OsGL1-3 is involved in cuticular wax biosynthesis and tolerance to water deficit in rice.

Ailing Liu,Yan Peng,Linzhi Li,Xiaoyun Zhou,Xiangyuan Wan,Hong Luo,Guofu Gao,Faxi Xu,Xianwen Zhang,Xinbo Chen,Jianhua Xiang

doi:10.1371/journal.pone.0116676

Abstract

Cuticular wax covers aerial organs of plants and functions as the outermost barrier against non-stomatal water loss. We reported here the functional characterization of the Glossy1(GL1)-homologous gene OsGL1-3 in rice using overexpression and RNAi transgenic rice plants. OsGL1-3 gene was ubiquitously expressed at different level in rice plants except root and its expression was up-regulated under ABA and PEG treatments. The transient expression of OsGL1-3–GFP fusion protein indicated that OsGL1-3 is mainly localized in the plasma membrane. Compared to the wild type, overexpression rice plants exhibited stunted growth, more wax crystallization on leaf surface, and significantly increased total cuticular wax load due to the prominent changes of C30–C32 aldehydes and C30 primary alcohols. While the RNAi knockdown mutant of OsGL1-3 exhibited no significant difference in plant height, but less wax crystallization and decreased total cuticular wax accumulation on leaf surface. All these evidences, together with the effects of OsGL1-3 on the expression of some wax synthesis related genes, suggest that OsGL1-3 is involved in cuticular wax biosynthesis. Overexpression of OsGL1-3 decreased chlorophyll leaching and water loss rate whereas increased tolerance to water deficit at both seedling and late-tillering stages, suggesting an important role of OsGL1-3 in drought tolerance.

Highlights

Rice (Oryza sativa L.) is one of the most important crops with very high economic and social values [1]
Water deficit treatment at late-tillering-stage had similar results as 4-leaf-stage seedling (Fig. 9). These results indicated that membrane integrity and cuticular permeability in OsGL1-3 overexpression transgenic lines are better protected against water deficit damage than in RNAi mutant lines and wild type (WT)
OsGL1-3 is a GL-related protein associated with cuticular wax biosynthesis

Summary

Introduction

Rice (Oryza sativa L.) is one of the most important crops with very high economic and social values [1]. Rice production requires large amount of water, while drought is becoming the key factor limiting rice production in water-limited areas. Tremendous efforts have been devoted to the screening of drought tolerant germplasm and breeding of water deficit tolerant rice cultivars [2,3,4]. Cuticular wax is the outermost barrier against nonstomatal water loss and plays important roles in interactions with environmental stresses. The cuticular wax loads in Arabidopsis almost doubled via the upregulation of wax-biosynthetic genes. Increasing attention has being focused on the importance of cuticular wax in water deficit tolerance [5,6,7]

Methods

Results

Conclusion