Genome-wide identification and expression patterns analysis of the DREB gene family under various abiotic stress in Lolium perenne.

As a primary limiting factor that substantially reduces crop yield and biomass production, abiotic stress necessitates a deeper understanding of the crucial regulatory role played by dehydration response element binding (DREB) transcription factors in plant adaptation. It remains limited in the important turf and forage grass perennial ryegrass (Lolium perenne) cultivated in temperate regions worldwide. In this study, 70 LpDREB members were identified from the released genome of perennial ryegrass and a systematic overview was presented. Phylogenetic analysis indicated that the LpDREB genes were grouped into 6 subgroups. Gene structure analysis suggested that the multitudinous LpDREB genes were without intron. Moreover, the interchromosomal evolutionary analysis indicated that tandem duplication events were the main cause of the expansion of LpDREB genes in this species. Expression profiles analysis showed that 70 LpDREB genes presented distinct expression patterns in response to different abiotic stresses. Among them, several LpDREB genes, including LpDREB2, LpDREB12, LpDREB38, LpDREB39, and LpDREB67, demonstrated multi-stress responsiveness (including cold, submergence, heat, and NaCl), indicating their potential function in regulating the tolerance of perennial ryegrass to various abiotic stresses. Functional validation in the yeast system primarily showed that LpDREB2 and LpDREB67 increased the yeast resistance to salt stress. The findings of this investigation establish a foundation for elucidating the functional roles of LpDREB genes in perennial ryegrass under environmental stress, offering potential applications in genetic improvement of forage, turfgrass, and crop species through targeted breeding strategies.