title: A rapid transcriptional activation is induced by the dormancy-breaking chemical hydrogen cyanamide in kiwifruit (Actinidia deliciosa) buds.
abstract: Budbreak in kiwifruit (Actinidia deliciosa) can be poor in locations that have warm winters with insufficient winter chilling. Kiwifruit vines are often treated with the dormancy-breaking chemical hydrogen cyanamide (HC) to increase and synchronize budbreak. This treatment also offers a tool to understand the processes involved in budbreak. A genomics approach is presented here to increase our understanding of budbreak in kiwifruit. Most genes identified following HC application appear to be associated with responses to stress, but a number of genes appear to be associated with the reactivation of growth. Three patterns of gene expression were identified: Profile 1, an HC-induced transient activation; Profile 2, an HC-induced transient activation followed by a growth-related activation; and Profile 3, HC- and growth-repressed. One group of genes that was rapidly up-regulated in response to HC was the glutathione S-transferase (GST) class of genes, which have been associated with stress and signalling. Previous budbreak studies, in three other species, also report up-regulated GST expression. Phylogenetic analysis of these GSTs showed that they clustered into two sub-clades, suggesting a strong correlation between their expression and budbreak across species.
authors: The New Zealand Institute for Plant and Food Research Limited, Mt Albert, Auckland, New Zealand. eric.walton@otago.ac.nz
authors: Eric F
authors: EF
authors: Walton
authors: Rong-Mei
authors: RM
authors: Wu
authors: Annette C
authors: AC
authors: Richardson
authors: Marcus
authors: M
authors: Davy
authors: Roger P
authors: RP
authors: Hellens
authors: Kate
authors: K
authors: Thodey
authors: Bart J
authors: BJ
authors: Janssen
authors: Andrew P
authors: AP
authors: Gleave
authors: Georgina M
authors: GM
authors: Rae
authors: Marion
authors: M
authors: Wood
authors: Robert J
authors: RJ
authors: Schaffer
mesh_terms: D029042:Actinidia / Q000187:drug effects* / Q000235:genetics* / Q000502:physiology; D003484:Cyanamide / Q000494:pharmacology*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation / Q000187:drug effects*
chemical_list: D010940:Plant Proteins; D003484:Cyanamide