The Genomic Basis of Red Fruit Color in Cultivated Tomato

Cultivated tomato (S. lycopersicum) owes the red color of its ripe fruits to the accumulation of the carotene lycopene. This peculiar characteristic arose recently during evolution, and is shared by only two species in the tomato clade, S. lycopersicum and S. pimpinellifolium. Transcriptional profiling of green- and red-fruited species showed a concerted shift in the expression of carotenoid biosynthetic genes: genes involved in lycopene biosynthesis being generally up-regulated in red-fruited species while those involved in lycopene utilization are down-regulated. Virus-Induced Gene silencing is being used to functionally characterize candidate genes controlling this peculiar characteristic.