(Box 3) Figure I.

Multiple mechanisms by which GABA promotes cell survival and stress tolerance. This scheme illustrates the proposed roles of GABA in maintaining cell viability during (a)biotic stress responses. (i) GABA shunts provide energy required for cell survival. (ii) The induction of ethylene (ET) by GABA can induce autophagy, which contributes to recycling damaged molecules and enhances stress tolerance. (iii) GABA can directly scavenge hydroxyl radicals (^.OH) and protect against oxidative stress-induced cell death. Green arrows indicate promotion, whereas red T-bars indicate inhibition.