Hwang Y H, Morris J T
Department of Biological Sciences, University of South Carolina, Columbia, South Carolina 29208.
Plant Physiol. 1991 May;96(1):166-71. doi: 10.1104/pp.96.1.166.
Higher pressure, up to several hundred pascal relative to ambient, is generated by hygrometric pressurization within the central hollow space of the stem in Spartina alterniflora. Dilution of oxygen and nitrogen by water vapor within the plant's internal gas space results in an influx of nitrogen and oxygen from the air and a net increase in the internal gas pressure at steady state. The nature of the pressure gradient suggests that small pores exist in the plant tissues. Moreover, the compact arrangement of leaf mesophyll cells creates a high resistance for the mass flow of gases and contributes to the higher pressure within leaves. After experimentally venting the internal pressure, outside air diffused through the basal area of the adaxial side of the leaves into the internal space and elevated pressure was restored.
互花米草茎干中央中空部分通过湿度增压产生相对于环境高达几百帕斯卡的较高压力。植物内部气体空间中水蒸气对氧气和氮气的稀释导致氮气和氧气从空气中流入，在稳态下内部气体压力净增加。压力梯度的性质表明植物组织中存在小孔。此外，叶肉细胞的紧密排列对气体的质量流产生了高阻力，并导致叶片内部压力升高。在通过实验排出内部压力后，外部空气通过叶片近轴面基部区域扩散到内部空间，压力得以恢复。
