展青霉素（PAT）是对人类危害最大的真菌毒素之一，其对苹果及其制品的污染在全球范围内都很严重。采用拮抗酵母控制并降解苹果及其制品中的PAT已展现出良好的应用前景。申请者前期研究胶红酵母控制苹果PAT及降解的应答调控机制，利用iTRAQ技术和转录组测序技术分析其降解PAT的差异表达蛋白和差异表达基因时，发现PAT处理的酵母中短链脱氢酶（SDR蛋白）的表达水平显著上调，说明SDR在胶红酵母降解PAT的过程中发挥着重要作用，但其参与PAT降解的分子机制未知。本项目拟以SDR蛋白为研究对象，测定SDR基因和蛋白在PAT刺激下的表达水平；构建SDR敲除及过量表达菌株，分析其在酵母降解PAT中的作用；外源表达并纯化SDR，分析其对PAT的催化机制；对调控SDR的转录因子及其调控机制进行研究，从而阐明SDR参与胶红酵母降解PAT的分子机制。研究成果可为拮抗酵母降解苹果及其制品中PAT的机制提供理论支撑。

Patulin is one of the mycotoxins that can cause serious health problems, which has been identified in apple fruit and its products throughout the world. Controlling and degradation of patulin on apple fruit and its products using antagonistic yeasts has represented a promising future. The applicant had studied the control of patulin in apples by Rhodotorula mucilaginosm and it's response and regulation mechanisms of degradation of patulin, the differentially expressed proteins and differentially expressed genes related to patulin degradation by R. mucilaginosa were analyzed through an iTRAQ-based proteomic analysis and RNA-Sequencing technology, short-chain dehydrogenase (SDR protein) in R. mucilaginosa treated with PAT was significantly up-regulated expressed. It is indicated that SDR protein play an important role in patulin degradation by R. mucilaginosa, but the molecular mechanism is not clear. In this study, SDR protein is selected to be the model object, the expression of SDR gene and SDR protein which are stimulated by patulin will be determined. SDR gene knockout mutants and overexpression strains of R. mucilaginosa will be constructed to prove the efficacy in patulin degradation. The catalytic mechanism of SDR protein on patulin was analyzed by heterologous expression and purification of SDR. The transcription factor of SDR and its regulation mechanism will be studied, so as to reveal the mechanisms of SDR protein in degrading patulin by R. mucilaginosa. The expected research results will provide theoretical evidence for the application of antagonistic yeasts to degrade PAT of apple fruit and its products.