Abstract
In this study, the metabolic and physiological impacts of an altered microclimate on quality-associated primary and secondary
metabolites in grape (Vitis vinifera) ‘Sauvignon Blanc’ berries was determined in a high-altitude vineyard. The leaf and lateral shoot
removal in the bunch zones altered the microclimate by increasing the exposure of the berries. The physical parameters (berry
diameter and weight), primary metabolites (sugars and organic acids), as well as bunch temperature and leaf water potential were
predominantly not affected by the treatment. The increased exposure led to higher levels of specific carotenoids and volatile
terpenoids in the exposed berries, with earlier berry stages reacting distinctly from the later developmental stages. Plastic/nonplastic
metabolite responses could be further classified to identify metabolites that were developmentally controlled and/or responded to the
treatment in a predictable fashion (assessed over two consecutive vintages). The study demonstrates that grapevine berries exhibit a
degree of plasticity within their secondary metabolites and respond physiologically to the increased exposure by increasing metabolites
with potential antioxidant activity. Taken together, the data provide evidence that the underlying physiological responses relate to the
maintenance of stress pathways by modulating antioxidant molecules in the berries.
