植物根系和叶片生长对水分亏缺的原初反应

细胞扩张生长是植物受水分亏缺影响最敏感的生理过程之一。主要在对细胞水分导性、细胞壁特性和延伸组织中溶质传输结果分析的基础上 ,从细胞、组织和器官水平上对细胞扩展生长进行了探讨。根系和叶片细胞主要通过以下 2个过程来补偿水分胁迫的作用 :调节扩展生长需要的细胞临界膨压 ;溶质在延伸组织中的运移。此外 ,还探讨了植物根系和叶片生长对水分亏缺的生理适应机制

Primary responses of root and leaf elongating growth under water deficits

Cell expansion is among the most sensitive processes in plants affected by drought which is the result of an imbalance in the plant between water uptake and water loss.Short term responses of hydraulic conductivity,cell wall yielding and solute transport in the root elongation zone are analyzed.The evaluation of the underlying mechanisms leads to a discussion of recent studies on biophysical aspects of cell expansion at a cellular,tissue and organ level.Two processes enable roots to compensate rapidly effects of water deficits originating in the medium:adjustment of the minimum pressure in cells required for expansion,and solute transport within the elongation zone. Limitations of root growth are discussed with respect to hydraulic,mechanical,and solute relations in the root elongation zone.Furthermore,mechanisms of adaptation to water deficits in roots and leaf expansion growth are discussed.