Functional interaction between two transcription factors involved in the developmental regulation of a small heat stress protein gene promoter
Hahsp17.6G1 is the promoter of a small heat stress protein (sHSP) from sunflower (Helianthus annuus) that is activated during zygotic embryogenesis, but which does not respond to heat stress. We report here the cloning of a transcription factor (TF), sunflower drought-responsive element binding factor 2 (HaDREB2), by one-hybrid interaction with functional cis-elements in Hahsp17.6G1. We have analyzed the functional interaction between HaDREB2 and a second transcription factor, sunflower heat stress factor A9 (HaHSFA9), which was previously assigned to the regulation of Hahsp17.6G1. HaDREB2 and HaHSFA9 synergistically trans-activate the Hahsp17.6G1 promoter in bombarded sunflower embryos. This synergistic interaction is heat stress factor (HSF) specific and requires the binding of both factors to the promoter. The C-terminal region of HaHSFA9 is sufficient for the HSF specificity. Our results represent an example of a functional interaction between members of the Apetala 2 (HaDREB2) and HSF (HaHSFA9) families of transcription factors. We suggest new roles in zygotic embryogenesis for specific members of the AP2 transcription factor family.
| Main Authors: | , , , , |
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| Format: | artículo biblioteca |
| Language: | English |
| Published: |
American Society of Plant Biologists
2005-10-21
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| Subjects: | Activator Fuction, Shock Proteins, Expression, Arabidopsis, Embryogenesis, Domain, Identification, Tolerance, Sunflower, Nerwork, |
| Online Access: | http://hdl.handle.net/10261/3347 |
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