Molecular characterization of diverse wheat germplasm for puroindoline proteins and their antimicrobial activity

Thirty different wheat genotypes, including landraces, cultivars, and related wild species, were analyzed for puroindoline genes and proteins. Full-length Pina and Pinb genes were amplified using gene-specific markers where 13 genotypes amplified both genes, while 17 genotypes had either one or none of the puroindoline genes. None of the puroindoline genes were detected in any of the Triticum durum cultivars. Genotypes with both puroindoline genes had a soft grain texture, while other genotypes had hard grains. Related nonprogenitor species with A, C, M, U, and S genomes also showed the presence of either one or both the puroindoline genes, indicating that these species can also be utilized for development of extra-soft wheat. SDS-PAGE analysis of selected wheat genotypes revealed that puroindoline proteins are approximately 13-14 kDa and the protein results were in agreement with the PCR results. Puroindoline proteins of selected 3 soft wheat genotypes HPW 89, Naphal, and IITR-9 also exhibited antimicrobial activity against gram-positive and gram-negative bacteria. Both genes of a soft wheat cultivar, HPW 89, were successfully cloned in the Escherichia coli DH-5 alpha strain. Introgression and molecular characterization of diverse Pina and Pinb genes to develop extra-soft wheat is in progress.