A role for ethylene in low-oxygen signaling in rice roots

Inhibitors of action and synthesis of ethylene (Ag+, norbornadien, Co2+) were able to reduce the level of ã-aminobutyric acid (Gaba) in rice roots during the development of an anaerobic environment. The inhibitory effect was reversed by the addition of the G protein activator 52-guanylylimidodiphosphate. Gaba accumulation was modulated by the presence of CO2 (inhibitor of ethylene action and synthesis) and stimulated by 2-chloroethylphosphonic acid (ethefon). These findings are consistent with a role of ethylene during a low-oxygen stress.