Cosgrove D J
Department of Biology, Pennsylvania State University, University Park 16802.
Int J Plant Sci. 1993;154(1):10-21. doi: 10.1086/297087.
Growing plant cells increase in volume principally by water uptake into the vacuole. There are only three general mechanisms by which a cell can modulate the process of water uptake: (a) by relaxing wall stress to reduce cell turgor pressure (thereby reducing cell water potential), (b) by modifying the solute content of the cell or its surroundings (likewise affecting water potential), and (c) by changing the hydraulic conductance of the water uptake pathway (this works only for cells remote from water potential equilibrium). Recent studies supporting each of these potential mechanisms are reviewed and critically assessed. The importance of solute uptake and hydraulic conductance is advocated by some recent studies, but the evidence is indirect and conclusions remain controversial. For most growing plant cells with substantial turgor pressure, it appears that reduction in cell turgor pressure, as a consequence of wall relaxation, serves as the major initiator and control point for plant cell enlargement. Two views of wall relaxation as a viscoelastic or a chemorheological process are compared and distinguished.
正在生长的植物细胞体积增加主要是通过液泡对水分的吸收。细胞调节水分吸收过程的一般机制只有三种：(a) 通过缓解细胞壁压力以降低细胞膨压（从而降低细胞水势）；(b) 通过改变细胞或其周围环境的溶质含量（同样影响水势）；(c) 通过改变水分吸收途径的水力传导率（这仅适用于远离水势平衡的细胞）。本文综述并批判性地评估了支持这些潜在机制的近期研究。一些近期研究主张溶质吸收和水力传导率的重要性，但证据是间接的，结论仍存在争议。对于大多数具有较大膨压的正在生长的植物细胞而言，由于细胞壁松弛导致的细胞膨压降低似乎是植物细胞增大的主要启动因素和控制点。本文比较并区分了将细胞壁松弛视为粘弹性过程或化学流变学过程的两种观点。
