Biosynthesis of wax esters in tissues of Sinapis alba L. seeds

The biosynthesis of wax esters has been investigated in maturing seeds of Sinapis alba. Exogenous long-chain alcohols are incorporated exclusively into alkyl moieties of wax esters. Oxidation of the long-chain alcohols is not detected. Exogenous fatty acids are incorporated into acyl moieties of wax esters to a low extent. A reduction of fatty acids to alcohols is not observed. Synthesis of wax esters is localized exclusively in the testa; both outer and inner integument are equally active in wax ester biosynthesis. The biosynthesis of wax esters is specific with regard to both chain length and degree of unsaturation of long-chain alcohols. Exogenous and endogenous sterols are not esterified.