Abstract: The plant cuticle, which connects with the external environment directly, is composed of an intermeshed cutin polyester membrane overlaid with free waxes. Plant cuticle forms specific structure and complex chemical composition in the long-term process of adaptation to outer environment. The most important function of cuticular wax is recognized as involving in blocking water loss through non-stomatal transpiration, thus improving the use efficiency of water in plant, and finally adapting to the drought environment. Drought stress can lead to metabolic changes in cuticular wax, which is eventually conducted through the regulation of gene expression. Recently, many wax metabolism-related genes involving in plant adaptation to drought stress have been discovered. Some genes have been cloned and used to improve the drought tolerance of crops. However, it is still not clear that the molecular mechanisms of these genes involve in drought tolerance as well as the relationship with ABA. Here, we review the changes of metabolism, including the composition and content of wax while plants adapting to water deficit conditions, and the main genes involved and their molecular biology. Understanding the role and molecular mechanism of cuticular wax in the adaptation of plants to drought may provide new molecular markers and important target genes for breeding the drought tolerance of agricultural crops, i.e., better service for agricultural practices.

Key words: plant cuticular, water deficit, wax metabolism, molecular biology