TAA1-mediated auxin biosynthesis is essential for hormone crosstalk and plant development
TAA1-mediated auxin biosynthesis is essential for hormone crosstalk and plant development
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DOI：
10.1016/j.cell.2008.01.047
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发表时间：
2008-04-04
期刊：
影响因子：
64.5
通讯作者：
Alonso, Jose M.
中科院分区：
文献类型：
--
作者：
Stepanova, Anna N.;Robertson-Hoyt, Joyce;Alonso, Jose M.
植物已经进化出巨大的能力，通过适应其生长和发育来应对环境变化。激素和发育信号之间的相互作用是产生这种巨大可塑性的关键机制。一个很好的例子是对乙烯激素的反应，这取决于组织类型、发育阶段和环境条件。通过表征拟南芥wei8突变体，我们发现一小群基因介导对乙烯的组织特异性反应。生化研究表明，WEI8 编码一种人们期待已久的色氨酸转氨酶 TAA1，该酶位于生长素生物合成途径的重要但遗传上尚未表征的吲哚-3-丙酮酸 (IPA) 分支中。对 TAA1 及其旁系同源物的分析揭示了局部生长素产生、组织特异性乙烯效应和器官发育之间的联系。因此，生长素生产的 IPA 途径是根据环境和发育线索产生稳定的生长素梯度的关键。
Plants have evolved a tremendous ability to respond to environmental changes by adapting their growth and development. The interaction between hormonal and developmental signals is a critical mechanism in the generation of this enormous plasticity. A good example is the response to the hormone ethylene that depends on tissue type, developmental stage, and environmental conditions. By characterizing the Arabidopsis wei8 mutant, we have found that a small family of genes mediates tissue-specific responses to ethylene. Biochemical studies revealed that WEI8 encodes a long-anticipated tryptophan aminotransferase, TAA1, in the essential, yet genetically uncharacterized, indole-3-pyruvic acid (IPA) branch of the auxin biosynthetic pathway. Analysis of TAA1 and its paralogues revealed a link between local auxin production, tissue-specific ethylene effects, and organ development. Thus, the IPA route of auxin production is key to generating robust auxin gradients in response to environmental and developmental cues.