Functional Analysis of Type III Secretion System hrcN Gene in Ralstonia solanacearum

doi:10.16409/j.cnki.2095-039x.2021.06.022

Abstract

Abstract: The gene hrcN is one of the structural genes of the type III secretion system (T3SS) in plant pathogens, and has an important influence on pathogenicity of pathogens. In this study, the gene hrcN was cloned from Ralstonia solanacearum strain CBM613 to perform bioinformatics analysis. The results showed that the gene was 1320 bp in length, encoding 439 amino acids. The protein HrcN was predicted to have no signal peptide and transmembrane region, and to be weakly hydrophilic. The protein HrcN is an ATPase, which is located in the cell inner membrane and cytoplasm. The growth rate of the hrcN^－ mutant had no significant difference with the wild-type strain in eutrophic media, but was significantly faster than that of the latter in the poor nutrition media After the gene hrcN was removed, motility of the hrcN^－ mutant and the wild-type strain had no significant change, but the biofilm formation ability of the hrcN^－ mutant was significantly reduced. Moreover, pathogenicity of the hrcN^－ mutant was decreased compared with the wild-type strain, and disease index was decreased, meanwhile the course of disease was prolonged， but its pathogenicity was not completely lost. The results indicated that the gene hrcN is an important gene associated with the pathogenicity of the R. solanacearum. Our study is of great significance to further explore the pathogenic mechanism of R. solanacearum and biocontrol of bacterial wilt.

Key words: Ralstonia solanacearum, T3SS, hrcN, gene knock-out, functional analysis

CLC Number:

S432.1

ZHOU Daxiang, LONG Quanzhou, YIN Youping, XIONG Shu. Functional Analysis of Type III Secretion System hrcN Gene in Ralstonia solanacearum[J]. Chinese Journal of Biological Control, 2021, 37(6): 1353-1362.

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