Identification and characterization of novel CC-NBS-LRR type disease resistance (R) gene homologue SBRGA114 from Sorghum (Sorghum bicolor)

Abstract

In the present study, the isolation and characterization of full-length CC-NBS-LRR type disease resistance (SbRGA114) homologous gene from sorghum (Sorghum bicolor (L.) Moench). Based on the short sequence information of previously isolated sorghum resistance gene analogue, SRGA114, a 3,220 bp composite cDNA was amplified using 5' and 3' rapid amplification of cDNA ends (RACE) technique. Further, the entire coding region of 2,733 bp was cloned by nested RT- PCR using specific primers designed for 5' and 3' RACE products. It encodes a predicted polypeptide of 910 amino acids with a computed molecular weight of 104.1kDa. The deduced SbRGA114 protein consists of an N-terminal coiled-coil (CC) domain, nucleotide binding site (NBS), three perfect leucine rich repeats (LRR) and nine potential N-linked glycosylation sites. These domains are known to participate in protein-protein interaction and signal transduction during plant response to pathogens. Sequence analysis of SbRGA114 showed high homology with reported NBS-LRR type resistance genes of maize, barley and rice.