THE ROLE OF PROLYL 4-HYDROXYLASES IN TOMATO FRUIT RIPENING

Abstract

Fruit ripening comprises a wide range of molecular and biochemical processes which lead to changes in texture, color, flavor and aroma. Ethylene coordinates most of these programmes according to extensive studies mainly on tomato which is the model system for fruit ripening. Gene expression analysis shows that tomato P4Hs have different patterns of expression during fruit ripening. Treatment of tomato pericarp discs at turning and light red stage of development with 2,4-pyridine dicarboxylate (PDCA), an inhibitor of prolyl 4-hydroxylases, resulted in reduced ethylene production and alterations in expression of arabinogalactan proteins (AGPs). However, there is no available information up to now linking AGPs and ethylene regulation. Analysis of the transcript levels of the major ACO genes, showed that PDCA down-regulated the expression of SIACO4. The role of P4Hs and AGPs in fruit ripening is currently under investigation.