Fruit-localized photoreceptors increases phenolic compounds in berry skins of Vitis vinifera L. cv Malbec

GONZÁLEZ, C.V.; FANZONE, M.; CORTÉS, L.E.; PEÑA-NEIRA, A.; BOTTINI, R.; BALLARÉ, C.; LIJAVETZKY, D.; BOCCALANDRO, H.

La Serena

Congreso; IX International Symposium on Grapevine Physiology and Biotechnology; 2013

Instituto de Investigaciones Agropecuarias, INIA, Chile. International Society for Horticultural Science

Besides playing an essential role in plant photosynthesis, light is also a source of information, which is perceived by plant photoreceptors as light stimuli. Photoreceptors are involved in many important biological processes, particularly phytochromes and cryptochromes have been reported to be involved in fruit pigmentation in other species (e.g. tomato and strawberry). The aims of this study were a) to characterize the diurnal patterns of the light environment within the clusters zone of a commercial vineyard (north ? south orientated rows) located in the Valle de Uco (Mendoza, Argentina); and b) to assess if the stimulation of fruit-localized photoreceptors may increase berry phenolic compounds.   We found that during the morning clusters were directly exposed to solar radiation, however they were subjected to low levels of UV-B (280-315 nm), PAR (400-700 nm) and red to far red ratio (R:RL, 660 ±5/720±5 nm) during remainder of the day. The modification of the cluster light environment by the supplementation of red (660 nm), far red (730 nm), blue (470 nm) and green (560 nm) light, increased berry skins total phenolic compounds at harvest without affecting sugar content, acidity nor berry size. We also analyzed several phenylpropaniod biosynthesis-related genes in order to correlate the metabolic and transcriptomic results.   We concluded that berry phytochrome and cryptochromes stimulation favor accumulation of flavonoid and non-flavonoid compounds, showing that under the assayed field conditions, fruit-photoreceptors are not saturated.