Novel Transcriptional Cascade Regulating Expression of Heat Stress Proteins during Seed Development of Arabidopsis
Within the Arabidopsis thaliana family of 21 heat stress transcription factors (Hsfs), HsfA9 is exclusively expressed in late stages of seed development. Here, we present evidence that developmental expression of HsfA9 is regulated by the seed-specific transcription factor ABSCISIC ACID-INSENSITIVE3...
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Published in | The Plant cell Vol. 19; no. 1; pp. 182 - 195 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Society of Plant Biologists
01.01.2007
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Subjects | |
Online Access | Get full text |
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Summary: | Within the Arabidopsis thaliana family of 21 heat stress transcription factors (Hsfs), HsfA9 is exclusively expressed in late stages of seed development. Here, we present evidence that developmental expression of HsfA9 is regulated by the seed-specific transcription factor ABSCISIC ACID-INSENSITIVE3 (ABI3). Intriguingly, ABI3 knockout lines lack detectable levels of HsfA9 transcript and protein, and further ectopic expression of ABI3 conferred the ability to accumulate HsfA9 in response to abscisic acid in transgenic plantlets. Consequently, the most abundant heat stress proteins (Hsps) in seeds (Hsp17.4-CI, Hsp17.7-CII, and Hsp101) were not detectable in the ABI3 knockout lines, but their expression could be detected in plants ectopically expressing HsfA9 in vegetative tissues. Furthermore, this seed-specific transcription factor cascade was reconstructed in transient β-glucuronidase reporter assays in mesophyll protoplasts by showing that ABI3 could activate the HsfA9 promoter, whereas HsfA9 in turn was shown to be a potent activator on the promoters of Hsp genes. Thus, our study establishes a genetic framework in which HsfA9 operates as a specialized Hsf for the developmental expression of Hsp genes during seed maturation. |
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Bibliography: | http://www.plantcell.org/ ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 www.plantcell.org/cgi/doi/10.1105/tpc.106.048165 Online version contains Web-only data. The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantcell.org) is: Pascal von Koskull-Döring (doeringp@bio.uni-frankfurt.de). To whom correspondence should be addressed. E-mail doeringp@bio.uni-frankfurt.de; fax 49-69-7982-9286. |
ISSN: | 1040-4651 1532-298X 1532-298X |
DOI: | 10.1105/tpc.106.048165 |