马铃薯StCYS6基因响应盐胁迫和致病疫霉侵染的初步研究OA北大核心CSTPCD

Breeding salt tolerance and late blight-resistant potatoes(Solanum tuberosum)is an important requirement for the development of the potato industry.In this study,key genes responding to salt stress and the invasion of the late blight pathogen Phytophthora infestans were screened by transcriptome sequencing.The results showed that the infection area of P.infestans on the leaves significantly increased after being treated with 100 mmol/L NaCl for 1 week,namely,salt stress significantly weakened the resistance of tissue-cultured potato to P.infestans.Transcriptome sequencing revealed that the expression of 3 780 potato genes changed significantly under salt stress,in which the cystatin 6(CYS6)gene significantly downregulated.qRT-PCR results further confirmed that StCYS6 gene expression was downregulated in potato leaves after salt stress,but upregulated after P.infestans invasion.Transient expression of the candidate gene StCYS6 in Nicotiana benthamiana leaves significantly enhanced resistance to P.infestans.Inactivation mutations showed that StCYS6 protein promoted plant resistance to P.infestans independent of its cysteine protease inhibitor activity.The analysis of salt tolerance and pathogen resistance of StCYS6 transgenic potato plants showed that the degree of wilting of potato leaves was significantly reduced,indicating that StCYS6 could significantly improve the salt tolerance of potatoes;However,StCYS6 transgenic potato plants did not significantly improve their resistance to P.infestans.This study obtained a candidate gene StCYS6 that could enhance the salt tolerance of potatoes,providing basic data for cultivating new varieties of stress resistant potatoes.