Solar UV-B and ABA Are Involved in Phenol Metabolism of Vitis vinifera L. Increasing Biosynthesis of Berry Skin Polyphenols

Abstract

It has been previously found that abscisic acid (ABA) participates in the activation of grapevine leaf tissue defense against potentially damaging effects of solar ultraviolet-B radiation (UV-B), apparently by triggering biosynthesis of phenols that filter the harmful radiation and act as antioxidants. The present work studies the effect of solar UV-B and exogenously applied ABA on berry growth, sugar accumulation, and phenol (anthocyanin and nonanthocyanin) profiles across berry development and ripening of Vitis vinifera L. cv. Malbec in a vineyard at 1450 m of altitude. The grapevines were exposed to relatively high UV-B irradiation (normal sunlight; +UV-B) and also to a reduced UV-B treatment (filter exclusion; -UV-B). These two UV-B treatments were combined with weekly spray applications to the leaves and berries of 1 mM ABA (+ABA) or H(2)O (-ABA). Reduction of UV-B delayed berry development and maturation, whereas the +UV-B and +ABA combined treatment hastened berry sugar and phenol accumulation. +UV-B/+ABA treatments also reduced berry growth and decreased sugar per berry without affecting sugar concentration (°Brix) at harvest. Berry skin ABA levels were higher in the +UV-B and +ABA combined treatment, which also hastened the onset of ripening up to 20 days. Berry skin ABA levels then decreased toward harvest, implying a possible role for ABA in the control of ripening in this nonclimacteric fruit. Under both +UV-B and +ABA treatments berry skin phenols were additively increased with a change in anthocyanin and nonanthocyanin profiles and increases in the proportion of phenols with high antioxidant capacity.

Accumulation Pattern of Flavonoids in Cabernet Sauvignon Grapes Grown in a Low-Latitude and High-Altitude Region

“…In terms of a particular cultivar, the accumulation of phenolic compounds depends largely on the terroir, such as vineyard soil, topography and climate (Gladstones, 2011). Vineyard altitude could result in variations in temperature, solar radiation and ultraviolet radiation, and these climate factors have been demonstrated to have a strong effect on the synthesis of phenolic compounds (Mateus et al, 2001;Berli et al, 2011). Studies have also examined the effects of vineyard altitude on phenolic and aromatic compounds in grapes and the wines produced (Mateus et al, 2001;Berli et al, 2013), but so far these studies have been concerned mainly with oceanic climate conditions such as the North European (like Portugal) and South American (such as Brazil and Argentina) climates.…”

Comparing phenolic composition of Cabernet Gernischet wines between rain-shelter cultivation and open-field cultivation

“…Many factors such as grape variety, edaphoclimatic conditions and cultural and technological practices, may influence the phenolic composition of wines (Cynkar et al 2009;Obreque-Slier et al 2010;Puértolas et al 2010;Meng et al 2013). It has been reported that rain-shelter cultivation effectively delayed the maturation of grapes (Berli et al 2011;Meng et al 2013), slowed sugar accumulation by reducing photosynthetically active radiation (PAR) (Chavarria et al 2008;Chavarria et al 2009;Conceição & Marin 2009), increased berry and cluster weight, and improved economic returns (Tangolar et al 2007). During the several last decades, although rain-shelter cultivation has been studied for its commercial value on table grapes and other fruits (Fanizza & Ricciardi 1991;Tangolar et al 2007;Chavarria et al 2011;Pedro Júnior et al 2011), few studies have focused on wine grapes and wine.…”

Changes in concentration of volatile compounds in response to defoliation of Muscat of Alexandria grapevines grown under a traditional farming system

“…Higher PAR and daytime temperatures in Pinihue location may explain higher Brix values of severely defoliated vines (Song et al, 2015). However, no known reason can explain why T1 showed higher TA than the control treatment since changes in radiation and temperature are not generally related to increases in TA (Berli et al, 2011).…”