Genome-wide identification and expression analysis of SnRK2 gene family in common bean (Phaseolus vulgaris L.) in response to abiotic stress

Sucrose non-fermenting-1 (SNF1)-related protein kinase2s (SnRK2s) were reported to be one of the critical factors in abscisic acid (ABA) signaling, playing important roles in response to biotic and abiotic stresses in plants. Common bean (Phaseolus vulgaris L.) is one of the most important protein crops, but little is known about SnRK2s (PvSnRK2s) in common bean. In this study, we identified and characterized PvSnRk2s at the genome-wide level. We identified 10 PvSnRK2 genes, which were divided into 4 groups by phylogenetic analysis. Stress response element (TC-rich repeats), MYB binding site involved in drought-inducibility (MBS), and low-temperature responsiveness element (LTR) were identified in the promoter regions of PvSnRK2s. Real-time fluorescence quantitative RT-PCR (RT-qPCR) was used to verify the expression profiles of 10 genes at 5 time points under high salt, drought and low temperature stresses. Results showed that the expression levels of PvSnRK2.2/2.9 of group II were much higher than that of the other groups’ members under drought stress, implying these genes might play an important role in the response of common bean to water deficiency. Furthermore, PvSnRK2.4 was significantly up-regulated under NaCl, Mnt (mannitol) and low-temperature stresses, indicating the gene may be one of the essential regulatory genes of common bean in response to the adverse external environment. This is the first comprehensive analysis of the SnRK2 genes in the common bean, which provided a basis for further elucidating the function of PvSnRK2 genes in the common bean.