粉红聚端孢(Trichothecium roseum)引起的心腐病是苹果主要果实病害。前期研究证明该菌产生的单端孢菌素（TCN）是心腐病关键致病因子，进一步发现TCN缺失突变体不能致病但引起侵染点周围果肉细胞消解，转录组数据暗示这种现象为一种细胞自噬，推测病原菌可能通过TCN抑制寄主细胞自噬和毒害寄主细胞双重作用促进侵染。本项目将综合组织细胞学、转录组学和遗传学等手段，证明TCN缺失突变体诱发的细胞消解为细胞自噬；证实TCN具有细胞自噬抑制和细胞毒性作用；进一步借助苹果自噬基因过表达转基因植株，分析TCN抑制细胞自噬作用在克服苹果防卫反应中的重要性。项目将有望发现一种毒素致病新机制，揭示TCN在心腐病中的致病机理，因而具有重要理论意义，研究结果对相关病害致病机理的研究也具有借鉴意义。

Apple core rot disease caused by Trichothecium roseum infection is a main fruit disease on apple, trichothecene produced by T. roseum is an important mycotoxin. We have generated TCN-defective mutants via gene knock out and found that these mutants were non-pathogenic and caused fruit tissue collapse beneath the inoculation sites, transcriptomic data implies autophagy activity related to tissue collapse. We postulate that TCN promotes infection via its dual effects in autophagy inhibition and cellular toxicity. To reveal the pathogenic mechanisms of TCN to apple, we will work on: 1) clarifying whether TCN-defective mutants do induce plant autophagy; 2) testing the dual effects of TCN in autophagy inhibition and cellular toxicity; 3) analyzing the importance of TCN-mediated autophagy suppression in overcoming apple defense reactions, which will be performed by generating transgenic plants overexpressing autophagy genes. This research project will reveal the pathogenic mechanisms of TCN, and might find a new mechanism for mycotoxin to behave as a pathogenicity factor. The results would be valuable for researches with other patho-systems.