棘孢木霉MYB36转录因子抗链格孢菌的分子调控机制

Trichoderma asperellum is an excellent biocontrol strain with broad spectrum of antifungal properties. We had identified a transcription factor MYB36 from T. asperellum that is strongly induced by stimulus of poplar leaf wither Alternaria alternata. Additionally, the transformed poplar (Populus davidiana × P. alba var. pyramidalis) overexpressing MYB36 showed highly improved resistance to A. alternata. Based on these studies, we will further investigate the mechanism of T. asperellum against A. alternata in this project. The T. asperellum strains that overexpression (Ta-Hi) and knockout/inhibited expression (Ta-In) of MYB36 will be generated for study. The resistant property to A. alternata conferred by MYB36 and hydrolytic enzyme activities and products of metabolism regulated by MYB36 will be studied by comparison the strains among Ta-Hi, Ta-In and Ta-Wt (wild type T. asperellum). RNA-Seq is used for identification of the target genes regulated by MYB36. The target genes directly regulated by MYB36 and cis-acting element bound by MYB36 in gene expression regulation will be determined by using ChIP-Seq experiments. Co-immunoprecipitation (CoIP) and yeast two hybrid are used in identification the proteins interact with MYB36, and the expression regulation activity affected by protein interaction of MYB36 will be further studied. These studies together will reveal the molecular mechanism of T. asperellum against A. alternata.

棘孢木霉是对植物病原真菌有广谱抗性的生防菌。我们从棘孢木霉中分离了强烈响应杨树叶枯病病原菌链格孢菌刺激的转录因子MYB36，将其转化山新杨转基因植株也显示出优良的抗叶枯病能力，提示其在棘孢木霉中起调控抗链格孢菌的作用。在此基础上拟研究MYB36抗链格孢菌机制。分别培育出MYB36基因过表达Ta-Hi木霉菌株以及敲除/抑制表达Ta-In木霉菌株，用野生型木霉Ta-Wt作对照，分析MYB36的抗链格孢菌能力，及其对抗菌相关水解酶及代谢产物的调控；用链格孢菌分泌物分别诱导Ta-Hi、Ta-In和Ta-Wt菌株，通过RNA-Seq鉴定MYB36的靶基因；利用ChiP-Seq鉴定MYB36直接调控的靶基因及其所结合的顺式作用元件；通过Co-IP与酵母双杂交研究MYB36的互作蛋白，并进一步研究蛋白互作对MYB36转录活性的调控。通过以上研究揭示棘孢木霉抗链格孢菌的分子机制。