Molecular characterization and phylogenetic analysis of NBS-LRR genes in wild relatives of eggplant (Solanum melongena L

Abstract

Eggplantor brinjal (Solanum melongena L.), is highly susceptible to various soil-borne diseases. The extensive use of chemical fungicides to combat these diseases can be minimized by identification of resistance gene analogs (RGAs) in wild species of cultivated plants.In the present study, degenerate PCR primers for the conserved regions ofnucleotide binding site-leucine rich repeat (NBS-LRR) were used to amplify RGAs from wild relatives of eggplant (Black nightshade (Solanum nigrum), Indian nightshade (Solanumviolaceum)and Solanu mincanum) which showed resistance to the bacterial wilt pathogen, Ralstonia solanacearumin the preliminary investigation. The amino acid sequence of the amplicons when compared to each other and to the amino acid sequences of known RGAs deposited in Gen Bank revealed significant sequence similarity. The phylogenetic analysis indicated that they belonged to the toll interleukin-1 receptors (TIR)-NBS-LRR type R-genes. Multiple sequence alignment with other known R genes showed significant homology with P-loop, Kinase 2 and GLPL domains of NBS-LRR class genes. There has been no report on R genes from these wild eggplants and hence the diversity analysis of these novel RGAs can lead to the identification of other novel R genes within the germplasm of different brinjal plants as well as other species of Solanum.