry (MS), to investigate secreted proteins in Nipponbare embryo cell suspension culture infected by Xoo. RESULTS A total of 32 protein spots changed significantly (p < 0.05) by more than 1.5 fold in gel intensity after Xoo inoculation, and were identified by MS. They represent protein products of 11 unique genes, seven from rice and four from Xoo. Of the rice proteins, six up-regulated proteins are involved in cell wall modification, the TCA cycle, glycolysis and redox, while a down-regulated protein, CHIT16, is involved in plant defense. Quantitative Real-Time PCR showed that transcript levels were not correlated with secreted protein levels. Of the Xoo proteins, three of them were possibly located in the extracellular space as shown by transient expression assays in rice protoplasts. Two of the Xoo proteins were previously reported to be likely involved in pathogenicity, and the third gene, Xoo3654, is likely a negative regulator of Xoo virulence as its overexpression reduced Xoo pathogenicity in our study. CONCLUSION Among the secreted proteins that responded to Xoo inoculation, we identified rice proteins involved in cell defense and Xoo proteins involved in pathogenicity. Our study also showed that Xoo3654 (X2) protein is likely a novel negative regulator of Xoo virulence. These results not only help us better understand the interaction between susceptible rice and Xoo, but also serve as a reference for studying the interaction between other plants and their pathogens.
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Affiliation(s)
- Xian Chen
- College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China ; State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, MOA Key Laboratory of Biotechnology in Plant Protection, Zhejiang Provincial Key Laboratory of Plant Virology, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Science, Hangzhou, 310021 China
| | - Zhiping Deng
- State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, MOA Key Laboratory of Biotechnology in Plant Protection, Zhejiang Provincial Key Laboratory of Plant Virology, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Science, Hangzhou, 310021 China
| | - Chulang Yu
- State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, MOA Key Laboratory of Biotechnology in Plant Protection, Zhejiang Provincial Key Laboratory of Plant Virology, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Science, Hangzhou, 310021 China
| | - Chengqi Yan
- State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, MOA Key Laboratory of Biotechnology in Plant Protection, Zhejiang Provincial Key Laboratory of Plant Virology, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Science, Hangzhou, 310021 China
| | - Jianping Chen
- State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, MOA Key Laboratory of Biotechnology in Plant Protection, Zhejiang Provincial Key Laboratory of Plant Virology, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Science, Hangzhou, 310021 China
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Yaryura PM, Conforte VP, Malamud F, Roeschlin R, de Pino V, Castagnaro AP, McCarthy Y, Dow JM, Marano MR, Vojnov AA. XbmR, a new transcription factor involved in the regulation of chemotaxis, biofilm formation and virulence in Xanthomonas citri subsp. citri. Environ Microbiol 2014; 17:4164-76. [PMID: 25346091 DOI: 10.1111/1462-2920.12684] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 10/19/2014] [Indexed: 12/22/2022]
Abstract
Xanthomonas citri subsp. citri (Xcc) is the causal agent of citrus canker. Biofilm formation on citrus leaves plays an important role in epiphytic survival of Xcc. Biofilm formation is affected by transposon insertion in XAC3733, which encodes a transcriptional activator of the NtrC family, not linked to a gene encoding a sensor protein, thus could be considered as an 'orphan' regulator whose function is poorly understood in Xanthomonas spp. Here we show that mutation of XAC3733 (named xbmR) resulted in impaired structural development of the Xcc biofilm, loss of chemotaxis and reduced virulence in grapefruit plants. All defective phenotypes were restored to wild-type levels by the introduction of PA2567 from Pseudomonas aeruginosa, which encodes a phosphodiesterase active in the degradation of cyclic diguanosine monophosphate (c-di-GMP). A knockout of xbmR led to a substantial downregulation of fliA that encodes a σ(28) transcription factor, as well as fliC and XAC0350 which are potential member of the σ(28) regulon. XAC0350 encodes an HD-GYP domain c-di-GMP phosphodiesterase. These findings suggest that XbmR is a key regulator of flagellar-dependent motility and chemotaxis exerting its action through a regulatory pathway that involves FliA and c-di-GMP.
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Affiliation(s)
- Pablo M Yaryura
- Instituto de Ciencia y Tecnología Dr. Cesar Milstein, Fundación Pablo Cassará, CONICET, Saladillo 2468, C1440FFX, Ciudad de Buenos Aires, Argentina
| | - Valeria P Conforte
- Instituto de Ciencia y Tecnología Dr. Cesar Milstein, Fundación Pablo Cassará, CONICET, Saladillo 2468, C1440FFX, Ciudad de Buenos Aires, Argentina
| | - Florencia Malamud
- Instituto de Ciencia y Tecnología Dr. Cesar Milstein, Fundación Pablo Cassará, CONICET, Saladillo 2468, C1440FFX, Ciudad de Buenos Aires, Argentina
| | - Roxana Roeschlin
- Instituto de Biología Molecular y Celular de Rosario (IBR)-Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET). Área Virología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Ocampo y Esmeralda, S2000FHN, Rosario, Argentina
| | - Verónica de Pino
- Instituto de Ciencia y Tecnología Dr. Cesar Milstein, Fundación Pablo Cassará, CONICET, Saladillo 2468, C1440FFX, Ciudad de Buenos Aires, Argentina
| | - Atilio P Castagnaro
- Estación Experimental Agroindustrial Obispo Colombres, Av. William Cross, 3150, Las Talitas, Tucumán, Argentina
| | - Yvonne McCarthy
- School of Microbiology, University College Cork, Cork, Ireland
| | - J Maxwell Dow
- School of Microbiology, University College Cork, Cork, Ireland
| | - María R Marano
- Instituto de Biología Molecular y Celular de Rosario (IBR)-Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET). Área Virología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Ocampo y Esmeralda, S2000FHN, Rosario, Argentina
| | - Adrián A Vojnov
- Instituto de Ciencia y Tecnología Dr. Cesar Milstein, Fundación Pablo Cassará, CONICET, Saladillo 2468, C1440FFX, Ciudad de Buenos Aires, Argentina
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González JF, Myers MP, Venturi V. The inter-kingdom solo OryR regulator of Xanthomonas oryzae is important for motility. MOLECULAR PLANT PATHOLOGY 2013; 14:211-21. [PMID: 23083431 PMCID: PMC6638885 DOI: 10.1111/j.1364-3703.2012.00843.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The LuxR-type transcriptional regulator OryR of the rice pathogen Xanthomonas oryzae pv. oryzae (Xoo) is a member of a subgroup of regulators found in plant-associated bacteria that are known to respond to plant signals. OryR has been shown previously to positively regulate the neighbouring pip gene and to be important for rice virulence. The role of this inter-kingdom signalling regulator was investigated through a genome-wide transcriptome analysis. OryR was found to positively regulate 220 genes, whereas 110 were down-regulated. A significant over-representation of movement-related genes among the positively regulated ones was found, including 30 flagellar genes, accounting for 14% of the up-regulated genes above the two-fold cut-off value. In Xoo, both swimming and swarming respond to rice macerate and OryR plays a role in the induction of both of these types of motility under these conditions. In this study, we have also shown that the flagellar regulator flhF contains a lux box-like element in its promoter region, similar to the oryR-regulated neighbouring pip gene; via the use of a transcriptional fusion reporter, it was shown that flhF is regulated by OryR. Finally, the role of OryR in motility was also demonstrated by the significant reduction in flagellin content in the oryR Xoo mutant with respect to the wild-type, as observed by in planta proteomics studies.
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Affiliation(s)
- Juan F González
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
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González JF, Venturi V. A novel widespread interkingdom signaling circuit. TRENDS IN PLANT SCIENCE 2013; 18:167-74. [PMID: 23089307 DOI: 10.1016/j.tplants.2012.09.007] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 09/14/2012] [Accepted: 09/21/2012] [Indexed: 05/08/2023]
Abstract
Extensive communication is believed to occur between eukaryotes and prokaryotes via signaling molecules; this field of research is now called interkingdom signaling. Recently, it has been discovered that many different plant-associated bacteria possess a protein closely related to the quorum-sensing (QS) LuxR-family protein that binds and responds to plant compounds. This LuxR protein does not have a cognate N-acyl homoserine lactone (AHL) signal synthase and therefore is regarded as a 'solo' or 'orphan'. The protein is involved in interkingdom signaling in rhizobia, xanthomonads, and pseudomonads, regulating processes important for plant-bacteria interaction. In this review, we focus on this new interkingdom signaling circuit, which is widespread among pathogenic and beneficial plant-associated bacteria.
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Affiliation(s)
- Juan F González
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy
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Chatnaparat T, Prathuangwong S, Ionescu M, Lindow SE. XagR, a LuxR homolog, contributes to the virulence of Xanthomonas axonopodis pv. glycines to soybean. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2012; 25:1104-17. [PMID: 22746827 DOI: 10.1094/mpmi-01-12-0008-r] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
A novel luxR homolog, termed XagR, in Xanthomonas axonopodis pv. glycines, the cause of soybean pustule, controls expression of pip, yapH, and at least 77 other genes. Although XagR and Pip are required for full virulence of X. axonopodis pv. glycines to soybean, constitutive overproduction of XagR suppresses infection. The xagR-dependent induction of pip occurs in planta only 2 days or more after inoculation. Although the transcription of xagR appears constitutive, XagR accumulates only in cells that have colonized soybean plants for more than 2 days suggesting that some components produced during the infection process mediate post-transcriptional control, likely by protecting XagR from proteolytic degradation. XagR modulates the adhesiveness of the pathogen during the infection process by suppressing the adhesin YapH. Although yapH mutants incite more infections of soybean leaves than the wild-type strain when topically applied under dry conditions, the mutant causes fewer infections when leaves are subject to simulated rain events after inoculation. Likewise, yapH mutants and cells in which XagR was overexpressed exhibited much more egress from infected leaves than the wild-type strain. Thus, XagR differentially modulates expression of a variety of genes during the infection process in response to feedback from plant molecules elaborated during infection to coordinate processes such as invasion, infection, and cell egress needed to complete the disease cycle.
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