Study of new NBS-LRR genes analogues in cucurbits native types in Iran

Nucleotide binding site leucine-rich repeats (NBS-LRR) accounting for the main disease resistance proteins play an important role in plant defense against pathogen attack. The current study aimed to identify new NBS-LRR gene members in native types of cucurbit species in Iran. Accordingly, DNAs of melon, cucumber and cantaloupe native types to Iran were identified using three primer pairs. PCR products of the expected size were generated and the obtained DNA was cloned using the pGEM-T. BLASTN algorithms were used to compare the insert sequences with sequences available at the Entrez nucleotide and protein. Phylogenetic analyses were conducted using the MEGA software. The results analysis suggests that cucurbit species native types’ genome contain new NBS_LRR resistance gene analogues against cucurbit pathogens. These resistance gene analogues are composed of genes related to both coiled-coil (CC) and toll-interleukin-receptor homology (TIR) domain containing NBS-LRR R-genes. Phylogenetic analysis of these genes shows that they include NBS-LRRs derived from a recent common ancestor. This study provides an insight into the evolution of NBS-LRR genes in the Cucurbit native type species genomes that are resistance analogues against cucurbit bacterial blight pathogen and tomato mosaic virus.