Induction of mitochondrial aldehyde dehydrogenase by submergence facilitates oxidation of acetaldehyde during re-aeration in rice.

Post-hypoxic injuries in plants are primarily caused by bursts of reactive oxygen species and acetaldehyde. In agreement with previous studies, we found accumulations of acetaldehyde in rice during re-aeration following submergence. During re-aeration, acetaldehyde-oxidizing aldehyde dehydrogenase (ALDH) activity increased, thereby causing the acetaldehyde content to decrease in rice. Interestingly, re-aerated rice plants showed an intense mitochondrial ALDH2a protein induction, even though ALDH2a mRNA was submergence induced and declined upon re-aeration. This suggests that rice ALDH2a mRNA is accumulated in order to quickly metabolize acetaldehyde that is produced upon re-aeration.