Genetic aspects of auxin biosynthesis and its regulation
Genetic aspects of auxin biosynthesis and its regulation
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DOI：
10.1111/ppl.12098
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发表时间：
2014-05-01
影响因子：
6.4
通讯作者：
Stepanova, Anna N.
中科院分区：
文献类型：
--
作者：
Brumos, Javier;Alonso, Jose M.;Stepanova, Anna N.
生长素是一种重要的植物激素，几乎控制着植物生命的各个方面，从胚胎发育到器官衰老。在过去的十年中，参与生长素运输，感知，信号和反应的关键基因已被确定和表征，但生长素生物合成的阐明已被证明是特别具有挑战性的。在植物中，大量的吲哚-3-乙酸（IAA）（生长素的主要生物活性形式）通过简单的两步法合成，其中通过色氨酸氨基转移酶（TAA 1/TAR）由l-色氨酸产生的吲哚-3-乙酸（IPyA）通过黄素单加氧酶的YUC家族转化为IAA。TAA 1/TAR和YUC基因家族是植物中第一个完整的生长素合成途径。对这些基因表达模式的详细分析表明，生长素的生物合成在植物发育中起着关键作用。这促使人们积极寻找调节IPyA途径时空活性的分子机制。除了TAA 1/TAR和YUC介导的生长素生物合成之外，已经假设了几种替代的IAA产生途径在植物中起作用，但它们的生物学意义尚未得到证实。在此，我们从遗传学的角度来描述植物生长素生物合成及其调控的现状，主要集中在拟南芥。
Auxin is an essential plant hormone that controls nearly every aspect of a plant's life, from embryo development to organ senescence. In the last decade the key genes involved in auxin transport, perception, signaling and response have been identified and characterized, but the elucidation of auxin biosynthesis has proven to be especially challenging. In plants, a significant amount of indole-3-acetic acid (IAA), the predominant biologically active form of auxin, is synthesized via a simple two-step route where indole-3-pyruvic acid (IPyA) produced from l-tryptophan by tryptophan aminotransferases (TAA1/TAR) is converted to IAA by the YUC family of flavin monooxygenases. The TAA1/TAR and YUC gene families constitute the first complete auxin biosynthetic pathway described in plants. Detailed characterization of these genes' expression patterns suggested a key role of local auxin biosynthesis in plant development. This has prompted an active search for the molecular mechanisms that regulate the spatiotemporal activity of the IPyA route. In addition to the TAA1/TAR and YUC-mediated auxin biosynthesis, several alternative routes of IAA production have been postulated to function in plants, but their biological significance is yet to be demonstrated. Herein, we take a genetic perspective to describe the current view of auxin biosynthesis and its regulation in plants, focusing primarily on Arabidopsis.