HrpS is a global regulator on Type III Secretion System (T3SS) and non-T3SS genes in pseudomonas savastanoi pv. phaseolicola

Jingru Wang, Xiaolong Shao, Yingchao Zhang, Yanan Zhu, Pan Yang, Jian Yuan, Tingting Wang, Chunyan Yin, Wei Wang, Sheng Chen, Haihua Liang, Xin Deng

Research output: Journal article publicationJournal articleAcademic researchpeer-review

8 Citations (Scopus)


The type III secretion system (T3SS) is the main machinery for Pseudomonas savastanoi and other gram-negative bacteria to invade plant cells. HrpR and HrpS form a hetero-hexamer, which activates the expression of HrpL, which induces all T3SS genes by binding to a ‘hrp box’ in promoters. However, the individual molecular mechanism of HrpR or HrpS has not been fully understood. Through chromatin immunoprecipitation coupled to high-throughput DNA sequencing, we found that HrpR, HrpS, and HrpL had four, 47, and 31 targets on the genome, respectively. HrpS directly bound to the promoter regions of a group of T3SS genes and non-T3SS genes. HrpS independently regulated these genes in a hrpL deletion strain. Additionally, a HrpS-binding motif (GTGCCAAA) was identified, which was verified by electrophoretic mobility shift assay and lux-reporter assay. HrpS also regulated motility and biofilm formation in P. savastanoi. The present study strongly suggests that HrpS alone can work as a global regulator on both T3SS and non-T3SS genes in P. savastanoi.

Original languageEnglish
Pages (from-to)1232-1243
Number of pages12
JournalMolecular Plant-Microbe Interactions
Issue number12
Publication statusPublished - 1 Dec 2018

ASJC Scopus subject areas

  • Physiology
  • Agronomy and Crop Science

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