Photomorphogenesis is repressed in the dark mainly by an E3 ubiquitin ligase complex comprising CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) and four homologous proteins called SUPPRESSOR OF PHYA‐105 (SPA1–SPA4) in Arabidopsis. This complex induces the ubiquitination and subsequent degradation of positively acting transcription factors (TFs; e.g. ELONGATED HYPOCOTYL (HY5), LONG HYPOCOTYL IN FAR‐RED 1 (HFR1), PRODUCTION OF ANTHOCYANIN PIGMENT 1 (PAP1) and others] in the dark to repress photomorphogenesis. Genomic evidence showed a large number of genes regulated by COP1 in the dark, of which many are direct targets of HY5. However, the genomic basis for the constitute photomorphogenic phenotype of
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
- NSF-PAR ID:
- 10248232
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- The Plant Journal
- Volume:
- 96
- Issue:
- 2
- ISSN:
- 0960-7412
- Page Range / eLocation ID:
- p. 260-273
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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spaQ remains unknown. Here, we show that >7200 genes are differentially expressed in thespaQ background compared to wild‐type in the dark. Comparison of the RNA sequencing (RNA‐Seq) data betweencop1 andspaQ revealed a large overlapping set of genes regulated by the COP1–SPA complex. In addition, many of the genes coordinately regulated by the COP1–SPA complex are also regulated by HY5 directly and indirectly. Taken together, our data reveal that SPA proteins repress photomorphogenesis by controlling gene expression in concert with COP1, likely through regulating the abundance of downstream TFs in light signaling pathways. Moreover, SPA proteins may function both in a COP1‐dependent and ‐independent manner in regulating many biological processes and developmental pathways in Arabidopsis. -
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