Control of antioxidant accumulation by plant hormones

CARLOS G. BARTOLI; MARÍA E. SENN; LUIS M. MAZORRA; GUSTAVO GERGOFF GROZEFF

Buenos Aires

Congreso; VII Congress Society for Free Radical Biology and Medicine. South American Group; 2013

Plant tissues contain a large diversity of antioxidants present in high amounts. These metabolites are important scavenging reactive oxygen species; however, some of them are now recognized participating in other physiological processes like cell expansion, division and differentiation. Consequently, their accumulation must be accurately controlled during plant growth and development in different tissues. We focus our experiments in the processes regulating the steady state of ascorbic acid in leaves. The amount and quality of light constitute the main ambient elements affecting AA accumulation. Its synthesis directly interacts with respiration; the last step of AA formation depends on the oxidation of its precursor feeding electrons in mitochondria electron transport chain. We present evidences showing the participation of the phytohormones gibberellins, brassinosteroids, ethylene and abscisic acid in the accumulation and synthesis of ascorbic acid. We also analyze the regulation exerted by phytohormones in plant respiration and the consequences for ascorbic acid synthesis under different light environment.