High-throughput Analysis Of Horizontal Resistance-related Genes Of Potato To Phytophthora Infestans By Virus Induced Gene Silence

Virus-induced gene silencing is an RNA-mediated antiviral defense response mechanism of plants. VIGS technique is a relatively efficient and quick method for high-throughput identification of gene function.Potato horizontal resistance to late blight is controlled by multiple minor genes, with race-nonspecific and quantitative characteristic. Level of this resistance is less than R-gene resistance, but it has resistance of many physiological strains. With a broad spectrum, durability and stability, the horizontal resistance has multiple resistance mechanism. At the same time, horizontal resistance can reduce the selection pressure of Phytophthora infestans physiological race, to some extent delay the pathogen variation. To elucidate function of resistance related genes is fundamental to understand the molecular basis of horizontal resistance to late blight.In this study, VIGS technology was used to high-throughput study of gene's function. We selected potato horizontal resistance-related genes and constructed recombinant TRV vectors. Through VIGS corresponding genes in Nicotiana benthamiana, we identified 11 potentially important genes in potato horizontal late blight resistance. The main findings are as follows:1. Compared with the N. benthamiana cDNA database, we selected 45 highly homologous genes, which have no less than 23 bp continuous matching sequence.2.38 target gene sequences were amplified using potato cDNA as template. All these target genes were inserted into TRV virus recombinant vectors. These vectors have been transformed into Agrobacterium.3. RT-PCR identification result demonstrated that endogenous target genes were silenced after VIGS experiment in N. benthamiana.4.12 genes were demonstrated as significant genes in process of horizontal resistance to late blight, according to late blight resistance identification in N. benthamiana. In summary, VIGS technique was used to identify 38 potato horizontal resistance-related genes'function in N. benthamiana. Totally,12 potentially important genes in potato horizontal resistant to late blight were identified.