Auxin transport promotes Arabidopsis lateral root initiation
Auxin transport promotes Arabidopsis lateral root initiation
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DOI：
10.1105/tpc.13.4.843
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发表时间：
2001-04-01
期刊：
影响因子：
11.6
通讯作者：
Bennett, M
中科院分区：
文献类型：
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作者：
Casimiro, I;Marchant, A;Bennett, M
拟南芥侧根发育为高等植物胚胎后器官发生的激素信号调控研究提供了一个模型。侧根起源于木质部极对面的几对中柱鞘细胞，它们产生一系列不对称的横向分裂。生长素运输抑制剂n -1-萘酞酸（NPA）通过阻断第一次横向分裂来阻止侧根的发育。我们研究了NPA作用的基础，通过使用细胞特异性报告细胞来证明木质部极中柱鞘细胞在生长素运输抑制剂存在下保持其身份。然而，NPA导致吲哚乙酸（IAA）在根尖积累，同时降低了对侧根形成至关重要的基础组织的水平。这种IAA的再分布模式与NPA阻断基部IAA从根尖向外的移动是一致的。无分生组织突变体1的侧根发育特征表明，侧根发育的起始和出芽阶段分别需要根基部和叶顶端生长素运输活动。
Lateral root development in Arabidopsis provides a model for the study of hormonal signals that regulate postembryonic organogenesis in higher plants. Lateral roots originate from pairs of pericycle cells, in several cell files positioned opposite the xylem pole, that initiate a series of asymmetric, transverse divisions. The auxin transport inhibitor N-1-naphthylphthalamic acid (NPA) arrests lateral root development by blocking the first transverse division(s). We investigated the basis of NPA action by using a cell-specific reporter to demonstrate that xylem pole pericycle cells retain their identity in the presence of the auxin transport inhibitor. However, NPA causes indoleacetic acid (IAA) to accumulate in the root apex while reducing levels in basal tissues critical for lateral root initiation. This pattern of IAA redistribution is consistent with NPA blocking basipetal IAA movement from the root tip. Characterization of lateral root development in the shoot meristemless1 mutant demonstrates that root basipetal and leaf acropetal auxin transport activities are required during the initiation and emergence phases, respectively, of lateral root development.