Natural occurring epialleles determine vitamin E accumulation in tomato fruits

QUADRANA L.; ALMEIDA J.; ASÍS R.; DUFFY T; DOMINGUEZ P.G.; BERMÚDEZ L.; CONTI G.; CORRÊA DA SILVA J.; COLOT V.; ASURMENDI S.; FERNIE A. R. ; ROSSI M.; PERALTA I. E; CARRARI F.

NATURE COMMUNICATIONS

Nature Communications

Lugar: Londres; Año: 2014

2041-1723

Vitamin E (VTE) content is a low heritability nutritional trait for which the genetic determinants are poorly understood. Here, we zoomed in on a previously recognized major tomato VTE QTL (mQTL9-2-6) and identified the causal gene as one encoding a 2-methyl-6-phytylquinol methyltransferases (namely VTE3(1)). This enzyme catalyzes one of the final steps in the biosynthesis of - and -tocopherols, which are the main forms of VTE. By reverse genetic approaches, expression analyses, siRNA profiling and DNA methylation assays, we demonstrate that mQTL9-2-6 is an expression QTL associated with differential methylation of a SINE retrotransposon located in the promoter region of VTE3(1). Consistent with the epigenetic nature of this QTL, DNA methylation can be spontaneously reverted leading to different epialleles affecting VTE3(1) expression and VTE content in fruits. These results thus describe the regulation of a nutritionally important metabolic QTL by naturally occurring epialleles and highlight the role of epigenetics in the determination of relevant agronomic traits.