Two-Component Sensor RhpS Promotes Induction of Pseudomonas syringae Type III Secretion System by Repressing Negative Regulator RhpR
The Pseudomonas syringae type III secretion system (T3SS) is induced during interaction with the plant or culture in minimal medium (MM). How the bacterium senses these environments to activate the T3SS is poorly understood. Here, we report the identification of a novel two-component system (TCS), R...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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The American Phytopathological Society
2007-03-01
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| Series: | Molecular Plant-Microbe Interactions |
| Online Access: | https://apsjournals.apsnet.org/doi/10.1094/MPMI-20-3-0223 |
| _version_ | 1811278031767994368 |
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| author | Yanmei Xiao Lefu Lan Chuntao Yin Xin Deng Douglas Baker Jian-Min Zhou Xiaoyan Tang |
| author_facet | Yanmei Xiao Lefu Lan Chuntao Yin Xin Deng Douglas Baker Jian-Min Zhou Xiaoyan Tang |
| author_sort | Yanmei Xiao |
| collection | DOAJ |
| description | The Pseudomonas syringae type III secretion system (T3SS) is induced during interaction with the plant or culture in minimal medium (MM). How the bacterium senses these environments to activate the T3SS is poorly understood. Here, we report the identification of a novel two-component system (TCS), RhpRS, that regulates the induction of P. syringae T3SS genes. The rhpR and rhpS genes are organized in an operon with rhpR encoding a putative TCS response regulator and rhpS encoding a putative biphasic sensor kinase. Transposon insertion in rhpS severely reduced the induction of P. syringae T3SS genes in the plant as well as in MM and significantly compromised the pathogenicity on host plants and hypersensitive response-inducing activity on nonhost plants. However, deletion of the rhpRS locus allowed the induction of T3SS genes to the same level as in the wild-type strain and the recovery of pathogenicity upon infiltration into plants. Overexpression of RhpR in the ΔrhpRS deletion strain abolished the induction of T3SS genes. However, overexpression of RhpR in the wild-type strain or overexpression of RhpR(D70A), a mutant of the predicted phosphorylation site of RhpR, in the ΔrhpRS deletion strain only slightly reduced the induction of T3SS genes. Based on these results, we propose that the phosphorylated RhpR represses the induction of T3SS genes and that RhpS reverses phosphorylation of RhpR under the T3SS-inducing conditions. Epistasis analysis indicated that rhpS and rhpR act upstream of hrpR to regulate T3SS genes. |
| first_indexed | 2024-04-13T00:28:31Z |
| format | Article |
| id | doaj.art-068b790e178742428a75d2444ed20df6 |
| institution | Directory Open Access Journal |
| issn | 0894-0282 1943-7706 |
| language | English |
| last_indexed | 2024-04-13T00:28:31Z |
| publishDate | 2007-03-01 |
| publisher | The American Phytopathological Society |
| record_format | Article |
| series | Molecular Plant-Microbe Interactions |
| spelling | doaj.art-068b790e178742428a75d2444ed20df62022-12-22T03:10:32ZengThe American Phytopathological SocietyMolecular Plant-Microbe Interactions0894-02821943-77062007-03-0120322323410.1094/MPMI-20-3-0223Two-Component Sensor RhpS Promotes Induction of Pseudomonas syringae Type III Secretion System by Repressing Negative Regulator RhpRYanmei XiaoLefu LanChuntao YinXin DengDouglas BakerJian-Min ZhouXiaoyan TangThe Pseudomonas syringae type III secretion system (T3SS) is induced during interaction with the plant or culture in minimal medium (MM). How the bacterium senses these environments to activate the T3SS is poorly understood. Here, we report the identification of a novel two-component system (TCS), RhpRS, that regulates the induction of P. syringae T3SS genes. The rhpR and rhpS genes are organized in an operon with rhpR encoding a putative TCS response regulator and rhpS encoding a putative biphasic sensor kinase. Transposon insertion in rhpS severely reduced the induction of P. syringae T3SS genes in the plant as well as in MM and significantly compromised the pathogenicity on host plants and hypersensitive response-inducing activity on nonhost plants. However, deletion of the rhpRS locus allowed the induction of T3SS genes to the same level as in the wild-type strain and the recovery of pathogenicity upon infiltration into plants. Overexpression of RhpR in the ΔrhpRS deletion strain abolished the induction of T3SS genes. However, overexpression of RhpR in the wild-type strain or overexpression of RhpR(D70A), a mutant of the predicted phosphorylation site of RhpR, in the ΔrhpRS deletion strain only slightly reduced the induction of T3SS genes. Based on these results, we propose that the phosphorylated RhpR represses the induction of T3SS genes and that RhpS reverses phosphorylation of RhpR under the T3SS-inducing conditions. Epistasis analysis indicated that rhpS and rhpR act upstream of hrpR to regulate T3SS genes.https://apsjournals.apsnet.org/doi/10.1094/MPMI-20-3-0223 |
| spellingShingle | Yanmei Xiao Lefu Lan Chuntao Yin Xin Deng Douglas Baker Jian-Min Zhou Xiaoyan Tang Two-Component Sensor RhpS Promotes Induction of Pseudomonas syringae Type III Secretion System by Repressing Negative Regulator RhpR Molecular Plant-Microbe Interactions |
| title | Two-Component Sensor RhpS Promotes Induction of Pseudomonas syringae Type III Secretion System by Repressing Negative Regulator RhpR |
| title_full | Two-Component Sensor RhpS Promotes Induction of Pseudomonas syringae Type III Secretion System by Repressing Negative Regulator RhpR |
| title_fullStr | Two-Component Sensor RhpS Promotes Induction of Pseudomonas syringae Type III Secretion System by Repressing Negative Regulator RhpR |
| title_full_unstemmed | Two-Component Sensor RhpS Promotes Induction of Pseudomonas syringae Type III Secretion System by Repressing Negative Regulator RhpR |
| title_short | Two-Component Sensor RhpS Promotes Induction of Pseudomonas syringae Type III Secretion System by Repressing Negative Regulator RhpR |
| title_sort | two component sensor rhps promotes induction of pseudomonas syringae type iii secretion system by repressing negative regulator rhpr |
| url | https://apsjournals.apsnet.org/doi/10.1094/MPMI-20-3-0223 |
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