AIM & METHODS:
At a local scale, kaolin particle-film technology is considered a short-term adaptation strategy to mitigate the adverse effects of global warming on viticulture. This study aimed to evaluate kaolin application effects on photochemistry and related defense responses of Touriga Franca (TF) and Touriga Nacional (TN) grapevines planted at two Portuguese winegrowing regions (Douro and Alentejo) over two summer seasons (2017 and 2018). For this purpose, chlorophyll a fluorescence transient analysis, leaf temperature, foliar metabolites, and the expression of genes related to heat stress (VvHSP70) and stress tolerance (VvWRKY18) were analysed.
RESULTS:
Kaolin application had an inhibitory effect on VvHSP70 expression, reinforcing its protective role against heat stress. However, VvWRKY18 gene expression and foliar metabolites accumulation revealed lower gene expression in TN-treated leaves and higher in TF at Alentejo, while lipid peroxidation levels decreased in both treated varieties and regions. The positive kaolin effect on the performance index parameter (PIABS) increased at ripening, mainly in TN, suggesting that stress responses can differ among varieties, depending on the initial acclimation to kaolin treatment. Moreover, changes on chlorophyll fluorescence transient analysis were more pronounced at the Douro site in 2017, indicating higher stress severity and impacts at this site, which boosted kaolin efficiency in alleviating summer stress.
SIGNIFICANCE OF THE STUDY:
Under applied contexts, kaolin application can be considered a promising practice to minimise summer stress impacts in grapevines grown in Mediterranean-like climate regions.
REFERENCE:
Bernardo S, Luzio A, Machado N, Ferreira H, Vives-Peris V, Malheiro AC, Correia C, Gómez-Cadenas A, Moutinho-Pereira J, Dinis L-T. Kaolin Application Modulates Grapevine Photochemistry and Defence Responses in Distinct Mediterranean-Type Climate Vineyards. Agronomy. 2021; 11(3):477. https://doi.org/10.3390/agronomy11030477
Image credit: https://www.imerys.com/minerals/kaolin
This abstract is republished in its original form, with headings inserted, as permitted by the following Creative Commons licence: https://creativecommons.org/licenses/by-nc-nd/4.0/