Cloning And Expression Analysis Of Genes Related To Phytophthora Capsici Resistance In Pepper

Phytophthora blight is a common disease which significantly influences the cultivating and production of pepper.In this study,the resistant pepper ’17-p63’ and the susceptible pepper ’16-217’ to Phytophthora capsici were used as test materials,and the Phytophthora capsici race NO.3 was used as the pathogen of resistance inoculation identification.Real-time PCR(qRT-PCR)and virus induced gene silencing(VIGS)were used to verify the function of the genes identified in the previous research;at the same time,the transcriptome sequencing method was used to excavate the pathway related to Phytophthora capsici resistance,and combined with the results of bulk sequencing analysis(BSA),the Phytophthora blight resistance genes in pepper were located.The main results are as follows:1.The expression patterns of 13 candidate genes in the BSA candidate region were analyzed by real-time PCR.The results showed that there were significant differences in their expression patterns at different time in different resistant and susceptible materials after inoculation with Phytophthora capsici.Eight genes possibly related to Phytophthora capsici resistance were screened out.2.The function of candidate genes Capana10g0023 74,Capana10g002414,Capana10g002268,Capana10g002284 and Capana10g002296 was preliminarily verified by VIGS.Disease resistance identification of the transformation plants induced by VIGS showed that,the resistant pepper ’17-p63’ were susceptible to the disease after silenced genes Capana10g002374 and Capana10g002414,Therefore,it was inferred that these two genes were related to the resistance to Phytophthora capsici in ’17-p63’.3.Root tissues harvested from ’17-p63’ and ’16-217’ inoculated with Phytophthora capsici for 0 h,12 h,36 h and 60 h were used for transcriptome sequencing.KEGG pathway enrichment analysis showed that 11 pathways such as phenylpropane biosynthesis were enriched in both parents.The genes in phenylpropane biosynthesis pathway was upregulated in Pepper after infected by Phytophthora capsici,which revealed that this pathway responded to the invasion of Phytophthora capsici.4.Jointly analysising the candidate regions of BSA and the hub genes from weighted gene co-expression network analysis,three candidate genes contributing to the Phytophthora capsici resistance in pepper were screened preliminarily.And the genes Capana07g002242 and Capana01g002997 may be the key genes related to resistance to Phytophthora capsici,and gene Capana10g002347 may be the major genes related to resistance to Phytophthora capsici.