title: Hypoxia and hydrogen cyanamide induce bud-break and up-regulate hypoxic responsive genes (HRG) and VvFT in grapevine-buds.
abstract: It has been reported that dormancy-breaking compound hydrogen cyanamide (HC) stimulates the fermentative pathway and inhibits respiration in grapevine-buds, 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 SYNTHASE (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 post-treatment 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 long-term, 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.
authors.affiliation: Laboratorio de Bioquímica Vegetal, Universidad de Chile, Casilla, 653 Santiago, Chile.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Vergara
authors.forename: Sebastián
authors.initials: S
authors.lastname: Rubio
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Pérez
mesh_terms: D000693:Anaerobiosis / Q000187:drug effects; D003484:Cyanamide / Q000494:pharmacology*; D035264:Flowers / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D017343:Genes, Plant / Q000235:genetics*; D010100:Oxygen / Q000494:pharmacology*; D057445:Plant Dormancy / Q000187:drug effects / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects*; D027843:Vitis / Q000187:drug effects / Q000235:genetics*
chemical_list: D010940:Plant Proteins; D014157:Transcription Factors; D003484:Cyanamide; D010100:Oxygen