Genome-wide exploration of the GDSL-type esterase/lipase gene family in rapeseed reveals several proteins active during early seedling development.

The Gly-Asp-Ser-Leu (GDSL)-type esterase/lipase proteins (GELP) are one of the most important families of lipolytic enzymes and play prominent roles in seed germination and early seedling establishment through mobilizing the lipids stored in seeds. However, there are no comprehensive studies systematically investigating the gene family in (), and their biological significance to these physiological processes are far from understood. In the present study, a total of 240  genes were identified in  cultivar "Zhongshuang 11" (ZS11), which is nearly 2.3-fold more genes than in . The  genes clustered into 5 clades based on phylogenetic analysis. Ten BnGELPs were identified through zymogram analysis of esterase activity followed by mass spectrometry, among which five clustered into the clade 5. Gene and protein architecture, gene expression, and -element analyses of genes in clade 5 suggested that they may play different roles in different tissues and in response to different abiotic stresses. and were slightly induced by cold, which may be attributed to two low-temperature responsive -acting regulatory elements present in their promoters. An increased activity of esterase isozymes by cold was also observed, which may reflect other cold inducible esterases/lipases in addition to the ten identified BnGELPs. This study provides a systemic view of the gene family and offers a strategy for researchers to identify candidate esterase/lipase genes responsible for lipid mobilization during seed germination and early seedling establishment.