OsGL1-3 is Involved in Cuticular Wax Biosynthesis and Tolerance to Water Deficit in Rice

<div><p>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 <i>OsGL1-3</i> in rice using overexpression and RNAi transgenic rice plants. <i>OsGL1-3</i> 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 <i>OsGL1-3</i> 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 <i>OsGL1-3</i> on the expression of some wax synthesis related genes, suggest that OsGL1-3 is involved in cuticular wax biosynthesis. Overexpression of <i>OsGL1-3</i> 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 <i>OsGL1-3</i> in drought tolerance.</p>