Use of metabolic profiling to study grape skin polyphenol behavior as a result of canopy microclimate manipulation in a 'Pinot noir' vineyard.

Canopy microclimate manipulation can have a significant effect on grapevine gene expression and can thus affect the yield of many important berry compounds. Focusing on only a few targeted phenolics in the past, advanced multimethod analytical approaches are opening up much wider possibilities to fill in the gaps of missing knowledge about plant secondary metabolism. Different leaf removal timings, leading to different microclimate scenarios, were thus introduced in a 'Pinot noir' vineyard to reveal related alterations of multiple classes of skin phenolics, including some rarely studied to date. Different accumulation trends during cluster development were detected not only between groups but also between individual compounds within groups. Although many significant changes were observed early in the season, these were later often less significant. However, at harvest, 31 of 72 detected compounds showed significant differences in comparison to control for at least one of three leaf removal approaches.