Abstract:
Discovering endogenous plant resistance genes is a critical preliminary foundation for breeding disease-resistant varieties. In this study, degenerate primers were designed based on the conserved domains of known plant NBS-LRR resistance genes, and
Passiflora edulis f. flavicarpa ‘Qinguo 9' was used as the experimental material to clone NBS-LRR resistance gene analogs(RGA) from its genome. The results showed that the NBS-LRR resistance genes of this cultivar could be divided into two types: TIR type and non-TIR type. Among them, there were 12 TIR-NBS-LRR subtypes(designated QRGA1 to QRGA12) and 4 non-TIR-NBS-LRR subtypes(designated QRGA13 to QRGA16). Phylogenetic analysis revealed that QRGA1~QRGA12 clustered with the reported tobacco TMV-resistance gene N and flax resistance gene
L6, with a homology of 86%. In contrast, QRGA13~QRGA16 clustered with rice bacterial blight-resistance gene
Xa-1 and
Arabidopsis pseudomonas syringae-resistance gene
RPM1, with a homology of 63%. Notably, the amino acids encoded by QRGA1~QRGA12 showed high similarity to TMV-resistant proteins and RPV1-resistant proteins from multiple plant species, indicating their potential research and application value. The findings of this study provide support for the discovering and subsequent application of resistance genes in
Passiflora edulis.