马铃薯不同发育阶段对PSTVd差异抗性的功能基因鉴定和机制研究

PSTVd disease is one of the most important factors causing potato loss in China. Study found that plants could show the typical symptoms after germination of potato seed tuber infected by PSTVd, while the plant didn't show symptoms after infection by PSTVd during the seedling period. This kind of latent phenomenon in potato production influences the prevention and control of diseases. This study will analyze the difference of RDRp expression level based on the different stages of potato development, explore the relationship between RDRp expression level and PSTVd resistance, finally reveal the molecular mechanisms of varietal resistance to PSTVd on different stages of potato development. And based on analysis of the transcriptome of the potato tubers and leaves before and after PSTVd infection, to identify the functional genes of expression differences, further to determine the related potato genes influenced by PSTVd silence pathway and causing the resistance performance differences. The study can not only clear the molecular mechanisms of PSTVd resistance difference in the different potato stages and the related functional genes in the host, but also is helpful to further reveal the pathogenesis of PSTVd and to explore new ways to prevent and control this potato disease.

PSTVd引发的马铃薯类病毒病害是造成我国马铃薯减产的重要因素之一。研究中发现，被PSTVd感染的马铃薯种薯块茎，萌发后植株可以表现出典型的病症，而在幼苗期植株感染PSTVd后，植株不表现病症。在马铃薯生产中这种症状潜隐现象影响对病害的判断及防控。本研究拟通过对马铃薯不同发育阶段RDRp表达水平差异分析，探索其与PSTVd抗性的相互关系，揭示马铃薯不同发育阶段对PSTVd抗性差异的分子机制；并通过转录组分析，对PSTVd侵染前后的马铃薯块茎及植株叶片的转录组进行比较，从中鉴定表达差异的功能基因，确定影响PSTVd沉默途径并引起抗性表现差异的马铃薯基因。该研究不仅能够明确在马铃薯不同发育阶段对PSTVd抗性差异的分子机制及相关寄主功能基因，同时有助于进一步揭示PSTVd的致病机理，为防治马铃薯类病毒病害探索新途径。

研究中发现，被PSTVd感染的马铃薯种薯块茎，萌发后植株可以表现出典型的病症，而在幼苗期植株感染PSTVd 后，植株不表现病症。在马铃薯生产中这种症状潜隐现象影响对病害的判断及防控。本项目通过构建PSTVd的侵染性克隆，利用PSTVd侵染性克隆分别侵染不同时期的马铃薯块茎和植株叶片，对各个样品的转录组数据进行分析，分组比较了不同样品间的功能基因的表达差异，以及每组样品间代谢通路的差异。分析和验证了RDRp基因在马铃薯抵抗PSTVd侵染过程中的作用。本研究结果不仅分析了在马铃薯不同发育阶段对PSTVd抗性差异的分子机制及相关寄主功能基因，同时有助于进一步揭示PSTVd的致病机理，为防治马铃薯类病毒病害探索新途径。