Discovery of an extended bundle sheath in Ricinus communis L. and its role as a temporal storage compartment for the iron chelator nicotianamine
Discovery of an extended bundle sheath in Ricinus communis L. and its role as a temporal storage compartment for the iron chelator nicotianamine
复制标题
蓖麻中延伸束鞘的发现及其作为铁螯合剂烟酰胺临时储存室的作用
作者：
T. Rutten;C. Krüger;M. Melzer;U. W. Stephan;R. Hell
延伸束鞘（EBS）是一个特殊的细胞层，可增强叶内光同化物的横向运输。这种鲜为人知的组织通常被认为是豆科植物特有的。我们在非豆科植物蓖麻的子叶和叶子中发现了 EBS。通过细胞学和免疫学研究，并使用铁螯合剂烟草胺的定位作为质量运输的既定指标，我们证实了其作为运输组织和时间库的作用。对蓖麻幼苗子叶的观察进一步证明，EBS 从发育的早期阶段就开始执行这些任务。这是首次获得有关 EBS 在非豆科植物中生理作用的信息。我们的结果支持其在高等植物中广泛存在的观点。
The extended bundle sheath (EBS) is a specialized layer of cells that enhances the lateral transport of photoassimilates within the leaf. This little-known tissue is often considered to be legume-specific. We identified an EBS in cotyledons and leaves of the non-legume Ricinus communis L. By means of cytological and immunological studies and using the localization of the iron-chelator nicotianamine as an established indicator for mass transport, we confirmed its role as a transport tissue and a temporal sink. Observations on cotyledons of Ricinus seedlings further proved that the EBS carries out these tasks from a very early stage of development onwards. This is the first time that information has been obtained on the physiological role of an EBS in a non-legume. Our results support the idea of its widespread occurrence among higher plants.