Protection by GABA and succinic semialdehyde of seed germination and some enzymatic activities against high concentration of hydroxylamine

Abstract

Hydroxylamine was found to stimulate germination of Lupinus albus at concentrations inferior to 10 mM and to inhibit it greatly at 20 mM concentration. This inhibition was partially restored by GABA or succinic semialdehyde. Hydroxylamine, at high concentrations, behaved as inhibitor in vivo on GABA 2-oxyglutarate amino-transferase and succinic semialdehyde dehydrogenase NAD-dependent, whereas it behaved as activator on succinic semialdehyde dehydrogenase NADP-dependent. No effects were observed on the enzymatic activities and the inhibited germination was partially restored, after GABA and succinic semialdehyde had been added to a growth medium with a 20 mM hydroxylamine concentration. A possible protection mechanism of GABA and succinic semialdehyde against hydroxylamine action is discussed.