Rice OsGL1-6 Is Involved in Leaf Cuticular Wax Accumulation and Drought Resistance

Abstract

Cuticular wax is a class of organic compounds that comprises the outermost layer of plant surfaces. Plant cuticular wax, the last barrier of self-defense, plays an important role in plant growth and development. The OsGL1-6 gene, a member of the fatty aldehyde decarbonylase gene family, is highly homologous to Arabidopsis CER1, which is involved in cuticular wax biosynthesis. However, whether OsGL1-6 participates in cuticular wax biosynthesis remains unknown. In this study, an OsGL1-6 antisense-RNA vector driven by its own promoter was constructed and introduced into the rice variety Zhonghua11 by Agrobacterium-mediated transformation to obtain several independent transgenic plants with decreased OsGL1-6 expression. These OsGL1-6 antisense-RNA transgenic plants showed droopy leaves at the booting stage, significantly decreased leaf cuticular wax deposition, thinner cuticle membrane, increased chlorophyll leaching and water loss rates, and enhanced drought sensitivity. The OsGL1-6 gene was constitutively expressed in all examined organs and was very highly expressed in leaf epidermal cells and vascular bundles. The transient expression of OsGL1-6-GFP fusion indicated that OsGL1-6 is localized in the endoplasmic reticulum. Qualitative and quantitative analysis of the wax composition using gas chromatography-mass spectrometry revealed a significantly reduced total cuticular wax load on the leaf blades of the OsGL1-6 antisense-RNA transgenic plants as well as markedly decreased alkane and aldehyde contents. Their primary alcohol contents increased significantly compared with those in the wild type plants, suggesting that OsGL1-6 is associated with the decarbonylation pathways in wax biosynthesis. We propose that OsGL1-6 is involved in the accumulation of leaf cuticular wax and directly impacts drought resistance in rice.

Improving Plant Water Use Efficiency through Molecular Genetics

“…Zhou and colleagues [100] carried out a functional analysis of OsGL1-6 in rice. OsGL1-6 is homologous to CER1 in Arabidopsis and Wda1 in rice, widely expressed in vegetative and reproductive organs, and especially highly expressed in leaf epidermal cells and vascular bundles.…”

Cold tolerance in rice germinating seeds revealed by deep RNAseq analysis of contrasting indica genotypes

“…Other two genes related with lipid metabolism which showed different expression levels between the two tested genotypes are 3-ketoacyl-CoA synthase and WAX2, both involved in wax biosynthesis. Recently, three different groups established a connection between wax biosynthesis in rice and drought tolerance via stress-induced wax accumulation [41,42]. Apparently, wax biosynthesis can also be stimulated by low temperature stress in rice, and our results suggest that the cold-tolerant seedlings synthesize more wax than the cold-sensitive ones under cold conditions.…”

Mapping the glaucousness suppressor Iw1 from wild emmer wheat “PI 481521”

“…In general, EW may affect water relations, protect plants from radiation, provide a physical barrier for toxic substances, enhance canopy reflectance, and increase grain yield [1][2][3]. Epicuticular wax also plays important roles in plant defense against bacterial and fungal pathogens, and impacts plantinsect interactions [2,4].…”