Deng Xin, Phillips Jonathan, Bräutigam Anne, Engström Peter, Johannesson Henrik, Ouwerkerk Pieter B F, Ruberti Ida, Salinas Julio, Vera Pablo, Iannacone Rina, Meijer Annemarie H, Bartels Dorothea
Max-Planck-Institut für Züchtungsforschung, Carl-von-Linné-Weg 10, Cologne D-50829, Germany.
Plant Mol Biol. 2006 Jun;61(3):469-89. doi: 10.1007/s11103-006-0023-x.
A subset of homeodomain leucine zipper proteins (HDZip) play a role in regulating adaptation responses including developmental adjustment to environmental cues in plants. Here we report the structural and functional characterisation of a dehydration responsive nuclear-targeted HDZip transcriptional regulator, CpHB-7. DNA-protein interaction studies suggest that CDeT6-19, a known ABA and dehydration responsive dehydrin gene, is a potential target gene of CpHB-7 in the desiccation-tolerant plant Craterostigma plantagineum. Transgenic plants that ectopically express CpHB-7 display reduced sensitivity towards ABA during seed germination and stomatal closure. Expression analysis reveals that genes with induced or repressed expression in CpHB-7 ectopic expression lines are either mostly repressed or induced by ABA, drought or salt treatment respectively, thus demonstrating that CpHB-7 modifies ABA-responsive gene expression as a negative regulator. CpHB-7 gene expression is also linked to early organ development, leading to the suggestion that CpHB-7 is functionally similar to the Arabidopsis transcription factor, ATHB-6.
同源异型域亮氨酸拉链蛋白（HDZip）的一个亚群在调节植物的适应性反应中发挥作用，包括对环境线索的发育调整。在此，我们报告了一种脱水响应性核靶向HDZip转录调节因子CpHB - 7的结构和功能特征。DNA - 蛋白质相互作用研究表明，已知的ABA和脱水响应性脱水素基因CDeT6 - 19是耐旱植物车前草中CpHB - 7的潜在靶基因。异位表达CpHB - 7的转基因植物在种子萌发和气孔关闭期间对ABA的敏感性降低。表达分析表明，在CpHB - 7异位表达系中表达被诱导或抑制的基因分别大多被ABA、干旱或盐处理抑制或诱导，从而表明CpHB - 7作为负调节因子修饰ABA响应基因的表达。CpHB - 7基因表达也与早期器官发育相关，这表明CpHB - 7在功能上类似于拟南芥转录因子ATHB - 6。
