橡胶树白粉菌保守效应蛋白致病机制研究  

Study on the Pathogenic Mechanism of a Conservative Effector Protein in Rubber Tree Powdery Mildew

作　　者：刘鑫雨 何礼娟 殷金瑶 林春花 李潇 缪卫国[1,2] LIU Xinyu;HE Lijuan;YIN Jinyao;LIN Chunhua;LI Xiao;MIAO Weiguo(School of Tropical Agriculture and Forestry,Hainan University,Haikou,Hainan 570228,China;Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests,Ministry of Education,Sanya,Hainan 572024,China)

机构地区：[1]海南大学热带农林学院,海南海口570228 [2]热带农林生物灾害绿色防控教育部重点实验室,海南三亚572024

出　　处：《热带作物学报》2024年第9期1886-1894,共9页Chinese Journal of Tropical Crops

基　　金：国家自然科学基金项目(No.31960518)。

摘　　要：白粉菌可侵染多种重要作物,而橡胶树白粉菌(Erysiphe quercicola)引起的橡胶树白粉病严重威胁天然橡胶产业。为探究橡胶树白粉菌致病分子机制,前期对橡胶树白粉菌HO-73菌株进行基因组测序分析,预测出133个潜在的效应蛋白(candiate secreted effector proteins, CSEPs),这类CSEPs仅在白粉菌群中具有同源蛋白。本研究鉴定了其中一个在橡胶树白粉菌中较为保守的效应蛋白—CSEP02974。利用酵母系统测定信号肽功能的试验表明,CSEP02974为分泌蛋白。利用农杆菌介导的本氏烟草转化,瞬时表达CSEP02974-GFP,并进行烟草中的定位分析,结果显示CSEP02974是一个细胞质效应蛋白。进一步在拟南芥表达CSEP02974可抑制几丁质和flg22诱导的活性氧(ROS)爆发和胼胝质积累,表明CSEP02974是白粉菌抑制植物免疫的毒性因子。通过喷施外源双链RNA,使橡胶树白粉菌中CSEP02974基因沉默。致病性分析表明,沉默该基因会导致病菌扩展侵染受抑制。综上,本研究鉴定到保守的橡胶树白粉菌致病因子,为进一步了解橡胶树-白粉菌的相互作用机制提供新的线索。Powdery mildew(Erysiphe quercicola)can infect a variety of economically important crops,and seriously threatens the rubber industry.In order to explore the molecular mechanism of the pathogenesis,the genome of E.quercicola(HO-73 strain)was sequenced and 133 candidate secreted effector proteins(candiate secreted effector proteins,CSEPs),which have homologous proteins only in other powdery mildew,were identified.An effector protein,CSEP02974,which is conserved in powdery mildew,was identified.The function of the signal peptide in secreted protein was assayed using the yeast secretion system.CSEP02974 was a cytoplasmic effector protein verified by using the Agrobacterium-mediated transient expression system and localization analysis.Further,CSEP02974 expression in Arabidopsis thaliana inhibited chitin-or flg22-induced callose deposition and ROS accumulation.The result suggests that CSEP02974 is a virulence factor in suppressing plant immunity.CSEP02974 was silenced by spraying exogenous double-stranded RNA on E.quercicola.Pathogenicity analysis showed that this gene silencing led to inhibitions of extended growth and infection.In conclusion,this study identified a key E quercicola virulence factor,which would provide an important clue on the mechanism of interaction between rubber tree and E.quercicola.

关 键 词：橡胶树 白粉菌 效应蛋白 

分 类 号：S432.1[农业科学—植物病理学]