Roles of Germin-like Protein Family in Response to Seed Germination and Shoot Branching in Brassica napus.

Abstract

Germin-like proteins (GLPs) play important roles in the regulation of various plant development processes, such as seed vigor, root and leaf development and disease resistance, while the roles of GLPs on agronomic traits are rarely studied in Brassica napus. Here, we identified GLPs family genes in rapeseed and analyzed their potential functions. There are 77 GLPs family genes (BnGLPs) in the Zhongshuang11 rapeseed reference genome, divided into a, b, c, d, e, f six subfamilies. Tissue expression profile analysis of BnGLPs revealed the following: e subfamily genes were highly expressed in early stages of silique, cotyledon, vegetative rosette and leaf development; f subfamily genes were highly expressed in seed development; genes of a subfamily were mainly expressed in the root; and genes of b, c, d subfamily exhibited low-level or no expression in above mentioned tissues. RT-qPCR analysis confirmed that the transcripts of two f subfamily members decreased dramatically during seed germination, suggesting that f subfamily proteins may play vital roles in the early stage of seed germination. Transcriptome analysis of axillary buds in sequential developing stages revealed that the transcripts of eight e subfamily genes showed a rapid increase at the beginning of shoot branching, implying that the e subfamily members played vital roles in branch development. These results demonstrate that rapeseed BnGLPs likely play essential roles in seedling development, root development and plant architecture, indicating that harnessing certain BnGLPs may contribute to the improvement of rapeseed yield.