玉米纹枯病菌诱导启动子P_(LHT1)核心顺式作用元件的鉴定  

Identification of key cis-element in a Rhizoctonia solani-inducible maize promoter P_(LHT1)

作　　者：陈静 位书佟 李宁 何康 申艳婷 丁新华 储昭辉 CHEN Jing, WEI Shu-tong, LINing , HE Kang, Shen Yan-ting, Ding Xin-hua, CHU Zhao-hui(State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Taian 271018, China)

机构地区：[1]山东农业大学农学院作物生物学国家重点实验室,泰安271018

出　　处：《植物病理学报》2018年第5期611-623,共13页Acta Phytopathologica Sinica

基　　金：国家自然科学基金(31601279;31771748);山东省现代农业产业技术体系(SDAIT-17-06)

摘　　要：玉米纹枯病是玉米上重要的病害之一,前期通过高通量测序筛选到一个受纹枯病菌诱导表达的玉米基因LHT1,为了揭示该基因的调控机制,本研究克隆了该基因的启动子区域(P_(LHT1))并对其病原诱导核心元件进行了鉴定。结果表明,P_(LHT1)包含有4个激发子响应元件、3个GT-1元件、4个SA响应元件、3个ABA响应元件、1个生长素响应元件和1个GA响应元件。该启动子在多个组织器官中高水平表达,且在接种纹枯病菌菌株YWK196后,该启动子在4 h内就能够高效诱导表达报告基因。启动子截短分析发现,-1 416 bp至-1 087 bp区间的缺失使P_(LHT1)丧失了受纹枯病菌诱导的能力,对照Plant CARE的分析结果,该区段含有3个已知的病原菌诱导元件GT-1,将该区段内的3个GT-1进行单个缺失后,发现-1 416 bp至-1 087 bp区段受纹枯病菌诱导的活性减弱并未完全丧失;此外,将3个GT-1元件同时替换为GGGGGG后,-1 416 bp至-1 087 bp区域不再响应纹枯病菌的侵染,这些结果说明,这3个GT-1元件在P_(LHT1)响应纹枯病菌的侵染中协同发挥作用。Banded sheath and leaf blight is an important disease on maize. In our previous study, a Rhizoctonia solani-inducible maize gene LHT1 was identified by RNA-seq. To reveal the regulation mechanism of this gene, its promoter Pumwas cloned and key cis-element in this promoter were identified in this study. According to the bioinformatic analysis, the PLFT1 contains four types of elicitor-responsive elements, three GT-1, five SA-responsive elements, three ABA-responsive elements, one auxin-responsive element and one GA-responsive element. Tissue-specific and pathogen-inducible expression analysis showed that the PLHT1 displayed high expression levels in multiple tissues and induced a high GUS expression within 4 h after inoculation with R. solani strain YWK196. Deletion analysis showed that the pathogen-inducible activity of PLHT1 was completely knocked out after deleting the -1 416 bp to -1 087 bp fragment. This region contains three GT-1 elements （GAAAAA） that were known to be pathogen- and salt-responsive elements. After deleting either of the three GT-1 elements, the -1 416 bp to -1 087 bp region displayed reductive pathogen-inducible activity. Furthermore, the -1 416 bp to -1 087 bp region lost the pathogen-inducible activity after replacing the three GT-1 with GGGGGG. These results indicated that these three GT-1 cis-elements in the Purr1 play synergistic roles in responding to R. solani infection.

关 键 词：玉米 立枯丝核菌 纹枯病 启动子 GT-1作用元件 

分 类 号：S432.1[农业科学—植物病理学]