بررسی الگوی بیان ژن‌های مرتبط با مقاومت به بیماری در گیاه سیب‌زمینی تحت تنش آلودگی با ویروس PVY

Potato virus Y is one of the most destructive viruses effecting summer crops that significantly affects the product yield and quality. The study of gene expression plays an essential role in understanding the mechanism of plants in dealing with environmental stresses. So far, more than 700 disease resistance genes from the NB-LRR family have been identified using RNA-Seq in potato. These genes cause plant systemic resistance against PVY infection and restrict virus movement in plant cells. Identifying and investigating resistance genes is important in breeding programs and in order to create virus resistant cultivars. The present study was conducted with the aim of investigating the expression pattern of two genes related to disease resistance in potato, in the resistant cultivar Khavaran under PVY infection stress. For this purpose, the RNA-Seq data available in SRA database was used, that is related to transcriptome sequencing of PVY infected potato plants. After quality control, data trimming and mapping on potato reference genome, differential gene expression analysis and gene ontology was performed using DESeq2. Then, 14-days old potato seedlings of Khavaran cultivar were inoculated with PVY to study the expression changes in target genes using real-time PCR. Sampling for RNA extraction was done within 4, 8, 12 and 24 hours, one week and 4 weeks post inoculation. According to the results, 2504 genes were differentially expressed in PVY infected treatments compared to control with 1% p-value. LOC102600816 and LOC102603056 were up-regulated. The products of these genes are N-like protein from NB-LRR family and related to potato resistance to Tobacco Mosaic Virus and WRKY transcription factor protein. According to gene ontology analysis, the mentioned genes are involved in resistance pathways, DNA binding, regulation of transcription by RNA polymerase II and effect on signaling pathway of plant immune responses. The results of investigating two target genes using real-time PCR confirmed the results of RNA-Seq analysis and showed an increase in their expression. The highest increase in the expression of mentioned genes was observed at one week and four weeks post virus inoculation. Total results indicate the important role of genes involved in resistance pathways in plant response to virus stress.