Premium
PHYTOCHROME‐INTERACTING FACTOR 3 mediates light‐dependent induction of tocopherol biosynthesis during tomato fruit ripening
Author(s) -
Gramegna Giovanna,
Rosado Daniele,
Sánchez Carranza Ana Paula,
Cruz Aline Bertinatto,
SimonMoya Miguel,
Llorente Briardo,
RodríguezConcepcíon Manuel,
Freschi Luciano,
Rossi Magdalena
Publication year - 2019
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.13467
Subject(s) - phytochrome , biosynthesis , tocopherol , biochemistry , ripening , derepression , biology , chemistry , gene expression , microbiology and biotechnology , gene , vitamin e , botany , antioxidant , red light , psychological repression
Tocopherols are important antioxidants exclusively produced in plastids that protect the photosynthetic apparatus from oxidative stress. These compounds with vitamin E activity are also essential dietary nutrients for humans. Although the tocopherol biosynthetic pathway has been elucidated, the mechanisms that regulate tocopherol production and accumulation remain elusive. Here, we investigated the regulatory mechanism underlying tocopherol biosynthesis during ripening in tomato fruits, which are an important source of vitamin E. Our results show that ripening under light conditions increases tocopherol fruit content in a phytochrome‐dependent manner by the transcriptional regulation of biosynthetic genes. Moreover, we show that light‐controlled expression of the GERANYLGERANYL DIPHOSPHATE REDUCTASE (SlGGDR) gene, responsible for the synthesis of the central tocopherol precursor phytyl diphosphate, is mediated by PHYTOCHROME‐INTERACTING FACTOR 3 (SlPIF3). In the absence of light, SlPIF3 physically interacts with the promoter of SlGGDR, down‐regulating its expression. By contrast, light activation of phytochromes prevents the interaction between SlPIF3 and the SlGGDR promoter, leading to transcriptional derepression and higher availability of the PDP precursor for tocopherol biosynthesis. The unraveled mechanism provides a new strategy to manipulate fruit metabolism towards improving tomato nutritional quality.