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Title: Rice phytochrome-interacting factor protein OsPIF14 represses OsDREB1B gene expression through an extended N-box and interacts preferentially with the active form of phytochrome B

DREB1/CBF genes, known as major regulators of plant stress responses, are rapidly and transiently induced by low temperatures. Using a yeast one-hybrid screening, we identified a putative Phytochrome-Interacting bHLH Factor (OsPIF14), as binding to the OsDREB1B promoter. bHLH proteins are able to bind to hexameric E-box (CANNTG) or N-box (CACG(A/C)G) motifs, depending on transcriptional activity. We have shown that OsPIF14 binds to the OsDREB1B promoter through two N-boxes and that the flanking regions of the hexameric core are essential for protein–DNA interaction and stability. We also showed that OsPIF14 down-regulates OsDREB1B gene expression in rice protoplasts, corroborating the OsPIF14 repressor activity observed in the transactivation assays using Arabidopsis protoplasts. Additionally, we showed that OsPIF14 is indeed a phytochrome interacting factor, which preferentially binds to the active form (Pfr) of rice phytochrome B. This raises the possibility that OsPIF14 activity might be modulated by light. However, we did not observe any regulation of the OsDREB1B gene expression by light under control conditions. Moreover, OsPIF14 gene expression was shown to be modulated by different treatments, such as drought, salt, cold and ABA. Interestingly, OsPIF14 showed also a specific cold-induced alternative splicing. Our results suggest the possibility that OsPIF14 is involved in cross-talkmore » between light and stress signaling through interaction with the OsDREB1B promoter. Finally, although in the absence of stress, OsDREB1B gene expression was not regulated by light, given previous reports, it remains possible that OsPIF14 has a role in light modulation of stress responses.« less
 [1] ;  [1] ;  [2] ;  [1] ;  [1] ;  [1] ;  [3] ;  [2] ;  [1] ;  [1]
  1. Nova Univ. of Lisbon, Oeiras (Portugal). Technical Inst. of Chemistry and Biology
  2. Univ. of California, Berkeley, CA (United States). Dept. of Plant and Microbial Biology and Plant Gene Expression Center (PGEC)
  3. Leiden Univ. (Netherlands). Inst. of Biology
Publication Date:
Grant/Contract Number:
FG03-87ER13742; GM-R01-47475; 5335-21000-032-00D
Accepted Manuscript
Journal Name:
Biochimica et Biophysica Acta (BBA) - Gene Regulatory Mechanisms
Additional Journal Information:
Journal Name: Biochimica et Biophysica Acta (BBA) - Gene Regulatory Mechanisms; Journal Volume: 1859; Journal Issue: 2; Journal ID: ISSN 1874-9399
Research Org:
Univ. of California, Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
59 BASIC BIOLOGICAL SCIENCES; Rice phytochrome-interacting factor 14 (OsPIF14); OsDREB1B; Protein–DNA interaction; Alternative splicing; Light regulation; Cold stress
OSTI Identifier: