Distinct gibberellin functions during and after grapevine bud dormancy release

Chuanlin Zheng, Atiako Kwame Acheampong, Zhaowan Shi, Tamar Halaly, Yuji Kamiya, Ron Ophir, David W Galbraith, Etti Or

Research output: Contribution to journalArticle

12 Scopus citations

Abstract

The molecular mechanism regulating dormancy release in grapevine buds is as yet unclear. It has been hypothesized that (i) abscisic acid (ABA) represses bud-meristem activity; (ii) perturbation of respiration induces an interplay between ethylene and ABA metabolism, which leads to removal of repression; and (iii) gibberellin (GA)-mediated growth is resumed. The first two hypothesis have been formally supported. The current study examines the third hypothesis regarding the potential involvement of GA in dormancy release. We found that during natural dormancy induction, levels of VvGA3ox, VvGA20ox, and VvGASA2 transcripts and of GA 1 were decreased. However, during dormancy release, expression of these genes was enhanced, accompanied by decreased expression of the bud-expressed GA-deactivating VvGA2ox. Despite indications for its positive role during natural dormancy release, GA application had inhibitory effects on bud break. Hydrogen cyanamide up-regulated VvGA2ox and down-regulated VvGA3ox and VvGA20ox expression, reduced GA 1 levels, and partially rescued the negative effect of GA. GA had an inhibitory effect only when applied simultaneously with bud-forcing initiation. Given these results, we hypothesize that during initial activation of the dormant bud meristem, the level of GA must be restricted, but after meristem activation an increase in its level serves to enhance primordia regrowth.

Original languageEnglish (US)
Pages (from-to)1635-1648
Number of pages14
JournalJournal of Experimental Botany
Volume69
Issue number7
DOIs
Publication statusPublished - Mar 24 2018

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Keywords

  • Bud
  • dormancy
  • GA 2-oxidase
  • GA 20-oxidase
  • GA 3-oxidase
  • gibberellin
  • grapevine
  • hydrogen cyanamide

ASJC Scopus subject areas

  • Physiology
  • Plant Science

Cite this

Zheng, C., Kwame Acheampong, A., Shi, Z., Halaly, T., Kamiya, Y., Ophir, R., ... Or, E. (2018). Distinct gibberellin functions during and after grapevine bud dormancy release. Journal of Experimental Botany, 69(7), 1635-1648. https://doi.org/10.1093/jxb/ery022