| dc.description.abstract | It has been reported that dormancy-breaking
compound hydrogen cyanamide (HC) stimulates the fermentative
pathway and inhibits respiration in grapevinebuds,
suggesting in this way, that a respiratory stress must
be involved in the release of buds from dormancy. Here,
we tested low-oxygen effect (hypoxia) on the bud-break
response of endodormant grapevine buds, and HC and
hypoxia effects on the expression of hypoxic responsive
genes (HRG) PYRUVATE DECARBOXYLASE (VvPDC),
ALCOHOL DEHYDROGENASE (VvADH2), SUCROSE SYN
THASE (VvSUSY), non-symbiotic HEMOGLOBIN (VvnsHb),
and on FLOWERING LOCUS T (VvFT), a transcription factor
related to dormancy release in Vitis. Hypoxia as HC, induce
transiently the expression of HRG and VvFT and hasten the
sprouting of endodormant grapevine-buds.During the first 24 h
after treatment, HRG and VvFT were strongly induced by
hypoxia, subsequently, their expressions fell, and 14 days posttreatment
increased again above control levels. These results
indicate that in the short-term, a respiratory stress, caused either
by oxygen deprivation or by inhibitors of respiration, induces
transiently the expression of HRG and VvFT, and in the longterm,
along with the advancement of bud-break, the expression
of these genes move forward in treated buds, suggesting that
these second induction that occurs just before bud-break is
developmentally regulated. | |
