辣椒CaSYT1的鉴定及其在疫霉侵染过程中的功能初探  

Identification of Pepper CaSYT1 and Its Function in Phytophthora capsici Infection

作　　者：刘艳艳[1] 丁颖 刘兴华[1] 郑佳秋[1] 刘志钦 LIU Yanyan;DING Ying;LIU Xinghua;ZHENG Jiaqiu;LIU Zhiqin(Jiangsu Coastal Area Institute of Agricultural Sciences,Yancheng,Jiangsu 224000,China;College of Agriculture,Fujian Agriculture and Forestry University,Fuzhou 350002,China)

机构地区：[1]江苏沿海地区农业科学研究所,江苏盐城224000 [2]福建农林大学农学院,福州350002

出　　处：《园艺学报》2024年第3期533-544,共12页Acta Horticulturae Sinica

基　　金：江苏省农业科技自主创新资金项目[CX(21)3031];江苏省农业重大新品种创制项目(PZCZ201715)。

摘　　要：为明确辣椒(Capsicum annuum)编码突触囊泡结合蛋白(Synaptotagmin,SYT)基因CaSYT1在辣椒应答疫霉侵染中可能发挥的作用,通过蛋白保守结构预测、亚细胞定位、疫霉及植物生长调节剂处理、瞬时表达、基因沉默等方法对CaSYT1的表达和功能进行了初步研究。结果表明:CaSYT1含有1个跨膜螺旋结构域和2个C2结构域,定位在细胞膜;CaSYT1的转录水平受疫霉侵染以及外源SA的诱导,且在疫霉侵染以及外源SA处理下CaSYT1启动子活性被激活并驱动了下游基因的转录表达;CaSYT1的瞬时表达能够诱发辣椒叶片内H_(2)O_(2)的大量积累,触发了明显的过敏性细胞坏死;CaSYT1沉默增强了辣椒应答疫霉侵染的抗病性,且伴随着CaPR1、NPR1、CaDEF1抗病相关基因的上调表达,暗示CaSYT1在辣椒应答疫霉侵染中起负调节作用,而其瞬时表达却能触发H2O2的积累和过敏性细胞坏死,表明CaSYT1以不依赖于细胞坏死和H_(2)O_(2)积累的方式在辣椒应答疫霉侵染中起着负调节作用。In order to clarify whether the gene CaSYT1 encoding Synaptotagmin(SYT)protein in pepper may play an important role in pepper’s response to Phytophthora capsici infection.The expression pattern and function of CaSYT1 were preliminarily studied by protein conserved structure prediction,subcellular localization,P.capsici and exogenous hormone treatments,transient expression and virus-induced gene silencing.The results showed that CaSYT1 contained one transmembrane helix domain and two C2 domains,which were located to the plasma membrane.The transcript levels of CaSYT1 were induced by P.capsici infection and exogenous hormone SA,and the CaSYT1 promoter activities were activated and trigger the expression of downstream genes under P.capsici infection and exogenous SA treatment.The transient expression of CaSYT1 can induce the accumulation of H_(2)O_(2) in pepper leaves and rigger obvious hypersensitive response(HR)-like cell death.CaSYT1 silencing enhanced pepper resistance to P.capsici infection,accompanied by up-regulated expression of resistance-related genes,including CaPR1,NPR1,and CaDEF1,suggesting CaSYT1 plays a negative regulatory role in pepper response to P.capsici infection.CaSYT1 transient expression can trigger H_(2)O_(2) accumulation and cell death,indicating that CaSYT1 plays a negative regulatory role in pepper response to P.capsici infection in a manner independent of cell death and H_(2)O_(2) accumulation.

关 键 词：辣椒 CaSYT1 疫霉 基因鉴定 信号通路 表达分析 

分 类 号：S641.3[农业科学—蔬菜学]