age Mutants of Arabidopsis exhibit altered auxin-regulated gene expression
age Mutants of Arabidopsis exhibit altered auxin-regulated gene expression
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DOI：
10.1105/tpc.10.10.1649
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发表时间：
1998-10-01
期刊：
影响因子：
11.6
通讯作者：
Theologis, A
中科院分区：
文献类型：
--
作者：
Oono, Y;Chen, QG;Theologis, A
构建了以吲哚乙酸(IAA)依赖方式通过PS-IAA4/5基因生长素反应域(AuxRDS)A和B(BA-GUS)表达β-葡萄糖醛酸苷酶(GUS)的拟南芥转基因株系。10(-7)M IAA处理幼苗后，GUS在根伸长区的表达优先增强。在AxR1、axr4和Aux1突变体中表达BA-GUS基因所需的生长素浓度是野生型背景下的10-100倍。在axr2和axr3突变体中未见GUS表达。转基因被用来分离表现生长素反应基因表达(AGE)改变的突变体。分离并鉴定了两个突变体Age1和Age2。AGE-1表现出对IAA的敏感性，在10(-8)M IAA存在下，GUS在根伸长区有较强的表达。相反，即使在没有外源IAA的情况下，AGE2也表现出与根维管组织相关的异位GUS表达。形态和分子分析表明，AGE-1和AGE-2等位基因参与了IAA对基因表达的调控。
An Arabidopsis transgenic line was constructed expressing beta-glucuronidase (GUS) via the auxin-responsive domains (AuxRDs) A and B (BA-GUS) of the PS-IAA4/5 gene in an indoleacetic acid (IAA)-dependent fashion. GUS expression was preferentially enhanced in the root elongation zone after treatment of young seedlings with 10(-7) M IAA. Expression of the BA-GUS gene in the axr1, axr4, and aux1 mutants required 10- to 100-fold higher auxin concentration than that in the wild-type background. GUS expression was nil in the axr2 and axr3 mutants. The transgene was used to isolate mutants exhibiting altered auxin-responsive gene expression (age). Two mutants, age1 and age2, were isolated and characterized. age1 showed enhanced sensitivity to IAA, with strong GUS expression localized in the root elongation zone in the presence of 10(-8) M IAA. In contrast, age2 exhibited ectopic GUS expression associated with the root vascular tissue, even in the absence of exogenous IAA. Morphological and molecular analyses indicated that the age1 and age2 alleles are involved in the regulation of gene expression in response to IAA.