Regulated Ethylene Insensitivity through the Inducible Expression of the Arabidopsis etr1-1 Mutant Ethylene Receptor in Tomato
Regulated Ethylene Insensitivity through the Inducible Expression of the Arabidopsis etr1-1 Mutant Ethylene Receptor in Tomato
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DOI：
10.1104/pp.109.151688
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发表时间：
2010-04-01
期刊：
影响因子：
7.4
通讯作者：
Gallie, Daniel R.
中科院分区：
文献类型：
--
作者：
Gallie, Daniel R.
乙烯是一种重要的激素，控制植物生长发育的几个方面，包括果实成熟和叶片和花瓣衰老。乙烯是在与膜上定位的受体结合后被察觉的，导致它们失活并诱导乙烯反应。在拟南芥中表达五种不同类型的受体，已描述的突变受体以显性负向方式抑制乙烯信号。一个这样的突变体，乙烯抗性1-1(etr1-1)，在拟南芥中导致了强烈的乙烯不敏感表型。在本研究中，利用可诱导启动子实现了拟南芥etr1-1在番茄(Solanum Lycopsicum)中的调控表达。在没有诱导剂的情况下，转基因幼苗对乙烯仍然敏感，但在它的存在下，诱导了乙烯不敏感的状态，导致在有乙烯存在的黑暗生长的幼苗中下胚轴和根的伸长，顶端挂钩的减少或缺失，以及乙烯诱导的E4表达的抑制。乙烯的敏感性水平可以由诱导剂的用量来控制，表明不敏感程度与etr1-1的表达呈线性关系。Etr1-1表达的诱导也抑制了对乙烯的内源反应以及果实的延迟成熟。诱导停止后，乙烯敏感性得以恢复。这些结果表明，通过控制突变受体的表达，能够在时间和数量上控制乙烯的反应。
Ethylene serves as an important hormone controlling several aspects of plant growth and development, including fruit ripening and leaf and petal senescence. Ethylene is perceived following its binding to membrane-localized receptors, resulting in their inactivation and the induction of ethylene responses. Five distinct types of receptors are expressed in Arabidopsis (Arabidopsis thaliana), and mutant receptors have been described that repress ethylene signaling in a dominant negative manner. One such mutant, ethylene resistant1-1 (etr1-1), results in a strong ethylene-insensitive phenotype in Arabidopsis. In this study, regulated expression of the Arabidopsis etr1-1 in tomato (Solanum lycopersicum) was achieved using an inducible promoter. In the absence of the inducer, transgenic seedlings remained sensitive to ethylene, but in its presence, a state of ethylene insensitivity was induced, resulting in the elongation of the hypocotyl and root in dark-grown seedlings in the presence of ethylene, a reduction or absence of an apical hook, and repression of ethylene-inducible E4 expression. The level of ethylene sensitivity could be controlled by the amount of inducer used, demonstrating a linear relationship between the degree of insensitivity and etr1-1 expression. Induction of etr1-1 expression also repressed the epinastic response to ethylene as well as delayed fruit ripening. Restoration of ethylene sensitivity was achieved following the cessation of the induction. These results demonstrate the ability to control ethylene responses temporally and in amount through the control of mutant receptor expression.