Identification and Expression Analysis of a Homologue of PR-1 Gene in Sorghum bicolor

Trichothecenes, zearalenone (ZEN), fumonisins and aflatoxins are mycotoxins produced by different Fusarium and Aspergillus spp. during infection of susceptible crops such as maize Antifungal peptides are crucial in restricting the growth of fungal hyphae into plant cells. In this study, a homologue of a PR-1 accession of Sorghum bicolor L. is identified and analysed for expression against a number of fungal strains. Based upon the amplification of a conserved region of nucleotide sequence, a complete cDNA clone for PR-1 homologue was obtained by rapid amplification of cDNA ends (RACE). The construction of a molecular phylogenetic analysis by Maximum Likelihood method coupled with an alignment of the nucleotide sequences of the RACE amplicons yielded a full-length coding sequence for a polypeptide chain, which shares more than 90% homology with the PR-1 like cDNA accessions. The deduced amino acid sequence corresponds to a protein of 145 amino acids with a predicted molecular weight of 15.572 KDa and an isoelectric point of 5.54; both of which are the characteristics of PR-1 proteins. RT-qPCR shows an up-regulated relative expression of PR-1 like expression in response to fungal infection as compared with the control plants. The results elucidate the existence of homologue of SbPR-1 in sorghum which upon further characterization could be used for an enhanced in-built resistance in sorghum cultivars. It will lead to reduced fungal infections and an increase in production of feed and fodder sorghum. (C) 2018 Friends Science Publishers