Abstract:

Pseudomonas donghuensis HYS is toxic to Caenorhabditis elegans but its mechanism is not fully understood. This study aims to investigate the roles of σ factor SigW and anti-σ factor RsiW in the toxicity of P. donghuensis HYS to C. elegans. Through the bioinformatics analysis of the mutation site sequence in the toxicity-reduced mutant of P. dongshanensis HYS,the target gene knockout mutant was constructed. Then with the help of research methods such as yeast two-hybrid,fluorescent quantitative PCR and P. dongshanensis -C. elegans interaction,etc.,the protein functions of related gene were verified. The results revealed that：（1）the gene rsiW was related to the toxicity of P. donghuensis HYS to C. elegans. （2）RsiW interacted with neighboring SigW（σ²⁴）on the genome at the protein level,forming a pair of σ factor and anti-σ factor. （3）The interaction between RsiW and SigW was involved in the toxicity of P. donghuensis HYS to C. elegans and there was a dose effect,i.e.,there was reducing effect when SigW expression was relatively strong. This study discovers that a pair of σ factor and anti-σ factor are involved in the toxicity of P. donghuensis HYS to C. elegans and provides new clues and ideas for further exploring the mechanism of virulence factors of Pseudomonas.

Key words: anti-σ factor RsiW, σ factor SigW, Pseudomonas donghuensis HYS, toxicity