Artículos de revistas
The dormancy-breaking stimuli “chilling, hypoxia and cyanamide exposure” up-regulate the expression of a-amylase genes in grapevine buds
Date
2014Registration in:
Journal of Plant Physiology 171 (2014) 373–381
dx.doi.org/10.1016/j.jplph.2013.11.009
Author
Rubio Vargas, Sebastián Gerardo
Donoso, Amanda
Pérez Correa, Francisco
Institutions
Abstract
It has been suggested that respiratory stress is involved in the mechanism underlying the dormancybreaking
effect of hydrogen cyanamide (H2CN2) and sodium azide in grapevine buds; indeed, reductions
in oxygen levels (hypoxia) and inhibitors of respiration promote bud-break in grapevines. In this study,
we showed that, hypoxia increased starch hydrolysis soluble sugar consumption and up-regulated the
expression of -amylase genes (Vv˛-AMYs) in grapevine buds, suggesting that these biochemical changes
induced by hypoxia, may play a relevant role in the release of buds from endodormancy (ED). Three of the
four Vv˛-AMY genes that are expressed in grapevine buds were up-regulated by hypoxia and a correlation
between changes in sugar content and level of Vv˛-AMY gene expression during the hypoxia treatment
was found, suggesting that soluble sugars mediate the effect of hypoxia on Vv˛-AMY gene expression.
Exogenous applications of soluble sugars and sugar analogs confirmed this finding and revealed that
osmotic stress induces the expression of Vv˛-AMY1 and Vv˛-AMY3 and that soluble sugars induces Vv˛-
AMY2 and Vv˛-AMY4 gene expression. Interestingly, the plant hormone gibberellic acid (GA3) induced the
expression of Vv˛-AMY3 and Vv˛-AMY4 genes, while dormancy breaking stimuli, chilling and cyanamide
exposure, mainly induced the expression of Vv˛-AMY1 and Vv˛-AMY2 genes, suggesting that these two
-amylase genes might be involved in the release of grapevine buds from the ED.