Particle film technology modulates xanthophyll cycle and photochemical dynamics of grapevines grown in the Douro Valley

Field-grown grapevines are often exposed to multiple environmental stresses, which challenges wine-growers develop sustainable measures sustain vine growth, yield, and quality. Under field conditions this task is demanding, due differences in the magnitudes of stresses associated plant responses. In study we explored hypothesis that kaolin-particle film application improves grapevine photoprotection through regulation xanthophyll cycle genes, limiting thermal dissipation excess energy under harsh conditions. Hence, selected two varieties, Touriga-Nacional (TN) Touriga-Franca (TF), grown Douro Demarcated Region, evaluated changes light mechanisms, components, expression genes during 2017 summer season. The results showed that, from veraison ripening, kaolin triggered up-regulation violaxanthin de-epoxidase ( VvVDE1 ) zeaxanthin epoxidase VvZEP1 indicating optimised cycle. Kaolin treatment also decreased chlorophyll (Chl a , Chl b (a+b) carotenoid (Car) accumulation increasing stress both varieties lowered non-photochemical quenching (NPQ) on suggesting long-term response stress. addition, kaolin-treated increased /Chl lower /Car ratios, displaying some features high adapted leaves. Overall, suggests enabled benefit fluctuating periods by managing content down-regulation photochemistry photoinhibition processes. Mediterranean conditions, can be considered an efficient method minimising impact grapevines. • Particle technology triggers foliar features. Light adaptation strategies mechanisms treated improved throughout maturation.