METABOLIC ROUTES OF BETA-(ISOXAZOLIN-5-ON-2-YL)-L-ALANINE (BIA), THE PRECURSOR OF THE NEUROTOXIN ODAP (BETA-N-OXALYL-L-ALPHA,BETA,-DIAMINOPROPIONIC ACID), IN DIFFERENT LEGUME SEEDLINGS

BIA, beta-(isoxazolin-5-on-2-yl)-alanine, is formed in high concentrat ions in the seedling stage of many plants belonging to the tribe Vicie ae. The metabolism of this compound in different legume seedlings has been studied by radioisotope feeding. In Lathyrus sativus, BIA is meta bolised to the neurotoxin ODAP (beta-N-oxalyl-alpha,beta-diaminopropio nic acid) and the gamma-glutamyl derivative of BIA. In L. odoratus see dlings BIA is metabolised to the decarboxylation product of the glutam yl derivative, and the glutamyl derivative is proposed as an intermedi ate. In Pisum sativum seedlings, the main part of BIA is not further m etabolised. While in Lens culinaris seedlings, besides the formation o f the glutamyl derivative, another four unknown amino acids were found . Approaches for the detoxification of Lathyrus sativus by genetic tra nsformation are suggested. (C) 1998 Elsevier Science Ltd. All rights r eserved.