W. L. Allan, K. Breitkreuz, J. Waller
2012
Citations
0
Influential Citations
25
Citations
Journal
Botany
Abstract
Succinate semialdehyde (SSA) is a mitochondrially generated intermediate in the metabolism of γ-aminobutyrate (GABA), which accumulates in response to a variety of biotic and abiotic stresses. SSA can be reduced to γ-hydroxybutyrate (GHB) in plants exposed to various abiotic stress conditions. Recent evidence indicates that distinct cytosolic and plastidial glyoxylate reductase isoforms from Arabidopsis thaliana (L.) Heynh (GLYR1 and GLYR2, respectively) catalyze the in vitro conversion of SSA to GHB, as well as glyoxylate to glycolate, via NADPH-dependent reactions. In the present study, recombinant Arabidopsis GLYR1 was demonstrated to catalyze the NADPH-dependent reduction of both glyoxylate and SSA simultaneously to glycolate and GHB, respectively. Six-hour time-course experiments with intact vegetative wild-type Arabidopisis plants subjected to submergence demonstrated that GHB accumulates in rosette leaves, and this is accompanied by increasing levels of GABA and alanine, NADH/NAD+ and NADPH/NADP+ r...