Zhao Y, Christensen S K, Fankhauser C, Cashman J R, Cohen J D, Weigel D, Chory J
Howard Hughes Medical Institute, Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
Science. 2001 Jan 12;291(5502):306-9. doi: 10.1126/science.291.5502.306.
Although auxin is known to regulate many processes in plant development and has been studied for over a century, the mechanisms whereby plants produce it have remained elusive. Here we report the characterization of a dominant Arabidopsis mutant, yucca, which contains elevated levels of free auxin. YUCCA encodes a flavin monooxygenase-like enzyme and belongs to a family that includes at least nine other homologous Arabidopsis genes, a subset of which appears to have redundant functions. Results from tryptophan analog feeding experiments and biochemical assays indicate that YUCCA catalyzes hydroxylation of the amino group of tryptamine, a rate-limiting step in tryptophan-dependent auxin biosynthesis.
尽管生长素已知可调节植物发育中的许多过程，并且已经研究了一个多世纪，但植物产生生长素的机制仍然难以捉摸。在这里，我们报告了一个显性拟南芥突变体yucca的特征，该突变体含有高水平的游离生长素。YUCCA编码一种类黄素单加氧酶，属于一个家族，该家族至少还包括其他九个同源拟南芥基因，其中一部分似乎具有冗余功能。色氨酸类似物饲喂实验和生化分析结果表明，YUCCA催化色胺氨基的羟基化，这是色氨酸依赖性生长素生物合成中的限速步骤。
