Gibberellin regulates UV-B-induced hypocotyl growth inhibition in Arabidopsis thaliana

Plant Signal Behav. 2021 Nov 2;16(11):1966587. doi: 10.1080/15592324.2021.1966587. Epub 2021 Aug 31.

Abstract

Plant response to light is a complex and diverse phenomenon. Several studies have elucidated the mechanisms via which light and hormones regulate hypocotyl growth. However, the hormone-dependent ultraviolet-B (UV-B) response in plants remains obscure. Involvement of gibberellins (GAs) in UV-B-induced hypocotyl inhibition and its mechanisms in Arabidopsis thaliana were investigated in the present research. UV-B exposure remarkably decreased the endogenous GA3 content through the UV RESISTANCE LOCUS 8 (UVR8) receptor pathway, and exogenous GA3 partially restored the hypocotyl growth. UV-B irradiation affected the expression levels of GA metabolism-related genes (GA20ox1, GA2ox1 and GA3ox1) in the hy5-215 mutant, resulting in increased GA content.ELONGATED HYPOCOTYL 5 (HY5) promoted the accumulation of DELLA proteins under UV-B radiation; HY5 appeared to regulate the abundance of DELLAs at the transcriptional level under UV-B. As a result, the GA3 content decreased, which eventually led to the shortening of the hypocotyl. To conclude, the present study provides new insight into the regulation of plant photomorphogenesis under UV-B.

Keywords: DELLA; GA; HY5; UV-B; UVR8; hypocotyl elongation.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics*
  • Arabidopsis / growth & development*
  • Arabidopsis / radiation effects*
  • Gene Expression Regulation, Plant
  • Genes, Plant
  • Genetic Variation
  • Genotype
  • Gibberellins / metabolism*
  • Hypocotyl / genetics*
  • Hypocotyl / growth & development*
  • Hypocotyl / radiation effects*
  • Mutation
  • Ultraviolet Rays / adverse effects*

Substances

  • Gibberellins

Grants and funding

This work was financially supported by the National Natural Science Foundation of China [grant no. 31670266 and 41976082]; the Natural Science Foundation of Guangdong Province [grant no. 2017A030313115 and 2021A1515010426]; the Undergraduate Students Scientific Research Foundation of South China Normal University. The research was also supported by Guangzhou Science and Technology Planning Project (No.2022010630080037).