β-ODAP accumulation could be related to low levels of superoxide anion and hydrogen peroxide in Lathyrus sativus L.

Level of the neuroexcitatory beta-N-oxalyl-L-alpha,beta-diaminopropionic acid (beta-ODAP) in grass pea (Lathyrus sativus L) varies with development and environmental stress. Reactive oxygen species (ROS) (mainly O-2(center dot-) and H2O2) are frequently reported to play important roles in plant development and in response to various stresses. To investigate the possible inter-relationship between contents of beta-ODAP and ROS, grass pea leaves have been analyzed for contents of beta-ODAP, O-2(center dot-) and H2O2. The results showed that leaves containing high levels of beta-ODAP, exhibited low levels of O-2(center dot-) and H2O2, while leaves with high contents of O-2(center dot-) and H2O2 accumulated little beta-ODAP. The application of pyridine or ABA which inhibit the production of O-2(center dot-) or H2O2 led to an increase in beta-ODAP contents in intact or detached young leaves, whereas inhibition of catalase activity using AT (3-amino-1,2,4-triazole), leading to an increase in H2O2 content, result in significant decrease in beta-ODAP levels of detached young leaves. In addition, inoculation of Rhizobium to young seedlings enhanced O-2(center dot-) and H2O2 levels, but reduced beta-ODAP contents in shoots. These results suggest that beta-ODAP accumulation could be related to low levels of superoxide anion and hydrogen peroxide in grass pea tissues. (C) 2010 Elsevier Ltd. All rights reserved.