Transfer cells are plant cells with secondary wall ingrowths. These cells are ubiquitous, occurring in all plant taxonomic groups and in algae and fungi. Transfer cells form from differentiated cells across developmental windows and in response to stress. They are considered to play a central role in nutrient distribution by facilitating high rates of transport at bottlenecks for apo-/symplasmic solute exchange. These properties are conferred by their unique structural features--an invaginated secondary wall ensheathed by an amplified area of plasma membrane enriched in a suite of solute transporters. Recent development of transfer cell experimental systems, combined with technologies to image the three-dimensional structure of wall ingrowths, is allowing identification of inductive and regulatory signals, discovery of sequential processes involved in their differentiation, and a search for transfer cell identity genes. A model of key events in differentiation of a transfer cell is presented to highlight areas for future investigation.

中文翻译：

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转移细胞：专门用于特殊目的的细胞

转移细胞是具有次生壁向内生长的植物细胞。这些细胞无处不在，存在于所有植物分类群以及藻类和真菌中。转移细胞从分化细胞跨越发育窗口形成并响应压力。它们被认为通过促进载脂蛋白/共质溶质交换瓶颈处的高传输速率在营养分配中发挥核心作用。这些特性是由它们独特的结构特征赋予的——内陷的次生壁被富含一组溶质转运蛋白的质膜放大区域所包裹。转移细胞实验系统的最新发展，结合对壁向内生长的三维结构进行成像的技术，可以识别诱导和调节信号，发现参与其分化的连续过程，并寻找转移细胞身份基因。介绍了转移细胞分化中的关键事件模型，以突出未来研究的领域。