Molecular Analysis of the ETR Locus: a Gene Involved in Ethylene Responses in Arabidopsis thaliana

植物激素乙烯调节高等植物的一系列生理和发育过程。虽然最近在阐明乙烯生物合成途径和一些乙烯调节过程的分子基础方面取得了很大进展，但对植物中的受体和相关的信号转导途径几乎一无所知。该计划的目标是克隆和鉴定拟南芥ETR基因座。ETR基因的突变已经被分离出来，这些突变导致植物对许多乙烯反应不敏感。生理证据表明，这些突变直接影响乙烯受体。通过染色体行走，已经获得了18kb的克隆基因组DNA，似乎携带ETR基因。研究人员打算鉴定该区域中代表ETR基因的特定序列，并获得突变型和野生型基因的全长cdna克隆。这些cdna克隆还将被用来操纵野生型和突变型基因产物在转基因拟南芥和其他一些植物中的表达水平。基因的工程突变将允许探索etr表型的显性本质。

The plant hormone, ethylene, regulates a wide range of physiological and developmental processes in higher plants. While a significant amount of progress has recently been made in the elucidation of the ethylene biosynthetic pathway and in the molecular bases for a number of ethylene regulated processes, virtually nothing is known about the receptor and associated signal transduction pathways in plants. The goal of this proposal is the molecular cloning and characterization of the ETR locus in Arabidopsis thalina. Mutations in the ETR locus have been isolated which cause insensitivity to a number of ethylene responses in the plant. Physiological evidence indicates that the mutations directly effect the ethylene receptor. From a chromosome walk, an 18 kb region of cloned genomic DNA has been obtained which appears to carry the ETR gene. The investigators intend to identify the specify sequences in this region that represent the ETR gene and to obtain full length cDNA clones of the mutant and wild type genes. The cDNA clones will also be used to manipulate the level of expression of the wild type and mutant gene products in transgenic Arabidopsis and in a number of other plant species. Engineered mutations in the gene will allow an exploration of the dominant nature of the etr phenotype.