Developmental and metabolic plasticity of white-skinned grape berries in response to Botrytis cinerea during noble rot

BLANCO-ULATE B, AMRINE KCH, COLLINS TS, RIVERO RM, VICENTE AR, MORALES-CRUZ A, DOYLE CL, YE Z, ALLEN G, HEYMANN H, EBELER SE, CANTU D.

PLANT PHYSIOLOGY.

AMER SOC PLANT BIOLOGISTS

Lugar: Rockville; Año: 2015

0032-0889

Noble rot results fromexceptional infections of ripe grape (Vitisvinifera) berries by Botrytis cinerea. Unlike bunch rot, noble rotpromotes favorable changes in grape berries and accumulation of secondarymetabolites that enhance wine grape composition. Noble rot-infected berries ofSémillon, a white-skinned variety, were collected over three years from acommercial vineyard at the same time fruit were harvested for botrytized wineproduction. Using an integrated transcriptomics and metabolomics approach, wedemonstrate that noble rot alters the metabolism of Sémillon berries by inducingbiotic and abiotic stress responses as well as ripening processes. During noble rot, Botrytis induced the expression of keyregulators of ripening-associated pathways, some of which are distinctive tonormal ripening of red-skinned cultivars. Enhancement of phenylpropanoid metabolism,characterized by a restricted flux in white-skinned berries, was a commonoutcome of noble rot and red-skinned berry ripening. Transcript and metaboliteanalyses together with enzymatic assays determined that the biosynthesis ofanthocyanins is a consistent hallmark of noble rot in Sémillon berries. Thebiosynthesis of terpenes and fatty acid aroma precursors also increased duringnoble rot. We finally characterized the impact of noble rot in botrytizedwines. Altogether the results of this work demonstrate that noble rot causes amajor reprogramming of berry development and metabolism. This positive/desirableinteraction between a fruit and a fungus stimulates pathways otherwise inactivein white-skinned berries, leading to greater accumulation of compounds involvedin the unique flavor and aroma of botrytized wines.