School of Agriculture, Food, and Wine, University of Adelaide, Waite Campus, Glen Osmond, South Australia 5064, Australia.
Ann Bot. 2010 Jun;105(7):1081-102. doi: 10.1093/aob/mcq027. Epub 2010 Apr 21.
Plants contain relatively few cell types, each contributing a specialized role in shaping plant function. With respect to plant nutrition, different cell types accumulate certain elements in varying amounts within their storage vacuole. The role and mechanisms underlying cell-specific distribution of elements in plants is poorly understood.
The phenomenon of cell-specific elemental accumulation has been briefly reviewed previously, but recent technological advances with the potential to probe mechanisms underlying elemental compartmentation have warranted an updated evaluation. We have taken this opportunity to catalogue many of the studies, and techniques used for, recording cell-specific compartmentation of particular elements. More importantly, we use three case-study elements (Ca, Cd and Na) to highlight the basis of such phenomena in terms of their physiological implications and underpinning mechanisms; we also link such distributions to the expression of known ion or solute transporters.
Element accumulation patterns are clearly defined by expression of key ion or solute transporters. Although the location of element accumulation is fairly robust, alterations in expression of certain solute transporters, through genetic modifications or by growth under stress, result in perturbations to these patterns. However, redundancy or induced pleiotropic expression effects may complicate attempts to characterize the pathways that lead to cell-specific elemental distribution. Accumulation of one element often has consequences on the accumulation of others, which seems to be driven largely to maintain vacuolar and cytoplasmic osmolarity and charge balance, and also serves as a detoxification mechanism. Altered cell-specific transcriptomics can be shown, in part, to explain some of this compensation.
植物包含的细胞类型相对较少，每种细胞在塑造植物功能方面都有专门的作用。就植物营养而言，不同的细胞类型在其储存液泡中以不同的量积累某些元素。细胞特异性元素分布的机制和作用在植物中尚未得到很好的理解。
细胞特异性元素积累现象以前曾被简要综述过，但最近在探测元素区室化潜在机制方面的技术进步，使得有必要进行更新评估。我们借此机会对许多研究进行了分类，并记录了特定元素的细胞特异性区室化所使用的技术。更重要的是，我们使用三个案例研究元素（Ca、Cd 和 Na）来突出这些现象的基础，包括它们的生理意义和潜在机制；我们还将这些分布与已知离子或溶质转运蛋白的表达联系起来。
元素积累模式是通过关键离子或溶质转运蛋白的表达来明确界定的。尽管元素积累的位置相当稳定，但通过遗传修饰或在胁迫下生长，某些溶质转运蛋白的表达发生变化，会导致这些模式发生波动。然而，冗余或诱导的多效性表达效应可能会使确定导致细胞特异性元素分布的途径复杂化。一种元素的积累通常会对其他元素的积累产生影响，这主要是为了维持液泡和细胞质的渗透压和电荷平衡，并作为一种解毒机制。部分可以通过改变细胞特异性转录组学来解释这种补偿。
