Bennett M J, Marchant A, Green H G, May S T, Ward S P, Millner P A, Walker A R, Schulz B, Feldmann K A
Department of Biological Sciences, University of Warwick, Coventry, CV4 7AL, UK.
Science. 1996 Aug 16;273(5277):948-50. doi: 10.1126/science.273.5277.948.
The plant hormone auxin regulates various developmental processes including root formation, vascular development, and gravitropism. Mutations within the AUX1 gene confer an auxin-resistant root growth phenotype and abolish root gravitropic curvature. Polypeptide sequence similarity to amino acid permeases suggests that AUX1 mediates the transport of an amino acid-like signaling molecule. Indole-3-acetic acid, the major form of auxin in higher plants, is structurally similar to tryptophan and is a likely substrate for the AUX1 gene product. The cloned AUX1 gene can restore the auxin-responsiveness of transgenic aux1 roots. Spatially, AUX1 is expressed in root apical tissues that regulate root gravitropic curvature.
植物激素生长素调节各种发育过程，包括根的形成、维管发育和向重力性。AUX1基因内的突变赋予了生长素抗性根生长表型，并消除了根的向重力性弯曲。与氨基酸通透酶的多肽序列相似性表明，AUX1介导一种氨基酸样信号分子的运输。吲哚-3-乙酸是高等植物中生长素的主要形式，其结构与色氨酸相似，可能是AUX1基因产物的底物。克隆的AUX1基因可以恢复转基因aux1根的生长素响应性。在空间上，AUX1在调节根向重力性弯曲的根尖组织中表达。
