The auxin, hydrogen peroxide and salicylic acid induced expression of the Arabidopsis GST6 promoter is mediated in part by an ocs element
The auxin, hydrogen peroxide and salicylic acid induced expression of the Arabidopsis GST6 promoter is mediated in part by an ocs element
复制标题
DOI：
10.1046/j.1365-313x.1999.00560.x
复制
发表时间：
1999-09-01
期刊：
影响因子：
7.2
通讯作者：
Singh, KB
中科院分区：
文献类型：
--
作者：
Chen, WQ;Singh, KB
谷胱甘肽转移酶（GST）是一种多功能酶，在许多植物逆境响应中起着关键作用。Ocs元件是在一些病原体和GST启动子中发现的增强子序列。我们以前分离出一个拟南芥GST基因，称为GST 6，其中包含一个ocs样元件。在这里，我们测试的作用，这个假定的ocs元件在响应生长素，水杨酸（SA）和过氧化氢（H2 O2）的GST 6表达中发挥的作用，使用瞬时测定和转基因拟南芥。在瞬时和转基因研究之间，以及在不同的植物组织中，对ocs元件进行基础和/或诱导表达的要求不同。GST 6启动子在用SA（84倍）或H2 O2（122倍）处理后的根中显示出最大的诱导，并且突变ocs元件的效果在根组织中最明显。然而，在任何情况下ocs元件的突变都不会消除GST 6的表达，这表明其他启动子元件也很重要。使用瞬时测定，鉴定了对GST 6表达至关重要的其它启动子元件，其也可能有助于介导ocs元件的活性。ocs元件在植物GST基因对SA和H_2O_2的转录反应中起作用的发现对于植物防御反应具有潜在的意义，其中SA和H_2O_2起着关键作用。
Glutathione S-transferases (GSTs) are multi-functional enzymes that play critical roles in a number of plant stress responses. Ocs elements are enhancer sequences found in some pathogen and GST promoters. We previously isolated an Arabidopsis GST gene, called GST6, which contained an ocs-like element. Here we tested the role this putative ocs element plays in GST6 expression in response to auxin, salicylic acid (SA) and hydrogen peroxide (H2O2) using a transient assay and transgenic Arabidopsis. The requirement for the ocs element for basal and/or induced expression varied between the transient and transgenic studies, and in different plant tissues. The GST6 promoter showed the largest induction in roots following treatment with SA (84-fold) or H2O2 (122-fold), and the effect of mutating the ocs element was most pronounced in root tissue. However, in no case did mutation of the ocs element abolish GST6 expression, suggesting that other promoter element(s) are also important. Using the transient assay, other promoter element(s) critical for GST6 expression were identified that may also help mediate the activity of the ocs element. The finding that the ocs element plays a role in the transcriptional response of a plant GST gene to SA and H2O2 has potential significance for the plant defense response, where SA and H2O2 play critical roles.