Supplemental red LED light promotes plant productivity, "photomodulates" fruit quality and increases Botrytis cinerea tolerance in strawberry.

This work provides new evidences on the effect of pre-harvest red (R), green (G), blue (B), and white (W-R: G: B; 1:1:1) LED light supplementation on production, nutraceutical quality and Botrytis cinerea control of harvested strawberry fruit. Yield, fruit color, firmness, soluble solid content, titratable acidity, primary and specialized metabolites, expression of targeted genes and mold development were analyzed in fruit from light-supplemented plants, starting from the strawberry flowering, radiating 250μmol m^-2 s^-1 of light for five hours per day (from 11:00 to 16:00 h), until the fruit harvest. Briefly, R light induced the highest productivity and targeted anthocyanin accumulation, whilst B and G lights increased the accumulation of primary and secondary metabolites especially belonging to ellagitannin and proanthocyanidin classes. R light also promoted pathogen tolerance in fruit by the upregulation of genes involved in cell wall development (F × aPE41), inhibition of fungus polygalacturonases...