A seed-specific heat-shock transcription factor involved in developmental regulation during embryogenesis in sunflower
A seed-specific heat-shock transcription factor involved in developmental regulation during embryogenesis in sunflower
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DOI：
10.1074/jbc.m207330200
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发表时间：
2002-11-15
影响因子：
4.8
通讯作者：
Jordano, J
中科院分区：
文献类型：
--
作者：
Almoguera, C;Rojas, A;Jordano, J
我们报告的克隆和功能特性的第一个热休克转录因子，在胚胎发生过程中，在没有环境压力的情况下，具体表达。在向日葵胚中，这个因子HaHSFA9反式激活了具有较差共识热激顺式元件的启动子，包括种子特异性Hahsp17.6G1基因。在向日葵胚中，提高Hahsp17.7G4启动子处的热激顺式元件一致性的突变损害了HaHSFA9的瞬时激活。相同的突变并不影响热激诱导的基因表达，该启动子在转基因烟草植物，但减少了发育激活的内源性热激转录因子（HSFs）在种子中。向日葵和其它植物如烟草，与脊椎动物系统的不同之处在于具有至少一种特异性HSF，其表达和（或）激活模式严格限于胚胎。我们的研究结果有力地表明，HaHSFA9是一个转录因子，它与Hahsp17.6G1的发育激活以及与Hahsp17.7G4相似的靶基因的发育激活密切相关。
We report the cloning and functional characterization of the first heat-shock transcription factor that is specifically expressed during embryogenesis in the absence of environmental stress. In sunflower embryos this factor, HaHSFA9, trans-activated promoters with poor consensus heat-shock cis-elements, including that of the seed-specific Hahsp17.6G1 gene. Mutations that improved the heat-shock cis-element consensus at the Hahsp17.7G4 promoter impaired transient activation by HaHSFA9 in sunflower embryos. The same mutations did not affect heat-shock-induced gene expression of this promoter in transgenic tobacco plants but reduced the developmental activation by endogenous heat-shock transcription factors (HSFs) in seeds. Sunflower, and perhaps other plants such as tobacco, differs from the vertebrate animal systems in having at least one specialized HSF with expression and (or) activation patterns strictly restricted to embryos. Our results strongly indicate that HaHSFA9 is a transcription factor critically involved in the developmental activation of Hahsp17.6G1 and in that of similar target genes as Hahsp17.7G4.