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

• Published in: Plant signaling & behavior 2021-11, Vol.16 (11), p.1966587-1966587
• Main Authors: Miao, Tingting, Li, Dezhi, Huang, Ziyuan, Huang, Yuewei, Li, Shaoshan, Wang, Yan
• Format: Article
• Language: English
• Subjects: Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis - radiation effects; DELLA; Gene Expression Regulation, Plant; Genes, Plant; Genetic Variation; Genotype; Gibberellins - metabolism; HY5; Hypocotyl - genetics; Hypocotyl - growth & development; Hypocotyl - radiation effects; hypocotyl elongation; Mutation; Research Paper; Ultraviolet Rays - adverse effects; UV-B; UVR8
• ISSN: 1559-2316; 1559-2324; 1559-2324
• DOI: 10.1080/15592324.2021.1966587

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 GA 3 content through the UV RESISTANCE LOCUS 8 (UVR8) receptor pathway, and exogenous GA 3 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 GA 3 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.