Light signal provides the spatial and temporal information for plants to adapt to the prevailing environmental conditions. Alterations in light quality and quantity can trigger robust changes in global gene expression. In
- Award ID(s):
- 1750361
- NSF-PAR ID:
- 10319788
- Date Published:
- Journal Name:
- Frontiers in Plant Science
- Volume:
- 12
- ISSN:
- 1664-462X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Summary Arabidopsis thaliana , two groups of key factors regulating those changes in gene expression areCONSTITUTIVE PHOTOMORPHOGENESIS /DEETIOLATED /FUSCA (COP /DET /FUS ) and a subset of basic helix‐loop‐helix transcription factors calledPHYTOCHROME ‐INTERACTING FACTORS (PIF s). Recently, rapid progress has been made in characterizing the E3 ubiquitin ligases for the light‐induced degradation ofPIF 1,PIF 3 andPIF 4; however, the E3 ligase(s) forPIF 5 remains unknown. Here, we show that theCUL 4COP 1–SPA complex is necessary for the red light‐induced degradation ofPIF 5. Furthermore,COP 1 andSPA proteins stabilizePIF 5 in the dark, but promote the ubiquitination and degradation ofPIF 5 in response to red light through the 26S proteasome pathway. Genetic analysis illustrates that overexpression of can partially suppress bothPIF 5cop1‐4 andspaQ seedling de‐etiolation phenotypes under dark and red‐light conditions. In addition, thePIF 5 protein level cycles under both diurnal and constant light conditions, which is also defective in thecop1‐4 andspaQ backgrounds. Bothcop1‐4 andspaQ show defects in diurnal growth pattern. Overexpression of partially restores growth defects inPIF 5cop1‐4 andspaQ under diurnal conditions, suggesting that theCOP 1–SPA complex plays an essential role in photoperiodic hypocotyl growth, partly through regulating thePIF 5 level. Taken together, our data illustrate how theCUL 4COP 1–SPA E3 ligase dynamically controls thePIF 5 level to regulate plant development. -
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