Uniform ripening (U) encodes a Golden 2-like transcription factor regulating tomato fruit chloroplast development

A LT POWELL, CV NGUYEN, T HILL, K L CHENG, R FIGUEROA-BALDERAS, H AKTAS, H ASHRAFI, C PONS, R FERNÁNDEZ-MUÑOZ, VICENTE AR, J LOPEZ-BALTAZAR, C S. BARRY, Y LIU, R CHETELAT, A GRANELL, A VAN DEYNZE, JJ. GIOVANNONI, AB. BENNETT

SCIENCE

AMER ASSOC ADVANCEMENT SCIENCE

Año: 2012

0036-8075

Modern tomato (Solanum lycopersicum) varieties are bred for uniform ripening (u) light green fruit phenotypes to facilitate harvests of evenly ripened fruit. U encodes a Golden 2-like (GLK) transcription factor, SlGLK2, which determines chlorophyll accumulation and distribution in developing fruit. In tomato, two GLKs, SlGLK1 and SlGLK2, are expressed in leaves, but only SlGLK2 is expressed in fruit. Over-expressing GLKs increased the chlorophyll content of fruit while SlGLK2 suppression recapitulated the u mutant phenotype. GLK over-expression enhanced fruit photosynthesis gene expression and chloroplast development leading to elevated carbohydrates and carotenoids in ripe fruit. Summarizing, SlGLK2 influences photosynthesis in developing fruit thereby contributing to mature fruit characteristics and suggesting that selection of u inadvertently compromised ripe fruit quality in exchange for desirable production traits.