Genome-wide characterization of the GPAT gene family in bean (Phaseolus vulgaris L.) and expression analysis under abiotic stress and melatonin

GPAT (sn-Glycerol-3-phosphate-1-O-acyltransferase) is a key enzyme in the biosynthesis of membrane lipids. Two kinds of GPATs are involved in the production of glycerolipids. While sn-1-GPATs are responsible for creating lysophosphatidic acid, sn-2-GPATs generate monoacylglycerol. GPAT genes of beans (Phaseolus vulgaris) have never been investigated before. This study aimed to assess the expression profiles of GPAT genes in common bean leaves under drought and salt stress and apply bioinformatics tools to the genome-wide analysis of GPAT gene family members. In the P. vulgaris genome, PvGPAT genes with molecular weights ranging from 50.2 to 60.4 kDa, amino acid counts ranging from 376 to 539, theoretical isoelectric points ranging from 8.41 to 9.46, and instability indices ranging from 31.84 to 51.38 were found. Based on the gene structure analysis, the expected number of exons and introns was between 2 and 12. The GPAT proteins from Arabidopsis thaliana, Glycine max, Vitis vinifera, Cicer arietinum, Lens culinaris, and P. vulgaris were analyzed phylogenetically. GPAT proteins of G. max and A. thaliana are evolutionarily related to those of beans. The PvGPAT4/PvGPAT10 and PvGPAT7/PvGPAT12 gene pairs were detected to be segmentally duplicated. In this work, qRT-PCR was performed on six PvGPAT genes, and the effects of salt, drought, and melatonin treatments on bean GPAT genes were studied. The role of melatonin in the response to salt and drought stress was investigated at the gene expression level. The findings of the present study will shed light on GPAT gene family members in beans and provide insight for future functional research.