Cysteine-Rich Peptide Genes of the Wheatgrass Thinopyrum elongatum

Cysteine-rich peptides play an important role in the plant defense system. The objective of this study was in silico searching for the genes encoding antimicrobial and signaling peptides in the genome of the tall wheatgrass Thinopyrum elongatum (Host) D.R. Dewey (2n = 14, EE), a wild cereal that is highly resistant to pathogens and abiotic stress. Bioinformatic analysis provided information for the identification in the tall wheatgrass genome of 154 novel genes coding for antimicrobial and signaling peptide precursors belonging to nine families. A number of cysteine-rich peptide genes were found to contain introns. The structure of peptide precursors and the location of the peptide genes on the wheatgrass chromosomes were determined. The highest similarity of the wheatgrass peptide sequences with homologous peptides from plants of the genera Triticum and Aegilops was demonstrated, supporting the cytogenetic data on the relatedness between genome E and genome D, as well as the genomes close to it. The data obtained contribute to the characterization of the molecular components of the Th. elongatum immune system and will serve as the basis for further studies of the mechanisms of resistance, as well as for the scientifically based practical use of this species as the resistance donor in wheat breeding.