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Gibberellin – Mechanism of Action

  1. Schwechheimer Claus

Published Online: 17 MAR 2014

DOI: 10.1002/9780470015902.a0023921

eLS

eLS

How to Cite

Claus, S. 2014. Gibberellin – Mechanism of Action. eLS. .

Author Information

  1. Technische Universität München, Freising, Germany

Publication History

  1. Published Online: 17 MAR 2014

Abstract

Since their discovery, gibberellin (GA) diterpenoid phytohormones have been used by agriculturalists and horticulturalists to control plant growth and to improve yield quantity and quality. Coordinated breeding efforts after World War II have led to strong yield increases following the introduction of dwarfing alleles that impair GA signalling in wheat and GA biosynthesis in rice, later named the ‘Green Revolution’. In the last two decades, the identity of the basic components of the GA signal transduction pathway has been elucidated. Core to GA action is the regulation of DELLA protein levels, repressors that control plant growth by negatively interfering mainly, but as it emerges not exclusively, with transcription regulator activities. Here, the author summarises the current knowledge of GA signal transduction, thereby putting an emphasis on the crosstalk of GA signalling with the light and jasmonic acid signalling pathways and with microtubule organisation.

Key Concepts:

  • Manipulation of gibberellin (GA) signalling has contributed to the ‘Green Revolution’.

  • DELLA proteins are GA-labile growth repressors that mainly, but not exclusively, repress transcription factors.

  • GA inactivates DELLAs by targeting them for degradation by the ubiquitin–proteasome system.

  • Alternative GA-independent DELLA inactivation mechanisms have been described.

  • GA and DELLAs repress PIF and BZR1 transcription factors to control light-regulated development.

  • GA and DELLAs antagonistically control different steps in the signal transduction of the phytohormone jasmonic acid.

  • GA and DELLAs modulate microtubule formation by modulating prefoldin activity.

Keywords:

  • arabidopsis;
  • gibberellin;
  • green revolution;
  • hormone;
  • Jasmonic acid;
  • microtubules;
  • prefoldin;
  • receptor;
  • rice;
  • transcription factor