ECTOPIC EXPRESSION OF THE ARABIDOPSIS TRANSCRIPTIONAL ACTIVATOR ATHB-1 ALTERS LEAF CELL FATE IN TOBACCO
ECTOPIC EXPRESSION OF THE ARABIDOPSIS TRANSCRIPTIONAL ACTIVATOR ATHB-1 ALTERS LEAF CELL FATE IN TOBACCO
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DOI：
10.1105/tpc.7.11.1773
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发表时间：
1995-11-01
期刊：
影响因子：
11.6
通讯作者：
CHUA, NH
中科院分区：
文献类型：
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作者：
AOYAMA, T;DONG, CH;CHUA, NH
拟南芥Athb-1是一个功能未知的同源盒基因。我们构建了一系列Athb-1衍生基因来研究其在转录调控和植物发育中的作用，通过瞬时表达实验发现，Athb-1可以反激活一个与特定DNA结合位点相连的启动子。当Athb-1或其嵌合衍生物与酵母转录因子GAL4或单纯疱疹病毒转录因子VP16的异源反激活域过表达时，会在黑暗中产生去脱落的表型，包括子叶扩张、真叶发育和下胚轴伸长的抑制。Athb-1或这两种嵌合衍生物的表达也会影响正常生长条件下栅栏薄壁的发育。这两种发育表型都是由糖皮质激素诱导的，转基因植株表达的嵌合转录因子包括Athb-1 DNA结合域、VP16反激活域和糖皮质激素受体域，严重诱导表型的植株子叶扩展也出现异常。我们的研究结果表明Athb-1是参与叶片发育的转录激活因子。
The Arabidopsis thaliana Athb-1 is a homeobox gene of unknown function. By analogy with homeobox genes of other organisms, its gene product, Athb-1, is most likely a transcription factor involved in developmental processes, We constructed a series of Athb-1-derived genes to examine the roles of Athb-1 in transcriptional regulation and plant development, Athb-1 was found to transactivate a promoter linked to a specific DNA binding site by transient expression assays, In transgenic tobacco plants, overexpression of Athb-1 or its chimeric derivatives with heterologous transactivating domains of the yeast transcription factor GAL4 or herpes simplex virus transcription factor VP16 conferred deetiolated phenotypes in the dark, including cotyledon expansion, true leaf development, and an inhibition of hypocotyl elongation, Expression of Athb-1 or the two chimeric derivatives also affected the development of palisade parenchyma under normal growth conditions, resulting in light green sectors in leaves and cotyledons, whereas other organs in the transgenic plants remained normal, Both developmental phenotypes were induced by glucocorticoid in transgenic plants expressing a chimeric transcription factor comprising the Athb-1 DNA binding domain, the VP16 transactivating domain, and the glucocorticoid receptor domain, Plants with severe inducible phenotypes showed additional abnormality in cotyledon expansion. Our results suggest that Athb-1 is a transcription activator involved in leaf development.