Characterization of the class IV homeodomain-leucine zipper gene family in Arabidopsis
Characterization of the class IV homeodomain-leucine zipper gene family in Arabidopsis
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DOI：
10.1104/pp.106.077388
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发表时间：
2006-08-01
期刊：
影响因子：
7.4
通讯作者：
Takahashi, Taku
中科院分区：
文献类型：
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作者：
Nakamura, Miyuki;Katsumata, Hiroshi;Takahashi, Taku
拟南芥基因组包含16个基因，属于IV类同源结构域-亮氨酸拉链基因家族。这些基因包括GLABRA2、ANTHOCURANINLESS2、FWA、拟南芥分生组织层1(ATML1)和原皮因子2(PDF2)。我们先前的研究发现，atml1 pdf2双突变体在新梢表皮细胞分化中存在严重缺陷。在这里，我们描述了这个基因家族的其他成员，我们将其命名为同源结构域GLABROUS1(HDG1)到HDG12。对携带细菌β-葡萄糖苷酸酶报告基因的转基因拟南芥植株的分析表明，一些启动子在地上部顶端分生组织和发育中的地上部器官的表皮层具有较高的活性，而另一些在生殖器官发育过程中暂时具有活性。发现该家族内高度保守的平行基因对的表达谱不一定重叠。对这些hdg基因的T-DNA插入突变体的分析表明，除hdg11等位基因外，所有突变体均未表现出异常表型。Hdg11突变体表现出毛状体的过度分枝。这种表型在hdg11 hdg12双突变体中增强。对于同一亚家族中的其他平行基因对和基因构建了双突变体。然而，仅在hdg3 atml1和hdg3 pdf2突变体中观察到了新的表型，这两个突变体都显示出子叶发育缺陷。这些观察表明，在细胞分化的不同方面，IV类同源结构域-亮氨酸拉链成员中的一些成员与该家族的其他成员冗余地发挥作用。利用聚合酶链式反应辅助从随机寡核苷酸及其重组蛋白中选择DNA，确定了其中两个家族成员的DNA结合位点。发现这些结合位点与先前发现的ATML1和PDF2的结合位点相似，对应于伪随机序列5‘-GCATTAAATGC-3’作为优先结合位点。
The Arabidopsis ( Arabidopsis thaliana) genome contains 16 genes belonging to the class IV homeodomain-Leucine zipper gene family. These include GLABRA2, ANTHOCYANINLESS2, FWA, ARABIDOPSIS THALIANA MERISTEM LAYER1 ( ATML1), and PROTODERMAL FACTOR2 (PDF2). Our previous study revealed that atml1 pdf2 double mutants have severe defects in the shoot epidermal cell differentiation. Here, we have characterized additional members of this gene family, which we designated HOMEODOMAIN GLABROUS1 (HDG1) through HDG12. Analyses of transgenic Arabidopsis plants carrying the gene-specific promoter fused to the bacterial beta-glucuronidase reporter gene revealed that some of the promoters have high activities in the epidermal layer of the shoot apical meristem and developing shoot organs, while others are temporarily active during reproductive organ development. Expression profiles of highly conserved paralogous gene pairs within the family were found to be not necessarily overlapping. Analyses of T-DNA insertion mutants of these HDG genes revealed that all mutants except hdg11 alleles exhibit no abnormal phenotypes. hdg11 mutants show excess branching of the trichome. This phenotype is enhanced in hdg11 hdg12 double mutants. Double mutants were constructed for other paralogous gene pairs and genes within the same subfamily. However, novel phenotypes were observed only for hdg3 atml1 and hdg3 pdf2 mutants that both exhibited defects in cotyledon development. These observations suggest that some of the class IV homeodomain-Leucine zipper members act redundantly with other members of the family during various aspects of cell differentiation. DNA-binding sites were determined for two of the family members using polymerase chain reaction-assisted DNA selection from random oligonucleotides with their recombinant proteins. The binding sites were found to be similar to those previously identified for ATML1 and PDF2, which correspond to the pseudopalindromic sequence 5'-GCATTAAATGC-3' as the preferential binding site.