Screening And Identification Differentially Expressed Genes Involving In The Temperature-dependent Resistance Against Potato Virus Y In Potato

Potato is one of the most important strategic crops for the food security and farmers’ income in China.However,as one of the largest asexual reproduction crops,potato is also infected by many viruses including PVY,resulting in serious decline in yield and quality.Our previous study showed that potato variety Exploit had good resistance to PVY at 22℃,but lost resistance at 30℃.So,we suppose that temperature may participate in the regulation of the resistance of Exploit against PVY.Based on this hypothesis,we compared and screened the differentially expressed genes(DEGs)of the Exploit after challenged by PVY at either 22℃ or 30℃ by using the second-generation sequencing technology,which lie the foundation for understanding the crosstalk between the antiviral mechanism and heat shock response in potato.The main results are as follows:1.At 5 days post inoculation(dpi),PVY induced obvious local lesions on the inoculated leaves of Exploit at both 22℃ and 30℃,but significantly more number of local lesions were generated at 30℃;At 20 days post inoculation,no obvious symptom and detectable virus was found on the up un-inoculated leaves of Exploit at 22℃,while necrotic spots were observed on the up un-inoculated leaves of Exploit at 30℃,and systemic infection of PVY was confirmed by both RT-PCR and q RT-PCR.2.Sequencing data released that 88 and 667 DEGs were co-regulated by temperature and virus challenge in the inoculated leaves at 5 dpi and in the systemic leaves at 20 dpi,respectively.These DEGs are mainly concentrated in pathways such as biosynthesis of secondary metabolites,energy metabolism,environmental adaptation to lipid metabolism,and amino acid metabolism through enrichment analysis.3.Nine genes were selected from the DEGs for preliminary functional identification by VIGS experiment in tobacco.Silencing of the homologous genes of HSP-83,NRG1 and SAG101 significantly altered tobacco resistance to PVY;Seven out of nine genes are located in the cytoplasm except NRG1 and NDR1 located in the membrane system.Meanwhile,yeast point-to-point hybridization showed that EDS1 interacted with CI proteins of PVY,and SAG101 interacted with both CI and NIB proteins of PVY.