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Ke X, Wu Z, Liu Y, Liang Y, Du M, Li Y. Isolation, Antimicrobial Effect and Metabolite Analysis of Bacillus amyloliquefaciens ZJLMBA1908 against Citrus Canker Caused by Xanthomonas citri subsp. citri. Microorganisms 2023; 11:2928. [PMID: 38138073 PMCID: PMC10746125 DOI: 10.3390/microorganisms11122928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 11/30/2023] [Accepted: 12/04/2023] [Indexed: 12/24/2023] Open
Abstract
Citrus canker caused by Xanthomonas citri subsp. citri is a devastating bacterial disease with severe implications for the citrus industry. Microorganisms possessing biocontrol capabilities against X. citri subsp. citri offer a highly promising strategy for healthy citrus management. In the present study, a broad-spectrum antagonist strain ZJLMBA1908 with potent antibacterial activity against X. citri subsp. citri was isolated from symptomatic lemon leaves, and identified as Bacillus amyloliquefaciens. Cell-free supernatant (CFS) of strain ZJLMBA1908 also exhibited remarkable antimicrobial activity, especially suppressing the growth of X. citri subsp. citri and Nigrospora oryzae, with inhibition rates of 27.71% and 63.75%, respectively. The antibacterial crude extract (CE) derived from the CFS displayed effective activity against X. citri subsp. citri. A preventive treatment using the CE significantly reduced the severity and incidence of citrus canker in a highly susceptible citrus host. Additionally, the CE maintained activity in the presence of protease and under a wide range of temperature and pH treatments. Applying high-performance liquid chromatography (HPLC) to separate and purify the CE resulted in the discovery of one highly potent anti-X. citri subsp. citri subfraction, namely CE3, which could completely inhibit the growth of X. citri subsp. citri. Liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) analysis revealed that CE3 mainly consisted of palmitic acid, surfactin C15, phytosphingosine and dihydrosphingosine. Taken together, the results contribute to the possible biocontrol mechanisms of B. amyloliquefaciens ZJLMBA1908, as well as providing a promising new candidate strain as a biological control agent for controlling citrus canker.
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Affiliation(s)
| | | | | | | | | | - Ya Li
- College of Coastal Agricultural Science, Guangdong Ocean University, Zhanjiang 524088, China; (X.K.); (Z.W.); (Y.L.); (Y.L.); (M.D.)
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Mani T, Joshi JB, Priyadharshini R, Sharmila JS, Uthandi S. Flagellin, a plant-defense-activating protein identified from Xanthomonas axonopodis pv. Dieffenbachiae invokes defense response in tobacco. BMC Microbiol 2023; 23:284. [PMID: 37798635 PMCID: PMC10552369 DOI: 10.1186/s12866-023-03028-z] [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: 03/14/2023] [Accepted: 09/22/2023] [Indexed: 10/07/2023] Open
Abstract
BACKGROUND Secretome analysis is a valuable tool to study host-pathogen protein interactions and to identify new proteins that are important for plant health. Microbial signatures elicit defense responses in plants, and by that, the plant immune system gets triggered prior to pathogen infection. Functional properties of secretory proteins from Xanthomonas axonopodis pv. dieffenbachiae (Xad1) involved in priming plant immunity was evaluated. RESULTS In this study, the secretome of Xad1 was analyzed under host plant extract-induced conditions, and mass spectroscopic analysis of differentially expressed protein was identified as plant-defense-activating protein viz., flagellin C (FliC). The flagellin and Flg22 peptides both elicited hypersensitive reaction (HR) in non-host tobacco, activated reactive oxygen species (ROS) scavenging enzymes, and increased pathogenesis-related (PR) gene expression viz., NPR1, PR1, and down-regulation of PR2 (β-1,3-glucanase). Protein docking studies revealed the Flg22 epitope of Xad1, a 22 amino acid peptide region in FliC that recognizes plant receptor FLS2 to initiate downstream defense signaling. CONCLUSION The flagellin or the Flg22 peptide from Xad1 was efficient in eliciting an HR in tobacco via salicylic acid (SA)-mediated defense signaling that subsequently triggers systemic immune response epigenetically. The insights from this study can be used for the development of bio-based products (small PAMPs) for plant immunity and health.
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Affiliation(s)
- Tamilarasi Mani
- Biocatalysts Laboratory, Department of Agricultural Microbiology, Directorate of Natural Resource Management, Tamil Nadu Agricultural University, Coimbatore, 641 003, India
| | - J Beslin Joshi
- Biocatalysts Laboratory, Department of Agricultural Microbiology, Directorate of Natural Resource Management, Tamil Nadu Agricultural University, Coimbatore, 641 003, India
- Centre for Water Resources Development and Management, Kozhikode, India
| | - R Priyadharshini
- Biocatalysts Laboratory, Department of Agricultural Microbiology, Directorate of Natural Resource Management, Tamil Nadu Agricultural University, Coimbatore, 641 003, India
- Department of Microbiology, Karpagam Academy of Higher Education, Coimbatore, India
| | - Jeya Sundara Sharmila
- Department of Nano Science and Technology, Directorate of Natural Resource Management, Tamil Nadu Agricultural University, Coimbatore, India
| | - Sivakumar Uthandi
- Biocatalysts Laboratory, Department of Agricultural Microbiology, Directorate of Natural Resource Management, Tamil Nadu Agricultural University, Coimbatore, 641 003, India.
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Su Y, Dai S, Li N, Gentile A, He C, Xu J, Duan K, Wang X, Wang B, Li D. Unleashing the Potential of EIL Transcription Factors in Enhancing Sweet Orange Resistance to Bacterial Pathologies: Genome-Wide Identification and Expression Profiling. Int J Mol Sci 2023; 24:12644. [PMID: 37628825 PMCID: PMC10454048 DOI: 10.3390/ijms241612644] [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: 07/10/2023] [Revised: 08/02/2023] [Accepted: 08/05/2023] [Indexed: 08/27/2023] Open
Abstract
The ETHYLENE INSENSITIVE3-LIKE (EIL) family is one of the most important transcription factor (TF) families in plants and is involved in diverse plant physiological and biochemical processes. In this study, ten EIL transcription factors (CsEILs) in sweet orange were systematically characterized via whole-genome analysis. The CsEIL genes were unevenly distributed across the four sweet orange chromosomes. Putative cis-acting regulatory elements (CREs) associated with CsEIL were found to be involved in plant development, as well as responses to biotic and abiotic stress. Notably, quantitative reverse transcription polymerase chain reaction (qRT-PCR) revealed that CsEIL genes were widely expressed in different organs of sweet orange and responded to both high and low temperature, NaCl treatment, and to ethylene-dependent induction of transcription, while eight additionally responded to Xanthomonas citri pv. Citri (Xcc) infection, which causes citrus canker. Among these, CsEIL2, CsEIL5 and CsEIL10 showed pronounced upregulation. Moreover, nine genes exhibited differential expression in response to Candidatus Liberibacter asiaticus (CLas) infection, which causes Citrus Huanglongbing (HLB). The genome-wide characterization and expression profile analysis of CsEIL genes provide insights into the potential functions of the CsEIL family in disease resistance.
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Affiliation(s)
- Yajun Su
- National Citrus Improvement Center, Hunan Agricultural University (Changsha Branch), Changsha 410128, China
- College of Horticulture, Hunan Agricultural University, Changsha 410128, China
- College of Plant Protection, Hunan Agricultural University, Changsha 410128, China (X.W.)
| | - Suming Dai
- National Citrus Improvement Center, Hunan Agricultural University (Changsha Branch), Changsha 410128, China
- College of Horticulture, Hunan Agricultural University, Changsha 410128, China
| | - Na Li
- National Citrus Improvement Center, Hunan Agricultural University (Changsha Branch), Changsha 410128, China
- College of Horticulture, Hunan Agricultural University, Changsha 410128, China
| | - Alessandra Gentile
- Department of Agriculture and Food Science, University of Catania, 95123 Catania, Italy;
| | - Cong He
- National Citrus Improvement Center, Hunan Agricultural University (Changsha Branch), Changsha 410128, China
- College of Horticulture, Hunan Agricultural University, Changsha 410128, China
| | - Jing Xu
- College of Plant Protection, Hunan Agricultural University, Changsha 410128, China (X.W.)
| | - Kangle Duan
- College of Plant Protection, Hunan Agricultural University, Changsha 410128, China (X.W.)
| | - Xue Wang
- College of Plant Protection, Hunan Agricultural University, Changsha 410128, China (X.W.)
| | - Bing Wang
- College of Plant Protection, Hunan Agricultural University, Changsha 410128, China (X.W.)
| | - Dazhi Li
- National Citrus Improvement Center, Hunan Agricultural University (Changsha Branch), Changsha 410128, China
- College of Horticulture, Hunan Agricultural University, Changsha 410128, China
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Xiao M, Hao G, Guo X, Feng L, Lin H, Yang W, Chen Y, Zhao K, Xiang L, Jiang X, Mei D, Hu Q. A high-quality chromosome-level Eutrema salsugineum genome, an extremophile plant model. BMC Genomics 2023; 24:174. [PMID: 37020189 PMCID: PMC10077641 DOI: 10.1186/s12864-023-09256-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 03/20/2023] [Indexed: 04/07/2023] Open
Abstract
BACKGROUND Eutrema salsugineum (2n = 14), a halophyte in the family Brassicaceae, is an attractive model to study abiotic stress tolerance in plants. Two versions of E. salsugineum genomes that previously reported were based on relatively short reads; thus, the repetitive regions were difficult to characterize. RESULTS We report the sequencing and assembly of the E. salsugineum (Shandong accession) genome using long-read sequencing and chromosome conformation capture data. We generated Oxford Nanopore long reads at high depth (> 60X) of genome coverage with additional short reads for error correction. The new assembly has a total size of 295.5 Mb with 52.8% repetitive sequences, and the karyotype of E. salsugineum is consistent with the ancestral translocation Proto-Calepineae Karyotype structure in both order and orientation. Compared with previous assemblies, this assembly has higher contiguity, especially in the centromere region. Based on this new assembly, we predicted 25,399 protein-coding genes and identified the positively selected genes associated with salt and drought stress responses. CONCLUSION The new genome assembly will provide a valuable resource for future genomic studies and facilitate comparative genomic analysis with other plants.
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Grants
- 31700164, 32171606, 31700323 the National Natural Science Foundation of China
- 31700164, 32171606, 31700323 the National Natural Science Foundation of China
- 31700164, 32171606, 31700323 the National Natural Science Foundation of China
- 31700164, 32171606, 31700323 the National Natural Science Foundation of China
- 31700164, 32171606, 31700323 the National Natural Science Foundation of China
- 31700164, 32171606, 31700323 the National Natural Science Foundation of China
- 31700164, 32171606, 31700323 the National Natural Science Foundation of China
- 31700164, 32171606, 31700323 the National Natural Science Foundation of China
- 31700164, 32171606, 31700323 the National Natural Science Foundation of China
- 31700164, 32171606, 31700323 the National Natural Science Foundation of China
- 31700164, 32171606, 31700323 the National Natural Science Foundation of China
- 31700164, 32171606, 31700323 the National Natural Science Foundation of China
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Affiliation(s)
- Meng Xiao
- Key Laboratory for Bio-Resource and Eco-Environment of Ministry of Education & Sichuan Zoige Alpine Wetland Ecosystem National Observation and Research Station, College of Life Science, Sichuan University, Chengdu, China
| | - Guoqian Hao
- Faculty of Agriculture, Forestry and Food Engineering, Yibin University, Yibin, 644007, Sichuan, China
| | - Xinyi Guo
- Key Laboratory for Bio-Resource and Eco-Environment of Ministry of Education & Sichuan Zoige Alpine Wetland Ecosystem National Observation and Research Station, College of Life Science, Sichuan University, Chengdu, China
| | - Landi Feng
- Key Laboratory for Bio-Resource and Eco-Environment of Ministry of Education & Sichuan Zoige Alpine Wetland Ecosystem National Observation and Research Station, College of Life Science, Sichuan University, Chengdu, China
| | - Hao Lin
- Key Laboratory for Bio-Resource and Eco-Environment of Ministry of Education & Sichuan Zoige Alpine Wetland Ecosystem National Observation and Research Station, College of Life Science, Sichuan University, Chengdu, China
| | - Wenjie Yang
- Key Laboratory for Bio-Resource and Eco-Environment of Ministry of Education & Sichuan Zoige Alpine Wetland Ecosystem National Observation and Research Station, College of Life Science, Sichuan University, Chengdu, China
| | - Yanyu Chen
- Key Laboratory for Bio-Resource and Eco-Environment of Ministry of Education & Sichuan Zoige Alpine Wetland Ecosystem National Observation and Research Station, College of Life Science, Sichuan University, Chengdu, China
| | - Kexin Zhao
- Key Laboratory for Bio-Resource and Eco-Environment of Ministry of Education & Sichuan Zoige Alpine Wetland Ecosystem National Observation and Research Station, College of Life Science, Sichuan University, Chengdu, China
| | - Ling Xiang
- Key Laboratory for Bio-Resource and Eco-Environment of Ministry of Education & Sichuan Zoige Alpine Wetland Ecosystem National Observation and Research Station, College of Life Science, Sichuan University, Chengdu, China
| | - Xinyao Jiang
- Key Laboratory for Bio-Resource and Eco-Environment of Ministry of Education & Sichuan Zoige Alpine Wetland Ecosystem National Observation and Research Station, College of Life Science, Sichuan University, Chengdu, China
| | - Dong Mei
- Key Laboratory for Bio-Resource and Eco-Environment of Ministry of Education & Sichuan Zoige Alpine Wetland Ecosystem National Observation and Research Station, College of Life Science, Sichuan University, Chengdu, China
| | - Quanjun Hu
- Key Laboratory for Bio-Resource and Eco-Environment of Ministry of Education & Sichuan Zoige Alpine Wetland Ecosystem National Observation and Research Station, College of Life Science, Sichuan University, Chengdu, China.
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Licciardello G, Caruso P, Bella P, Boyer C, Smith MW, Pruvost O, Robene I, Cubero J, Catara V. Pathotyping Citrus Ornamental Relatives with Xanthomonas citri pv. citri and X. citri pv. aurantifolii Refines Our Understanding of Their Susceptibility to These Pathogens. Microorganisms 2022; 10:microorganisms10050986. [PMID: 35630430 PMCID: PMC9148020 DOI: 10.3390/microorganisms10050986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/01/2022] [Accepted: 05/05/2022] [Indexed: 11/16/2022] Open
Abstract
Xanthomonas citri pv. citri (Xcc) and X. citri pv. aurantifolii (Xca) are causal agents of Citrus Bacterial Canker (CBC), a devastating disease that severely affects citrus plants. They are harmful organisms not reported in Europe or the Mediterranean Basin. Host plants are in the Rutaceae family, including the genera Citrus, Poncirus, and Fortunella, and their hybrids. In addition, other genera of ornamental interest are reported as susceptible, but results are not uniform and sometimes incongruent. We evaluated the susceptibility of 32 ornamental accessions of the Rutaceae family belonging to the genera Citrus, Fortunella, Atalantia, Clausena, Eremocitrus, Glycosmis, Microcitrus, Murraya, Casimiroa, Calodendrum, and Aegle, and three hybrids to seven strains of Xcc and Xca. Pathotyping evaluation was assessed by scoring the symptomatic reactions on detached leaves. High variability in symptoms and bacterial population was shown among the different strains in the different hosts, indicative of complex host–pathogen interactions. The results are mostly consistent with past findings, with the few discrepancies probably due to our more complete experimental approach using multiple strains of the pathogen and multiple hosts. Our work supports the need to regulate non-citrus Rutaceae plant introductions into areas, like the EU and Mediterranean, that are currently free of this economically important pathogen.
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Affiliation(s)
- Grazia Licciardello
- Dipartimento di Agricoltura Alimentazione e Ambiente, Università degli Studi di Catania, 95130 Catania, Italy;
- Centro di Ricerca Olivicoltura, Frutticoltura e Agrumicoltura-Consiglio per la Ricerca in Agricoltura e L’analisi Dell’Economia Agraria (CREA), 95024 Acireale, Italy;
| | - Paola Caruso
- Centro di Ricerca Olivicoltura, Frutticoltura e Agrumicoltura-Consiglio per la Ricerca in Agricoltura e L’analisi Dell’Economia Agraria (CREA), 95024 Acireale, Italy;
| | - Patrizia Bella
- Dipartimento di Scienze Agrarie, Alimentari e Forestali, Università degli Studi di Palermo, 90128 Palermo, Italy;
| | - Claudine Boyer
- CIRAD, UMR Peuplements Végétaux et Bioagresseurs en Milieu Tropical (PVBMT), 97410 Saint Pierre, La Réunion, France; (C.B.); (O.P.); (I.R.)
| | - Malcolm W. Smith
- Department of Agriculture & Fisheries, Bundaberg Research Station, Bundaberg, QLD 4670, Australia;
| | - Olivier Pruvost
- CIRAD, UMR Peuplements Végétaux et Bioagresseurs en Milieu Tropical (PVBMT), 97410 Saint Pierre, La Réunion, France; (C.B.); (O.P.); (I.R.)
| | - Isabelle Robene
- CIRAD, UMR Peuplements Végétaux et Bioagresseurs en Milieu Tropical (PVBMT), 97410 Saint Pierre, La Réunion, France; (C.B.); (O.P.); (I.R.)
| | - Jaime Cubero
- Departamento de Protección Vegetal, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria/Consejo Superior de Investigaciones Científicas, 28040 Madrid, Spain;
| | - Vittoria Catara
- Dipartimento di Agricoltura Alimentazione e Ambiente, Università degli Studi di Catania, 95130 Catania, Italy;
- Correspondence: ; Tel.: +39-095-714-7370
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Wang W, Li T, Chen Q, Yao S, Deng L, Zeng K. CsWRKY25 Improves Resistance of Citrus Fruit to Penicillium digitatum via Modulating Reactive Oxygen Species Production. FRONTIERS IN PLANT SCIENCE 2022; 12:818198. [PMID: 35082819 PMCID: PMC8784754 DOI: 10.3389/fpls.2021.818198] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 12/15/2021] [Indexed: 05/27/2023]
Abstract
WRKY transcription factors (TFs) play crucial roles in the regulation of biotic stress. Citrus is the most productive fruit in the world. It is of great value to investigate the regulatory molecular mechanism of WRKYs in improving disease resistance. In this research, the transcription level of CsWRKY25 was upregulated in P. digitatum infected citrus peel, and CsWRKY25 activated the expression of three target genes (RbohB, RbohD, and PR10). Besides, the Agrobacterium-mediated transient overexpression of CsWRKY25 has also been shown to enhance resistance to P. digitatum in citrus, and caused the accumulation of hydrogen peroxide and lignin. The accumulation of ROS also activated the antioxidant system, the catalase (CAT), peroxidase (POD), and cinnamyl alcohol dehydrogenase (CAD) genes were significant upregulated, leading to activation of antioxidant enzymes. In addition, the up-regulated expression of MPK5 and MPK6 genes suggested that the regulatory role of CsWRKY25 might be related to the phosphorylation process. In conclusion, CsWRKY25 could enhance the resistance to P. digitatum via modulating ROS production and PR genes in citrus peel.
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Affiliation(s)
- Wenjun Wang
- College of Food Science, Southwest University, Chongqing, China
| | - Ting Li
- College of Food Science, Southwest University, Chongqing, China
| | - Qi Chen
- College of Food Science, Southwest University, Chongqing, China
| | - Shixiang Yao
- College of Food Science, Southwest University, Chongqing, China
- Research Center of Food Storage & Logistics, Southwest University, Chongqing, China
| | - Lili Deng
- College of Food Science, Southwest University, Chongqing, China
- Research Center of Food Storage & Logistics, Southwest University, Chongqing, China
| | - Kaifang Zeng
- College of Food Science, Southwest University, Chongqing, China
- Research Center of Food Storage & Logistics, Southwest University, Chongqing, China
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Wu B, Li N, Deng Z, Luo F, Duan Y. Selection and Evaluation of a Thornless and HLB-Tolerant Bud-Sport of Pummelo Citrus With an Emphasis on Molecular Mechanisms. FRONTIERS IN PLANT SCIENCE 2021; 12:739108. [PMID: 34531892 PMCID: PMC8438139 DOI: 10.3389/fpls.2021.739108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 08/04/2021] [Indexed: 06/01/2023]
Abstract
The selection of elite bud-sports is an important breeding approach in horticulture. We discovered and evaluated a thornless pummelo bud-sport (TL) that grew more vigorously and was more tolerant to Huanglongbing (HLB) than the thorny wild type (W). To reveal the underlying molecular mechanisms, we carried out whole-genome sequencing of W, and transcriptome comparisons of W, TL, and partially recovered thorny "mutants" (T). The results showed W, TL, and T varied in gene expression, allelic expression, and alternative splicing. Most genes/pathways with significantly altered expression in TL compared to W remained similarly altered in T. Pathway and gene ontology enrichment analysis revealed that the expression of multiple pathways, including photosynthesis and cell wall biosynthesis, was altered among the three genotypes. Remarkably, two polar auxin transporter genes, PIN7 and LAX3, were expressed at a significantly lower level in TL than in both W and T, implying alternation of polar auxin transport in TL may be responsible for the vigorous growth and thornless phenotype. Furthermore, 131 and 68 plant defense-related genes were significantly upregulated and downregulated, respectively, in TL and T compared with W. These genes may be involved in enhanced salicylic acid (SA) dependent defense and repression of defense inducing callose deposition and programmed cell death. Overall, these results indicated that the phenotype changes of the TL bud-sport were associated with tremendous transcriptome alterations, providing new clues and targets for breeding and gene editing for citrus improvement.
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Affiliation(s)
- Bo Wu
- School of Computing, Clemson University, Clemson, SC, United States
| | - Na Li
- United States Department of Agriculture-Agriculture Research Service-United States Horticultural Research Laboratory, Fort Pierce, FL, United States
- College of Horticulture, Hunan Agricultural University, Changsha, China
| | - Zhanao Deng
- Department of Environmental Horticulture, Gulf Coast Research and Education Center, IFAS, University of Florida, Wimauma, FL, United States
| | - Feng Luo
- School of Computing, Clemson University, Clemson, SC, United States
| | - Yongping Duan
- United States Department of Agriculture-Agriculture Research Service-United States Horticultural Research Laboratory, Fort Pierce, FL, United States
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Li Q, Qin X, Qi J, Dou W, Dunand C, Chen S, He Y. CsPrx25, a class III peroxidase in Citrus sinensis, confers resistance to citrus bacterial canker through the maintenance of ROS homeostasis and cell wall lignification. HORTICULTURE RESEARCH 2020; 7:192. [PMID: 33328465 PMCID: PMC7705758 DOI: 10.1038/s41438-020-00415-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 09/02/2020] [Accepted: 09/04/2020] [Indexed: 05/21/2023]
Abstract
Citrus bacterial canker (CBC) results from Xanthomonas citri subsp. citri (Xcc) infection and poses a grave threat to citrus production. Class III peroxidases (CIII Prxs) are key proteins to the environmental adaptation of citrus plants to a range of exogenous pathogens, but the role of CIII Prxs during plant resistance to CBC is poorly defined. Herein, we explored the role of CsPrx25 and its contribution to plant defenses in molecular detail. Based on the expression analysis, CsPrx25 was identified as an apoplast-localized protein that is differentially regulated by Xcc infection, salicylic acid, and methyl jasmone acid in the CBC-susceptible variety Wanjincheng (C. sinensis) and the CBC-resistant variety Calamondin (C. madurensis). Transgenic Wanjincheng plants overexpressing CsPrx25 were generated, and these transgenic plants exhibited significantly increased CBC resistance compared with the WT plants. In addition, the CsPrx25-overexpressing plants displayed altered reactive oxygen species (ROS) homeostasis accompanied by enhanced H2O2 levels, which led to stronger hypersensitivity responses during Xcc infection. Moreover, the overexpression of CsPrx25 enhanced lignification as an apoplastic barrier for Xcc infection. Taken together, the results highlight how CsPrx25-mediated ROS homeostasis reconstruction and cell wall lignification can enhance the resistance of sweet orange to CBC.
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Affiliation(s)
- Qiang Li
- Citrus Research Institute, Southwest University/Chinese Academy of Agricultural Sciences, Chongqing, 400712, China
| | - Xiujuan Qin
- Citrus Research Institute, Southwest University/Chinese Academy of Agricultural Sciences, Chongqing, 400712, China
| | - Jingjing Qi
- Citrus Research Institute, Southwest University/Chinese Academy of Agricultural Sciences, Chongqing, 400712, China
| | - Wanfu Dou
- Citrus Research Institute, Southwest University/Chinese Academy of Agricultural Sciences, Chongqing, 400712, China
| | - Christophe Dunand
- Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, CNRS, UPS, Auzeville-Tolosane, 31320, France
| | - Shanchun Chen
- Citrus Research Institute, Southwest University/Chinese Academy of Agricultural Sciences, Chongqing, 400712, China.
| | - Yongrui He
- Citrus Research Institute, Southwest University/Chinese Academy of Agricultural Sciences, Chongqing, 400712, China.
- Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, 401331, Chongqing, China.
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Fu H, Zhao M, Xu J, Tan L, Han J, Li D, Wang M, Xiao S, Ma X, Deng Z. Citron C-05 inhibits both the penetration and colonization of Xanthomonas citri subsp. citri to achieve resistance to citrus canker disease. HORTICULTURE RESEARCH 2020; 7:58. [PMID: 32377349 PMCID: PMC7193574 DOI: 10.1038/s41438-020-0278-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Revised: 02/05/2020] [Accepted: 02/12/2020] [Indexed: 06/11/2023]
Abstract
Citrus canker, caused by Xanthomonas citri subsp. citri (Xcc), is a serious bacterial disease that affects citrus production worldwide. Citron C-05 (Citrus medica) is the only germplasm in the Citrus genus that has been identified to exhibit strong resistance to Xcc. However, it has not been determined when, where, and how Xcc is restricted in the tissues of Citron C-05 during the infection process. In the present study, we investigated the spatiotemporal growth dynamics of an eGFP-labeled virulent Xcc (eGFP-Xcc) strain in Citron C-05 along with five susceptible biotypes (i.e., lemon, pummelo, sour orange, sweet orange, and ponkan mandarin) upon inoculation via the spraying or leaf infiltration of a bacterial suspension. The results from extensive confocal laser scanning microscopy analyses showed that while Xcc grew rapidly in plants of all five susceptible genotypes, Xcc was severely restricted in the epidermal and mesophyll cell layers of the leaves of Citron C-05 in the early stage of infection. Not surprisingly, resistance against Xcc in Citron C-05 was found to be associated with the production of reactive oxygen species and hypersensitive response-like cell death, as well as greater upregulation of several defense-related genes, including a pathogenesis-related gene (PR1) and a glutathione S-transferase gene (GST1), compared with sweet orange as a susceptible control. Taken together, our results not only provide further valuable details of the spatiotemporal dynamics of the host entry, propagation, and spread of Xcc in both resistant and susceptible citrus plants but also suggest that resistance to Xcc in Citron C-05 may be attributed to the activation of multiple defense mechanisms.
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Affiliation(s)
- Hongyan Fu
- College of Horticulture, Hunan Agricultural University, 410128 Changsha, Hunan China
- National Center for Citrus Improvement, 410128 Changsha, Hunan China
| | - Mingming Zhao
- College of Horticulture, Hunan Agricultural University, 410128 Changsha, Hunan China
- National Center for Citrus Improvement, 410128 Changsha, Hunan China
| | - Jing Xu
- College of Horticulture, Hunan Agricultural University, 410128 Changsha, Hunan China
- National Center for Citrus Improvement, 410128 Changsha, Hunan China
| | - Limei Tan
- National Center for Citrus Improvement, 410128 Changsha, Hunan China
| | - Jian Han
- Hunan Horticultural Research Institute, 410125 Changsha, Hunan China
| | - Dazhi Li
- College of Horticulture, Hunan Agricultural University, 410128 Changsha, Hunan China
- National Center for Citrus Improvement, 410128 Changsha, Hunan China
| | - Meijun Wang
- College of Horticulture, Hunan Agricultural University, 410128 Changsha, Hunan China
| | - Shunyuan Xiao
- Institute for Bioscience and Biotechnology Research & Department of Plant Sciences and Landscape Architecture, University of Maryland College Park, Rockville, MD 20850 USA
| | - Xianfeng Ma
- College of Horticulture, Hunan Agricultural University, 410128 Changsha, Hunan China
- National Center for Citrus Improvement, 410128 Changsha, Hunan China
| | - Ziniu Deng
- College of Horticulture, Hunan Agricultural University, 410128 Changsha, Hunan China
- National Center for Citrus Improvement, 410128 Changsha, Hunan China
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10
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Chen Y, Bendix C, Lewis JD. Comparative Genomics Screen Identifies Microbe-Associated Molecular Patterns from ' Candidatus Liberibacter' spp. That Elicit Immune Responses in Plants. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:539-552. [PMID: 31790346 DOI: 10.1094/mpmi-11-19-0309-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Citrus huanglongbing (HLB), caused by phloem-limited 'Candidatus Liberibacter' bacteria, is a destructive disease threatening the worldwide citrus industry. The mechanisms of pathogenesis are poorly understood and no efficient strategy is available to control HLB. Here, we used a comparative genomics screen to identify candidate microbe-associated molecular patterns (MAMPs) from 'Ca. Liberibacter' spp. We identified the core genome from multiple 'Ca. Liberibacter' pathogens, and searched for core genes with signatures of positive selection. We hypothesized that genes encoding putative MAMPs would evolve to reduce recognition by the plant immune system, while retaining their essential functions. To efficiently screen candidate MAMP peptides, we established a high-throughput microtiter plate-based screening assay, particularly for citrus, that measured reactive oxygen species (ROS) production, which is a common immune response in plants. We found that two peptides could elicit ROS production in Arabidopsis and Nicotiana benthamiana. One of these peptides elicited ROS production and defense gene expression in HLB-tolerant citrus genotypes, and induced MAMP-triggered immunity against the bacterial pathogen Pseudomonas syringae. Our findings identify MAMPs that boost immunity in citrus and could help prevent or reduce HLB infection.
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Affiliation(s)
- Yuan Chen
- Plant Gene Expression Center, United States Department of Agriculture-Agricultural Research Service and Department of Plant and Microbial Biology, University of California-Berkeley, 800 Buchanan Street, Albany, CA 94710, U.S.A
| | - Claire Bendix
- Plant Gene Expression Center, United States Department of Agriculture-Agricultural Research Service and Department of Plant and Microbial Biology, University of California-Berkeley, 800 Buchanan Street, Albany, CA 94710, U.S.A
| | - Jennifer D Lewis
- Plant Gene Expression Center, United States Department of Agriculture-Agricultural Research Service and Department of Plant and Microbial Biology, University of California-Berkeley, 800 Buchanan Street, Albany, CA 94710, U.S.A
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11
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Endophyte Bacillus velezensis Isolated from Citrus spp. Controls Streptomycin-Resistant Xanthomonas citri subsp. citri That Causes Citrus Bacterial Canker. AGRONOMY-BASEL 2019. [DOI: 10.3390/agronomy9080470] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Citrus bacterial canker (CBC), caused by the plant pathogenic bacterium Xanthomonas citri subsp. citri (Xcc), is a devastating disease in many commercial citrus cultivars. Every year, CBC causes a substantial reduction in fruit quality and quantity that corresponds to significant economic losses worldwide. Endophytic microorganisms produce numerous bioactive secondary metabolites that can control plant pathogens. We investigated the antagonistic activities of 66 endophytic bacteria isolated from nine citrus cultivars to control streptomycin-resistant Xcc. The suspension of Endophytic Bacteria-39 (EB-39), identified as Bacillus velezensis, exhibited the highest antibacterial activity against three wild-type and six streptomycin-resistant Xcc strains, with the inhibition zones between 39.47 ± 1.6 and 45.31 ± 1.6 mm. The ethyl acetate extract of EB-39 also controlled both wild-type and streptomycin-resistant Xcc strains, with the inhibition zones between 29.28 ± 0.6 and 33.88 ± 1.3 mm. Scanning electron microscopy indicated the ethyl acetate extract of EB-39-induced membrane damage and lysis. The experiments using the detached leaves of a susceptible Citrus species showed that EB-39 significantly reduced the incidence of canker on the infected leaves by 38%. These results strongly suggest that our newly isolated EB-39 is a novel biocontrol agent against CBC caused by wild-type and streptomycin-resistant Xcc strains.
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12
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Hao G, Ammar D, Duan Y, Stover E. Transgenic citrus plants expressing a ‘Candidatus Liberibacter asiaticus’ prophage protein LasP235 display Huanglongbing-like symptoms. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.aggene.2019.100085] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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13
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Pitino M, Allen V, Duan Y. LasΔ5315 Effector Induces Extreme Starch Accumulation and Chlorosis as Ca. Liberibacter asiaticus Infection in Nicotiana benthamiana. FRONTIERS IN PLANT SCIENCE 2018; 9:113. [PMID: 29467782 PMCID: PMC5808351 DOI: 10.3389/fpls.2018.00113] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 01/22/2018] [Indexed: 05/21/2023]
Abstract
Huanglongbing (HLB), a destructive plant bacterial disease, severely impedes worldwide citrus production. HLB is associated with a phloem-limited α-proteobacterium, Candidatus Liberibacter asiaticus (Las). Las infection causes yellow shoots and blotchy mottle on leaves and is associated with excessive starch accumulation. However, the mechanisms underlying the starch accumulation remain unknown. We previously showed that the Las5315mp effector induced callose deposition and cell death in Nicotiana benthamiana. In this study, we demonstrated that Las can experimentally infect N. benthamiana via dodder transmission. Furthermore, we revealed another key function of the Las5315 effector by demonstrating that transient expression of the truncated form of the effector, LasΔ5315, induced excessive starch accumulation by 6 fold after 8 dpi in N. benthamiana after removal of the chloroplast transit peptide from the Las5315mp. The induction mechanisms of LasΔ5315 in N. benthamiana were attributed to the up-regulation of ADP-glucose pyrophosphorylase, granule-bound starch synthase, soluble starch synthase, and starch branching enzyme for increasing starch production, and to the significant down-regulation of the starch degradation enzymes: alpha-glucosidase, alpha-amylase, and glycosyl hydrolase for decreasing starch degradation. This is the first report that Las can infect the model plant N. benthamiana. Using this model plant, we demonstrated that the LasΔ5315 effector caused the most prominent HLB symptoms, starch accumulation and chlorosis as Las infection in N. benthamiana. Altogether the Las 5315 effector is critical for Las pathogenesis, and therefore, an important target for interference.
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Affiliation(s)
| | | | - Yongping Duan
- US Horticultural Research Laboratory, USDA-ARS, Fort Pierce, FL, United States
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14
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Shi Q, Febres VJ, Zhang S, Yu F, McCollum G, Hall DG, Moore GA, Stover E. Identification of Gene Candidates Associated with Huanglongbing Tolerance, Using 'Candidatus Liberibacter asiaticus' Flagellin 22 as a Proxy to Challenge Citrus. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2018; 31:200-211. [PMID: 29148926 DOI: 10.1094/mpmi-04-17-0084-r] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The 22-amino acid (flg22) pathogen-associated molecular pattern from the flagellin of Xanthomonas citri subsp. citri has been shown to induce defense responses correlated with citrus canker resistance. Here, flg22 of 'Candidatus Liberibacter asiaticus', the putative causal agent of Huanglongbing (HLB), elicited differential defense responses that were weaker than those from Xcc-flg22, between those of the HLB-tolerant mandarin cultivar Sun Chu Sha and susceptible grapefruit cultivar Duncan. Transcriptomics was used to compare the effect of CLas-flg22 and Xcc-flg22 between the citrus genotypes and identified 86 genes induced only by CLas-flg22 in the tolerant mandarin. Expression of 16 selected genes was validated, by reverse transcription-quantitative polymerase chain reaction, and was evaluated in citrus during 'Ca. L. asiaticus' infection. Differential expression of a number of genes occurred between tolerant and susceptible citrus infected with 'Ca. L. asiaticus', suggesting their involvement in HLB tolerance. In addition, several genes were similarly regulated by CLas-flg22 and 'Ca. L. asiaticus' treatments, while others were oppositely regulated in the tolerant mandarin, suggesting similarity and interplay between CLas-flg22 and 'Ca. L. asiaticus'-triggered defenses. Genes identified are valuable in furthering the study of HLB tolerance mechanisms and, potentially, for screening for HLB-tolerant citrus using CLas-flg22 as a pathogen proxy.
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Affiliation(s)
- Qingchun Shi
- 1 U.S. Horticultural Research Laboratory, USDA/ARS, Fort Pierce, FL, U.S.A
| | - Vicente J Febres
- 2 Horticultural Sciences Department, University of Florida, Gainesville, FL, U.S.A.; and
| | - Shujian Zhang
- 1 U.S. Horticultural Research Laboratory, USDA/ARS, Fort Pierce, FL, U.S.A
| | - Fahong Yu
- 3 Interdisciplinary Center for Biotechnology Research, University of Florida
| | - Greg McCollum
- 1 U.S. Horticultural Research Laboratory, USDA/ARS, Fort Pierce, FL, U.S.A
| | - David G Hall
- 1 U.S. Horticultural Research Laboratory, USDA/ARS, Fort Pierce, FL, U.S.A
| | - Gloria A Moore
- 2 Horticultural Sciences Department, University of Florida, Gainesville, FL, U.S.A.; and
| | - Ed Stover
- 1 U.S. Horticultural Research Laboratory, USDA/ARS, Fort Pierce, FL, U.S.A
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15
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Shimada T, Endo T, Rodríguez A, Fujii H, Goto S, Matsuura T, Hojo Y, Ikeda Y, Mori IC, Fujikawa T, Peña L, Omura M. Ectopic accumulation of linalool confers resistance to Xanthomonas citri subsp. citri in transgenic sweet orange plants. TREE PHYSIOLOGY 2017; 37:654-664. [PMID: 28131994 DOI: 10.1093/treephys/tpw134] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 01/05/2017] [Indexed: 05/21/2023]
Abstract
In order to clarify whether high linalool content in citrus leaves alone induces strong field resistance to citrus canker caused by Xanthomonas citri subsp. citri (Xcc), and to assess whether this trait can be transferred to a citrus type highly sensitive to the bacterium, transgenic 'Hamlin' sweet orange (Citrus sinensis L. Osbeck) plants over-expressing a linalool synthase gene (CuSTS3-1) were generated. Transgenic lines (LIL) with the highest linalool content showed strong resistance to citrus canker when spray inoculated with the bacterium. In LIL plants inoculated by wounding (multiple-needle inoculation), the linalool level was correlated with the repression of the bacterial titer and up-regulation of defense-related genes. The exogenous application of salicylic acid, methyl jasmonate or linalool triggered responses similar to those constitutively induced in LIL plants. The linalool content in Ponkan mandarin leaves was significantly higher than that of leaves from six other representative citrus genotypes with different susceptibilities to Xcc. We propose that linalool-mediated resistance might be unique to citrus tissues accumulating large amounts of volatile organic compounds in oil cells. Linalool might act not only as a direct antibacterial agent, but also as a signal molecule involved in triggering a non-host resistance response against Xcc.
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Affiliation(s)
- Takehiko Shimada
- Institute of Fruit Tree and Tea Science (NIFTS), National Agriculture and Bio-Oriented Research Organization (NARO), Shizuoka 424-0292, Japan
| | - Tomoko Endo
- Institute of Fruit Tree and Tea Science (NIFTS), National Agriculture and Bio-Oriented Research Organization (NARO), Shizuoka 424-0292, Japan
| | - Ana Rodríguez
- Fundecitrus, Av. Dr. Adhemar de Barros Pereira, 201, 14807-040 Vila Melhado, Araraquara, Sao Paulo, Brazil
- Instituto de Biología Molecular y Celular de Plantas (IBMCP/CSIC-UPV), Ingeniero Fausto Elio, Valencia 46022, Spain
| | - Hiroshi Fujii
- Institute of Fruit Tree and Tea Science (NIFTS), National Agriculture and Bio-Oriented Research Organization (NARO), Shizuoka 424-0292, Japan
| | - Shingo Goto
- Institute of Fruit Tree and Tea Science (NIFTS), National Agriculture and Bio-Oriented Research Organization (NARO), Shizuoka 424-0292, Japan
| | - Takakazu Matsuura
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki 710-0046, Japan
| | - Yuko Hojo
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki 710-0046, Japan
| | - Yoko Ikeda
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki 710-0046, Japan
| | - Izumi C Mori
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki 710-0046, Japan
| | - Takashi Fujikawa
- Institute of Fruit Tree and Tea Science (NIFTS), National Agriculture and Bio-Oriented Research Organization (NARO), Shizuoka 424-0292, Japan
| | - Leandro Peña
- Fundecitrus, Av. Dr. Adhemar de Barros Pereira, 201, 14807-040 Vila Melhado, Araraquara, Sao Paulo, Brazil
- Instituto de Biología Molecular y Celular de Plantas (IBMCP/CSIC-UPV), Ingeniero Fausto Elio, Valencia 46022, Spain
| | - Mitsuo Omura
- Faculty of Agriculture, Shizuoka University, Shizuoka 422-8529, Japan
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16
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Pitino M, Armstrong CM, Duan Y. Molecular mechanisms behind the accumulation of ATP and H 2O 2 in citrus plants in response to ' Candidatus Liberibacter asiaticus' infection. HORTICULTURE RESEARCH 2017; 4:17040. [PMID: 35211319 PMCID: PMC7713647 DOI: 10.1038/hortres.2017.40] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 06/29/2017] [Accepted: 07/05/2017] [Indexed: 05/22/2023]
Abstract
Candidatus Liberibacter asiaticus (Las) is a fastidious, phloem-restricted pathogen with a significantly reduced genome, and attacks all citrus species with no immune cultivars documented to date. Like other plant bacterial pathogens, Las deploys effector proteins into the organelles of plant cells, such as mitochondria and chloroplasts to manipulate host immunity and physiology. These organelles are responsible for the synthesis of adenosine triphosphate (ATP) and have a critical role in plant immune signaling during hydrogen peroxide (H2O2) production. In this study, we investigated H2O2 and ATP accumulation in relation to citrus huanglongbing (HLB) in addition to revealing the expression profiles of genes critical for the production and detoxification of H2O2 and ATP synthesis. We also found that as ATP and H2O2 concentrations increased in the leaf, so did the severity of the HLB symptoms, a trend that remained consistent among the four different citrus varieties tested. Furthermore, the upregulation of ATP synthase, a key enzyme for energy conversion, may contribute to the accumulation of ATP in infected tissues, whereas downregulation of the H2O2 detoxification system may cause oxidative damage to plant macromolecules and cell structures. This may explain the cause of some of the HLB symptoms such as chlorosis or leaf discoloration. The findings in this study highlight important molecular and physiological mechanisms involved in the host plants' response to Las infection and provide new targets for interrupting the disease cycle.
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Affiliation(s)
- Marco Pitino
- USDA-ARS, US Horticultural Research Laboratory, 2001 S. Rock Road, Fort Pierce, 34945 FL USA
| | - Cheryl M Armstrong
- USDA-ARS, US Horticultural Research Laboratory, 2001 S. Rock Road, Fort Pierce, 34945 FL USA
| | - Yongping Duan
- USDA-ARS, US Horticultural Research Laboratory, 2001 S. Rock Road, Fort Pierce, 34945 FL USA
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17
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Magalhães DM, Scholte LLS, Silva NV, Oliveira GC, Zipfel C, Takita MA, De Souza AA. LRR-RLK family from two Citrus species: genome-wide identification and evolutionary aspects. BMC Genomics 2016; 17:623. [PMID: 27515968 PMCID: PMC4982124 DOI: 10.1186/s12864-016-2930-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 07/12/2016] [Indexed: 11/17/2022] Open
Abstract
Background Leucine-rich repeat receptor-like kinases (LRR-RLKs) represent the largest subfamily of plant RLKs. The functions of most LRR-RLKs have remained undiscovered, and a few that have been experimentally characterized have been shown to have important roles in growth and development as well as in defense responses. Although RLK subfamilies have been previously studied in many plants, no comprehensive study has been performed on this gene family in Citrus species, which have high economic importance and are frequent targets for emerging pathogens. In this study, we performed in silico analysis to identify and classify LRR-RLK homologues in the predicted proteomes of Citrus clementina (clementine) and Citrus sinensis (sweet orange). In addition, we used large-scale phylogenetic approaches to elucidate the evolutionary relationships of the LRR-RLKs and further narrowed the analysis to the LRR-XII group, which contains several previously described cell surface immune receptors. Results We built integrative protein signature databases for Citrus clementina and Citrus sinensis using all predicted protein sequences obtained from whole genomes. A total of 300 and 297 proteins were identified as LRR-RLKs in C. clementina and C. sinensis, respectively. Maximum-likelihood phylogenetic trees were estimated using Arabidopsis LRR-RLK as a template and they allowed us to classify Citrus LRR-RLKs into 16 groups. The LRR-XII group showed a remarkable expansion, containing approximately 150 paralogs encoded in each Citrus genome. Phylogenetic analysis also demonstrated the existence of two distinct LRR-XII clades, each one constituted mainly by RD and non-RD kinases. We identified 68 orthologous pairs from the C. clementina and C. sinensis LRR-XII genes. In addition, among the paralogs, we identified a subset of 78 and 62 clustered genes probably derived from tandem duplication events in the genomes of C. clementina and C. sinensis, respectively. Conclusions This work provided the first comprehensive evolutionary analysis of the LRR-RLKs in Citrus. A large expansion of LRR-XII in Citrus genomes suggests that it might play a key role in adaptive responses in host-pathogen co-evolution, related to the perennial life cycle and domestication of the citrus crop species. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2930-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Diogo M Magalhães
- Instituto Agronômico, Centro de Citricultura Sylvio Moreira, Cordeirópolis, São Paulo, Brazil.,Departamento de Genética e Biologia Molecular, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Larissa L S Scholte
- Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais, Grupo de Genômica e Biologia Computacional, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Nicholas V Silva
- Instituto Agronômico, Centro de Citricultura Sylvio Moreira, Cordeirópolis, São Paulo, Brazil
| | - Guilherme C Oliveira
- Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais, Grupo de Genômica e Biologia Computacional, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil.,Instituto Tecnológico Vale - ITV, Belém, Pará, Brazil
| | - Cyril Zipfel
- The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Marco A Takita
- Instituto Agronômico, Centro de Citricultura Sylvio Moreira, Cordeirópolis, São Paulo, Brazil
| | - Alessandra A De Souza
- Instituto Agronômico, Centro de Citricultura Sylvio Moreira, Cordeirópolis, São Paulo, Brazil.
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18
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Xiao D, Liu ST, Wei YP, Zhou DY, Hou XL, Li Y, Hu CM. cDNA-AFLP analysis reveals differential gene expression in incompatible interaction between infected non-heading Chinese cabbage and Hyaloperonospora parasitica. HORTICULTURE RESEARCH 2016; 3:16034. [PMID: 27602230 PMCID: PMC4962739 DOI: 10.1038/hortres.2016.34] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Revised: 07/04/2016] [Accepted: 07/05/2016] [Indexed: 06/06/2023]
Abstract
Non-heading Chinese cabbage (Brassica rapa ssp. chinensis) is one of the main green leafy vegetables in the world, especially in China, with significant economic value. Hyaloperonospora parasitica is a fungal pathogen responsible for causing downy mildew disease in Chinese cabbage, which greatly affects its production. The objective of this study was to identify transcriptionally regulated genes during incompatible interactions between non-heading Chinese cabbage and H. parasitica using complementary DNA-amplified fragment length polymorphism (cDNA-AFLP). We obtained 129 reliable differential transcript-derived fragments (TDFs) in a resistant line 'Suzhou Qing'. Among them, 121 upregulated TDFs displayed an expression peak at 24-48 h post inoculation (h.p.i.). Fifteen genes were further selected for validation of cDNA-AFLP expression patterns using quantitative reverse transcription PCR. Results confirmed the altered expression patterns of 13 genes (86.7%) revealed by the cDNA-AFLP. We identified four TDFs related to fungal resistance among the 15 TDFs. Furthermore, comparative analysis of four TDFs between resistant line 'Suzhou Qing' and susceptible line 'Aijiao Huang' showed that transcript levels of TDF14 (BcLIK1_A01) peaked at 48 h.p.i. and 25.1-fold increased in the resistant line compared with the susceptible line. Similarly, transcript levels of the other three genes, TDF42 (BcCAT3_A07), TDF75 (BcAAE3_A06) and TDF88 (BcAMT2_A05) peaked at 24, 48 and 24 h.p.i. with 25.1-, 100- and 15.8-fold increases, respectively. The results suggested that the resistance genes tended to transcribe at higher levels in the resistance line than in the susceptible line, which may provide resistance against pathogen infections. The present study might facilitate elucidating the molecular basis of the infection process and identifying candidate genes for resistance improvement of susceptible cultivars.
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Affiliation(s)
- Dong Xiao
- Horticulture Department, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
- State Key Laboratory of Crop Genetics & Germplasm Enhancement, Ministry of Agriculture, Nanjing 210095, China
| | - Shi-Tuo Liu
- Horticulture Department, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
- State Key Laboratory of Crop Genetics & Germplasm Enhancement, Ministry of Agriculture, Nanjing 210095, China
| | - Yan-Ping Wei
- Horticulture Department, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
- State Key Laboratory of Crop Genetics & Germplasm Enhancement, Ministry of Agriculture, Nanjing 210095, China
| | - Dao-Yun Zhou
- Horticulture Department, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
- State Key Laboratory of Crop Genetics & Germplasm Enhancement, Ministry of Agriculture, Nanjing 210095, China
| | - Xi-Lin Hou
- Horticulture Department, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
- State Key Laboratory of Crop Genetics & Germplasm Enhancement, Ministry of Agriculture, Nanjing 210095, China
| | - Ying Li
- Horticulture Department, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
- State Key Laboratory of Crop Genetics & Germplasm Enhancement, Ministry of Agriculture, Nanjing 210095, China
| | - Chun-Mei Hu
- Horticulture Department, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
- State Key Laboratory of Crop Genetics & Germplasm Enhancement, Ministry of Agriculture, Nanjing 210095, China
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19
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Yu X, Armstrong CM, Zhou M, Duan Y. Bismerthiazol Inhibits Xanthomonas citri subsp. citri Growth and Induces Differential Expression of Citrus Defense-Related Genes. PHYTOPATHOLOGY 2016; 106:693-701. [PMID: 26882850 DOI: 10.1094/phyto-12-15-0328-r] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Citrus canker, caused by Xanthomonas citri ssp. citri, is a serious disease that causes substantial economic losses to the citrus industry worldwide. The bactericide bismerthiazol has been used to control rice bacterial blight (X. oryzae pv. oryzae). In this paper, we demonstrate that bismerthiazol can effectively control citrus canker by both inhibiting the growth of X. citri ssp. citri and triggering the plant's host defense response through the expression of several pathogenesis-related genes (PR1, PR2, CHI, and RpRd1) and the nonexpresser of PR genes (NPR1, NPR2, and NPR3) in 'Duncan' grapefruit, especially at early treatment times. In addition, we found that bismerthiazol induced the expression of the marker genes CitCHS and CitCHI in the flavonoid pathway and the PAL1 (phenylalanine ammonia lyase 1) gene in the salicylic acid (SA) biosynthesis pathway at different time points. Moreover, bismerthiazol also induced the expression of the priming defense-associated gene AZI1. Taken together, these results indicate that the induction of the defense response in 'Duncan' grapefruit by bismerthiazol may involve the SA signaling pathway and the priming defense and that bismerthiazol may serve as an alternative to copper bactericides for the control of citrus canker.
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Affiliation(s)
- Xiaoyue Yu
- First and third authors: Nanjing Agriculture University, Nanjing 210095, China; and first, second, and fourth authors: U.S. Horticultural Research Laboratory, USDA-ARS, Fort Pierce, FL 34945
| | - Cheryl M Armstrong
- First and third authors: Nanjing Agriculture University, Nanjing 210095, China; and first, second, and fourth authors: U.S. Horticultural Research Laboratory, USDA-ARS, Fort Pierce, FL 34945
| | - Mingguo Zhou
- First and third authors: Nanjing Agriculture University, Nanjing 210095, China; and first, second, and fourth authors: U.S. Horticultural Research Laboratory, USDA-ARS, Fort Pierce, FL 34945
| | - Yongping Duan
- First and third authors: Nanjing Agriculture University, Nanjing 210095, China; and first, second, and fourth authors: U.S. Horticultural Research Laboratory, USDA-ARS, Fort Pierce, FL 34945
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