mir160和WOX5过量表达对拟南芥根冠细胞的不同的影响

Differential Impacts of mir160- and WOX5-Overexpression on Arabidopsis Root Cap Cells

摘要: WOX5和mir160过量表达均可在拟南芥根冠中诱导未分化的细胞累积，但这些根冠细胞间是否存在差异目前并不十分明了。本研究发现在mir160和WOX5过表达诱导产生的根冠细胞对秋水仙素呈现出不同的响应模式。在相同秋水仙素浓度处理条件下，WOX5过表达诱导产生中央根冠细胞(即柱细胞和柱干细胞)显著膨大(p < 0.01)，而侧根冠细胞无明显膨大；相反，经秋水仙素处理后mir160过量表达的幼苗中侧根冠细胞明显膨大，而柱细胞膨大的幅度相对较小。mir160和WOX5过表达诱导的根冠细胞对秋水仙素的不同响应表明该两条途径诱导产生的根冠细胞间存在差异，暗示其诱导机理可能不同。

Abstract: Both WOX5- and mir160-overexpression can induce the accumulation of undifferentiated cells in the Arabidopsis root cap, but it is not clear whether there are any differences between the induced undifferentiated root cap cells. In this study, we have found that root cap cells induced by mir160 and WOX5 showed different response patterns to colchicine. Under the same colchicine concentration, WOX5-induced root cap cells in the central region (i.e. columella stem cells and columella cells) expand significantly, while lateral root cap cells did not; on the other hand, in colchicine treated seedlings with mir160-overexpressing seedlings, lateral root cap cells expanded more significantly than columella stem cells and columella cells. The different responses of root cap cells induced by WOX5- and mir160-overexpression to colchicine indicate that the root cap cells induced by the two different genes show distinct characteristics and suggest that the induction mechanisms may be different.