Genome-wide analysis of the GPAT gene family in wheat and the potential roles of TaGPAT58 and its homologs in male reproductive development

TL;DR

This study identifies and characterizes the GPAT gene family in wheat, focusing on TaGPAT58's role in male reproductive development and fertility.

Contribution

The study provides the first comprehensive analysis of the GPAT gene family in wheat and identifies TaGPAT58's role in male fertility.

Findings

Sixty-four TaGPAT genes were identified and classified into three clades with conserved motifs and structures.

TaGPAT58 is specifically expressed in trinucleate pollen and its silencing causes pollen defects and reduced fertility.

Segmental duplication is the main driver of TaGPAT gene family expansion in wheat.

Abstract

The glycerol-3-phosphate acyltransferase (GPAT) gene family plays a critical role in the biosynthesis of lipids in plants. However, the GPAT gene family has not yet been systematically analyzed in wheat, and in particular, the relationship between the GPAT genes and male fertility in wheat (Triticum aestivum L.) remains unclear. In this study, a total of 64 TaGPAT genes were identified at the whole-genome level and classified into three clades. The genes within each clade exhibited conserved motif distributions and gene structures, whereas clear differences were observed among the different clades. A synteny analysis indicated that segmental duplication was the major driving force for the expansion of the TaGPAT gene family. An analysis of the expression pattern showed that the TaGPAT genes showed distinct expression patterns among different tissues and reproductive stages, with some genes preferentially expressed in roots, grains, or spikes, and specific TaGPAT genes reaching peak expression at key meiotic stages. In the temperature-sensitive male-sterile wheat line YS3038, TaGPAT58 was specifically highly expressed at the trinucleate pollen stage under fertile conditions, and the encoded protein was localized to the endoplasmic reticulum. Virus-induced gene silencing targeted to TaGPAT58 resulted in a reduction in the number of pollen, abnormal pollen morphology, and a significant decrease in the seed-setting rate. Collectively, this study provides a comprehensive characterization of the TaGPAT gene family in wheat and evidence that TaGPAT58 and its two homoeologous genes are involved in male reproductive development, thereby offering important insights into the molecular mechanisms of male sterility and the exploitation of heterosis in wheat.

Figures