可变剪接在棉花-大丽轮枝菌互作中的全基因组分析

AS (alternative splicing) is an important mechanism for regulation of gene expression, which has acted vital role for plant resistance. Cotton Verticillium wilt, a soil-borne vascular disease caused by verticillium dahliae, result in leaf curl, necrosis and defoliation, and is called “cancer of cotton”. Therefore, it is extremely significant to research the mechanism of AS modulated during cotton-verticillium dahliae interactions. .In this research, using high-throughput, paired-end RNA sequencing, we will analyze the isoform-level expression and splicing features of Hai 1 infected with verticillium dahliae, and analyze the frequency of AS events. Through GO and KEGG, the biological functions of differently spliced genes will be analyzed. On this basis, the characteristics of alternative spliced R genes will be clear. Besides, isoforms of alternative spliced R genes, which were differentially expressed, will be cloned and preliminary function analyzed. This research will illuminate genome-wide alternative splicing landscapes and the molecular mechanism involved in cotton defense reaction of AS, which provides new insights into cotton verticillium wilt resistance.

可变剪接是转录后基因表达调控的重要机制，在植物抗病反应中发挥重要的作用。棉花黄萎病是由大丽轮枝菌引起的一种侵染维管束的土传病害，导致棉花叶片失绿变黄，蕾铃脱落，严重时造成棉株死亡，被称为“棉花的癌症”。因此，研究可变剪接在棉花和大丽轮枝菌互作中的调控机制对于棉花黄萎病抗性改良具有重要意义。.本项目以高抗棉花黄萎病的海岛棉品种海1为材料，利用高通量的双端RNA-seq技术，分析大丽轮枝菌侵染后，海1的差异表达基因和剪接变体，明确不同类型可变剪接的发生概率。通过GO和KEGG分析差异剪接基因所涉及的生物学功能。在此基础上，明确R基因中可变剪接的变化特征。筛选差异表达的R基因剪接变体，探明其剪接特征和初步功能。本研究结果将阐明大丽轮枝菌侵染海1过程中，全基因组范围内可变剪接的动态变化和R基因剪接变体在维持棉花防御反应的动态平衡机理，为生产上探索棉花黄萎病抗性改良的调控机制提供理论依据。

棉花黄萎病是由大丽轮枝菌引起的一种土传病害，被称为“棉花的癌症”，严重危害棉花生产。因此，研究黄萎病抗病机制对于棉花抗病品种改良具有重要意义。本项目以高抗棉花黄萎病的海岛棉品种海1为材料，利用高通量RNA-seq技术，分析大丽轮枝菌V991侵染后，海1发生可变剪接的情况。并利用陆地棉中棉所36和海1杂交获得的渐渗系群体，通过温室、人工病圃和大田鉴定黄萎病抗性，筛选出高抗黄萎病的渐渗系MBI8255，同时利用已有的遗传图谱对其遗传背景进行分析。以渐渗系MBI8255和感病亲本中棉所36为研究对象，对大丽轮枝菌V991侵染初期的棉苗根部组织进行生理生化指标检测，发现POD和PPO活性与黄萎病抗性可随着V991的侵染进程而呈现正相关关系，而MDA含量与黄萎病抗性则表现出负相关关系。利用RNA-seq技术进行转录组测序，共鉴别出77412个表达基因，获得23180个差异表达基因。通过时序表达模式分析，筛选出大量与黄萎病抗性相关的信号通路，包括显著性富集的苯丙烷生物合成、植物激素信号转导和类黄酮生物合成等代谢通路，为进一步解析棉花抗黄萎病的分子机制奠定了基础。