Identification and Characterization of Reduced Epicuticular Wax Mutants in Rice (Oryza sativa L.)

Epicuticular wax forms the outermost protective barrier of the aerial surfaces of land plants and works in concert with other components of the plant cuticle to prevent uncontrolled loss of water and provide protection against an array of external environmental stresses. In this study, chemically-mutagenized populations of rice (Oryza sativa L.) derived from approximately 4,750 M2 families were screened for adhesion of water droplets resulting in a wet leaf/glossy (wlg) phenotype. Mutants were identified in eleven independently-derived M2 families. SEM analysis confirmed the association of the wlg phenotype with changes in the epicuticular wax crystals of these plants. The phenotypes of five of these mutants were confirmed to be the result of single recessive gene mutations. Evaluation of mutants from three of the eleven M2 families revealed significant reductions (> 50%) in surface wax content and increased cuticle membrane permeability.