Epidermal transpiration and stomatal responses to humidity: Some hypotheses explored
Epidermal transpiration and stomatal responses to humidity: Some hypotheses explored
复制标题
表皮蒸腾作用和气孔对湿度的反应：探讨了一些假设
DOI：
10.1111/1365-3040.ep11571796
复制
发表时间：
1984
期刊：
影响因子：
--
通讯作者：
D. W. Sheriff
中科院分区：
文献类型：
--
作者：
D. W. Sheriff
讨论了受表皮蒸发和蒸腾流至表皮蒸发位点的水力传导影响的气孔对湿度的响应。最近对表皮内壁蒸发的估计过高，因为假设细胞壁表面完全湿润，并且叶子通常被认为是等温的。有人认为，湿度下降会增加表皮的蒸发，并且气孔会对随之而来的水势下降做出反应。角质层转换与气孔导度成反比。因此，表皮的蒸发取决于气孔、边界层和角质层的电导，并且取决于表皮内壁的蒸发。气孔对湿度的响应将随着边界层电导的变化而变化。蒸腾流的电导是表皮水势的决定因素。如果流动是共质的，则相邻细胞的水势将比非质外流动时更相似。结论是，活体组织中的流动在长距离上主要是共质体，但在较短的距离上，它逐渐成为质外体，并且气孔对湿度的反应是由整个表皮的水势介导的。
Stomatal responses to humidity as affected by both evaporation from the epidermis and the hydraulic conductance of the transpiration stream to evaporation sites on the epidermis are discussed. Recent estimates of evaporation from the inner walls of the epidermis are too high because the cell wall surfaces were assumed completely wet, and leaves have usually been considered isothermal. It is suggested that a fall in humidity increases evaporation from the epidermis, and that stomata respond to the consequent fall in water potential. Cuticular transiration is inversely related to stomatal conductance. Thus, evaporation from the epidermis is dependent on the stomatal, boundary layer, and cuticular conductances, and on evaporation from the inner walls of the epidermis. Stomatal responses to humidity will change as the boundary layer conductance changes. The conductance of the transpiration stream is a determinant of the water potential of the epidermis. Water potentials of adjacent cells will be more similar if flow is symplastic than if it is apoplastic. It is concluded that flow in living tissues is primarily symplastic over long distances, but over shorter distances it is increasingly apoplastic, and that stomatal responses to humidity are mediated by the water potential of the whole epidermis.