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Barreda L, Brosse C, Boutet S, Perreau F, Rajjou L, Lepiniec L, Corso M. Specialized metabolite modifications in Brassicaceae seeds and plants: diversity, functions and related enzymes. Nat Prod Rep 2024. [PMID: 38323463 DOI: 10.1039/d3np00043e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
Covering: up to 2023Specialized metabolite (SM) modifications and/or decorations, corresponding to the addition or removal of functional groups (e.g. hydroxyl, methyl, glycosyl or acyl group) to SM structures, contribute to the huge diversity of structures, activities and functions of seed and plant SMs. This review summarizes available knowledge (up to 2023) on SM modifications in Brassicaceae and their contribution to SM plasticity. We give a comprehensive overview on enzymes involved in the addition or removal of these functional groups. Brassicaceae, including model (Arabidopsis thaliana) and crop (Brassica napus, Camelina sativa) plant species, present a large diversity of plant and seed SMs, which makes them valuable models to study SM modifications. In this review, particular attention is given to the environmental plasticity of SM and relative modification and/or decoration enzymes. Furthermore, a spotlight is given to SMs and related modification enzymes in seeds of Brassicaceae species. Seeds constitute a large reservoir of beneficial SMs and are one of the most important dietary sources, providing more than half of the world's intake of dietary proteins, oil and starch. The seed tissue- and stage-specific expressions of A. thaliana genes involved in SM modification are presented and discussed in the context of available literature. Given the major role in plant phytochemistry, biology and ecology, SM modifications constitute a subject of study contributing to the research and development in agroecology, pharmaceutical, cosmetics and food industrial sectors.
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Affiliation(s)
- Léa Barreda
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France.
| | - Céline Brosse
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France.
| | - Stéphanie Boutet
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France.
| | - François Perreau
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France.
| | - Loïc Rajjou
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France.
| | - Loïc Lepiniec
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France.
| | - Massimiliano Corso
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France.
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Hamilton CD, Zaricor B, Dye CJ, Dresserl E, Michaels R, Allen C. Ralstonia solanacearum pandemic lineage strain UW551 overcomes inhibitory xylem chemistry to break tomato bacterial wilt resistance. Mol Plant Pathol 2024; 25:e13395. [PMID: 37846613 PMCID: PMC10782650 DOI: 10.1111/mpp.13395] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 08/01/2023] [Accepted: 09/15/2023] [Indexed: 10/18/2023]
Abstract
Plant-pathogenic Ralstonia strains cause bacterial wilt disease by colonizing xylem vessels of many crops, including tomato. Host resistance is the best control for bacterial wilt, but resistance mechanisms of the widely used Hawaii 7996 tomato breeding line (H7996) are unknown. Using growth in ex vivo xylem sap as a proxy for host xylem, we found that Ralstonia strain GMI1000 grows in sap from both healthy plants and Ralstonia-infected susceptible plants. However, sap from Ralstonia-infected H7996 plants inhibited Ralstonia growth, suggesting that in response to Ralstonia infection, resistant plants increase inhibitors in their xylem sap. Consistent with this, reciprocal grafting and defence gene expression experiments indicated that H7996 wilt resistance acts in both above- and belowground plant parts. Concerningly, H7996 resistance is broken by Ralstonia strain UW551 of the pandemic lineage that threatens highland tropical agriculture. Unlike other Ralstonia, UW551 grew well in sap from Ralstonia-infected H7996 plants. Moreover, other Ralstonia strains could grow in sap from H7996 plants previously infected by UW551. Thus, UW551 overcomes H7996 resistance in part by detoxifying inhibitors in xylem sap. Testing a panel of xylem sap compounds identified by metabolomics revealed that no single chemical differentially inhibits Ralstonia strains that cannot infect H7996. However, sap from Ralstonia-infected H7996 contained more phenolic compounds, which are known to be involved in plant antimicrobial defence. Culturing UW551 in this sap reduced total phenolic levels, indicating that the resistance-breaking Ralstonia strain degrades these chemical defences. Together, these results suggest that H7996 tomato wilt resistance depends in part on inducible phenolic compounds in xylem sap.
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Affiliation(s)
- Corri D. Hamilton
- Department of Plant PathologyUniversity of Wisconsin MadisonMadisonWisconsinUSA
- Department of Microbiology and ImmunologyUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Beatriz Zaricor
- Department of Plant PathologyUniversity of Wisconsin MadisonMadisonWisconsinUSA
| | - Carolyn Jean Dye
- Department of Plant PathologyUniversity of Wisconsin MadisonMadisonWisconsinUSA
| | - Emma Dresserl
- Department of Plant PathologyUniversity of Wisconsin MadisonMadisonWisconsinUSA
| | - Renee Michaels
- Department of Plant PathologyUniversity of Wisconsin MadisonMadisonWisconsinUSA
| | - Caitilyn Allen
- Department of Plant PathologyUniversity of Wisconsin MadisonMadisonWisconsinUSA
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Rajkumari N, Chowrasia S, Nishad J, Ganie SA, Mondal TK. Metabolomics-mediated elucidation of rice responses to salt stress. Planta 2023; 258:111. [PMID: 37919614 DOI: 10.1007/s00425-023-04258-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 10/01/2023] [Indexed: 11/04/2023]
Abstract
MAIN CONCLUSION Role of salinity responsive metabolites of rice and its wild species has been discussed. Salinity stress is one of the important environmental stresses that severely affects rice productivity. Although, several vital physio-biochemical and molecular responses have been activated in rice under salinity stress which were well described in literatures, the mechanistic role of salt stress and microbes-induced metabolites to overcome salt stress in rice are less studied. Nevertheless, over the years, metabolomic studies have allowed a comprehensive analyses of rice salt stress responses. Hence, we review the salt stress-triggered alterations of various metabolites in rice and discuss their significant roles toward salinity tolerance. Some of the metabolites such as serotonin, salicylic acid, ferulic acid and gentisic acid may act as signaling molecules to activate different downstream salt-tolerance mechanisms; whereas, the other compounds such as amino acids, sugars and organic acids directly act as protective agents to maintain osmotic balance and scavenger of reactive oxygen species during the salinity stress. The quantity, type, tissues specificity and time of accumulation of metabolites induced by salinity stress vary between salt-sensitive and tolerant rice genotypes and thus, contribute to their different degrees of salt tolerance. Moreover, few tolerance metabolites such as allantoin, serotonin and melatonin induce unique pathways for activation of defence mechanisms in salt-tolerant varieties of rice, suggesting their potential roles as the universal biomarkers for salt tolerance. Therefore, these metabolites can be applied exogenously to the sensitive genotypes of rice to enhance their performance under salt stress. Furthermore, the microbes of rhizosphere also participated in rice salt tolerance either directly or indirectly by regulating their metabolic pathways. Thus, this review for the first time offers valuable and comprehensive insights into salt-induced spatio-temporal and genotype-specific metabolites in different genotypes of rice which provide a reference point to analyze stress-gene-metabolite relationships for the biomarker designing in rice. Further, it can also help to decipher several metabolic systems associated with salt tolerance in rice which will be useful in developing salt-tolerance cultivars by conventional breeding/genetic engineering/exogenous application of metabolites.
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Affiliation(s)
- Nitasana Rajkumari
- ICAR-National Institute for Plant Biotechnology, LBS Centre, New Delhi, 110012, India
- ICAR-Indian Agricultural Research Institute, Pusa, New Delhi, 110012, India
| | - Soni Chowrasia
- ICAR-National Institute for Plant Biotechnology, LBS Centre, New Delhi, 110012, India
- Department of Bioscience and Biotechnology, Banastahli Vidyapith, Tonk, Rajasthan, 304022, India
| | - Jyoti Nishad
- ICAR-National Institute for Plant Biotechnology, LBS Centre, New Delhi, 110012, India
| | - Showkat Ahmad Ganie
- Plant Molecular Sciences and Centre of Systems and Synthetic Biology, Department of Biological Sciences, Royal Holloway University of London, Egham, TW20 0EX, Surrey, UK
- School of Life Sciences, University of Essex, Colchester, CO4 3SQ, UK
| | - Tapan Kumar Mondal
- ICAR-National Institute for Plant Biotechnology, LBS Centre, New Delhi, 110012, India.
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Gu Y, Li T, Zhou NY. Redundant and scattered genetic determinants for coumarin biodegradation in Pseudomonas sp. strain NyZ480. Appl Environ Microbiol 2023; 89:e0110923. [PMID: 37815346 PMCID: PMC10617510 DOI: 10.1128/aem.01109-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 08/18/2023] [Indexed: 10/11/2023] Open
Abstract
Coumarin (COU) is both a naturally derived phytotoxin and a synthetic pollutant which causes hepatotoxicity in susceptible humans. Microbes have potentials in COU biodegradation; however, its underlying genetic determinants remain unknown. Pseudomonas sp. strain NyZ480, a robust COU degrader, has been isolated and proven to grow on COU as its sole carbon source. In this study, five homologs of xenobiotic reductase A scattered throughout the chromosome of strain NyZ480 were identified, which catalyzed the conversion of COU to dihydrocoumarin (DHC) in vitro. Phylogenetic analysis indicated that these COU reductases belong to different subgroups of the old yellow enzyme family. Moreover, two hydrolases (CouB1 and CouB2) homologous to the 3,4-dihydrocoumarin hydrolase in the fluorene degradation were found to accelerate the generation of melilotic acid (MA) from DHC. CouC, a new member from the group A flavin monooxygenase, was heterologously expressed and purified, catalyzing the hydroxylation of MA to produce 3-(2,3-dihydroxyphenyl)propionate (DHPP). Gene deletion and complementation of couC indicated that couC played an essential role in the COU catabolism in strain NyZ480, considering that the genes involved in the downstream catabolism of DHPP have been characterized (Y. Xu and N. Y. Zhou, Appl Environ Microbiol 86:e02385-19, 2020) and homologous catabolic cluster exists in strain NyZ480. This study elucidated the genetic determinants for complete degradation of COU by Pseudomonas sp. strain NyZ480.IMPORTANCECoumarin (COU) is a phytochemical widely distributed in the plant kingdom and also artificially produced as an ingredient for personal care products. Hence, the environmental occurrence of COU has been reported in different places. Toxicologically, COU was proven hepatotoxic to individuals with mutations in the CYP2A6 gene and listed as a group 3 carcinogen by the International Agency for Research on Cancer and thus has raised increasing concerns. Until now, different physicochemical methods have been developed for the removal of COU, whereas their practical applications were hampered due to high cost and the risk of secondary contamination. In this study, genetic evidence and biochemical characterization of the COU degradation by Pseudomonas sp. strain NyZ480 are presented. With the gene and strain resources provided here, better managements of the hazards that humans face from COU could be achieved, and the possible microbiota-plant interaction mediated by the COU-utilizing rhizobacteria could also be investigated.
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Affiliation(s)
- Yichao Gu
- State Key Laboratory of Microbial Metabolism & School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
- Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University, Shanghai, China
| | - Tao Li
- State Key Laboratory of Microbial Metabolism & School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
- Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University, Shanghai, China
| | - Ning-Yi Zhou
- State Key Laboratory of Microbial Metabolism & School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
- Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University, Shanghai, China
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Abstract
The group of strains constituting the Ralstonia solanacearum species complex (RSSC) is a prominent model for the study of plant-pathogenic bacteria because of its impact on agriculture, owing to its wide host range, worldwide distribution, and long persistence in the environment. RSSC strains have led to numerous studies aimed at deciphering the molecular bases of virulence, and many biological functions and mechanisms have been described to contribute to host infection and pathogenesis. In this review, we put into perspective recent advances in our understanding of virulence in RSSC strains, both in terms of the inventory of functions that participate in this process and their evolutionary dynamics. We also present the different strategies that have been developed to combat these pathogenic strains through biological control, antimicrobial agents, plant genetics, or microbiota engineering.
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Affiliation(s)
- Fabienne Vailleau
- LIPME, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France; ,
| | - Stéphane Genin
- LIPME, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France; ,
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Baroukh C, Cottret L, Pires E, Peyraud R, Guidot A, Genin S. Insights into the metabolic specificities of pathogenic strains from the Ralstonia solanacearum species complex. mSystems 2023; 8:e0008323. [PMID: 37341493 PMCID: PMC10470067 DOI: 10.1128/msystems.00083-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 04/14/2023] [Indexed: 06/22/2023] Open
Abstract
All the strains grouped under the species Ralstonia solanacearum represent a species complex responsible for many diseases on agricultural crops throughout the world. The strains have different lifestyles and host range. Here, we investigated whether specific metabolic pathways contribute to strain diversification. To this end, we carried out systematic comparisons on 11 strains representing the diversity of the species complex. We reconstructed the metabolic network of each strain from its genome sequence and looked for the metabolic pathways differentiating the different reconstructed networks and, by extension, the different strains. Finally, we conducted an experimental validation by determining the metabolic profile of each strain with the Biolog technology. Results revealed that the metabolism is conserved between strains, with a core metabolism composed of 82% of the pan-reactome. The three species composing the species complex could be distinguished according to the presence/absence of some metabolic pathways, in particular, one involving salicylic acid degradation. Phenotypic assays revealed that the trophic preferences on organic acids and several amino acids such as glutamine, glutamate, aspartate, and asparagine are conserved between strains. Finally, we generated mutants lacking the quorum-sensing-dependent regulator PhcA in four diverse strains, and we showed that the phcA-dependent trade-off between growth and production of virulence factors is conserved across the R. solanacearum species complex. IMPORTANCE Ralstonia solanacearum is one of the most important threats to plant health worldwide, causing disease on a very large range of agricultural crops such as tomato or potato. Behind the R. solanacearum name are hundreds of strains with different host range and lifestyle, classified into three species. Studying the differences between strains allows to better apprehend the biology of the pathogens and the specificity of some strains. None of the published genomic comparative studies have focused on the metabolism of the strains so far. We developed a new bioinformatic pipeline to build high-quality metabolic networks and used a combination of metabolic modeling and high-throughput phenotypic Biolog microplates to look for the metabolic differences between 11 strains across the three species. Our study revealed that genes encoding enzymes are overall conserved, with few variations between strains. However, more variations were observed when considering substrate usage. These variations probably result from regulation rather than the presence or absence of enzymes in the genome.
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Affiliation(s)
- Caroline Baroukh
- LIPME, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | - Ludovic Cottret
- LIPME, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | - Emma Pires
- LIPME, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | - Rémi Peyraud
- LIPME, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | - Alice Guidot
- LIPME, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | - Stéphane Genin
- LIPME, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
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Zhang H, Xu Y, Huang Y, Xiong X, Wu X, Yuan G, Zheng D. Tn-seq identifies Ralstonia solanacearum genes required for tolerance of plant immunity induced by exogenous salicylic acid. Mol Plant Pathol 2023; 24:536-548. [PMID: 36912695 DOI: 10.1111/mpp.13321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/20/2023] [Accepted: 02/20/2023] [Indexed: 05/18/2023]
Abstract
Ralstonia solanacearum, the causal agent of the devastating bacterial wilt disease, is of particular interest to the scientific community. The repertoire of type III effectors plays an important role in the evasion of plant immunity, but tolerance to plant immunity is also crucial for the survival and virulence of R. solanacearum. Nevertheless, a systematic study of R. solanacearum tolerance to plant immunity is lacking. In this study, we used exogenous salicylic acid (SA) to improve the immunity of tomato plants, followed by transposon insertion sequencing (Tn-seq) analysis and the identification of R. solanacearum genes associated with tolerance to plant immunity. Target gene deletion revealed that the lipopolysaccharide (LPS) production genes RS_RS02830, RS_RS03460, and RS_RS03465 are essential for R. solanacearum tolerance to plant immunity, and their expression is induced by plant immunity, thereby expanding our knowledge of the pathogenic function of R. solanacearum LPS. SA treatment increased the relative abundance of transposon insertion mutants of four genes, including two genes with unknown function, RS_RS11975 and RS_RS07760. Further verification revealed that deletion of RS_RS11975 or RS_RS07760 resulted in reduced in vivo competitive indexes but increased tolerance to plant immunity induced by SA treatment, suggesting that these two genes contribute to the trade-off between tolerance to plant immunity and fitness cost. In conclusion, this work identified and validated R. solanacearum genes required for tolerance to plant immunity and provided essential information for a more complete view of the interaction between R. solanacearum and the host plant.
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Affiliation(s)
- Huimeng Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Agro-environment and Agro-product Safety, College of Agriculture, Guangxi University, Nanning, China
| | - Yanan Xu
- Pharmaceutical College, Guangxi Medical University, Nanning, China
| | - Yingying Huang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Agro-environment and Agro-product Safety, College of Agriculture, Guangxi University, Nanning, China
| | - Xiaoqi Xiong
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Agro-environment and Agro-product Safety, College of Agriculture, Guangxi University, Nanning, China
| | - Xiaogang Wu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Agro-environment and Agro-product Safety, College of Agriculture, Guangxi University, Nanning, China
| | - Gaoqing Yuan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Agro-environment and Agro-product Safety, College of Agriculture, Guangxi University, Nanning, China
| | - Dehong Zheng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Agro-environment and Agro-product Safety, College of Agriculture, Guangxi University, Nanning, China
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Truchon AN, Dalsing BL, Khokhani D, MacIntyre A, McDonald BR, Ailloud F, Klassen J, Gonzalez-Orta ET, Currie C, Prior P, Lowe-Power TM, Allen C. Plant-Pathogenic Ralstonia Phylotypes Evolved Divergent Respiratory Strategies and Behaviors To Thrive in Xylem. mBio 2023; 14:e0318822. [PMID: 36744950 DOI: 10.1128/mbio.03188-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Bacterial pathogens in the Ralstonia solanacearum species complex (RSSC) infect the water-transporting xylem vessels of plants, causing bacterial wilt disease. Strains in RSSC phylotypes I and III can reduce nitrate to dinitrogen via complete denitrification. The four-step denitrification pathway enables bacteria to use inorganic nitrogen species as terminal electron acceptors, supporting their growth in oxygen-limited environments such as biofilms or plant xylem. Reduction of nitrate, nitrite, and nitric oxide all contribute to the virulence of a model phylotype I strain. However, little is known about the physiological role of the last denitrification step, the reduction of nitrous oxide to dinitrogen by NosZ. We found that phylotypes I and III need NosZ for full virulence. However, strains in phylotypes II and IV are highly virulent despite lacking NosZ. The ability to respire by reducing nitrate to nitrous oxide does not greatly enhance the growth of phylotype II and IV strains. These partial denitrifying strains reach high cell densities during plant infection and cause typical wilt disease. However, unlike phylotype I and III strains, partial denitrifiers cannot grow well under anaerobic conditions or form thick biofilms in culture or in tomato xylem vessels. Furthermore, aerotaxis assays show that strains from different phylotypes have different oxygen and nitrate preferences. Together, these results indicate that the RSSC contains two subgroups that occupy the same habitat but have evolved divergent energy metabolism strategies to exploit distinct metabolic niches in the xylem. IMPORTANCE Plant-pathogenic Ralstonia spp. are a heterogeneous globally distributed group of bacteria that colonize plant xylem vessels. Ralstonia cells multiply rapidly in plants and obstruct water transport, causing fatal wilting and serious economic losses of many key food security crops. The virulence of these pathogens depends on their ability to grow to high cell densities in the low-oxygen xylem environment. Plant-pathogenic Ralstonia can use denitrifying respiration to generate ATP. The last denitrification step, nitrous oxide reduction by NosZ, contributes to energy production and virulence for only one of the three phytopathogenic Ralstonia species. These complete denitrifiers form thicker biofilms in culture and in tomato xylem, suggesting they are better adapted to hypoxic niches. Strains with partial denitrification physiology form less biofilm and are more often planktonic. They are nonetheless highly virulent. Thus, these closely related bacteria have adapted their core metabolic functions to exploit distinct microniches in the same habitat.
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Payá C, Minguillón S, Hernández M, Miguel SM, Campos L, Rodrigo I, Bellés JM, López-Gresa MP, Lisón P. SlS5H silencing reveals specific pathogen-triggered salicylic acid metabolism in tomato. BMC Plant Biol 2022; 22:549. [PMID: 36443652 PMCID: PMC9706870 DOI: 10.1186/s12870-022-03939-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 11/11/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND Salicylic acid (SA) is a major plant hormone that mediates the defence pathway against pathogens. SA accumulates in highly variable amounts depending on the plant-pathogen system, and several enzyme activities participate in the restoration of its levels. Gentisic acid (GA) is the product of the 5-hydroxylation of SA, which is catalysed by S5H, an enzyme activity regarded as a major player in SA homeostasis. GA accumulates at high levels in tomato plants infected by Citrus Exocortis Viroid (CEVd), and to a lesser extend upon Pseudomonas syringae DC3000 pv. tomato (Pst) infection. RESULTS We have studied the induction of tomato SlS5H gene by different pathogens, and its expression correlates with the accumulation of GA. Transient over-expression of SlS5H in Nicotiana benthamiana confirmed that SA is processed by SlS5H in vivo. SlS5H-silenced tomato plants were generated, displaying a smaller size and early senescence, together with hypersusceptibility to the necrotrophic fungus Botrytis cinerea. In contrast, these transgenic lines exhibited an increased defence response and resistance to both CEVd and Pst infections. Alternative SA processing appears to occur for each specific pathogenic interaction to cope with SA levels. In SlS5H-silenced plants infected with CEVd, glycosylated SA was the most discriminant metabolite found. Instead, in Pst-infected transgenic plants, SA appeared to be rerouted to other phenolics such as feruloyldopamine, feruloylquinic acid, feruloylgalactarate and 2-hydroxyglutarate. CONCLUSION Using SlS5H-silenced plants as a tool to unbalance SA levels, we have studied the re-routing of SA upon CEVd and Pst infections and found that, despite the common origin and role for SA in plant pathogenesis, there appear to be different pathogen-specific, alternate homeostasis pathways.
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Affiliation(s)
- C. Payá
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas (CSIC), Universitat Politècnica de València (UPV), Ciudad Politécnica de la Innovación (CPI) 8 E, Ingeniero Fausto Elio s/n, 46011 Valencia, Spain
| | - S. Minguillón
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas (CSIC), Universitat Politècnica de València (UPV), Ciudad Politécnica de la Innovación (CPI) 8 E, Ingeniero Fausto Elio s/n, 46011 Valencia, Spain
| | - M. Hernández
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas (CSIC), Universitat Politècnica de València (UPV), Ciudad Politécnica de la Innovación (CPI) 8 E, Ingeniero Fausto Elio s/n, 46011 Valencia, Spain
| | - S. M. Miguel
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas (CSIC), Universitat Politècnica de València (UPV), Ciudad Politécnica de la Innovación (CPI) 8 E, Ingeniero Fausto Elio s/n, 46011 Valencia, Spain
| | - L. Campos
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas (CSIC), Universitat Politècnica de València (UPV), Ciudad Politécnica de la Innovación (CPI) 8 E, Ingeniero Fausto Elio s/n, 46011 Valencia, Spain
| | - I. Rodrigo
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas (CSIC), Universitat Politècnica de València (UPV), Ciudad Politécnica de la Innovación (CPI) 8 E, Ingeniero Fausto Elio s/n, 46011 Valencia, Spain
| | - J. M. Bellés
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas (CSIC), Universitat Politècnica de València (UPV), Ciudad Politécnica de la Innovación (CPI) 8 E, Ingeniero Fausto Elio s/n, 46011 Valencia, Spain
| | - M. P. López-Gresa
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas (CSIC), Universitat Politècnica de València (UPV), Ciudad Politécnica de la Innovación (CPI) 8 E, Ingeniero Fausto Elio s/n, 46011 Valencia, Spain
| | - P. Lisón
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas (CSIC), Universitat Politècnica de València (UPV), Ciudad Politécnica de la Innovación (CPI) 8 E, Ingeniero Fausto Elio s/n, 46011 Valencia, Spain
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Osei R, Yang C, Wei L, Jin M, Boamah S. Effects of Combined Application of Salicylic Acid and Proline on the Defense Response of Potato Tubers to Newly Emerging Soft Rot Bacteria (Lelliottia amnigena) Infection. Sustainability 2022; 14:8870. [DOI: 10.3390/su14148870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Potato soft rot, caused by the pathogenic bacterium Lelliottia amnigena (Enterobacter amnigenus), is a serious and widespread disease affecting global potato production. Both salicylic acid (SA) and proline (Pro) play important roles in enhancing potato tuber resistance to soft rot. However, the combined effects of SA and Pro on defense responses of potato tubers to L. amnigena infection remain unknown. Hence, the combined effects of SA and Pro in controlling newly emerging potato soft rot bacteria were investigated. Sterilized healthy potato tubers were pretreated with 1.5 mM SA and 2.0 mM Pro 24 h before an inoculation of 0.3 mL of L. amnigena suspension (3.69 × 107 CFU mL−1). Rotting was noticed on the surfaces of the hole where the L. amnigena suspension was inoculated. Application of SA and Pro with L. amnigena lowered the activity of pectinase, protease, pectin lyase, and cellulase by 64.3, 77.8, 66.4 and 84.1%, and decreased malondialdehyde and hydrogen peroxide contents by 77.2% and 83.8%, respectively, compared to the control. The activities of NADPH oxidase, superoxide dismutase, peroxide, catalase, polyphenol oxidase, phenylalanine ammonia-lyase, cinnamyl alcohol dehydrogenase, 4-coumaryl-CoA ligase and cinnamate-4-hydroxylase were increased in the potato tubers with combined treatments by 91.4, 92.4, 91.8, 93.5, 94.9, 91.3, 96.2, 94.7 and 97.7%, respectively, compared to untreated stressed tubers. Six defense-related genes, pathogenesis-related protein, tyrosine-protein kinase, Chitinase-like protein, phenylalanine ammonia-lyase, pathogenesis-related homeodomain protein, and serine protease inhibitor, were induced in SA + Pro treatment when compared with individual application of SA or Pro. This study indicates that the combined treatment of 1.5 mM SA and 2.0 mM Pro had a synergistic effect in controlling potato soft rot caused by a newly emerging bacterium.
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Du H, Yang J, Chen B, Zhang X, Xu X, Wen C, Geng S. Dual RNA-seq Reveals the Global Transcriptome Dynamics of Ralstonia solanacearum and Pepper ( Capsicum annuum) Hypocotyls During Bacterial Wilt Pathogenesis. Phytopathology 2022; 112:630-642. [PMID: 34346759 DOI: 10.1094/phyto-01-21-0032-r] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Bacterial wilt, caused by Ralstonia solanacearum, is a serious disease in pepper. However, the interaction between the pathogen and pepper remains largely unknown. This study aimed to gain insights into determinants of pepper susceptibility and R. solanacearum pathogenesis. We assembled the complete genome of R. solanacearum strain Rs-SY1 and identified 5,106 predicted genes, including 84 type III effectors (T3E). RNA-seq was used to identify differentially expressed genes (DEGs) in susceptible pepper CM334 at 1 and 5 days postinoculation (dpi) with R. solanacearum. Dual RNA-seq was used to simultaneously capture transcriptome changes in the host and pathogen at 3 and 7 dpi. A total of 1,400, 3,335, 2,878, and 4,484 DEGs of pepper (PDEGs) were identified in the CM334 hypocotyls at 1, 3, 5, and 7 dpi, respectively. Functional enrichment of the PDEGs suggests that inducing ethylene production, suppression of photosynthesis, downregulation of polysaccharide metabolism, and weakening of cell wall defenses may contribute to successful infection by R. solanacearum. When comparing in planta and nutrient agar growth of the R. solanacearum, 218 and 1,042 DEGs of R. solanacearum (RDEGs) were detected at 3 and 7 dpi, respectively. Additional analysis of the RDEGs suggested that enhanced starch and sucrose metabolism, and upregulation of virulence factors may promote R. solanacearum colonization. Strikingly, 26 R. solanacearum genes were found to have similar DEG patterns during a variety of host-R. solanacearum interactions. This study provides a foundation for a better understanding of the transcriptional changes during pepper-R. solanacearum interactions and will aid in the discovery of potential susceptibility and virulence factors.
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Affiliation(s)
- Heshan Du
- Beijing Vegetable Research Center, Beijing Academy of Agricultural and Forestry Sciences, Beijing 100097, China
- National Engineering Research Center for Vegetables, Beijing 100097, China
- Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing 100097, China
| | - Jingjing Yang
- Beijing Vegetable Research Center, Beijing Academy of Agricultural and Forestry Sciences, Beijing 100097, China
- National Engineering Research Center for Vegetables, Beijing 100097, China
- Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing 100097, China
| | - Bin Chen
- Beijing Vegetable Research Center, Beijing Academy of Agricultural and Forestry Sciences, Beijing 100097, China
- National Engineering Research Center for Vegetables, Beijing 100097, China
- Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing 100097, China
| | - Xiaofen Zhang
- Beijing Vegetable Research Center, Beijing Academy of Agricultural and Forestry Sciences, Beijing 100097, China
- National Engineering Research Center for Vegetables, Beijing 100097, China
- Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing 100097, China
| | - Xiulan Xu
- Beijing Vegetable Research Center, Beijing Academy of Agricultural and Forestry Sciences, Beijing 100097, China
- National Engineering Research Center for Vegetables, Beijing 100097, China
- Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing 100097, China
| | - Changlong Wen
- Beijing Vegetable Research Center, Beijing Academy of Agricultural and Forestry Sciences, Beijing 100097, China
- National Engineering Research Center for Vegetables, Beijing 100097, China
- Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing 100097, China
| | - Sansheng Geng
- Beijing Vegetable Research Center, Beijing Academy of Agricultural and Forestry Sciences, Beijing 100097, China
- National Engineering Research Center for Vegetables, Beijing 100097, China
- Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing 100097, China
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12
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Syrova DS, Shaposhnikov AI, Yuzikhin OS, Belimov AA. Destruction and Transformation of Phytohormones By Microorganisms. APPL BIOCHEM MICRO+ 2022. [DOI: 10.1134/s0003683822010094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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13
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Rico-Jiménez M, Roca A, Krell T, Matilla MA. A bacterial chemoreceptor that mediates chemotaxis to two different plant hormones. Environ Microbiol 2022; 24:3580-3597. [PMID: 35088505 PMCID: PMC9543091 DOI: 10.1111/1462-2920.15920] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/14/2022] [Accepted: 01/20/2022] [Indexed: 11/30/2022]
Abstract
Indole-3-acetic acid (IAA) is the main naturally occurring auxin and is produced by organisms of all kingdoms of life. In addition to the regulation of plant growth and development, IAA plays an important role in the interaction between plants and growth-promoting and phytopathogenic bacteria by regulating bacterial gene expression and physiology. We show here that a IAA metabolizing plant-associated Pseudomonas putida isolate exhibits chemotaxis to IAA that is independent of auxin metabolism. We found that IAA chemotaxis is based on the activity of the PcpI chemoreceptor and heterologous expression of pcpI conferred IAA taxis to different environmental and human pathogenic isolates of the Pseudomonas genus. Using ligand screening, microcalorimetry and quantitative chemotaxis assays, we found that PcpI failed to bind IAA directly, but recognized and mediated chemoattractions to various aromatic compounds, including the phytohormone salicylic acid. The expression of pcpI and its role in the interactions with plants was also investigated. PcpI extends the range of central signal molecules recognized by chemoreceptors. To our knowledge, this is the first report on a bacterial receptor that responds to two different phytohormones. Our study reinforces the multifunctional role of IAA and salicylic acid as intra- and inter-kingdom signal molecules. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Miriam Rico-Jiménez
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Amalia Roca
- Department of Microbiology, Facultad de Farmacia, Campus Universitario de Cartuja, Universidad de Granada, 18071, Granada, Spain
| | - Tino Krell
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Miguel A Matilla
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Granada, Spain
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Syed‐Ab‐Rahman SF, Arkhipov A, Wass TJ, Xiao Y, Carvalhais LC, Schenk PM. Rhizosphere bacteria induce programmed cell death defence genes and signalling in chilli pepper. J Appl Microbiol 2022; 132:3111-3124. [DOI: 10.1111/jam.15456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 07/14/2021] [Accepted: 12/03/2021] [Indexed: 11/28/2022]
Affiliation(s)
- Sharifah Farhana Syed‐Ab‐Rahman
- Plant‐Microbe Interactions Laboratory School of Agriculture and Food Sciences The University of Queensland Brisbane Queensland 4072 Australia
| | - Alexander Arkhipov
- Plant‐Microbe Interactions Laboratory School of Agriculture and Food Sciences The University of Queensland Brisbane Queensland 4072 Australia
| | - Taylor J. Wass
- Plant‐Microbe Interactions Laboratory School of Agriculture and Food Sciences The University of Queensland Brisbane Queensland 4072 Australia
| | - Yawen Xiao
- Plant‐Microbe Interactions Laboratory School of Agriculture and Food Sciences The University of Queensland Brisbane Queensland 4072 Australia
| | - Lilia C. Carvalhais
- Queensland Alliance for Agriculture and Food Innovation The University of Queensland Ecosciences Precinct GPO Box 267 Queensland 4001 Australia
| | - Peer M. Schenk
- Plant‐Microbe Interactions Laboratory School of Agriculture and Food Sciences The University of Queensland Brisbane Queensland 4072 Australia
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Wu T, Zhang H, Bi Y, Yu Y, Liu H, Yang H, Yuan B, Ding X, Chu Z. Tal2c Activates the Expression of OsF3H04g to Promote Infection as a Redundant TALE of Tal2b in Xanthomonas oryzae pv. oryzicola. Int J Mol Sci 2021; 22:ijms222413628. [PMID: 34948428 PMCID: PMC8707247 DOI: 10.3390/ijms222413628] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 12/15/2021] [Accepted: 12/16/2021] [Indexed: 12/11/2022] Open
Abstract
Xanthomonas oryzae delivers transcription activator-like effectors (TALEs) into plant cells to facilitate infection. Following economic principles, the redundant TALEs are rarely identified in Xanthomonas. Previously, we identified the Tal2b, which activates the expression of the rice 2-oxoglutarate-dependent dioxygenase gene OsF3H03g to promote infection in the highly virulent strain of X. oryzae pv. oryzicola HGA4. Here, we reveal that another clustered TALE, Tal2c, also functioned as a virulence factor to target rice OsF3H04g, a homologue of OsF3H03g. Transferring Tal2c into RS105 induced expression of OsF3H04g to coincide with increased susceptibility in rice. Overexpressing OsF3H04g caused higher susceptibility and less salicylic acid (SA) production compared to wild-type plants. Moreover, CRISPR–Cas9 system-mediated editing of the effector-binding element in the promoters of OsF3H03g or OsF3H04g was found to specifically enhance resistance to Tal2b- or Tal2c-transferring strains, but had no effect on resistance to either RS105 or HGA4. Furthermore, transcriptome analysis revealed that several reported SA-related and defense-related genes commonly altered expression in OsF3H04g overexpression line compared with those identified in OsF3H03g overexpression line. Overall, our results reveal a functional redundancy mechanism of pathogenic virulence in Xoc in which tandem Tal2b and Tal2c specifically target homologues of host genes to interfere with rice immunity by reducing SA.
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Affiliation(s)
- Tao Wu
- State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai’an 271018, China; (T.W.); (H.Z.); (Y.Y.); (H.L.)
- State Key Laboratory of Hybrid Rice, Hubei Hongshan Laboratory, College of Life Sciences, Wuhan University, Wuhan 430072, China;
| | - Haimiao Zhang
- State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai’an 271018, China; (T.W.); (H.Z.); (Y.Y.); (H.L.)
- Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, College of Plant Protection, Shandong Agricultural University, Tai’an 271018, China
| | - Yunya Bi
- State Key Laboratory of Hybrid Rice, Hubei Hongshan Laboratory, College of Life Sciences, Wuhan University, Wuhan 430072, China;
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China;
| | - Yue Yu
- State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai’an 271018, China; (T.W.); (H.Z.); (Y.Y.); (H.L.)
| | - Haifeng Liu
- State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai’an 271018, China; (T.W.); (H.Z.); (Y.Y.); (H.L.)
| | - Hong Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China;
| | - Bin Yuan
- Institute of Plant Protection and Soil Fertilizer, Hubei Academy of Agricultural Sciences, Wuhan 430064, China;
| | - Xinhua Ding
- State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai’an 271018, China; (T.W.); (H.Z.); (Y.Y.); (H.L.)
- Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, College of Plant Protection, Shandong Agricultural University, Tai’an 271018, China
- Correspondence: (X.D.); (Z.C.); Tel.: +86-538-8245569 (X.D.); +86-27-68752095 (Z.C.)
| | - Zhaohui Chu
- State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai’an 271018, China; (T.W.); (H.Z.); (Y.Y.); (H.L.)
- State Key Laboratory of Hybrid Rice, Hubei Hongshan Laboratory, College of Life Sciences, Wuhan University, Wuhan 430072, China;
- Correspondence: (X.D.); (Z.C.); Tel.: +86-538-8245569 (X.D.); +86-27-68752095 (Z.C.)
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Georgoulis SJ, Shalvarjian KE, Helmann TC, Hamilton CD, Carlson HK, Deutschbauer AM, Lowe-Power TM. Genome-Wide Identification of Tomato Xylem Sap Fitness Factors for Three Plant-Pathogenic Ralstonia Species. mSystems 2021;:e0122921. [PMID: 34726495 DOI: 10.1128/mSystems.01229-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Plant-pathogenic Ralstonia spp. colonize plant xylem and cause wilt diseases on a broad range of host plants. To identify genes that promote growth of diverse Ralstonia strains in xylem sap from tomato plants, we performed genome-scale genetic screens (random barcoded transposon mutant sequencing screens [RB-TnSeq]) in three strains spanning the genetic, geographical, and physiological range of plant-pathogenic Ralstonia: Ralstonia solanacearum IBSBF1503, Ralstonia pseudosolanacearum GMI1000, and Ralstonia syzygii PSI07. Contrasting mutant fitness phenotypes in culture media versus in xylem sap suggest that Ralstonia strains are adapted to ex vivo xylem sap and that culture media impose foreign selective pressures. Although wild-type Ralstonia grew in sap and in rich medium with similar doubling times and to a similar carrying capacity, more genes were essential for growth in sap than in rich medium. Each strain required many genes associated with envelope remodeling and repair processes for full fitness in xylem sap. These genes were associated with peptidoglycan peptide formation (murI), secretion of periplasmic proteins (tatC), periplasmic protein folding (dsbA), synthesis of osmoregulated periplasmic glucans (mdoGH), and lipopolysaccharide (LPS) biosynthesis. Mutant strains with mutations in four genes had strong, sap-specific fitness defects in all strain backgrounds: murI, thiC, purU, and a lipoprotein (RSc2007). Many amino acid biosynthesis genes were required for fitness in both minimal medium and xylem sap. Multiple mutants with insertions in virulence regulators had gains of fitness in culture media and neutral fitness in sap. Our genome-scale genetic screen identified Ralstonia fitness factors that promote growth in xylem sap, an ecologically relevant condition. IMPORTANCE Traditional transposon mutagenesis genetic screens pioneered molecular plant pathology and identified core virulence traits like the type III secretion system. TnSeq approaches that leverage next-generation sequencing to rapidly quantify transposon mutant phenotypes are ushering in a new wave of biological discovery. Here, we have adapted a genome-scale approach, random barcoded transposon mutant sequencing (RB-TnSeq), to discover fitness factors that promote growth of three related bacterial strains in a common niche, tomato xylem sap. Fitness of the wild type and mutants show that Ralstonia spp. are adapted to grow well in xylem sap from their natural host plant, tomato. Our screen identified multiple sap-specific fitness factors with roles in maintaining the bacterial envelope. These factors include putative adaptations to resist plant defenses that may include antimicrobial proteins and specialized metabolites that damage bacterial membranes.
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Bauters L, Stojilković B, Gheysen G. Pathogens pulling the strings: Effectors manipulating salicylic acid and phenylpropanoid biosynthesis in plants. Mol Plant Pathol 2021; 22:1436-1448. [PMID: 34414650 PMCID: PMC8518561 DOI: 10.1111/mpp.13123] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 07/15/2021] [Accepted: 08/01/2021] [Indexed: 06/01/2023]
Abstract
During evolution, plants have developed sophisticated ways to cope with different biotic and abiotic stresses. Phytohormones and secondary metabolites are known to play pivotal roles in defence responses against invading pathogens. One of the key hormones involved in plant immunity is salicylic acid (SA), of which the role in plant defence is well established and documented. Plants produce an array of secondary metabolites categorized in different classes, with the phenylpropanoids as major players in plant immunity. Both SA and phenylpropanoids are needed for an effective immune response by the plant. To successfully infect the host, pathogens secrete proteins, called effectors, into the plant tissue to lower defence. Secreted effectors can interfere with several metabolic or signalling pathways in the host to facilitate infection. In this review, we will focus on the different strategies pathogens have developed to affect the levels of SA and phenylpropanoids to increase plant susceptibility.
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Affiliation(s)
- Lander Bauters
- Department of BiotechnologyFaculty of Bioscience EngineeringGhent UniversityGhentBelgium
| | - Boris Stojilković
- Department of BiotechnologyFaculty of Bioscience EngineeringGhent UniversityGhentBelgium
| | - Godelieve Gheysen
- Department of BiotechnologyFaculty of Bioscience EngineeringGhent UniversityGhentBelgium
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Yang L, Guan D, Valls M, Ding W. Sustainable natural bioresources in crop protection: antimicrobial hydroxycoumarins induce membrane depolarization-associated changes in the transcriptome of Ralstonia solanacearum. Pest Manag Sci 2021; 77:5170-5185. [PMID: 34255407 DOI: 10.1002/ps.6557] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 05/07/2021] [Accepted: 07/13/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Ralstonia solanacearum is one of the most devastating pathogens affecting crop production worldwide. The hydroxycoumarins (umbelliferone, esculetin and daphnetin) represent sustainable natural bioresources on controlling plant bacterial wilt. However, the antibacterial mechanism of hydroxycoumarins against plant pathogens still remains poorly understood. RESULTS Here we characterized the effect of three hydroxycoumarins on the transcriptome of R. solanacearum. All three hydroxycoumarins were able to kill R. solanacearum, but their antibacterial activity impacted differently the bacterial transcriptome, indicating that their modes of action might be different. Treatment of R. solanacearum cultures with hydroxycoumarins resulted in a large number of differentially expressed genes (DEGs), involved in basic cellular functions and metabolic process, such as down-regulation of genes involved in fatty acid synthesis, lipopolysaccharides biosynthesis, RNA modification, ribosomal submits, oxidative phosphorylation and electrontransport, as well as up-regulation of genes involved in transcriptional regulators, drug efflux, and oxidative stress responses. Future studies based on in vitro experiments are proposed to investigate lipopolysaccharides biosynthesis pathway leading to R. solanacearum cell death caused by hydroxycoumarins. Deletion of lpxB substantially inhibited the growth of R. solanacearum, and reduced virulence of pathogen on tobacco plants. CONCULSION Our transcriptomic analyses show that specific hydroxycoumarins suppressed gene expression involved in fatty acid synthesis, RNA modification, ribosomal submits, oxidative phosphorylation and electrontransport. These findings provide evidence that hydroxycoumarins inhibit R. solanacearum growth through multi-target effect. Hydroxycoumarins could serve as sustainable natural bioresources against plant bacterial wilt through membrane destruction targeting the lipopolysaccharides biosynthesis pathway.
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Affiliation(s)
- Liang Yang
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University, Chongqing, China
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Barcelona, Spain
| | - Dailu Guan
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Barcelona, Spain
| | - Marc Valls
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Barcelona, Spain
- Genetics Section, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Wei Ding
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University, Chongqing, China
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Zhou X, Wang Y, Li C, Xu Y, Su X, Yang T, Zhang X. Differential Expression Pattern of Pathogenicity-Related Genes of Ralstonia pseudosolanacearum YQ Responding to Tissue Debris of Casuarina equisetifolia. Phytopathology 2021; 111:1918-1926. [PMID: 33822646 DOI: 10.1094/phyto-11-20-0490-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Ralstonia solanacearum species complex (RSSC) contains a group of destructive plant pathogenic bacteria, causing bacterial wilt of >200 species of crops and trees, such as Casuarina equisetifolia, worldwide. RSSC can survive in the soil environment for a long time and start infection after activation by host plants. This study conducted a transcriptome analysis on the expression pattern of the pathogenicity-related genes of a new isolated RSSC strain YQ (Ralstonia pseudosolanacearum phylotype I-16) in response to C. equisetifolia cladophyll (a branch of a stem that resembles and functions as a leaf) and root debris under in vitro culture. The cladophyll debris induced more genes up-regulated than the root debris, including pathogenicity-related genes involved in motility, effectors, type III secretion systems, quorum sensing, and plant cell wall degradation. Besides, many differentially expressed genes were related to transcriptional regulator such as cyclic dimeric guanosine monophosphate. Moreover, the cultures with cladophyll debris induced a faster wilting in bioassays, and the cell swimming was enhanced by cladophyll exudate. C. equisetifolia cladophylls could activate the expression of pathogenicity-related genes of strain YQ and accelerate infection. Our findings suggest that litterfall management in C. equisetifolia forests, or even other plantations, should receive attention to prevent the induction of bacterial wilt disease caused by RSSC.
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Affiliation(s)
- Xiang Zhou
- Collaborative Innovation Center of Zhejiang Green Pesticide, National Joint Local Engineering Laboratory of Biopesticide High-Efficient Preparation, School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou 311300, People's Republic of China
| | - Yue Wang
- Collaborative Innovation Center of Zhejiang Green Pesticide, National Joint Local Engineering Laboratory of Biopesticide High-Efficient Preparation, School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou 311300, People's Republic of China
| | - Chuqiao Li
- Collaborative Innovation Center of Zhejiang Green Pesticide, National Joint Local Engineering Laboratory of Biopesticide High-Efficient Preparation, School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou 311300, People's Republic of China
| | - Yuanyou Xu
- Collaborative Innovation Center of Zhejiang Green Pesticide, National Joint Local Engineering Laboratory of Biopesticide High-Efficient Preparation, School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou 311300, People's Republic of China
| | - Xiu Su
- Collaborative Innovation Center of Zhejiang Green Pesticide, National Joint Local Engineering Laboratory of Biopesticide High-Efficient Preparation, School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou 311300, People's Republic of China
| | - Tian Yang
- Collaborative Innovation Center of Zhejiang Green Pesticide, National Joint Local Engineering Laboratory of Biopesticide High-Efficient Preparation, School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou 311300, People's Republic of China
| | - Xinqi Zhang
- Collaborative Innovation Center of Zhejiang Green Pesticide, National Joint Local Engineering Laboratory of Biopesticide High-Efficient Preparation, School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou 311300, People's Republic of China
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Gupta P, De B. Influence of calcium channel modulators on the production of serotonin, gentisic acid, and a few other biosynthetically related phenolic metabolites in seedling leaves of salt tolerant rice variety Nonabokra. Plant Signal Behav 2021; 16:1929732. [PMID: 34024248 PMCID: PMC8331021 DOI: 10.1080/15592324.2021.1929732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 05/09/2021] [Accepted: 05/10/2021] [Indexed: 06/12/2023]
Abstract
Rice, a most salt-sensitive cereal plant, adopts diverse pathways to withstand sodium chloride-induced salinity-related adversities. During the present study, attempt was made to understand the role of calcium on metabolite profile of the leaves of salt tolerant rice seedlings of variety of Nonabokra under sodium chloride induced salinity, by Gas Chromatography-Mass Spectrometry-based metabolomics approach. Calcium availability in the seedlings was reduced or enhanced applying inhibitors (vanadyl sulfate, lanthanum chloride, and verapamil) or promoters of calcium influx (calcimycin also known as calcium ionophore A23187) in the sodium chloride (100 mM) supplemented growth medium. Growth medium of ten-day-old seedlings was replaced by sodium chloride supplemented hydroponic solution with promotor or inhibitors of calcium channel. Fifteen days old seedlings were harvested. It was observed that depletion of calcium availability increased the level of serotonin and gentisic acid whereas increased calcium level decreased these metabolites. It was concluded from the results that production of the signaling molecules serotonin and gentisic acids was elevated in calcium-deficient seedlings under salt stress the condition that was considered as control during the experiment. The two signaling molecules probably help this tolerant rice variety Nonabokra to withstand the salt-induced adversities.
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Affiliation(s)
- Poulami Gupta
- Department of Botany, University of Calcutta, Kolkata, India
| | - Bratati De
- Department of Botany, University of Calcutta, Kolkata, India
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Zhu X, Mazard J, Robe E, Pignoly S, Aguilar M, San Clemente H, Lauber E, Berthomé R, Galaud JP. The Same against Many: AtCML8, a Ca 2+ Sensor Acting as a Positive Regulator of Defense Responses against Several Plant Pathogens. Int J Mol Sci 2021; 22:10469. [PMID: 34638807 DOI: 10.3390/ijms221910469] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 09/21/2021] [Accepted: 09/24/2021] [Indexed: 01/11/2023] Open
Abstract
Calcium signals are crucial for the activation and coordination of signaling cascades leading to the establishment of plant defense mechanisms. Here, we studied the contribution of CML8, an Arabidopsis calmodulin-like protein in response to Ralstonia solanacearum and to pathogens with different lifestyles, such as Xanthomonas campestris pv. campestris and Phytophtora capsici. We used pathogenic infection assays, gene expression, RNA-seq approaches, and comparative analysis of public data on CML8 knockdown and overexpressing Arabidopsis lines to demonstrate that CML8 contributes to defense mechanisms against pathogenic bacteria and oomycetes. CML8 gene expression is finely regulated at the root level and manipulated during infection with Ralstonia, and CML8 overexpression confers better plant tolerance. To understand the processes controlled by CML8, genes differentially expressed at the root level in the first hours of infection have been identified. Overexpression of CML8 also confers better tolerance against Xanthomonas and Phytophtora, and most of the genes differentially expressed in response to Ralstonia are differentially expressed in these different pathosystems. Collectively, CML8 acts as a positive regulator against Ralstonia solanaceraum and against other vascular or root pathogens, suggesting that CML8 is a multifunctional protein that regulates common downstream processes involved in the defense response of plants to several pathogens.
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Abstract
Plant pathogen effector proteins are key to pathogen virulence. In susceptible host Brassicas, the clubroot pathogen, Plasmodiophora brassicae, induces the production of nutrient-sink root galls, at the site of infection. Among a list of 32 P. brassiae effector candidates previously reported by our group, we identified SSPbP53 as a putative apoplastic cystatin-like protein highly expressed during the secondary infection. Here we found that SSPbP53 encoding gene is conserved among several P. brassicae pathotypes and that SSPbP53 is an apoplastic protein able to directly interact with and inhibit cruciferous papain-like cysteine proteases (PLCPs), specifically Arabidopsis XYLEM CYSTEINE PEPTIDASE 1 (AtXCP1). The severity of clubroot disease is greatly reduced in the Arabidopsis xcp1 null mutant (AtΔxcp1) after infection with P. brassicae resting spores, indicating that the interaction of P. brassicae SSPbP53 with XCP1 is important to clubroot susceptibility. SSPbP53 is the first cystatin-like effector identified and characterized for a plant pathogenic protist.
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Affiliation(s)
- Edel Pérez-López
- Department of Biology, University of Saskatchewan, Saskatoon, Canada.,Department of Plant Sciences, University Laval, Criv, Quebec City, Canada
| | | | - Yangdou Wei
- Department of Biology, University of Saskatchewan, Saskatoon, Canada
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Xi D, Li X, Gao L, Zhang Z, Zhu Y, Zhu H. Application of exogenous salicylic acid reduces disease severity of Plasmodiophora brassicae in pakchoi (Brassica campestris ssp. chinensis Makino). PLoS One 2021; 16:e0248648. [PMID: 34166377 DOI: 10.1371/journal.pone.0248648] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 03/02/2021] [Indexed: 01/07/2023] Open
Abstract
Clubroot is one of the most serious diseases affecting Brassicaceae plants worldwide. However, there is no effective control method for clubroot. Salicylic acid (SA) is a plant hormone that plays a critical role in plant defense. In our study, we found the disease severity of a clubroot-sensitive cultivar of pakchoi, Xinxiaqing, was reduced with 0.6mM exogenous SA after the infection of P. brassicae. To investigate the mechanism of SA-reduced disease severity against clubroot, then we analyzed the plant growth, alteration of antioxidant enzyme system, and related gene expression of Xinxiaqing. Results showed that the clubroot incidence rate and disease index were decreased after being treated with 0.6 mM exogenous SA. Furthermore, plant growth, reactive oxygen species (ROS) contents, and membrane lipid peroxidation were changed. The activities of antioxidant enzymes, including superoxide dismutase (SOD), ascorbic acid-peroxidase (APX), catalase (CAT), and glutathione reductase (GR), were increased. Additionally, the production rates of malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide anion (O2·-) were also inhibited. The expression levels of genes, encoding SOD, APX, CAT, and GR, were increased. By summering all results, we conclude that 0.6 mM SA contributes to the reduction of disease severity to clubroot by increasing the activities of antioxidant enzymes, abilities of osmotic regulation, and ROS scavenging to reduce the clubroot-induced damage in pakchoi.
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24
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Abstract
Salicylic acid (SA) is an essential plant defense hormone that promotes immunity against biotrophic and semibiotrophic pathogens. It plays crucial roles in basal defense and the amplification of local immune responses, as well as the establishment of systemic acquired resistance. During the past three decades, immense progress has been made in understanding the biosynthesis, homeostasis, perception, and functions of SA. This review summarizes the current knowledge regarding SA in plant immunity and other biological processes. We highlight recent breakthroughs that substantially advanced our understanding of how SA is biosynthesized from isochorismate, how it is perceived, and how SA receptors regulate different aspects of plant immunity. Some key questions in SA biosynthesis and signaling, such as how SA is produced via another intermediate, benzoic acid, and how SA affects the activities of its receptors in the transcriptional regulation of defense genes, remain to be addressed.
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Affiliation(s)
- Yujun Peng
- Department of Botany, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada; , , ,
| | - Jianfei Yang
- Department of Botany, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada; , , ,
- College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Xin Li
- Department of Botany, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada; , , ,
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Yuelin Zhang
- Department of Botany, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada; , , ,
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Hamilton CD, Steidl OR, MacIntyre AM, Hendrich CG, Allen C. Ralstonia solanacearum Depends on Catabolism of Myo-Inositol, Sucrose, and Trehalose for Virulence in an Infection Stage-Dependent Manner. Mol Plant Microbe Interact 2021; 34:669-679. [PMID: 33487004 DOI: 10.1094/mpmi-10-20-0298-r] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The soilborne pathogen Ralstonia solanacearum causes a lethal bacterial wilt disease of tomato and many other crops by infecting host roots, then colonizing the water-transporting xylem vessels. Tomato xylem sap is nutritionally limiting but it does contain some carbon sources, including sucrose, trehalose, and myo-inositol. Transcriptomic analyses revealed that R. solanacearum expresses distinct catabolic pathways at low cell density (LCD) and high cell density (HCD). To investigate the links between bacterial catabolism, infection stage, and virulence, we measured in planta fitness of bacterial mutants lacking specific carbon catabolic pathways expressed at either LCD or HCD. We hypothesized that early in disease, during root infection, the bacterium depends on carbon sources catabolized at LCD, while HCD carbon sources are only required later in disease during stem colonization. A R. solanacearum ΔiolG mutant unable to use the LCD-catabolized nutrient myo-inositol was defective in tomato root colonization, but after it reached the stem this strain colonized and caused symptoms as well as wild type. In contrast, R. solanacearum mutants unable to use the HCD-catabolized nutrients sucrose (ΔscrA), trehalose (ΔtreA), or both (ΔscrA/treA), infected roots as well as wild-type R. solanacearum but were defective in colonization and competitive fitness in midstems and had reduced virulence. Further, xylem sap from tomato plants colonized by ΔscrA, ΔtreA, or ΔscrA/treA R. solanacearum mutants contained twice as much sucrose as sap from plants colonized by wild-type R. solanacearum. Together, these findings suggest that quorum sensing specifically adapts R. solanacearum metabolism for success in the different nutritional environments of plant roots and xylem sap.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Corri D Hamilton
- Department of Plant Pathology University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI 53706, U.S.A
| | - Olivia R Steidl
- Department of Plant Pathology University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI 53706, U.S.A
| | - April M MacIntyre
- Department of Plant Pathology University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI 53706, U.S.A
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI 53706, U.S.A
| | - Connor G Hendrich
- Department of Plant Pathology University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI 53706, U.S.A
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI 53706, U.S.A
| | - Caitilyn Allen
- Department of Plant Pathology University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI 53706, U.S.A
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26
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Zhou F, Last RL, Pichersky E. Degradation of salicylic acid to catechol in Solanaceae by SA 1-hydroxylase. Plant Physiol 2021; 185:876-891. [PMID: 33793924 PMCID: PMC8133591 DOI: 10.1093/plphys/kiaa096] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 12/07/2020] [Indexed: 05/16/2023]
Abstract
The hormone salicylic acid (SA) plays crucial roles in plant defense, stress responses, and in the regulation of plant growth and development. Whereas the biosynthetic pathways and biological functions of SA have been extensively studied, SA catabolism is less well understood. In this study, we report the identification and functional characterization of an FAD/NADH-dependent SA 1-hydroxylase from tomato (Solanum lycopersicum; SlSA1H), which catalyzes the oxidative decarboxylation of SA to catechol. Transcript levels of SlSA1H were highest in stems and its expression was correlated with the formation of the methylated catechol derivatives guaiacol and veratrole. Consistent with a role in SA catabolism, SlSA1H RNAi plants accumulated lower amounts of guaiacol and failed to produce any veratrole. Two O-methyltransferases involved in the conversion of catechol to guaiacol and guaiacol to veratrole were also functionally characterized. Subcellular localization analyses revealed the cytosolic localization of this degradation pathway. Phylogenetic analysis and functional characterization of SA1H homologs from other species indicated that this type of FAD/NADH-dependent SA 1-hydroxylases evolved recently within the Solanaceae family.
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Affiliation(s)
- Fei Zhou
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Robert L Last
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48823, USA
- Department of Plant Biology, Michigan State University, East Lansing, MI 48823, USA
| | - Eran Pichersky
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
- Author for correspondence:
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Alonso-Díaz A, Satbhai SB, de Pedro-Jové R, Berry HM, Göschl C, Argueso CT, Novak O, Busch W, Valls M, Coll NS. A genome-wide association study reveals cytokinin as a major component in the root defense responses against Ralstonia solanacearum. J Exp Bot 2021; 72:2727-2740. [PMID: 33475698 PMCID: PMC8006551 DOI: 10.1093/jxb/eraa610] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 01/19/2021] [Indexed: 05/30/2023]
Abstract
Bacterial wilt caused by the soil-borne pathogen Ralstonia solancearum is economically devastating, with no effective methods to fight the disease. This pathogen invades plants through their roots and colonizes their xylem, clogging the vasculature and causing rapid wilting. Key to preventing colonization are the early defense responses triggered in the host's root upon infection, which remain mostly unknown. Here, we have taken advantage of a high-throughput in vitro infection system to screen natural variability associated with the root growth inhibition phenotype caused by R. solanacearum in Arabidopsis during the first hours of infection. To analyze the genetic determinants of this trait, we have performed a genome-wide association study, identifying allelic variation at several loci related to cytokinin metabolism, including genes responsible for biosynthesis and degradation of cytokinin. Further, our data clearly demonstrate that cytokinin signaling is induced early during the infection process and cytokinin contributes to immunity against R. solanacearum. This study highlights a new role for cytokinin in root immunity, paving the way for future research that will help in understanding the mechanisms underpinning root defenses.
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Affiliation(s)
- Alejandro Alonso-Díaz
- Centre for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Barcelona, Spain
| | - Santosh B Satbhai
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr Bohr-Gasse 3, Vienna 1030, Austria
- Salk Institute For Biological Studies, Plant Molecular and Cellular Biology Laboratory, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Roger de Pedro-Jové
- Centre for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Barcelona, Spain
| | - Hannah M Berry
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO 80523, USA
- Cell and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Christian Göschl
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr Bohr-Gasse 3, Vienna 1030, Austria
| | - Cristiana T Argueso
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO 80523, USA
| | - Ondrej Novak
- Laboratory of Growth Regulators, Olomouc, The Czech Republic
| | - Wolfgang Busch
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr Bohr-Gasse 3, Vienna 1030, Austria
- Salk Institute For Biological Studies, Plant Molecular and Cellular Biology Laboratory, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Marc Valls
- Centre for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Barcelona, Spain
- Genetics Department, University of Barcelona, Barcelona, Spain
| | - Núria S Coll
- Centre for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Barcelona, Spain
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28
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Yang L, Wei Z, Valls M, Ding W. Metabolic Profiling of Resistant and Susceptible Tobaccos Response Incited by Ralstonia pseudosolanacearum Causing Bacterial Wilt. Front Plant Sci 2021; 12:780429. [PMID: 35069638 PMCID: PMC8780990 DOI: 10.3389/fpls.2021.780429] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 11/24/2021] [Indexed: 05/16/2023]
Abstract
The causal agent of bacterial wilt, Ralstonia pseudosolanacearum, can cause significant economic losses during tobacco production. Metabolic analyses are a useful tool for the comprehensive identification of plant defense response metabolites. In this study, a gas chromatography-mass spectrometry (GC-MS) approach was used to identify metabolites differences in tobacco xylem sap in response to R. pseudosolanacearum CQPS-1 in two tobacco cultivars: Yunyan87 (susceptible to R. pseudosolanacearum) and K326 (quantitatively resistant). Metabolite profiling 7 days post inoculation with R. pseudosolanacearum identified 88 known compounds, 42 of them enriched and 6 depleted in the susceptible cultivar Yunyan87, while almost no changes occurred in quantitatively resistant cultivar K326. Putrescine was the most enriched compound (12-fold) in infected susceptible tobacco xylem, followed by methyl-alpha-d-glucopyranoside (9-fold) and arabinitol (6-fold). Other sugars, amino acids, and organic acids were also enriched upon infection. Collectively, these metabolites can promote R. pseudosolanacearum growth, as shown by the increased growth of bacterial cultures supplemented with xylem sap from infected tobacco plants. Comparison with previous metabolic data showed that beta-alanine, phenylalanine, and leucine were enriched during bacterial wilt in both tobacco and tomato xylem.
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Affiliation(s)
- Liang Yang
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University, Chongqing, China
| | - Zhouling Wei
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University, Chongqing, China
| | - Marc Valls
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB, Barcelona, Spain
- Genetics Section, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Wei Ding
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University, Chongqing, China
- *Correspondence: Wei Ding,
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29
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De Saeger J, Park J, Chung HS, Hernalsteens JP, Van Lijsebettens M, Inzé D, Van Montagu M, Depuydt S. Agrobacterium strains and strain improvement: Present and outlook. Biotechnol Adv 2020; 53:107677. [PMID: 33290822 DOI: 10.1016/j.biotechadv.2020.107677] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 11/03/2020] [Accepted: 11/28/2020] [Indexed: 12/12/2022]
Abstract
Almost 40 years ago the first transgenic plant was generated through Agrobacterium tumefaciens-mediated transformation, which, until now, remains the method of choice for gene delivery into plants. Ever since, optimized Agrobacterium strains have been developed with additional (genetic) modifications that were mostly aimed at enhancing the transformation efficiency, although an optimized strain also exists that reduces unwanted plasmid recombination. As a result, a collection of very useful strains has been created to transform a wide variety of plant species, but has also led to a confusing Agrobacterium strain nomenclature. The latter is often misleading for choosing the best-suited strain for one's transformation purposes. To overcome this issue, we provide a complete overview of the strain classification. We also indicate different strain modifications and their purposes, as well as the obtained results with regard to the transformation process sensu largo. Furthermore, we propose additional improvements of the Agrobacterium-mediated transformation process and consider several worthwhile modifications, for instance, by circumventing a defense response in planta. In this regard, we will discuss pattern-triggered immunity, pathogen-associated molecular pattern detection, hormone homeostasis and signaling, and reactive oxygen species in relationship to Agrobacterium transformation. We will also explore alterations that increase agrobacterial transformation efficiency, reduce plasmid recombination, and improve biocontainment. Finally, we recommend the use of a modular system to best utilize the available knowledge for successful plant transformation.
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Affiliation(s)
- Jonas De Saeger
- Laboratory of Plant Growth Analysis, Ghent University Global Campus, Incheon 406-840, South Korea; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium; Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Jihae Park
- Laboratory of Plant Growth Analysis, Ghent University Global Campus, Incheon 406-840, South Korea; Department of Marine Sciences, Incheon National University, Incheon 406-840, South Korea
| | - Hoo Sun Chung
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium; Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | | | - Mieke Van Lijsebettens
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium; Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Dirk Inzé
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium; Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Marc Van Montagu
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium; Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Stephen Depuydt
- Laboratory of Plant Growth Analysis, Ghent University Global Campus, Incheon 406-840, South Korea; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium; Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium.
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30
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Jung J, Kim SK, Jung SH, Jeong MJ, Ryu CM. Sound Vibration-Triggered Epigenetic Modulation Induces Plant Root Immunity Against Ralstonia solanacearum. Front Microbiol 2020; 11:1978. [PMID: 32973716 PMCID: PMC7472266 DOI: 10.3389/fmicb.2020.01978] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 07/27/2020] [Indexed: 12/21/2022] Open
Abstract
Sound vibration (SV) is one of the several environmental stimuli that induce physiological changes in plants including changes in plant immunity. Immune activation is a complicated process involving epigenetic modifications, however, SV-induced epigenetic modifications remain unexplored. Here, we performed an integrative analysis comprising chromatin immunoprecipitation (ChIP) and microRNA sequencing (miRNA-seq) to understand the role of SV-mediated epigenetic modifications in immune activation in Arabidopsis thaliana against the root pathogen Ralstonia solanacearum. Plants exposed to SV (10 kHz) showed abundant H3K27me3 modification in the promoter regions of aliphatic glucosinolate biosynthesis and cytokinin signaling genes, leading to transcriptional changes that promote immunity. Additionally, 10 kHz SV down-regulated miR397b expression, thus activating three target LACCASE transcripts that mediate cell wall reinforcement via lignin accumulation. Taken together, SV triggers epigenetic modification of genes involved in secondary metabolite biosynthesis, defense hormone signaling, and pre-formed defense in A. thaliana, leading to the activation of plant immunity against R. solanacearum.
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Affiliation(s)
- Jihye Jung
- Molecular Phytobacteriology Laboratory, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea.,Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Seon-Kyu Kim
- Personalized Genomic Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea
| | - Sung-Hee Jung
- Molecular Phytobacteriology Laboratory, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea.,Biosystems and Bioengineering Program, University of Science and Technology, Daejeon, South Korea
| | - Mi-Jeong Jeong
- National Institute of Agricultural Science, Rural Development Administration, Wanju, South Korea
| | - Choong-Min Ryu
- Molecular Phytobacteriology Laboratory, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea.,Biosystems and Bioengineering Program, University of Science and Technology, Daejeon, South Korea
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31
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Shen F, Yin W, Song S, Zhang Z, Ye P, Zhang Y, Zhou J, He F, Li P, Deng Y. Ralstonia solanacearum promotes pathogenicity by utilizing l-glutamic acid from host plants. Mol Plant Pathol 2020; 21:1099-1110. [PMID: 32599676 PMCID: PMC7368120 DOI: 10.1111/mpp.12963] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 05/20/2020] [Indexed: 05/22/2023]
Abstract
Ralstonia solanacearum is an important bacterial pathogen that can infect a broad range of plants worldwide. A previous study showed that R. solanacearum could respond to exogenous organic acids or amino acids to modulate cell motility. However, it was unclear whether R. solanacearum uses these compounds to control infection. In this study, we found that R. solanacearum GMI1000 uses host plant metabolites to enhance the biosynthesis of virulence factors. We demonstrated that l-glutamic acid from host plants is the key active component associated with increased extracellular polysaccharide production, cellulase activity, swimming motility, and biofilm formation in R. solanacearum GMI1000. In addition, l-glutamic acid also promoted colonization of R. solanacearum cells in the roots and stems of tomato plants and accelerated disease incidence. Furthermore, genetic screening and biochemical analysis suggested that RS01577, a hybrid sensor histidine kinase/response regulator, is involved in l-glutamic acid signalling in R. solanacearum. Mutations in RS01577 and exogenous addition of l-glutamic acid to the GMI1000 wild-type strain had overlapping effects on both the transcriptome and biological functions of R. solanacearum, including on motility, biofilm formation, and virulence. Thus, our results have established a new interaction mechanism between R. solanacearum and host plants that highlights the complexity of the virulence regulation mechanism and may provide new insight into disease control.
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Affiliation(s)
- Fangfang Shen
- College of AgricultureSouth China Agricultural UniversityGuangzhouChina
| | - Wenfang Yin
- College of AgricultureSouth China Agricultural UniversityGuangzhouChina
| | - Shihao Song
- College of AgricultureSouth China Agricultural UniversityGuangzhouChina
| | - Zhihan Zhang
- College of AgricultureSouth China Agricultural UniversityGuangzhouChina
| | - Peiyi Ye
- College of AgricultureSouth China Agricultural UniversityGuangzhouChina
| | - Yong Zhang
- College of Resources and EnvironmentSouthwest UniversityChongqingChina
| | - Jianuan Zhou
- College of AgricultureSouth China Agricultural UniversityGuangzhouChina
| | - Fei He
- College of AgricultureSouth China Agricultural UniversityGuangzhouChina
| | - Peng Li
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan ProvinceCollege of Life SciencesHainan Normal UniversityHaikouChina
| | - Yinyue Deng
- School of Pharmaceutical Sciences (Shenzhen)Sun Yat‐sen UniversityGuangzhouChina
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32
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Su L, Zhang L, Nie D, Kuramae EE, Shen B, Shen Q. Bacterial Tomato Pathogen Ralstonia solanacearum Invasion Modulates Rhizosphere Compounds and Facilitates the Cascade Effect of Fungal Pathogen Fusarium solani. Microorganisms 2020; 8:E806. [PMID: 32471167 DOI: 10.3390/microorganisms8060806] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/15/2020] [Accepted: 05/22/2020] [Indexed: 01/30/2023] Open
Abstract
Soil-borne pathogen invasions can significantly change the microbial communities of the host rhizosphere. However, whether bacterial Ralstonia solanacearum pathogen invasion influences the abundance of fungal pathogens remains unclear. In this study, we combined high-throughput sequencing, qPCR, liquid chromatography and soil culture experiments to analyze the rhizosphere fungal composition, co-occurrence of fungal communities, copy numbers of functional genes, contents of phenolic acids and their associations in healthy and bacterial wilt-diseased tomato plants. We found that R. solanacearum invasion increased the abundance of the soil-borne pathogen Fusarium solani. The concentrations of three phenolic acids in the rhizosphere soil of bacterial wilt-diseased tomato plants were significantly higher than those in the rhizosphere soil of healthy tomato plants. In addition, the increased concentrations of phenolic acids significantly stimulated F. solani growth in the soil. Furthermore, a simple fungal network with fewer links, nodes and hubs (highly connected nodes) was found in the diseased tomato plant rhizosphere. These results indicate that once the symptom of bacterial wilt disease is observed in tomato, the roots of the wilt-diseased tomato plants need to be removed in a timely manner to prevent the enrichment of other fungal soil-borne pathogens. These findings provide some ecological clues for the mixed co-occurrence of bacterial wilt disease and other fungal soil-borne diseases.
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MacIntyre AM, Barth JX, Pellitteri Hahn MC, Scarlett CO, Genin S, Allen C. Trehalose Synthesis Contributes to Osmotic Stress Tolerance and Virulence of the Bacterial Wilt Pathogen Ralstonia solanacearum. Mol Plant Microbe Interact 2020; 33:462-473. [PMID: 31765286 DOI: 10.1094/mpmi-08-19-0218-r] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The xylem-dwelling plant pathogen Ralstonia solanacearum changes the chemical composition of host xylem sap during bacterial wilt disease. The disaccharide trehalose, implicated in stress tolerance across all kingdoms of life, is enriched in sap from R. solanacearum-infected tomato plants. Trehalose in xylem sap could be synthesized by the bacterium, the plant, or both. To investigate the source and role of trehalose metabolism during wilt disease, we evaluated the effects of deleting the three trehalose synthesis pathways in the pathogen: TreYZ, TreS, and OtsAB, as well as its sole trehalase, TreA. A quadruple treY/treS/otsA/treA mutant produced 30-fold less intracellular trehalose than the wild-type strain missing the trehalase enzyme. This trehalose-nonproducing mutant had reduced tolerance to osmotic stress, which the bacterium likely experiences in plant xylem vessels. Following naturalistic soil-soak inoculation of tomato plants, this triple mutant did not cause disease as well as wild-type R. solanacearum. Further, the wild-type strain out-competed the trehalose-nonproducing mutant by over 600-fold when tomato plants were coinoculated with both strains, showing that trehalose biosynthesis helps R. solanacearum overcome environmental stresses during infection. An otsA (trehalose-6-phosphate synthase) single mutant behaved similarly to ΔtreY/treS/otsA in all experimental settings, suggesting that the OtsAB pathway is the dominant trehalose synthesis pathway in R. solanacearum.
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Affiliation(s)
- April M MacIntyre
- Department of Plant Pathology, University of Wisconsin-Madison, U.S.A
| | - John X Barth
- Department of Plant Pathology, University of Wisconsin-Madison, U.S.A
| | | | - Cameron O Scarlett
- Analytical Instrumentation Center, School of Pharmacy, University of Wisconsin-Madison
| | - Stéphane Genin
- LIPM, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | - Caitilyn Allen
- Department of Plant Pathology, University of Wisconsin-Madison, U.S.A
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Nagai A, Torres PB, Duarte LML, Chaves ALR, Macedo AF, Floh EIS, de Oliveira LF, Zuccarelli R, Dos Santos DYAC. Signaling pathway played by salicylic acid, gentisic acid, nitric oxide, polyamines and non-enzymatic antioxidants in compatible and incompatible Solanum-tomato mottle mosaic virus interactions. Plant Sci 2020; 290:110274. [PMID: 31779908 DOI: 10.1016/j.plantsci.2019.110274] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 09/13/2019] [Indexed: 05/26/2023]
Abstract
Plants are exposed to a vast array of pathogens. The interaction between them may be classified in compatible and incompatible. Polyamines (PAs) are involved in defense responses, as well as salicylic acid (SA), gentisic acid (GA) and nitric oxide (NO), which can increase the content of reactive oxygen species (ROS), creating a harsh environment to the pathogen. ROS can also damage the host cell and they can be controlled by ascorbate and glutathione. Among phytopathogens, one of the major threats to tomato crops is tomato mottle mosaic virus (ToMMV). Resistance against this virus probably involves the Tm-22 gene. This work aimed to analyze signaling and antioxidant molecules in the defense response against ToMMV in Solanum pimpinellifolium and in S. lycopersicum 'VFNT'. In S. pimpinellifolium plants inoculated with ToMMV, an increase in NO, SA, GA, ascorbate and oxidized glutathione and a decrease in the content of PAs were observed. Characteristic symptoms of diseased plants and high absorbance values in PTA-ELISA indicated a compatible interaction. In VFNT-inoculated plants, less significant differences were noticed. Symptoms and viral concentration were not detected, indicating an incompatible interaction, possibly associated with the effector-triggered immunity (ETI) response.
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Affiliation(s)
- Alice Nagai
- Laboratório de Fitoquímica, Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil.
| | - Priscila Bezerra Torres
- Laboratório de Fitoquímica, Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| | | | | | - Amanda Ferreira Macedo
- Laboratório de Biologia Celular de Plantas, Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| | - Eny Iochevet Segal Floh
- Laboratório de Biologia Celular de Plantas, Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| | - Leandro Francisco de Oliveira
- Laboratório de Biologia Celular de Plantas, Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| | - Rafael Zuccarelli
- Laboratório de Fisiologia do Desenvolvimento Vegetal, Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
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Zhang Y, Zhang W, Han L, Li J, Shi X, Hikichi Y, Ohnishi K. Involvement of a PadR regulator PrhP on virulence of Ralstonia solanacearum by controlling detoxification of phenolic acids and type III secretion system. Mol Plant Pathol 2019; 20:1477-1490. [PMID: 31392803 PMCID: PMC6804342 DOI: 10.1111/mpp.12854] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Ralstonia solanacearum can metabolize ferulic acid (FA) and salicylic acid (SA), two representative phenolic acids, to protect it from toxicity of phenolic acids. Here, we genetically demonstrated a novel phenolic acid decarboxylase regulator (PadR)-like regulator PrhP as a positive regulator on detoxification of SA and FA in R. solanacearum. Although the ability to degrade SA and FA enhances the infection process of R. solanacearum toward host plants, PrhP greatly contributes to the infection process besides degradation of SA and FA. Our results from the growth assay, promoter activity assay, RNA-seq and qRT-PCR revealed that PrhP plays multiple roles in the virulence of R. solanacearum: (1) positively regulates expression of genes for degradation of SA and FA; (2) positively regulates expression of genes encoding type III secretion system (T3SS) and type III effectors both in vitro and in planta; (3) positively regulates expression of many virulence-related genes, such as the flagella, type IV pili and cell wall degradation enzymes; and (4) is important for the extensive proliferation in planta. The T3SS is one of the essential pathogenicity determinants in many pathogenic bacteria, and PrhP positively regulates its expression mediated with the key regulator HrpB but through some novel pathway to HrpB in R. solanacearum. This is the first report on PadR regulators to regulate the T3SS and it could improve our understanding of the various biological functions of PadR regulators and the complex regulatory pathway on T3SS in R. solanacearum.
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Affiliation(s)
- Yong Zhang
- College of Resources and EnvironmentSouthwest UniversityChongqingChina
- Key Laboratory of Efficient Utilization of Soil and Fertilizer ResourcesChongqing
| | - Weiqi Zhang
- College of Resources and EnvironmentSouthwest UniversityChongqingChina
| | - Liangliang Han
- College of Resources and EnvironmentSouthwest UniversityChongqingChina
- Research Institute of Molecular Genetics, Kochi UniversityKochiJapan
| | - Jing Li
- The Ninth Peoples Hospital of ChongqingChongqingChina
| | - Xiaojun Shi
- College of Resources and EnvironmentSouthwest UniversityChongqingChina
- Key Laboratory of Efficient Utilization of Soil and Fertilizer ResourcesChongqing
| | - Yasufumi Hikichi
- Laboratory of Plant Pathology and BiotechnologyKochi UniversityKochiJapan
| | - Kouhei Ohnishi
- Research Institute of Molecular Genetics, Kochi UniversityKochiJapan
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Hao G, Naumann TA, Vaughan MM, McCormick S, Usgaard T, Kelly A, Ward TJ. Characterization of a Fusarium graminearum Salicylate Hydroxylase. Front Microbiol 2019; 9:3219. [PMID: 30671040 PMCID: PMC6331432 DOI: 10.3389/fmicb.2018.03219] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 12/11/2018] [Indexed: 11/13/2022] Open
Abstract
Salicylic acid (SA) plays an important role in regulating plant defense responses against pathogens. However, pathogens have evolved ways to manipulate plant SA-mediated defense signaling. Fusarium graminearum causes Fusarium head blight (FHB) and reduces crop yields and quality by producing various mycotoxins. In this study, we aimed to identify the salicylate hydroxylase in F. graminearum and determine its role in wheat head blight development. We initially identified a gene in F. graminearum strain NRRL 46422 that encodes a putative salicylate hydroxylase (designated FgShyC). However, the FgShyC deletion mutant showed a similar ability to degrade SA as wild-type strain 46422; nor did overexpression of FgShyC in E. coli convert SA to catechol. The results indicate that FgShyC is not involved in SA degradation. Further genome sequence analyses resulted in the identification of eight salicylate hydroxylase candidates. Upon addition of 1 mM SA, FGSG_03657 (designated FgShy1), was induced approximately 400-fold. Heterologous expression of FgShy1 in E. coli converted SA to catechol, confirming that FgShy1 is a salicylate hydroxylase. Deletion mutants of FgShy1 were greatly impaired but not completely blocked in SA degradation. Expression analyses of infected tissue showed that FgShy1 was induced during infection, but virulence assays revealed that deletion of FgShy1 alone was not sufficient to affect FHB severity. Although the Fgshy1 deletion mutant did not reduce pathogenicity, we cannot rule out that additional salicylate hydroxylases are present in F. graminearum and characterization of these enzymes will be necessary to fully understand the role of SA-degradation in FHB pathogenesis.
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Affiliation(s)
- Guixia Hao
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture – Agricultural Research Service, Peoria, IL, United States
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Qi G, Chen J, Chang M, Chen H, Hall K, Korin J, Liu F, Wang D, Fu ZQ. Pandemonium Breaks Out: Disruption of Salicylic Acid-Mediated Defense by Plant Pathogens. Mol Plant 2018; 11:1427-1439. [PMID: 30336330 DOI: 10.1016/j.molp.2018.10.002] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 09/30/2018] [Accepted: 10/09/2018] [Indexed: 05/26/2023]
Abstract
Salicylic acid (SA) or 2-hydroxybenoic acid is a phenolic plant hormone that plays an essential role in plant defense against biotrophic and semi-biotrophic pathogens. In Arabidopsis, SA is synthesized from chorismate in the chloroplast through the ICS1 (isochorismate synthase I) pathway during pathogen infection. The transcription co-activator NPR1 (Non-Expresser of Pathogenesis-Related Gene 1), as the master regulator of SA signaling, interacts with transcription factors to induce the expression of anti-microbial PR (Pathogenesis-Related) genes. To establish successful infections, plant bacterial, oomycete, fungal, and viral pathogens have evolved at least three major strategies to disrupt SA-mediated defense. The first strategy is to reduce SA accumulation directly by converting SA into its inactive derivatives. The second strategy is to interrupt SA biosynthesis by targeting the ICS1 pathway. In the third major strategy, plant pathogens deploy different mechanisms to interfere with SA downstream signaling. The wide array of strategies deployed by plant pathogens highlights the crucial role of disruption of SA-mediated plant defense in plant pathogenesis. A deeper understanding of this topic will greatly expand our knowledge of how plant pathogens cause diseases and consequently pave the way for the development of more effective ways to control these diseases.
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Affiliation(s)
- Guang Qi
- State Key Laboratory of Wheat and Maize Crop Science and College of Agronomy, Henan Agricultural University, Zhengzhou 450002, China; Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Jian Chen
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing 210014, China; Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Ming Chang
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing 210014, China; Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Huan Chen
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing 210014, China; Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Katherine Hall
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - John Korin
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Fengquan Liu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing 210014, China.
| | - Daowen Wang
- State Key Laboratory of Wheat and Maize Crop Science and College of Agronomy, Henan Agricultural University, Zhengzhou 450002, China.
| | - Zheng Qing Fu
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA.
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Yang L, Wu L, Yao X, Zhao S, Wang J, Li S, Ding W. Hydroxycoumarins: New, effective plant-derived compounds reduce Ralstonia pseudosolanacearum populations and control tobacco bacterial wilt. Microbiol Res 2018; 215:15-21. [PMID: 30172302 DOI: 10.1016/j.micres.2018.05.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 04/26/2018] [Accepted: 05/12/2018] [Indexed: 12/11/2022]
Abstract
Plant wilt disease caused by the soilborne bacterial pathogen Ralstonia pseudosolanacearum is one of the most devastating plant diseases; however, no effective protection against this disease has been developed. Coumarins are important natural plant-derived compounds with a wide range of bioactivities and extensive applications in medicine and agriculture. In the present study, three hydroxycoumarins (Hycs), umbelliferone (UM), esculetin (ES) and daphnetin (DA) significantly inhibited the growth of R. pseudosolanacearum on solid medium in a concentration-dependent manner, and the minimum inhibitory concentration (MICs) of these compounds was 325 mg L-1, 125 mg L-1 and 75 mg L-1, respectively. The percentage of live cells of R. pseudosolanacearum when supplemented with UM, ES, and DA was 63.61%, 17.81% and 7.23%, respectively, which were significantly lower than the DMSO treatment with 92%. Furthermore, irrigating roots with hydroxycoumarins (Hycs) 24 h before inoculation with R. pseudosolanacearum significantly delayed the occurrence of tobacco bacterial wilt, with the control efficiency of the DA treatment (the most efficient of Hycs treatment) 80.03%, 69.83%, 59.19%, 45.49%, 44.12%, 38.27% at 6, 8, 10, 12, 14, and 16 days after inoculation, respectively. Compared with the DMSO treatment, the pathogen populations of tobacco stems supplemented with 100 mg L-1 DA were the lowest, with population significantly reduced by 22.46%, 27.34%, and 18.06% at 4, 7, and 10 days after inoculation, respectively. Based on this study, these Hycs could be applied as potential protective agents in the management of tobacco bacterial wilt.
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Affiliation(s)
- Liang Yang
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University, Chongqing, 400715, China
| | - Lintong Wu
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University, Chongqing, 400715, China
| | - Xiaoyuan Yao
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University, Chongqing, 400715, China
| | - Shiyuan Zhao
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University, Chongqing, 400715, China
| | - Jiao Wang
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University, Chongqing, 400715, China
| | - Shili Li
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University, Chongqing, 400715, China
| | - Wei Ding
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University, Chongqing, 400715, China.
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Khokhani D, Tran TM, Lowe-Power TM, Allen C. Plant Assays for Quantifying Ralstonia solanacearum Virulence. Bio Protoc 2018; 8:e3028. [PMID: 34395814 DOI: 10.21769/bioprotoc.3028] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 09/07/2018] [Accepted: 09/10/2018] [Indexed: 12/15/2022] Open
Abstract
Virulence assays are powerful tools to study microbial pathogenesis in vivo. Good assays track disease development and, coupled with targeted mutagenesis, can identify pathogen virulence factors. Disease development in plants is extremely sensitive to environmental factors such as temperature, atmospheric humidity, and soil water level, so it can be challenging to standardize conditions to achieve consistent results. Here, we present optimized and validated experimental conditions and analysis methods for nine assays that measure specific aspects of virulence in the phytopathogenic bacterium Ralstonia solanacearum, using tomato as the model host plant.
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Affiliation(s)
- Devanshi Khokhani
- Department of Bacteriology, University of Wisconsin-Madison, Madison, USA
| | - Tuan Minh Tran
- School of Biological Sciences, Nanyang Technological University, Singapore
| | | | - Caitilyn Allen
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, USA
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Lowe-Power TM, Khokhani D, Allen C. How Ralstonia solanacearum Exploits and Thrives in the Flowing Plant Xylem Environment. Trends Microbiol 2018; 26:929-942. [PMID: 29941188 DOI: 10.1016/j.tim.2018.06.002] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 05/24/2018] [Accepted: 06/04/2018] [Indexed: 10/28/2022]
Abstract
The plant wilt pathogen Ralstonia solanacearum thrives in the water-transporting xylem vessels of its host plants. Xylem is a relatively nutrient-poor, high-flow environment but R. solanacearum succeeds there by tuning its own metabolism and altering xylem sap biochemistry. Flow influences many traits that the bacterium requires for pathogenesis. Most notably, a quorum sensing system mediates the pathogen's major transition from a rapidly dividing early phase that voraciously consumes diverse food sources and avidly adheres to plant surfaces to a slower-growing late phase that can use fewer nutrients but produces virulence factors and disperses effectively. This review discusses recent findings about R. solanacearum pathogenesis in the context of its flowing in planta niche, with emphasis on R. solanacearum metabolism in plants.
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Affiliation(s)
- Tiffany M Lowe-Power
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI 53706, USA; Current address: Department of Plant and Microbial Biology, University of California-Berkeley, Berkeley, CA 94720, USA
| | - Devanshi Khokhani
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI 53706, USA; Current address: Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Caitilyn Allen
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI 53706, USA.
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Abstract
Microorganisms are found everywhere, and they are closely associated with plants. Because the establishment of any plant-microbe association involves chemical communication, understanding crosstalk processes is fundamental to defining the type of relationship. Although several metabolites from plants and microbes have been fully characterized, their roles in the chemical interplay between these partners are not well understood in most cases, and they require further investigation. In this review, we describe different plant-microbe associations from colonization to microbial establishment processes in plants along with future prospects, including agricultural benefits.
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Affiliation(s)
- Fernanda Oliveira Chagas
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo (FCFRP-USP), Avenida do Café, s/n, 14040-903, Ribeirão Preto-SP, Brazil.
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Zhalnina K, Louie KB, Hao Z, Mansoori N, da Rocha UN, Shi S, Cho H, Karaoz U, Loqué D, Bowen BP, Firestone MK, Northen TR, Brodie EL. Dynamic root exudate chemistry and microbial substrate preferences drive patterns in rhizosphere microbial community assembly. Nat Microbiol 2018; 3:470-80. [PMID: 29556109 DOI: 10.1038/s41564-018-0129-3] [Citation(s) in RCA: 706] [Impact Index Per Article: 117.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 02/13/2018] [Indexed: 11/09/2022]
Abstract
Like all higher organisms, plants have evolved in the context of a microbial world, shaping both their evolution and their contemporary ecology. Interactions between plant roots and soil microorganisms are critical for plant fitness in natural environments. Given this co-evolution and the pivotal importance of plant-microbial interactions, it has been hypothesized, and a growing body of literature suggests, that plants may regulate the composition of their rhizosphere to promote the growth of microorganisms that improve plant fitness in a given ecosystem. Here, using a combination of comparative genomics and exometabolomics, we show that pre-programmed developmental processes in plants (Avena barbata) result in consistent patterns in the chemical composition of root exudates. This chemical succession in the rhizosphere interacts with microbial metabolite substrate preferences that are predictable from genome sequences. Specifically, we observed a preference by rhizosphere bacteria for consumption of aromatic organic acids exuded by plants (nicotinic, shikimic, salicylic, cinnamic and indole-3-acetic). The combination of these plant exudation traits and microbial substrate uptake traits interact to yield the patterns of microbial community assembly observed in the rhizosphere of an annual grass. This discovery provides a mechanistic underpinning for the process of rhizosphere microbial community assembly and provides an attractive direction for the manipulation of the rhizosphere microbiome for beneficial outcomes.
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Wilson DC, Kempthorne CJ, Carella P, Liscombe DK, Cameron RK. Age-Related Resistance in Arabidopsis thaliana Involves the MADS-Domain Transcription Factor SHORT VEGETATIVE PHASE and Direct Action of Salicylic Acid on Pseudomonas syringae. Mol Plant Microbe Interact 2017; 30:919-929. [PMID: 28812948 DOI: 10.1094/mpmi-07-17-0172-r] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Arabidopsis thaliana exhibits a developmentally regulated disease-resistance response known as age-related resistance (ARR), a process that requires intercellular accumulation of salicylic acid (SA), which is thought to act as an antimicrobial agent. ARR is characterized by enhanced resistance to some pathogens at the late adult-vegetative and reproductive stages. While the transition to flowering does not cause the onset of ARR, both processes involve the MADS-domain transcription factor SHORT VEGETATIVE PHASE (SVP). In this study, ARR-defective svp mutants were found to accumulate reduced levels of intercellular SA compared with wild type in response to Pseudomonas syringae pv. tomato. Double mutant and overexpression analyses suggest that SVP and SOC1 (SUPPRESSOR OF OVEREXPRESSION OF CO 1) act antagonistically, such that SVP is required for ARR to alleviate the negative effects of SOC1 on SA accumulation. In vitro, SA exhibited antibacterial and antibiofilm activity at concentrations similar to those measured in the intercellular space during ARR. In vivo, P. syringae pv. tomato formed biofilm-like aggregates in young susceptible plants, while this was drastically reduced in mature ARR-competent plants, which accumulate intercellular SA. Collectively, these results reveal a novel role for the floral regulators SVP and SOC1 in disease resistance and provide evidence that SA acts directly on pathogens as an antimicrobial agent. [Formula: see text] Copyright © 2017 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .
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Affiliation(s)
- Daniel C Wilson
- 1 McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4K1, Canada; and
| | | | - Philip Carella
- 1 McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4K1, Canada; and
| | - David K Liscombe
- 2 Vineland Research and Innovation Centre, 4890 Victoria Avenue N., Vineland Station, Ontario, L0R 2E0, Canada
| | - Robin K Cameron
- 1 McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4K1, Canada; and
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Bocsanczy AM, Huguet-Tapia JC, Norman DJ. Comparative Genomics of Ralstonia solanacearum Identifies Candidate Genes Associated with Cool Virulence. Front Plant Sci 2017; 8:1565. [PMID: 28955357 PMCID: PMC5601409 DOI: 10.3389/fpls.2017.01565] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 08/28/2017] [Indexed: 06/01/2023]
Abstract
Strains of the Ralstonia solanacearum species complex in the phylotype IIB group are capable of causing Bacterial Wilt disease in potato and tomato at temperatures lower than 24°C. The capability of these strains to survive and to incite infection at temperatures colder than their normally tropical boundaries represents a threat to United States agriculture in temperate regions. In this work, we used a comparative genomics approach to identify orthologous genes linked to the lower temperature virulence phenotype. Six R. solanacearum cool virulent (CV) strains were compared to six strains non-pathogenic at low temperature (NPLT). CV strains can cause Bacterial Wilt symptoms at temperatures below 24°C, while NPLT cannot. Four R. solanacearum strains were sequenced for this work in order to complete the comparison. An orthologous genes comparison identified 44 genes present only in CV strains and 19 genes present only in NPLT strains. Gene annotation revealed a high percentage of genes compared with whole genomes in the transcriptional regulator and transport categories. A single nucleotide polymorphism (SNP) analysis identified 265 genes containing conserved non-synonymous SNPs in CV strains. Ten genes in the pathogenicity category were identified in this group. Comparisons of type 3 secretion system, type 6 secretion system (T6SS) clusters, and associated effectors did not indicate a correlation with the CV phenotype except for one T6SS VGR effector potentially associated with the CV phenotype. This is the first R. solanacearum genomic comparative analysis of multiple strains with different temperature related virulence. The candidate genes identified by this comparison are potential factors involved in virulence at low temperatures that need to be investigated. The high percentage of transcriptional regulators among the genes present only in CV strains supports the hypothesis that temperature dependent regulation of virulence genes explains the differential virulence phenotype at low temperatures. This comparison contributes to find new possible connections of temperature dependent virulence to the previously described complex regulatory system involving quorum-sensing, phenotype conversion (phcA), acyl-HSL production and responses to SA. It also added novel candidate T6SS effectors and useful detailed information about the T6SS in R. solanacearum.
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Affiliation(s)
- Ana M. Bocsanczy
- Mid-Florida Research and Education Center, Department of Plant Pathology, University of Florida, ApopkaFL, United States
| | - Jose C. Huguet-Tapia
- Department of Plant Pathology, University of Florida, GainesvilleFL, United States
| | - David J. Norman
- Mid-Florida Research and Education Center, Department of Plant Pathology, University of Florida, ApopkaFL, United States
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Li J, Pang Z, Trivedi P, Zhou X, Ying X, Jia H, Wang N. 'Candidatus Liberibacter asiaticus' Encodes a Functional Salicylic Acid (SA) Hydroxylase That Degrades SA to Suppress Plant Defenses. Mol Plant Microbe Interact 2017; 30:620-630. [PMID: 28488467 DOI: 10.1094/mpmi-12-16-0257-r] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Pathogens from the fastidious, phloem-restricted 'Candidatus Liberibacter' species cause the devastating Huanglongbing (HLB) disease in citrus worldwide and cause diseases on many solanaceous crops and plants in the Apiaceae family. However, little is known about the pathogenic mechanisms due to the difficulty in culturing the corresponding 'Ca. Liberibacter' species. Here, we report that the citrus HLB pathogen 'Ca. L. asiaticus' uses an active salicylate hydroxylase SahA to degrade salicylic acid (SA) and suppress plant defenses. Purified SahA protein displays strong enzymatic activity to degrade SA and its derivatives. Overexpression of SahA in transgenic tobacco plants abolishes SA accumulation and hypersensitive response (HR) induced by nonhost pathogen infection. By degrading SA, 'Ca. L. asiaticus' not only enhances the susceptibility of citrus plants to both nonpathogenic and pathogenic Xanthomonas citri but also attenuates the responses of citrus plants to exogenous SA. In addition, foliar spraying of 2,1,3-benzothiadiazole and 2,6-dichloroisonicotinic acid, SA functional analogs not degradable by SahA, displays comparable (and even better) effectiveness with SA in suppressing 'Ca. L. asiaticus' population growth and HLB disease progression in infected citrus trees under field conditions. This study demonstrates one or more pathogens suppress plant defenses by degrading SA and establish clues for developing novel SA derivatives-based management approaches to control the associated plant diseases.
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Affiliation(s)
- Jinyun Li
- Citrus Research and Education Center, Department of Microbiology and Cell Science, University of Florida, 700 Experiment Station Road, Lake Alfred, FL 33850, U.S.A
| | - Zhiqian Pang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, University of Florida, 700 Experiment Station Road, Lake Alfred, FL 33850, U.S.A
| | - Pankaj Trivedi
- Citrus Research and Education Center, Department of Microbiology and Cell Science, University of Florida, 700 Experiment Station Road, Lake Alfred, FL 33850, U.S.A
| | - Xiaofeng Zhou
- Citrus Research and Education Center, Department of Microbiology and Cell Science, University of Florida, 700 Experiment Station Road, Lake Alfred, FL 33850, U.S.A
| | - Xiaobao Ying
- Citrus Research and Education Center, Department of Microbiology and Cell Science, University of Florida, 700 Experiment Station Road, Lake Alfred, FL 33850, U.S.A
| | - Hongge Jia
- Citrus Research and Education Center, Department of Microbiology and Cell Science, University of Florida, 700 Experiment Station Road, Lake Alfred, FL 33850, U.S.A
| | - Nian Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, University of Florida, 700 Experiment Station Road, Lake Alfred, FL 33850, U.S.A
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Yang L, Li S, Qin X, Jiang G, Chen J, Li B, Yao X, Liang P, Zhang Y, Ding W. Exposure to Umbelliferone Reduces Ralstonia solanacearum Biofilm Formation, Transcription of Type III Secretion System Regulators and Effectors and Virulence on Tobacco. Front Microbiol 2017; 8:1234. [PMID: 28713361 PMCID: PMC5492427 DOI: 10.3389/fmicb.2017.01234] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 06/19/2017] [Indexed: 12/04/2022] Open
Abstract
Ralstonia solanacearum is one of the most devastating phytopathogens and causes bacterial wilt, which leads to severe economic loss due to its worldwide distribution and broad host range. Certain plant-derived compounds (PDCs) can impair bacterial virulence by suppressing pathogenic factors of R. solanacearum. However, the inhibitory mechanisms of PDCs in bacterial virulence remain largely unknown. In this study, we screened a library of coumarins and derivatives, natural PDCs with fused benzene and α-pyrone rings, for their effects on expression of the type III secretion system (T3SS) of R. solanacearum. Here, we show that umbelliferone (UM), a 7-hydroxycoumarin, suppressed T3SS regulator gene expression through HrpG–HrpB and PrhG–HrpB pathways. UM decreased gene expression of six type III effectors (RipX, RipD, RipP1, RipR, RipTAL, and RipW) of 10 representative effector genes but did not alter T2SS expression. In addition, biofilm formation of R. solanacearum was significantly reduced by UM, though swimming activity was not affected. We then observed that UM suppressed the wilting disease process by reducing colonization and proliferation in tobacco roots and stems. In summary, the findings reveal that UM may serve as a plant-derived inhibitor to manipulate R. solanacearum T3SS and biofilm formation, providing proof of concept that these key virulence factors are potential targets for the integrated control of bacterial wilt.
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Affiliation(s)
- Liang Yang
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest UniversityChongqing, China
| | - Shili Li
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest UniversityChongqing, China
| | - Xiyun Qin
- Yunnan Academy of Tobacco Agricultural ResearchYuxi, China
| | - Gaofei Jiang
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest UniversityChongqing, China.,Laboratoire des Interactions Plantes-Microorganismes, UMR441, Institut National de la Recherche AgronomiqueCastanet-Tolosan, France
| | - Juanni Chen
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest UniversityChongqing, China
| | - Bide Li
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest UniversityChongqing, China
| | - Xiaoyuan Yao
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest UniversityChongqing, China
| | - Peibo Liang
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest UniversityChongqing, China
| | - Yong Zhang
- College of Resources and Environment, Southwest UniversityChongqing, China
| | - Wei Ding
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest UniversityChongqing, China
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Leonard S, Hommais F, Nasser W, Reverchon S. Plant-phytopathogen interactions: bacterial responses to environmental and plant stimuli. Environ Microbiol 2017; 19:1689-1716. [DOI: 10.1111/1462-2920.13611] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 11/09/2016] [Accepted: 11/16/2016] [Indexed: 01/06/2023]
Affiliation(s)
- Simon Leonard
- University of Lyon, Université Claude Bernard Lyon 1; INSA-Lyon, CNRS, UMR5240, Microbiologie, Adaptation, Pathogénie, 10 rue Raphaël Dubois Villeurbanne F-69622 France
| | - Florence Hommais
- University of Lyon, Université Claude Bernard Lyon 1; INSA-Lyon, CNRS, UMR5240, Microbiologie, Adaptation, Pathogénie, 10 rue Raphaël Dubois Villeurbanne F-69622 France
| | - William Nasser
- University of Lyon, Université Claude Bernard Lyon 1; INSA-Lyon, CNRS, UMR5240, Microbiologie, Adaptation, Pathogénie, 10 rue Raphaël Dubois Villeurbanne F-69622 France
| | - Sylvie Reverchon
- University of Lyon, Université Claude Bernard Lyon 1; INSA-Lyon, CNRS, UMR5240, Microbiologie, Adaptation, Pathogénie, 10 rue Raphaël Dubois Villeurbanne F-69622 France
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Schandry N. A Practical Guide to Visualization and Statistical Analysis of R. solanacearum Infection Data Using R. Front Plant Sci 2017; 8:623. [PMID: 28484483 PMCID: PMC5401893 DOI: 10.3389/fpls.2017.00623] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 04/06/2017] [Indexed: 05/11/2023]
Abstract
This paper describes and summarizes approaches for visualization and statistical analysis using data from Ralstonia solanacearum infection experiments based on methods and concepts that are broadly applicable. Members of the R. solanacearum species complex cause bacterial wilt disease. Bacterial wilt is a lethal plant disease and has been studied for over 100 years. During this time various methods to quantify disease and different ways to analyze the generated data have been employed. Here, I aim to provide a general background on three distinct and commonly used measures of disease: the area under the disease progression curve, longitudinal recordings of disease severity and host survival. I will discuss how one can proceed with visualization, statistical analysis, and interpretation using different datasets while revisiting the general concepts of statistical analysis. Datasets and R code to perform all analyses discussed here are included in the supplement.
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