The B-Box-Containing MicroProtein miP1a/BBX31 Regulates Photomorphogenesis and UV-B Protection
| Autor: | Premachandran Yadukrishnan, Sourav Datta, Ulla Dolde, Souvika Bakshi, Stephan Wenkel, Maneesh Lingwan, Shyam K. Masakapalli, Arpita Yadav |
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| Rok vydání: | 2018 |
| Předmět: |
0106 biological sciences
Light Signal Transduction DNA Repair Physiology DNA repair Ultraviolet Rays Regulator Arabidopsis Plant Science 01 natural sciences Transcription (biology) Gene Expression Regulation Plant Genetics Transcriptional regulation Gene Transcription factor biology Chemistry Arabidopsis Proteins Articles biology.organism_classification Cell biology Photomorphogenesis 010606 plant biology & botany Transcription Factors |
| Zdroj: | Plant physiology. 179(4) |
| ISSN: | 1532-2548 |
| Popis: | The bZIP transcription factor ELONGATED HYPOCOTYL5 (HY5) represents a major hub in the light-signaling cascade both under visible and UV-B light. The mode of transcriptional regulation of HY5, especially under UV-B light, is not well characterized. B-BOX (BBX) transcription factors regulate HY5 transcription and also posttranscriptionally modulate HY5 to control photomorphogenesis under white light. Here, we identify BBX31 as a key signaling intermediate in visible and UV-B light signal transduction in Arabidopsis (Arabidopsis thaliana). BBX31 expression is induced by UV-B radiation in a fluence-dependent manner. HY5 directly binds to the promoter of BBX31 and regulates its transcript levels. Loss- and gain-of-function mutants of BBX31 indicate that it acts as a negative regulator of photomorphogenesis under white light but is a positive regulator of UV-B signaling. Genetic interaction studies suggest that BBX31 regulates photomorphogenesis independent of HY5. We found no evidence for a direct BBX31-HY5 interaction, and they primarily regulate different sets of genes in white light. Under high doses of UV-B radiation, BBX31 promotes the accumulation of UV-protective flavonoids and phenolic compounds. It enhances tolerance to UV-B radiation by regulating genes involved in photoprotection and DNA repair in a HY5-dependent manner. Under UV-B radiation, overexpression of BBX31 enhances HY5 transcriptional levels in a UV RESISTANCE LOCUS8-dependent manner, suggesting that BBX31 might regulate HY5 transcription. |
| Databáze: | OpenAIRE |
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