马铃薯StCYS6基因响应盐胁迫和致病疫霉侵染的初步研究  

Initial Study on the Response of Potato(Solanum tuberosum)StCYS6 Gene to Salt Stress and Phytophthora infestans Infection

作　　者：赵鼎 王路遥[1,2,4] 舒海东 李子豪 董莎萌 ZHAO Ding;WANG Lu-Yao;SHU Hai-Dong;LI Zi-Hao;DONG Suo-Meng(College of Plant Protection,Nanjing Agricultural University,Nanjing 210095,China;The Key Laboratory of Integrated Management of Crop Diseases and Pests(Ministry of Education),Nanjing Agricultural University,Nanjing 210095,China;School of Agriculture and Biology,Shanghai Jiao Tong University,Shanghai 200240,China;Agricultural Genomics Institute at Shenzhen,Chinese Academy of Agricultural Sciences,Shenzhen 518120,China)

机构地区：[1]南京农业大学植物保护学院,南京210095 [2]南京农业大学教育部农作物生物灾害综合治理重点实验室,南京210095 [3]上海交通大学农业与生物学院,上海200240 [4]中国农业科学院深圳农业基因组研究所,深圳518120

出　　处：《农业生物技术学报》2024年第6期1236-1249,共14页Journal of Agricultural Biotechnology

基　　金：国家马铃薯产业技术体系(CARS09);广东省基础与应用基础研究重大项目(2021B0301030004);中国博士后科学基金(2022M711660)。

摘　　要：培育耐盐碱和抗晚疫病的马铃薯(Solanum tuberosum)是马铃薯产业发展的重要需求之一。为初步解析马铃薯响应盐胁迫和晚疫病的病原—致病疫霉(Phytophthora infestans)侵染的机制,本研究通过转录组测序筛选响应盐胁迫和致病疫霉侵染的关键基因。结果显示,对于育苗块培养4周后的马铃薯组培苗,用100 mmol/L NaCl处理1周后,致病疫霉在叶片上的侵染面积显著增大,即盐胁迫使马铃薯对致病疫霉的抵抗能力显著减弱;转录组测序发现,盐胁迫条件下3780个马铃薯基因表达发生显著变化,其中半胱氨酸蛋白酶抑制子6(cystatin 6,CYS6)基因显著下调表达。qRT-PCR结果进一步证明,StCYS6基因在盐胁迫处理的马铃薯叶片中下调表达,而在致病疫霉侵染后上调表达;StCYS6基因在本氏烟草(Nicotiana benthamiana)叶片中瞬时表达可显著提升植株对致病疫霉的抗性。失活突变体的瞬时表达结果显示,StCYS6蛋白促进烟草对致病疫霉的抗性并不依赖于其半胱氨酸蛋白酶抑制子活性。对StCYS6转基因马铃薯植株进行耐盐性和致病疫霉抗性分析,结果显示,马铃薯叶片的萎蔫程度显著降低,即StCYS6能够显著提升马铃薯耐盐能力;但是,StCYS6转基因马铃薯植株对致病疫霉的抗性没有明显改善。本研究获得可增强马铃薯耐盐能力的候选基因StCYS6,为培育抗逆马铃薯新品种提供基础资料。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 3780 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.

关 键 词：马铃薯 盐胁迫 致病疫霉 半胱氨酸蛋白酶抑制子6(CYS6) 

分 类 号：S432.1[农业科学—植物病理学]