Ulmasov T, Hagen G, Guilfoyle T
Department of Biochemistry, University of Missouri, Columbia 65211.
Plant Mol Biol. 1994 Nov;26(4):1055-64. doi: 10.1007/BF00040688.
The octopine synthase (ocs or ocs-like) element has been previously reported to be responsive to the plant hormones, auxin, salicylic acid, and methyl jasmonate. Using transient assays with carrot protoplasts, we have demonstrated that an ocs element from the soybean auxin-inducible GH2/4 promoter is not only activated by strong auxins (i.e., 2,4-dichlorophenoxyacetic acid, 2,4,5-trichlorophenoxyacetic acid, alpha-naphthalene acetic acid) and salicylic acid, but also by weak auxin analogues (beta-naphthalene acetic acid), inactive auxin analogs (i.e., 2,3-dichlorophenoxyacetic acid, 2,4,6-trichlorophenoxyacetic acid), and inactive salicylic acid analogs (3-hydroxybenzoic acid and 4-hydroxybenzoic acid). Our results indicate that the ocs element in the GH2/4 promoter is not selectively induced by plant hormones and might function similarly to tandem AP-1 sites in some animal glutathione S-transferase (GST) genes. The ocs element, like the AP-1 sites in animal GST promoters, may be induced not only by certain hormones but also by some non-hormonal stress-inducing or electrophilic agents.
以前有报道称章鱼碱合酶（ocs或ocs样）元件对植物激素生长素、水杨酸和茉莉酸甲酯有反应。通过对胡萝卜原生质体进行瞬时分析，我们证明了来自大豆生长素诱导型GH2/4启动子的一个ocs元件不仅被强生长素（即2,4-二氯苯氧乙酸、2,4,5-三氯苯氧乙酸、α-萘乙酸）和水杨酸激活，而且还被弱生长素类似物（β-萘乙酸）、无活性生长素类似物（即2,3-二氯苯氧乙酸、2,4,6-三氯苯氧乙酸）以及无活性水杨酸类似物（3-羟基苯甲酸和4-羟基苯甲酸）激活。我们的结果表明，GH2/4启动子中的ocs元件并非由植物激素选择性诱导，其功能可能与某些动物谷胱甘肽S-转移酶（GST）基因中的串联AP-1位点类似。ocs元件与动物GST启动子中的AP-1位点一样，可能不仅被某些激素诱导，还被一些非激素应激诱导剂或亲电试剂诱导。
