食线虫真菌应答土壤抑菌作用的分子机制

Soil fungistasis is one of the vital factors which reducing control effecais of fungal agents against soil-borne diseases.In this project, nematicidal fungi Arthrobotrys oligospora or Pochonia chlamydosporia was used as targets.Firstly, samples of ungerminated conidia of the targets were prepared when challanged by soil and fungistatic microbes.The samples were used to form the correlative combinations with the germinated or ungernimated condia prepared from normal conditions.Secondly,by a serial methods used in proteomics studis, including iTRAQ - HPLC - LC-MS/MS, the differential proteomics of the conidial samples were characterized. Finally, based on analysis on the differential proteins,including protein species,functions,signaling pathways, metabolism pathway,function of vital proteins (enzymes) were confirmed by methodes of gene knockout and fluorescence quantitative PCR. Objects of this study were attempted to elucidate the molecular mechanism of fungal agent responding to soil fungistasis. Results will provide novel information for us to understand the molecular mechanism of soil fungistasis, and promote the progress of bioncontrol of soil-borne diseases.

土壤抑菌作用是影响土传病害生防制剂防效的关键因素之一。本项目围绕线虫生防真菌应答土壤抑菌作用的分子机制，以本研究团队完成基因组和蛋白组分析的线虫生防菌Arthrobotrys oligospora或Pochonia chlamydosporia为研究材料，首先，在土壤及其微生物抑菌胁迫下制备不萌发的生防菌孢子样本，并与非抑菌条件下制备的不萌发孢子和正常萌发孢子组成关联样本；其次，采用差异蛋白质组学系列研究方法，分析关联样本的蛋白质表达种类、表达量差异、差异蛋白的功能以及涉及的信号传导通路及代谢途径；最后，利用基因敲除和荧光定量PCR方法对土壤抑菌胁迫下影响生防菌萌发、生长的关键蛋白（酶）及信号传导通路中关键酶基因进行功能验证；进而揭示线虫生防真菌应答土壤抑菌作用的分子机制。研究结果对深度认识土壤抑菌作用形成机制及促进土传病害的生物防治有重要科学价值。

土壤抑菌作用是影响生防菌剂根际定殖的主要障碍，本项目研究食线虫真菌在土壤抑菌作用胁迫下分生孢子的应答分子机制。采用蛋白组结合目的基因敲出验证等方法研究了土壤、土壤抑菌作用（氨气、苯甲醛）抑菌作用胁迫下捕食线虫真菌Arthrobotrys oligospora孢子的应答机制，取得以下主要研究结果：微生物产生的抑菌物质氨气使A. oligospora的Ras/MAP途径相关蛋白下调表达而抑制孢子的DNA合成和蛋白翻译，进而抑制孢子萌发（Int J Biochem Cell Biol, 2018, 98: 104-114）；抑制物质苯甲醛通过下调A. oligospora的翻译、呼吸链、线粒体相关蛋白表达和抑制孢子DNA合成而抑制孢子萌发（J Proteomics, 2019, 192:358-365）。本项研究科学意义在于首次揭示生防制剂应答土壤抑菌作用的分子机制，为促进土传病害的生物防治有重要意义。