# Genome-Wide Identification of G3BP Family in U’s Triangle Brassica Species and Analysis of Its Expression in B. napus

## TL;DR

This study identifies and analyzes G3BP family genes in Brassica species, focusing on their role in stress responses and seed traits in B. napus.

## Contribution

The first genome-wide identification and analysis of the G3BP family in Brassica species, with a focus on B. napus.

## Key findings

- G3BP family genes were identified in six Brassica species, including gene structure, motifs, and phylogeny.
- Expression patterns of BnaG3BP genes were analyzed in response to various stresses and seed traits.
- Two cold-responsive BnaG3BP DEGs were validated for inducibility using qRT-PCR.

## Abstract

The RasGAP SH3 domain binding protein (G3BP) is a highly conserved family of proteins in eukaryotic organisms that coordinates signal transduction and post-transcriptional gene regulation and functions in the formation of stress granules. G3BPs have important roles in abiotic/biotic stresses in mammals, and recent research suggests that they have similar functions in higher plants. Brassica contains many important oilseeds, vegetables, and ornamental plants, but there are no reports on the G3BP family in Brassica species. In this study, we identified G3BP family genes from six species of the U’s triangle (B. rapa, B. oleracea, B. nigra, B. napus, B. juncea, and B. carinata) at the genome-wide level. We then analyzed their gene structure, protein motifs, gene duplication type, phylogeny, subcellular localization, SSR loci, and upstream miRNAs. Based on transcriptome data, we analyzed the expression patterns of B. napus G3BP (BnaG3BP) genes in various tissues/organs in response to Sclerotinia disease, blackleg disease, powdery mildew, dehydration, drought, heat, cold, and ABA treatments, and its involvement in seed traits including germination, α-linolenic acid content, oil content, and yellow seed. Several BnaG3BP DEGs might be regulated by BnaTT1. The qRT-PCR assay validated the inducibility of two cold-responsive BnaG3BP DEGs. This study will enrich the systematic understanding of Brassica G3BP family genes and lay a molecular basis for the application of BnaG3BP genes in stress tolerance, disease resistance, and quality improvement in rapeseed.