n nnnTransfer cells are highly modified plant cells specialized inthe transport of solutes. They differentiate at many plant exchangesurfaces, including phloem loading and unloading zones suchas those present in the sink organs and seeds. In maize (Zeamays) seeds, transfer cells are located at the base of the endosperm.It is currently unknown how apical-basal polarity is establishedor why the peripheral cells at the base of the endosperm differentiateinto transfer instead of aleurone cells. Here, we show thatin epidermal cells committed to develop into aleurone cells,the ectopic expression of the transfer cell-specific transcriptionalactivator Myb-Related Protein-1 (MRP-1) is sufficient to temporarilytransform them into transfer cells. These transformed cellsacquire distinct transfer cell features, such as cell wall ingrowthsand an elongated shape. In addition, they express a number ofMRP-1 target genes presumably involved in defense. We also showthat the expression of MRP-1 is needed to maintain the transfercell phenotype. Later in development, an observed reductionin the ectopic expression of MRP-1 was followed by the reversionof the transformed cells, which then acquire aleurone cell features.展开▼
机译：ABSTRACTn n
n TOP n <字体颜色= 464c53>抽象 n 介绍 n 结果 n 讨论 n 方法 n 参考文献 n n nnnTransfer细胞是高度修饰的植物细胞，专门用于 tr溶质。它们在许多植物交换 表面上有所区别，包括韧皮部的装卸区，如 ，如存在于水槽器官和种子中的区域。在玉米（ Zea mays ）种子中，转移细胞位于胚乳的基部。 目前尚不清楚顶基极性如何 或为什么胚乳基部的外周细胞分化成 而不是糊粉细胞转移。在这里，我们显示 在致力于发展成糊粉细胞的表皮细胞中， 异位表达与转移细胞特异性转录 激活剂Myb相关Protein-1（ MRP-1 ）足以将它们暂时 转化为转移细胞。这些转化的细胞 具有独特的转移细胞特征，例如细胞壁向内生长 和细长的形状。此外，它们表达许多可能与防御有关的 MRP-1靶基因。我们还显示 ，需要MRP-1的表达来维持转移 细胞表型。在开发的后期，观察到MRP-1异位表达降低 ，然后转化的细胞恢复 ，然后获得糊粉细胞特征。 / SUP>
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