S17 - Session O1 - Keynote: Carotenoid content in mature tomato fruits under soil water deficit: accounting the role of pre-maturing processes though carotenoid kinetics and cell microscopy

Authors: Thomas Breniere *, Nadia Bertin, Anne-Laure Fanciullino

Soil water deficit triggers a wide range of plant adaptation responses that interact with the initiation, development and maturation of reproductive organs. In the case of tomato (Solanum Lycopersicum L.) that is part of human diet, those processes may interact with the accumulation of micronutrients in the fruit tissue. As precursors of vitamins or anti-oxydants, those micronutrients and more precisely the family of carotenoids, play a determinant role in human health. Carotenoid distributed in fruit tissue are mainly produced and stored in plastid endosymbotic organelles. For the green fruit, most plastid are chlorophyllic rich, green pigmented chloroplasts. At maturation, the majority of chloroplast transitions to carotenoid rich, red pigmented chromoplasts. While the impact of soil drought on mature fleshy fruit carotenoid content has been partially investigated, little data is available on the kinetics of carotenoid and chlorophyl fruit content. Our study provides a dynamic of chlorophyll to carotenoid content with fruit sampling at six development stages ; from 5 days post anthesis to 60 days post anthesis on 6 contrasted genotypes under two different water regimes. Biochemistry analyses have been supplemented by microscopy data to assess the weight of pre-maturation profile (pigments distribution, fruit cell number and size) in the final fruit carotenoid content. This work will contribute to characterize fruit health potential submitted to climatic drought or water-scarce irrigation policy.