THE PARTICIPATION OF OXIDATIVE STRESS IN CHLOROPLAST-CHROMOPLAST TRANSITION

BALDET, PIERRE; BRÈS, CÉCILE; ALEGRE, MATÍAS LEONEL; JUST, DANIEL; BARTOLI, CARLOS GUILLERMO; STEELHEART, CHARLOTTE ; ROTHAN, CHRISTOPHE; GERGOFF GROZEFF, GUSTAVO ESTEBAN

CORDOBA

Congreso; XXXII Reunión Argentina XVI Congreso Latinoamericano de FISIOLOGIA VEGETAL; 2018

SOCIEDAD ARGENTINA DE FISIOLOGIA VEGETAL

The transformation ofchloroplasts into chromoplasts is an important part of the fruit developmentinvolving several processes. The disassembling of chloroplast structure andsynthesis and accumulation of lycopene constitute dominating aspects of thisripening step. The increase of reactive oxygen species concentration during thistransition has been observed but it may be a side-associated effect. The aim ofthis work is to demonstrate if oxidative stress plays an active role duringchloroplast-chromoplast transition. Plants with reduced ascorbic acid (AA)content are prone to develop oxidative stress especially under changingenvironments. Tomato deficient plants in GDP-L-galactosephosphorylase, the first enzyme committed to the synthesis of AA were used. Wildtype and AA deficient plants with green mature fruits were transferred to highlight condition to trigger oxidative stress. Hydrogen peroxide production andoxidative damage increased during transition from green to red stages, but unexpectedlywas more pronounced in wild type fruits. Associatedwith this increment of oxidative stress an acceleration of ripening wasobserved suggesting the participation of reactive oxygen species in fruitdevelopment.