马铃薯晚疫病菌相关分子模式INF1与其识别受体ELR互作免疫机制研究

Potato is the fourth most important food crop in the world and plays an important role to the food safety of our country. But potato production severely suffers from late blight caused by Phytophthora infestans. In the past dozens of years, because of the fast evolution of RXLR effectors, R gene-mediated resistance can be quickly lost. In contrast, pathogen-associated molecular patterns (PAMPs) are much more conserved and thus can lead more durable resistance. INF1 is a well-characterized PAMP secreted by P. infestans. Its receptor called ELR (elicitin response) was recently successfully cloned from a wild potato. It has been proved that overexpression of ELR in susceptible potato cultivar Désirée can increase potato resistance to a certain level in a lab-controlled condition. The aim of this project is to screen and identify the regulatory genes involved in the interaction of INF1 and ELR by proteomics techniques such as isobaric tag for relative and absolute quantitation (iTRAQ) and high-throughput functional analysis. After this research, we can further understand the immunological mechanism based on the interaction of INF1 and ELR. This can provide fundamental basis and technology strategy for breeding durable resistant potato against late blight.

马铃薯是世界第四大粮食作物，对维护我国粮食安全起着重要作用，然而由Phytophthora infestans所引起的晚疫病严重威胁着马铃薯生产。在过去几十年间，由R基因介导的马铃薯抗性往往由于RXLR类无毒基因的快速进化而迅速丧失。而PAMP在进化上非常保守，因此由PAMP诱导的抗性更为持久。INF1是一种研究地较为清楚的由P. infestans分泌的PAMP，近期在马铃薯野生种中成功分离克隆了INF1的受体基因ELR。前期研究证明，在感病马铃薯栽培种Désirée中超量表达ELR，室内接种条件下可以在一定程度上提高马铃薯对晚疫病的抗性。本项目旨在通过iTRAQ等蛋白质组学技术以及高通量基因功能分析筛选鉴定参与INF1和ELR互作免疫反应的调控基因。通过本研究进一步了解INF1和ELR互作免疫调控机制，为马铃薯晚疫病持久抗性育种提供理论基础和技术策略。

PAMP在进化上非常保守，由PAMP诱导免疫反应可以为马铃薯提供更为持久的晚疫病抗性。INF1是晚疫病菌分泌的一种PAMP，本人前期研究发现其在马铃薯中的受体为ELR，但INF1和ELR识别后对抗性的调控机制仍不清楚。本项目旨在通过蛋白质组学等途径，通过高通量基因功能筛选鉴定，明确参与INF1和ELR互作免疫反应的调控基因。通过烟草INF1和ELR互作反应的iTRAQ分析，共鉴定到2964个蛋白，其中32个受INF1诱导差异表达，包括15个上调表达蛋白和17个下调表达蛋白。进一步对8个上调表达的差异蛋白基因进行了功能验证，通过对目标蛋白基因进行病毒诱导沉默（VIGS）后射瞬时表达INF1基因，发现ATP依赖的转运蛋白和60S核糖体蛋白对INF1诱导的的免疫反应非常必要。研究结果为进一步明确INF1/ELR互作的免疫调控机制提供了基础，对马铃薯晚疫病持久抗性改良具有理论和应用价值。