Conditional Repression of AUXIN BINDING PROTEIN1 Reveals That It Coordinates Cell Division and Cell Expansion during Postembryonic Shoot Development in Arabidopsis and Tobacco
Conditional Repression of AUXIN BINDING PROTEIN1 Reveals That It Coordinates Cell Division and Cell Expansion during Postembryonic Shoot Development in Arabidopsis and Tobacco
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DOI：
10.1105/tpc.108.059048
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发表时间：
2008-10-01
期刊：
影响因子：
11.6
通讯作者：
Fleming, Andrew J.
中科院分区：
文献类型：
--
作者：
Braun, Nils;Wyrzykowska, Joanna;Fleming, Andrew J.
生长素结合蛋白1（ABP1）是植物生长素作用的重要介质。ABP1在发育过程中的功能需求的分析受到阻碍，因为在拟南芥中的无效突变体的胚胎致死。在这里，我们使用ABP1的条件性抑制，以调查其功能在营养芽发育。使用诱导型细胞免疫方法和诱导型反义构建体，我们发现，ABP1活性降低导致叶生长严重迟缓，涉及细胞分裂频率的改变，内循环诱导模式的改变，细胞扩增的减少，以及早期生长素响应基因表达的变化。此外，在芽顶端分生组织中ABP1活性的局部抑制揭示了ABP1在细胞板形成和细胞形状中的额外作用。此外，在推定的叶起始的网站上的细胞比其他地区的分生组织更敏感的ABP1镇压。分生组织对ABP1失活的这种空间背景依赖性反应和这里提供的其他数据与ABP1作为细胞分裂和扩张的协调者的模型一致，其中局部生长素水平影响ABP1的有效性。
AUXIN BINDING PROTEIN1 (ABP1) has long been characterized as a potentially important mediator of auxin action in plants. Analysis of the functional requirement for ABP1 during development was hampered because of embryo lethality of the null mutant in Arabidopsis thaliana. Here, we used conditional repression of ABP1 to investigate its function during vegetative shoot development. Using an inducible cellular immunization approach and an inducible antisense construct, we showed that decreased ABP1 activity leads to a severe retardation of leaf growth involving an alteration in cell division frequency, an altered pattern of endocycle induction, a decrease in cell expansion, and a change in expression of early auxin responsive genes. In addition, local repression of ABP1 activity in the shoot apical meristem revealed an additional role for ABP1 in cell plate formation and cell shape. Moreover, cells at the site of presumptive leaf initiation were more sensitive to ABP1 repression than other regions of the meristem. This spatial context-dependent response of the meristem to ABP1 inactivation and the other data presented here are consistent with a model in which ABP1 acts as a coordinator of cell division and expansion, with local auxin levels influencing ABP1 effectiveness.