Genome wide comprehensive characterization and expression analysis of RBOH genes revealed drought stress response in mung bean (Vigna radiate L.)

Abstract

Respiratory burst oxidase homologs (RBOHs) play a pivotal role as key producer of reactive oxygen species (ROS) during broad range of biological processes including plant growth, development, hormonal signalling and environmental stress responses in plants. Since, the availability of mung bean (Vigna radiata) genome sequences, the identification and characterization of the RBOH gene family in mung bean remain unknown. Therefore, the current study focuses on identifying and characterizing nine RBOH genes, designated as VraRBOH, in mung bean. The VraRBOH genes were characterized using all sort of bioinformatics analysis for distribution, structural and phylogenic organization in mung bean genome. Further, their expression level was assessed during drought stress in mung bean. The chromosomal distribution analysis showed the presence of VraRBOH genes on six chromosomes only rather than scattering in whole genome. All VraRBOH genes exhibited conserved domain including those for binding of FAD, NADPH ribose and NADPH region in C-terminal region during multiple sequence alignment analysis. The VraRBOH genes harboured the introns ranged from 0 (VraRBOH1) to 23 (VraRBOH4). The phylogenetic tree consisted of five major groups with subgroups. The presence of the cis-regulatory elements in the VraRBOH gene promoter regions suggested the biologically active nature of these genes in mung bean. Semi quantitative reverse transcriptase PCR analysis revealed that VraRBOH4 exhibited exponential expression at the transcript level in the time-course experiment of drought stress in mung bean. Conversely, the remaining VraRBOH genes displayed either up- or down-regulation at specific time points of the drought stress treatment. The identified and characterized VraRBOH gene family offers a valuable resource for both fundamental and applied research aimed at comprehending mung bean's tolerance to abiotic stress.