The occurrence of enzymes involved in phenylpropanoid metabolism in the tapetum fraction of anthers.

The contents of another loculus were separated in a pollen and tapetum fraction. The following enzymes involved in phenylpropanoid metabolism were present in the tapetum fraction: shikimate dehydrogenase; phenylalanine ammonialyase; cinnamic acid 4-hydroxylase; SAM (S-adenosylmethionine): caffeate 3-O-methyltransferase; hydroxycinnamate: CoA ligase; "flavanone synthase"; chalcone-flavanone isomerase; SAM: 3',4'-dihydroxyflavonoid 3'-O-methyltransferase; O-glucosyltransferase. It is postulated, that these enzymes derived from the tapetum catalyze the different steps of phenylpropanoid metabolism at or in cavities of the exine after their transfer into the loculus.