PHOTOSYNTHESIS OF IVY LEAVES (HEDERA-HELIX L) AFTER HEAT-STRESS .3. STOMATAL BEHAVIOR

作     者：BAUER, H 

作者机构：Institut für Allgemeine Botanik der Universität Innsbruck Austria 

出 版 物：《ZEITSCHRIFT FUR PFLANZENPHYSIOLOGIE》 

年 卷 期：1979年第92卷第3期

页      面：277-283页

核心收录：

主　　题：heat stress stomatal conductance intercellular CO 2 -Concentration k a , k′ a conductance of the boundary layer for water vapour and CO 2 , respectively (cm S −1 ) k s , k′ s stomatal conductance for water vapour and CO 2 , respectively (cm s −1 ) c a , c− a concentration of water vapour and CO 2 , respectively, in the ambient air (μg cm −3 ) c i , c′ i concentration of water vapour and CO 2 , respectively, in the intercellular spaces (μg cm −3 ) Tr transpiration (μg cm −2 s −1 ) F n net photosynthesis (μg cm −2 s −1 ) 

摘      要：Stomatal responses to light/dark-changes and exposure to various ambient CO 2 -concentrations of previously heat-stressed (30 min at 44, 46, or 48 °C) leaves of Hedera helix L. were studied. Stomatal conductance (k′ s ) and the intercellular CO 2 -concentration (c′ i ) were calculated from simultaneous measurements of transpiration and CO 2 -gas exchange in an open system. Stomatal responses to changes in c′ i were delayed during the first hours after heat stress and stomatal opening in light and closure in darkness were incomplete. 24 hours after stress, the stomata were able to react again as fast as before the stress, but k− s in light was still reduced. When the leaves were flushed with CO 2 poor air, however, the stomata opened almost completely. This indicates that the reduction of k− s after heat stress was caused by the raised c′ i due to reduced photosynthetic CO 2 uptake. As long as photosynthesis was impaired after heat stress, the CO 2 -sensitivity of the stomata was abnormal: related to the same c′ i , the stomata were open wider in heat-stressed leaves than in non-stressed ones.