Uptake of mercury vapor by wheat. An assimilation model

Journal Article · Wed Mar 01 04:00:00 EST 1978 · Plant Physiol.; (United States)

DOI:https://doi.org/10.1104/pp.61.3.430· OSTI ID:7052443

Browne, C L; Fang, S C

Using a whole-plant chamber and /sup 203/Hg-labeled mercury, a quantitative study was made of the effect of environmental parameters on the uptake, by wheat (Triticum aestivum), of metallic mercury vapor, an atmospheric pollutant. Factors were examined in relation to their influence on components of the gas-assimilation model, U(Hg) = (C/sub A' -- C/sub L')/(r/sub L.Hg/ + r/sub M.Hg/) where U(Hg) is the rate of mercury uptake per unit leaf surface, C/sub A'/ is the ambient mercury vapor concentration, C/sub L'/ is the mercury concentration at immobilization sites within the plant (assumed to be zero), r/sub L.Hg/ is the total leaf resistance to mercury vapor exchange, and r/sub M.Hg/ is a residual term to account for unexplained physical and biochemical resistances to mercury vapor uptake. Essentially all mercury vapor uptake was confined to the leaves. r/sub L.Hg/ was particularly influenced by illumination (0 to 12.8 klux), but unaffected by ambient temperature (17 to 33/sup 0/C) and mercury vapor concentration (0 to 40 ..mu..g m/sup -3/). The principal limitation to mercury vapor uptake was r/sub M.Hg/, which was linearly related to leaf temperature, but unaffected by mercury vapor concentration and illumination, except for apparent high values in darkness. Knowing C/sub A'/ and estimating r/sub L.Hg/ and r/sub M.Hg/ from experimental data, mercury vapor uptake by wheat in light was accurately predicted for several durations of exposure using the above model.

• Research Organization: Oregon State Univ., Corvallis
• OSTI ID: 7052443
• Journal Information: Plant Physiol.; (United States), Journal Name: Plant Physiol.; (United States) Vol. 61:3; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

550500 -- Metabolism
550501 -- Metabolism-- Tracer Techniques
560303* -- Chemicals Metabolism & Toxicology-- Plants-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AIR POLLUTION
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOMASS
CEREALS
DAYS LIVING RADIOISOTOPES
ELECTROMAGNETIC RADIATION
ENERGY SOURCES
EVEN-ODD NUCLEI
FLUIDS
GASES
GRAMINEAE
GRASS
HEAVY NUCLEI
ISOTOPES
LEAVES
MATHEMATICAL MODELS
MERCURY 203
MERCURY ISOTOPES
NUCLEI
PLANTS
POLLUTION
RADIATIONS
RADIOISOTOPES
RENEWABLE ENERGY SOURCES
TEMPERATURE EFFECTS
UPTAKE
VAPORS
VISIBLE RADIATION
WHEAT