Glycerol-3-Phosphate Acyltransferase 3 (OsGPAT3) is required for anther development and male fertility in rice.

Xiao Men,Mingjiao Chen,Zhijing Luo,Sheng Quan,Wanqi Liang,Qianfei Zhang,Dabing Zhang,Jianxin Shi,Lu Zhu,Gaibin Lian

doi:10.1093/jxb/erw445

Xiao Men, Mingjiao Chen + Show 8 more

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https://doi.org/10.1093/jxb/erw445

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Abstract

Lipid molecules are key structural components of plant male reproductive organs, such as the anther and pollen. Although advances have been made in the understanding of acyl lipids in plant reproduction, the metabolic pathways of other lipid compounds, particularly glycerolipids, are not fully understood. Here we report that an endoplasmic reticulum-localized enzyme, Glycerol-3-Phosphate Acyltransferase 3 (OsGPAT3), plays an indispensable role in anther development and pollen formation in rice. OsGPAT3 is preferentially expressed in the tapetum and microspores of the anther. Compared with wild-type plants, the osgpat3 mutant displays smaller, pale yellow anthers with defective anther cuticle, degenerated pollen with defective exine, and abnormal tapetum development and degeneration. Anthers of the osgpat3 mutant have dramatic reductions of all aliphatic lipid contents. The defective cuticle and pollen phenotype coincide well with the down-regulation of sets of genes involved in lipid metabolism and regulation of anther development. Taking these findings together, this work reveals the indispensable role of a monocot-specific glycerol-3-phosphate acyltransferase in male reproduction in rice.

Highlights

Male reproductive development in higher plants is a complicated biological process that includes the development of the anther and the generation of pollen (Liu and Qu, 2008; Ma, 2005; Sanders et al, 1999; Zhang et al, 2011; Zhang and Wilson, 2009)
We report the functional analysis of an endoplasmic reticulum (ER)-localized Glycerol-3-phosphate acyltransferases (GPATs), Glycerol-3-Phosphate Acyltransferase 3 (OsGPAT3), which plays a crucial role in rice male fertility
Normal pollen grains appeared in wild-type anthers at stage 9, while shrunken and irregularly shaped pollen grains, which became completely aborted at the later stages, were observed in osgpat3 (Fig. 2G, H)

Summary

Introduction

Male reproductive development in higher plants is a complicated biological process that includes the development of the anther and the generation of pollen (Liu and Qu, 2008; Ma, 2005; Sanders et al, 1999; Zhang et al, 2011; Zhang and Wilson, 2009). The innermost cell layer of the anther wall, the tapetum, which encompasses the meiotic cells (microsporocytes) at the center, plays a crucial role in regulating programmed anther development and microspore/pollen formation (Li et al, 2006; Parish and Li, 2010; Zhang and Yang, 2014). Recent studies have demonstrated that there is a high level of conservation between anther development and pollen formation in plants, highlighting their joint function in plant reproduction (Gómez et al, 2015; Huang et al, 2015)

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