Deciphering the role of monoacylglycerol lipases (MAGL) under abiotic stress and lipid metabolism in soybean (Glycine max L.)

Abstract

SummaryMonoacylglycerol lipase (MAGL) is involved in the last step of triacylglycerol breakdown by hydrolysing the monoacylglycerol (MAG) to free fatty acid and glycerol. In the present study, 21 and 38 MAGL genes were identified in Glycine max (cultivated soybean) and Glycine soja (wild) genomes, respectively. Gene‐specific association performed using whole genome resequencing data by mixed linear model showed a significant association with total seed oil, linolenic, and oleic acid content. Subsequent haplotypic analysis revealed allelic variations for MAGL genes in soybean germplasm. Diversity analysis indicated a balancing selection of MAGL genes in cultivated soybean compared to wild soybean. Transient expression of three candidate MAGL proteins in Nicotiana tabacum leaves showed chloroplast‐specific localization, which is the site for fatty acid biosynthesis. An extensive transcriptomic evaluation revealed comparatively higher expression of five genes in soybean seeds, and nine genes showed higher expression under abiotic stress conditions like drought and heat. The quantitative real‐time PCR analysis of three candidate MAGL genes showed differential expression under arsenic and silicon supplementation. Gene co‐expression analysis showed the interaction of MAGL with diacylglycerol acyltransferase and triacylglycerol. In addition, confocal microscopy and fluorescence‐activated cell sorting (FACS) analysis of yeast expressing four GmMAGL genes showed altered lipid deposition, leading to smaller and more dispersed lipid droplets, suggesting its significant role in lipid metabolism. Manipulation of MAGL can be a pragmatic strategy to improve abiotic stress tolerance, likely by membrane lipid remodeling under environmental stress. Similarly, MAGL could be strategically utilized to enhance oil yield by regulating lipid metabolism.