AUX1 promotes lateral root formation by facilitating indole-3-acetic acid distribution between sink and source tissues in the Arabidopsis seedling
AUX1 promotes lateral root formation by facilitating indole-3-acetic acid distribution between sink and source tissues in the Arabidopsis seedling
复制标题
DOI：
10.1105/tpc.010354
复制
发表时间：
2002-03-01
期刊：
影响因子：
11.6
通讯作者：
Sandberg, G
中科院分区：
文献类型：
--
作者：
Marchant, A;Bhalerao, R;Sandberg, G
拟南芥根的构型是由茎源信号如硝酸盐和生长素调节的。我们报告，在假定的生长素流入载体AUX 1的突变修改根结构的结果，在吲哚-3-乙酸（IAA）源和库组织之间的激素运输中断。气相色谱选择反应监测-质谱测量结果表明，aux 1突变体表现出改变IAA分布在年轻的叶和根组织，主要的IAA源和库器官，分别在发展中的幼苗。使用生长素诱导的报告IAA 2：：uidA的表达研究表明，AUX 1促进IAA加载到叶维管运输系统。AUX 1还促进IAA在初生根顶的卸载和侧根原基的发育。外源应用的合成生长素1-萘乙酸是能够拯救aux 1侧根表型，这意味着根生长素水平是次优的侧根原基在突变体的启动。
Arabidopsis root architecture is regulated by shoot-derived signals such as nitrate and auxin. We report that mutations in the putative auxin influx carrier AUX1 modify root architecture as a result of the disruption in hormone transport between indole-3-acetic acid (IAA) source and sink tissues. Gas chromatography-selected reaction monitoring-mass spectrometry measurements revealed that the aux1 mutant exhibited altered IAA distribution in young leaf and root tissues, the major IAA source and sink organs, respectively, in the developing seedling. Expression studies using the auxin-inducible reporter IAA2::uidA revealed that AUX1 facilitates IAA loading into the leaf vascular transport system. AUX1 also facilitates IAA unloading in the primary root apex and developing lateral root primordium. Exogenous application of the synthetic auxin 1-naphthylacetic acid is able to rescue the aux1 lateral root phenotype, implying that root auxin levels are suboptimal for lateral root primordium initiation in the mutant.