Epicuticular waxes of maize as affected by the interaction of mutantgl8 withgl3, gl4 andgl15.

Abstract

Chemical composition of epicuticular waxes from double mutants of maizegl2gl8, gl3gl8, gl4gl8 andgl15gl8 is compared to that of the wild type and of the single mutants. The wax composition was moderately affected in the double mutants studied. Meanwhile, free fatty acids became a normal class constituent of the waxes. The sites of action of the single mutants as deduced from previous studies are confirmed. The influence ofgl2, gl3 andgl4 on the terminal steps of the chain elongation process ingl2gl8, gl3gl8 andgl4gl8 genotypes is presented and discussed. The study ofgl3gl8 waxes also confirms that the mutantgl3 induces a metabolic defect defiitely different from those ofgl2 andgl4. The pattern of alkanes fromgl15gl8 is unusual, supporting the thesis thatgl15 controls mainly alkane synthesis. However, based on variations induced on wax composition, its manner of action is difficult to account for. Taken together, the available data on single and double mutants affecting wax synthesis in maize suggest that elongases might be heteromeric enzymes.