Chang C, Kwok S F, Bleecker A B, Meyerowitz E M
Division of Biology 156-29, California Institute of Technology, Pasadena 91125.
Science. 1993 Oct 22;262(5133):539-44. doi: 10.1126/science.8211181.
Ethylene behaves as a hormone in plants, regulating such aspects of growth and development as fruit ripening, flower senescence, and abscission. Ethylene insensitivity is conferred by dominant mutations in the ETR1 gene early in the ethylene signal transduction pathway of Arabidopsis thaliana. The ETR1 gene was cloned by the method of chromosome walking. Each of the four known etr1 mutant alleles contains a missense mutation near the amino terminus of the predicted protein. Although the sequence of the amino-terminal half of the deduced ETR1 protein appears to be novel, the carboxyl-terminal half is similar in sequence to both components of the prokaryotic family of signal transducers known as the two-component systems. Thus, an early step in ethylene signal transduction in plants may involve transfer of phosphate as in prokaryotic two-component systems. The dominant etr1-1 mutant gene conferred ethylene insensitivity to wild-type Arabidopsis plants when introduced by transformation.
乙烯在植物中作为一种激素发挥作用，调节生长和发育的诸多方面，如果实成熟、花朵衰老和脱落。在拟南芥乙烯信号转导途径早期，ETR1基因中的显性突变赋予了对乙烯的不敏感性。ETR1基因通过染色体步移法克隆得到。四个已知的etr1突变等位基因中的每一个在预测蛋白质的氨基末端附近都含有一个错义突变。尽管推导的ETR1蛋白质氨基末端一半的序列似乎是新的，但羧基末端一半的序列与原核生物信号转导器家族的两个组分系统的两个组分相似。因此，植物中乙烯信号转导的早期步骤可能像原核生物双组分系统一样涉及磷酸转移。当通过转化引入时，显性的etr1-1突变基因赋予野生型拟南芥植物对乙烯的不敏感性。
