Relationship between oxalic acid and the metabolism of ß-N-oxalyl-α,ß-diaminopropionic acid (ODAP) in grass pea (Lathyrus sativus L.)

Abstract

Lathyrus sativits L., a member of the annual Leguminosae family, is not only resistant to drought and cold, but also to many plant diseases, insect pests, and barrenness. Moreover, it is highly nutritive and hence an ideal forage crop. However, the seeds of Lathyrus sativus contain P-N-oxalyl-alpha,beta-diaminopropionic acid (ODAP), the main element causing lathyrism. Previous studies indicated that ODAP could form from the oxalylation Of L-alpha,beta-diaminopropionic acid (DAPA), while DAPA synthesis needed the participation of oxalyl-Co-A resulting from the combination of oxalic acid and Co-A; i.e., oxalic acid is one of the precursors of ODAP biosynthesis. Glycolate oxidase (GO), generally existing in the leaves of the C, plant, can catalyze not only the transformation of glycolic acid to glyoxalic acid, but also that of glyoxalic acid to oxalic acid. This study investigated the relationship between the change of oxalic acid and the accumulation of ODAP in different organs at different development stages of grass pea treated with exogenous oxalic acid, butyl hydroxybutynoate (BHB, inhibitor of GO synthesis), and under water stress; evaluated the relationship between the adversity and the accumulation of oxalic acid and ODAP; and provided a new strategy for selecting grass pea with environment-tolerance and low toxicity.