Comparative and expression analysis of MYB transcription factor genes in groundnut (Arachis hypogaea L.)

The myeloblastosis (MYB) superfamily is one of the largest transcription factor families in the plant kingdom, and has diverse functions in plants, including regulating biotic and abiotic stresses. In this study, a total of 108 MYB protein sequences were identified and characterized through an insilico approach. We confirmed that the MYB proteins had three conserved repeats (R1, R2, and R3). The putative functions of AhyMYB genes were predicted on the basis of 31 functional groups formed from a comparative phylogenetic analysis. Important cisregulatory motifs, such as ABRE, TGA, ARE, LTR and TATA were present in the upstream regions of AhyMYB genes, and also some post-translational modifications were identified in the present study. Drought- stress was induced in five elite groundnut genotypes (Dh 256, Dh 257, GPBD 4, TMV 2, and JL 24) at flowering and peg initiation stages, and the expression patterns of five selected AhyMYB genes were investigated in these genotypes. In the drought-tolerant genotypes (Dh 256 and Dh 257), at the peg initiation stage, five drought-related transcription MYB factor genes showed greater up-regulation compared with the drought-susceptible genotypes. Among the five genes used in the study, AhyMYB17 gene showed higher expression in JL 24 (moderately drought resistant) compared to untreated control plants at the peg initiation stage. These results indicated the possible involvement of MYB transcription factor genes in regulating the drought stress conditions in groundnut. In-silico analysis, along with the expression studies of AhyMYB genes will definitely help in understanding the stress-response mechanism in groundnut.