Roles of the cer-j and cer-p loci in determining the epicuticular wax composition on barley seedling leaves

Abstract

Quantitative analyses of the composition of the epicuticular wax present on primary leaves of the barley eceriferum mutants cer-j59 and cer-p37, grown under various environmental conditions, were carried out, using column, thin layer and gas liquid chromatography. Comparisons of the wax composition on the mutants to that on the wild type Bonus, grown under identical conditions, led to the following conclusions: The cer-p locus regulates the amount of precursors available for epicuticular wax production. Mutations at the cer-j locus inhibit the production and use of (1) C26 fatty chains in the synthesis of the free acids, aldehydes and free and ester alcohols and (2) C29, C31 and C33 fatty chains in the synthesis of hydrocarbons. Although growing Bonus in the dark produces a partial phenocopy of the cer-j locus, light and the cer-j locus are shown to control different facets of wax biosynthesis.