Auxin-dependent regulation of lateral root positioning in the basal meristem of Arabidopsis
Auxin-dependent regulation of lateral root positioning in the basal meristem of Arabidopsis
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DOI：
10.1242/dev.02753
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发表时间：
2007-02-15
期刊：
影响因子：
4.6
通讯作者：
Beeckman, Tom
中科院分区：
文献类型：
--
作者：
De Smet, Ive;Tetsumura, Takuya;Beeckman, Tom
在植物中，调节侧生器官沿主根定位的发育机制目前尚不清楚。我们提供了关于如何在模型植物拟南芥中以时空方式控制侧根起始的证据。首先，侧根沿着主轴以规则的左右交替模式间隔开，这与重力引起的波动相关，并取决于 AUX1，这是一种对向地性反应至关重要的生长素流入载体。其次，我们发现证据表明，中柱鞘细胞侧根起始的启动可能发生在基底分生组织中，这与根的这一部分的生长素敏感性升高相关。这种局部生长素反应性以 15 小时的固定间隔随着表达峰值而振荡。生长素报告基因最大值中的每个峰值与连续侧根的形成相关。第三，在 INDOLE-3-ACETIC ACID14（单根）作用之前，基底分生组织中的生长素信号触发中柱鞘细胞形成侧根。
In plants, the developmental mechanisms that regulate the positioning of lateral organs along the primary root are currently unknown. We present evidence on how lateral root initiation is controlled in a spatiotemporal manner in the model plant Arabidopsis thaliana. First, lateral roots are spaced along the main axis in a regular left-right alternating pattern that correlates with gravity-induced waving and depends on AUX1, an auxin influx carrier essential for gravitropic response. Second, we found evidence that the priming of pericycle cells for lateral root initiation might take place in the basal meristem, correlating with elevated auxin sensitivity in this part of the root. This local auxin responsiveness oscillates with peaks of expression at regular intervals of 15 hours. Each peak in the auxin-reporter maximum correlates with the formation of a consecutive lateral root. Third, auxin signaling in the basal meristem triggers pericycle cells for lateral root initiation prior to the action of INDOLE-3-ACETIC ACID14 (SOLITARY ROOT).