玉米大斑病菌转录因子Flo8的基因克隆及表达规律分析

发布时间：2018-01-19 18:20

本文关键词： 玉米大斑病菌转录因子 cAMP信号途径 qRT-PCR　出处：《农业生物技术学报》2017年10期 　论文类型：期刊论文

【摘要】：Flo8是cAMP信号途径下游的重要转录因子,与真菌的生长发育密切相关。本研究旨在获得玉米大斑病菌(Setosphaeria turcica)转录因子Flo8编码基因,并分析其在病菌侵染结构发育过程及病菌侵染寄主早期阶段的表达模式,为深入探索该转录因子在病菌发育及致病过程中的功能奠定基础。本研究以白色念珠菌(Candida albicans)Flo8氨基酸序列为探针在玉米大斑病菌数据库中进行同源搜索,利用PCR技术对玉米大斑病菌转录因子Flo8的编码基因进行克隆,通过GSDS、Prot Param、SOMPA和SMART在线软件进行基因及其编码产物结构特征预测分析,利用WoLF PSORT分析蛋白的亚细胞定位;利用qRTPCR技术研究其在病菌侵染结构形成过程中不同阶段的转录水平。结果表明,玉米大斑病菌中存在1个含有LisH保守结构域的蛋白,属于典型的FLO8同源蛋白,将其编码基因命名为StFlo8。该基因DNA全长为2 384 bp,c DNA全长为2 037 bp,含有6个内含子,7个外显子,编码678个氨基酸。表达规律分析结果表明,与菌丝时期相比,StFlo8在孢子时期及芽管时期表达量显著降低,在附着胞时期和侵染丝时期表达量显著升高,达到菌丝时期的4倍以上;而在侵染感病寄主叶片过程中,StFlo8表达量呈现先下调后上调再下调的趋势,并在接种后18 h表达量达到最高,约为接种初期的2倍。以上结果表明StFlo8参与调控病菌附着胞发育及侵染丝形成,该结果为进一步研究StFlo8基因的功能及玉米大斑病菌的侵染机制提供了理论依据。
[Abstract]:Flo8 is an important transcription factor downstream of cAMP signaling pathway. The aim of this study was to obtain the transcription factor Flo8 coding gene of Setosphaeria turcica. The expression patterns of the pathogen in the early stage of infection and host were analyzed. In order to further explore the function of the transcription factor in the development and pathogenicity of Candida albicans. in this study, Candida albicans. The amino acid sequence of Flo8 was homologous searched in the database of Corn spot fungus. The coding gene of Flo8 was cloned by PCR technique. SOMPA and SMART software were used to predict the structural characteristics of genes and their encoded products, and WoLF PSORT was used to analyze the subcellular localization of proteins. QRTPCR technique was used to study the transcription level in different stages of infection structure formation. The results showed that there was a protein containing the conserved domain of LisH in the pathogen. It is a typical FLO8 homologous protein, and its coding gene is named StFlo8. The DNA length of the gene is 2 384 BP, and the length of DNA is 2 037 BP. It contains 6 introns and 7 exons and encodes 678 amino acids. The results of expression analysis showed that the expression of StFlo8 in spore stage and bud tube stage was significantly lower than that in hyphae stage. The expression level increased significantly at the appressant stage and the infection stage, and reached more than 4 times of the mycelium stage. The expression of StFlo8 in infected host leaves showed a tendency of down-regulation, then up-regulation and down-regulation, and reached the highest level at 18 h after inoculation. The results showed that StFlo8 was involved in the development of appressorium and the formation of infected filaments. The results provided a theoretical basis for the further study of the function of StFlo8 gene and the infection mechanism of Corn spot fungus.
【作者单位】：河北农业大学生命科学学院/河北省植物生理与分子病理学重点实验室;
【基金】：国家自然科学基金(No.31301616和No.31601598) 河北省自然科学基金(No.C2016204160) 河北省高等学校科学技术研究项目(No.QN2016071)
【分类号】：S435.131.4
【正文快照】： *同等贡献作者玉米大斑病菌(Setosphaeria turcica)是一种侵染玉米(Zea mays)的重要丝状病原真菌,其引起的玉米大斑病(northern corn leaf blight)在世界低温潮湿地域分布广泛,对玉米生产造成巨大的经济损失(宋文静等,2008)。由于该病菌生理分化明显,容易变异,近年来由其引发

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