Hahb-4, a homeobox-leucine zipper gene potentially involved in abscisic acid-dependent responses to water stress in sunflower
Hahb-4, a homeobox-leucine zipper gene potentially involved in abscisic acid-dependent responses to water stress in sunflower
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DOI：
10.1046/j.1365-3040.2002.00853.x
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发表时间：
2002-05-01
影响因子：
7.3
通讯作者：
Chan, RL
中科院分区：
文献类型：
--
作者：
Gago, GM;Almoguera, C;Chan, RL
同源结构域亮氨酸拉链蛋白构成了仅在植物中发现的转录因子家族。我们已经表征了编码向日葵同源盒亮氨酸拉链蛋白 Hahb-4 (Helianthus annuus homeobox-4) 的全长 cDNA。完整的 cDNA 长 674 个碱基对，包含 177 个氨基酸的开放阅读框，属于 Hd-Zip I 亚家族。 Northern blot和RNAse A保护分析表明，Hahb-4的表达在整个幼苗、根、茎和叶中受到水分亏缺的快速、强烈和可逆的诱导。当幼苗接受激素脱落酸 (ABA) 处理时，观察到类似的 Hahb-4 表达快速诱导。用 ABA 处理或遭受水分胁迫的幼苗制备的细胞核显示，特异性结合序列 5'-CAAT(A/T)ATTG-3' 的蛋白质显着增加，这些蛋白质在体外被 Hahb-4 识别，表明活性蛋白质是响应这些处理而合成的。 Hahb-4 基因的启动子区域包含与某些 ABA 响应元件 (ABRE) 中存在的 G 盒一致的序列。我们认为 Hahb-4 可能在控制向日葵对水分胁迫的 ABA 介导反应的子集的信号级联中发挥作用。
Homeodomain-leucine zipper proteins constitute a family of transcription factors found only in plants. We have characterized a full-length cDNA encoding the sunflower homeobox-leucine zipper protein Hahb-4 (Helianthus annuus homeobox-4). The complete cDNA is 674 base pairs long and contains an open reading frame of 177 amino acids that belongs to the Hd-Zip I subfamily. Northern blot and RNAse A protection analysis show that the expression of Hahb-4 is rapidly, strongly and reversibly induced by water deficit in whole seedlings, roots, stems and leaves. A similar fast induction of Hahb-4 expression is observed when seedlings are subjected to a treatment with the hormone abscisic acid (ABA). Nuclei prepared from seedlings treated with ABA or subjected to water stress show a significant increase of protein(s) that specifically bind the sequence 5'-CAAT(A/T)ATTG-3', recognized in vitro by Hahb-4, suggesting that an active protein is synthesized in response to these treatments. The promoter region of the Hahb-4 gene contains sequences that fit the consensus for a G-box present in some ABA responsive elements (ABREs). We propose that Hahb-4 may function in signalling cascade(s) that control(s) a subset of the ABA-mediated responses of sunflower to water stress.