Establishment of polarity in lateral organs of plants
Establishment of polarity in lateral organs of plants
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DOI：
10.1016/s0960-9822(01)00392-x
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发表时间：
2001-08-21
期刊：
影响因子：
9.2
通讯作者：
Bowman, JL
中科院分区：
文献类型：
--
作者：
Eshed, Y;Baum, SF;Bowman, JL
背景资料：植物侧生器官的不对称发育是由器官原基沿其近轴/远轴沿着方向划分为不同的结构域而开始的。最近的一个模型提出，分生组织bom信号，以浓度依赖的方式，差异激活PHABULOSA样基因，这反过来又抑制abaxial促进因子。到目前为止，没有abaxial因素已被确定，当妥协产生adaxialized organs.Results：在任何密切相关的基因KANADI 1（KAN 1）或KANADI 2（KAN 2）的单突变体对植物形态几乎没有影响。然而，在kan 1和kan 2双突变体植物，有一个远轴细胞类型的替代，在大多数侧部器官的近轴。极性建立中的改变与PHB样基因的表达结构域中的扩增和先前描述的轴向促进YABBY基因的表达中的减少相关。在整个叶原基的KANADI基因的异位表达的结果在近轴细胞类型到远轴的，侧叶片扩张失败，和维管组织formation.Conclusion：KANADI损失和获得的功能等位基因的表型表明，这些基因的精细调节极性建立的核心。因此，它们很可能是PHB介导的分生组织产生的信号传导的靶标，该信号传导模式为侧向器官原基，PHB样基因和轴外促进的KANADI和YABBY基因似乎在原基出现之前在整个原基原基中表达，然后局限于它们相应的结构域。这表明植物侧生器官极性的建立是通过原基出现后ab/ad因子之间的相互抑制作用发生的，这与经典解剖实验的结果一致。
Background: Asymmetric development of plant lateral organs initiates by partitioning of organ primordia into distinct domains along their adaxial/abaxial axis. A recent model proposes that a meristem-bom signal, acting in a concentration-dependent manner, differentially activates PHABULOSA-like genes, which in turn suppress abaxial-promoting factors. As yet, no abaxial factors have been identified that when compromised give rise to adaxialized organs.Results: Single mutants in either of the closely related genes KANADI1 (KAN1) or KANADI2 (KAN2) have little or no effect on plant morphology. However, in kan1 kan2 double mutant plants, there is a replacement of abaxial cell types by adaxial ones in most lateral organs. The alterations in polarity establishment are associated with expansion in the expression domain of the PHB-like genes and reduction in the expression of the previously described abaxial-promoting YABBY genes. Ectopic expression of either of the KANADI genes throughout leaf primordia results in dramatic transformation of adaxial cell types into abaxial ones, failure of lateral blade expansion, and vascular tissue formation.Conclusion: The phenotypes of KANADI loss- and gain-of-function alleles suggest that fine regulation of these genes is at the core of polarity establishment. As such, they are likely to be targets of the PHB-mediated meristem-born signaling that patterns lateral organ primordia, PHB-like genes and the abaxial-promoting KANADI and YABBY genes appear to be expressed throughout primordia anlagen before becoming confined to their corresponding domains as primordia arise. This suggests that the establishment of polarity in plant lateral organs occurs via mutual repression interactions between ab/ad factors after primordium emergence, consistent with the results of classical dissection experiments.