Exogenous ABA increases yield in field-grown wheat with a moderate water restriction

TRAVAGLIA C; REINOSO H; COHEN A; LUNA C; TOMMASINO E; CASTILLO C; BOTTINI R

JOURNAL OF PLANT GROWTH REGULATION

SPRINGER

Año: 2010 vol. 29 p. 366 - 374

0721-7595

It has been previously found that abscisic acid (ABA) participates in 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 non-anthocyanin) 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 H2O (-ABA). Reduction of UV-B delayed berry development and maturation, while the +UV-B and +ABA combined treatment hastened berry sugar and the accumulation of phenols. +UV-B/+ABA treatments also reduced berry growth and decreased sugar per berry without affecting sugar concentration (ºBrix) 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 towards harvest, implying a possible role for ABA in the control of ripening in this non-climacteric fruit. Under both, +UV-B and +ABA treatments berry skin phenols were additively increased with a change in anthocyanin and non-anthocyanin profiles, and increases in the proportion of phenols with high antioxidant capacity.