Resistance to transpiration of the sites of evaporation within the leaf

Journal Article · Thu Jun 01 04:00:00 EDT 1978 · Plant Physiol.; (United States)

DOI:https://doi.org/10.1104/pp.61.6.1000· OSTI ID:6743939

Farquhar, G D; Raschke, K

The rates of transpiration from the upper and lower surfaces of leaves of Gossypium hirsutum, Xanthium sturmarium, and Zea mays were compared with the rates at which helium diffused across those leaves. There was no evidence for effects of CO/sub 2/ concentration or rate of evaporation on the resistance to water loss from the evaporating surface (''resistance of the mesophyll wall to transpiration'') and no evidence for any significant wall resistance in turgid tissues. The possible existence of a wall resistance was also tested in leaves of Commelina communis and Tulipa gesneriana whose epidermis could be easily peeled. Only when an epidermis was removed from a leaf, evaporation from the mesophyll tissue declined. We conclude that under conditions relevant to studies of stomatal behavior, the water vapor pressure at the sites of evaporation is equal to the saturation vapor pressure.

• Research Organization: Michigan State Univ., East Lansing
• OSTI ID: 6743939
• Journal Information: Plant Physiol.; (United States), Journal Name: Plant Physiol.; (United States) Vol. 61:6; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

550500* -- Metabolism
59 BASIC BIOLOGICAL SCIENCES
BIOMASS
BODY
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CEREALS
CHALCOGENIDES
CRYOGENIC FLUIDS
DIFFUSION
ELEMENTS
ENERGY SOURCES
EPIDERMIS
EPITHELIUM
FLUIDS
GRAMINEAE
GRASS
HELIUM
KINETICS
LEAVES
MAIZE
NONMETALS
OPENINGS
ORGANS
OXIDES
OXYGEN COMPOUNDS
PLANTS
RARE GASES
RENEWABLE ENERGY SOURCES
SKIN
STOMATA
TISSUES
TRANSPIRATION