Reduced naphthylphthalamic acid binding in the tir3 mutant of Arabidopsis is associated with a reduction in polar auxin transport and diverse morphological defects
Reduced naphthylphthalamic acid binding in the tir3 mutant of Arabidopsis is associated with a reduction in polar auxin transport and diverse morphological defects
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DOI：
10.1105/tpc.9.5.745
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发表时间：
1997-05-01
期刊：
影响因子：
11.6
通讯作者：
Estelle, M
中科院分区：
文献类型：
--
作者：
Ruegger, M;Dewey, E;Estelle, M
生长素极性运输在植物生长发育的调控中起着重要作用。为了鉴定参与这一过程的基因，我们开发了一种遗传程序来筛选拟南芥中对生长素转运抑制剂的反应发生改变的突变体。我们总共回收了16个独立的突变体，它们定义了7个基因，称为转运抑制剂反应（TIR）基因，其中一个基因TIR 3的隐性突变导致对转运抑制剂的反应改变，极性生长素运输的减少和可归因于吲哚-3-乙酸分布变化的各种形态缺陷。最显著的是，TIR 3幼苗在侧根产生方面严重缺陷，这是已知依赖于极性生长素从芽运输到根的过程。此外，tir 3植物显示顶端优势的减少以及角果、花梗、根和花序的伸长减少。生物化学研究表明tir 3植物具有减少的N-1-萘基邻苯二甲酰胺（NPA）结合位点的数量，这表明tir 3基因是表达、定位或者，TIR 3基因可以编码NBP。因为tir 3突变体在NPA结合方面具有实质性缺陷，所以它们的表型为NBP在植物生长和发育中的作用提供了遗传证据。
Polar auxin transport plays a key role in the regulation of plant growth and development. To identify genes involved in this process, we have developed a genetic procedure to screen for mutants of Arabidopsis that are altered in their response to auxin transport inhibitors, We recovered a total of 16 independent mutants that defined seven genes, called TRANSPORT INHIBITOR RESPONSE (TIR) genes, Recessive mutations in one of these genes, TIR3, result in altered responses to transport inhibitors, a reduction in polar auxin transport, and a variety of morphological defects that can be ascribed to changes in indole-3-acetic acid distribution, Most dramatically, tir3 seedlings are strongly deficient in lateral root production, a process that is known to depend on polar auxin transport from the shoot into the root, In addition, tir3 plants display a reduction in apical dominance as well as decreased elongation of siliques, pedicels, roots, and the inflorescence, Biochemical studies indicate that tir3 plants have a reduced number of N-1-naphthylphthalamic (NPA) binding sites, suggesting that the TIR3 gene is required for expression, localization, or stabilization of the NPA binding protein (NBP), Alternatively, the TIR3 gene may encode the NBP, Because the tir3 mutants have a substantial defect in NPA binding, their phenotype provides genetic evidence for a role for the NBP in plant growth and development.