Biologia plantarum 17:400-404, 1975 | DOI: 10.1007/BF02921050
Transpiration rate and intercellular diffusive resistance in the tobacco leaf
- 1 Institute of Experimental Botany, Czechoslovak Academy of Sciences, Praha
The increase in the measured transpiration rate in tobacco leaves due to the experimentally decreased humidity of the bulk air was found to be significantly lower than the theoretical value calculated from the change of water vapour concentration gradients. Boundary layer and stomatal diffusive resistances remained unchanged under experimental conditions with no change of net photosynthetic CO2 uptake. This suggests an increase in intercellular diffusive resistance with an increase in water vapour concentration gradient which is the driving force of water vapour diffusive part of transpiration flux.
The increase can be ascribed to the lengthening of intercellular diffusive pathway as steeper water vapour concentration gradient in intercellular spaces results in an increased evaporating surface of intercellular cells thus moving the effective plane of vaporization in leaf mesophyll further inwards. Due to different and independent changes of concentration gradients for water vapour and CO2, different length of intercellular diffusive pathways for CO2 and water vapour may be expected.
Received: June 23, 1975; Published: November 1, 1975 Show citation
References
- Jarvis, P. G., Slatyer, R. O.: A controlled-environment chamber for studies of gas exchange by each surface of a leaf.-CSIRO Aust. Div. Land Res. tech. Paper29: 2-16, 1966.
- Jones, H. G., Slatyer, R. O.: Effects of intercellular resistances on estimates of the intercellular resistance to CO2 uptake by plant leaves.-Aust. J. biol. Sci.25: 443-453, 1972.
Go to original source... - Slavík, B.: An analogue model for the estimation of the transmesophyllar diffusive resistance for CO2 in a photosynthetizing amphistomatous anisolateral leaf.-In:Unger, K.: Biophysik pflanzlicher Systeme. Fischer Verlag, Jena 1975a.
- Slavík, B.: Experimental evidence and calculation of transmesophyllar diffusive resistance in an anisolateral amphistomatous leaf.-XII internat. bot. Congress. P. 413. Leningrad 1975b.