News: CRAG scientists find out that tomatoes use light to “see” how ripe they are.
CRAG scientists led by Briardo Llorente and Manuel Rodriguez-Concepcion unveiled that tomatoes use a ‘recycled’ light-dependent mechanism to ‘see’ inside them and adjust their color to their ripening state. When the tomato fruit is green (due to the presence of chlorophylls), the light that penetrates the flesh becomes poor in red.
Specific light receptors detect this light and transduce the signal to prevent the production of carotenoids (the pigments that give tomatoes their characteristic red color). But when chlorophylls start to degrade, the amount of red light increases and this is signalled by the light receptors to promote carotenoid biosynthesis, which in turn contributes to the change in color associated to tomato ripening.
The work, carried out in collaboration with scientists at with the Institut Català de Ciències Fotòniques (ICFO) and published in "The Plant Journal" (http://onlinelibrary.wiley.com/doi/10.1111/tpj.13094/abstract), also shows how to modify the discovered mechanism in order to obtain carotenoid-enriched fruits, wich are healthier and commercially more eye-catching.