Abstract
Glycinebetaine (GB) is known as a compatible solute and accumulated by many plants under abiotic stresses. Betaine aldehyde dehydrogenase (BADH) is catalyses the last step in GB synthesis in plants. Rice, albeit it is considered to be a typical non-GB accumulator, has most probably peroxisomal BADHs (OsBADH1 and OsBADH2). Thus it is interesting to investigate the function of rice BADHs. In the present study, we expressed OsBADH1 and OsBADH2 in Escherichia coli and purified to homogeneity. Using these recombinant proteins, we investigated their enzymatic properties. Rice BADHs catalyzed the oxidation of 4-aminobutyraldehyde, 3-aminopropionaldehyde, and 4-N-trimethyl-aminobutyraldehyde. We also found that rice BADHs are able to catalyze the oxidation of acetaldehyde. These data may suggest that rice BADHs may be involved in the detoxification of various aldehydes in rice.
