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Title: Water relations and photosynthesis of a desert CAM plant, Agave deserti

Abstract

The water relations and photosynthesis of Agave deserti Engelm., a plant exhibiting Crassulacean acid metabolism, were measured in the Colorado desert. Although no natural stomatal opening of A. deserti occurred in the summer of 1975, it could be induced by watering. The resistance for water vapor diffusion from a leaf (R/sub wv/) became less than 20 sec cm/sup -1/ when the soil water potential at 10 cm became greater than --3 bars, as would occur after a 7-mm rainfall. As a consequence of its shallow root system (mean depth of 8 cm), A. deserti responded rapidly to the infrequent rains, and the succulent nature of its leaves allowed stomatal opening to continue for up to 8 days after the soil became drier than the plant. When the leaf temperature at night was increased from 5 to 20 C, R/sub wv/ increased 5-fold, emphasizing the importance of cool nighttime temperatures for gas exchange by this plant. Although most CO/sub 2/ uptake occurred at night, a secondary light-dependent rise in CO/sub 2/ influx generally occurred after dawn. The transpiration ratio (mass of water transpired/mass of CO/sub 2/ fixed) had extremely low values of 18 for a winter day, and approximately 25 formore » an entire year.« less

Authors:
Publication Date:
Research Org.:
Univ. of California, Los Angeles
OSTI Identifier:
7213001
Resource Type:
Journal Article
Journal Name:
Plant Physiol.; (United States)
Additional Journal Information:
Journal Volume: 58:4
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; 59 BASIC BIOLOGICAL SCIENCES; DESERTS; PLANTS; PHOTOSYNTHESIS; TRANSPIRATION; AMBIENT TEMPERATURE; CARBON DIOXIDE; COLORADO; DIFFUSION; GASES; LEAVES; METABOLISM; PH VALUE; RAIN; ROOTS; SEASONS; SOILS; STOMATA; UPTAKE; WATER; WATER VAPOR; ARID LANDS; ATMOSPHERIC PRECIPITATIONS; BIOMASS; CARBON COMPOUNDS; CARBON OXIDES; CHALCOGENIDES; CHEMICAL REACTIONS; ENERGY SOURCES; FLUIDS; HYDROGEN COMPOUNDS; NORTH AMERICA; OPENINGS; OXIDES; OXYGEN COMPOUNDS; PHOTOCHEMICAL REACTIONS; RENEWABLE ENERGY SOURCES; ROCKY MOUNTAIN REGION; SYNTHESIS; USA; VAPORS; 510100* - Environment, Terrestrial- Basic Studies- (-1989); 550500 - Metabolism; 551000 - Physiological Systems

Citation Formats

Nobel, P S. Water relations and photosynthesis of a desert CAM plant, Agave deserti. United States: N. p., 1976. Web. doi:10.1104/pp.58.4.576.
Nobel, P S. Water relations and photosynthesis of a desert CAM plant, Agave deserti. United States. https://doi.org/10.1104/pp.58.4.576
Nobel, P S. Fri . "Water relations and photosynthesis of a desert CAM plant, Agave deserti". United States. https://doi.org/10.1104/pp.58.4.576.
@article{osti_7213001,
title = {Water relations and photosynthesis of a desert CAM plant, Agave deserti},
author = {Nobel, P S},
abstractNote = {The water relations and photosynthesis of Agave deserti Engelm., a plant exhibiting Crassulacean acid metabolism, were measured in the Colorado desert. Although no natural stomatal opening of A. deserti occurred in the summer of 1975, it could be induced by watering. The resistance for water vapor diffusion from a leaf (R/sub wv/) became less than 20 sec cm/sup -1/ when the soil water potential at 10 cm became greater than --3 bars, as would occur after a 7-mm rainfall. As a consequence of its shallow root system (mean depth of 8 cm), A. deserti responded rapidly to the infrequent rains, and the succulent nature of its leaves allowed stomatal opening to continue for up to 8 days after the soil became drier than the plant. When the leaf temperature at night was increased from 5 to 20 C, R/sub wv/ increased 5-fold, emphasizing the importance of cool nighttime temperatures for gas exchange by this plant. Although most CO/sub 2/ uptake occurred at night, a secondary light-dependent rise in CO/sub 2/ influx generally occurred after dawn. The transpiration ratio (mass of water transpired/mass of CO/sub 2/ fixed) had extremely low values of 18 for a winter day, and approximately 25 for an entire year.},
doi = {10.1104/pp.58.4.576},
url = {https://www.osti.gov/biblio/7213001}, journal = {Plant Physiol.; (United States)},
number = ,
volume = 58:4,
place = {United States},
year = {1976},
month = {10}
}