We have shown that ectopic expression of two genes
encoding transcription factors, Delila (Del) and Rosea1
(Ros1), from snapdragons, under the control of the fruitspecific
E8 promoter, results in increased expression of all
the genes committed to anthocyanin biosynthesis to create
intensely purple tomato fruit [14]. While growing the purple
tomatoes, we observed that they had improved shelf life
compared to wild-type, red fruit. The shelf life of food is
defined as the period during which a stored product remains
suitable for consumption and is normally determined by the
degree of softening, shriveling, and rotting of fruit. Consequently,
both fruit softening late during ripening and pathogen
infection influence the shelf life of tomatoes. Purple fruit from
Del/Ros1 tomato plants have normal size, shape, and number
of seeds. However, purple fruit exhibit delayed ripening after
breaker compared to red fruit. This is evident from the appearance
of the purple fruit both on the vine and during postharvest
storage and from a reduced level of fungal infection under
either condition (Figures 1A and 1B).