SlMBP3 controls tomato fruit texture
Fleshiness and texture are essential fruit traits determining whether tomato varieties are suitable for processing or fresh consumption. Here we uncover the role of SlMBP3 as a master regulator of locular tissue differentiation and show that its expression level underlies variability of inner tissue texture. The study reveals that the “All-flesh” trait is associated with a deletion at the SlMBP3 locus and softness of ripe fruit is determined at early developmental stage, not only during ripening. Impairing SlMBP3 expression leads to the absence of locular gel and results in massive transcriptomic reprogramming involving diverse transcription factor families and a number of cell wall-related genes, many being under direct regulation of SlMBP3. These findings define new breeding targets for designing tomato varieties, and possibly other fleshy fruits, with improved texture and show that tomato breeders inadvertently selected alleles of SlAGL11 locus, the SlMBP3 homolog, that avoid detrimental effects of dual SlMBP3/SlAGL11 mutants.