Aa. Carbonellbarrachina et al., THE INFLUENCE OF ARSENIC CHEMICAL FORM AND CONCENTRATION ON SPARTINA PATENS AND SPARTINA-ALTERNIFLORA GROWTH AND TISSUE ARSENIC CONCENTRATION, Plant and soil, 198(1), 1998, pp. 33-43
Arsenic (As) uptake by two perennial coastal marsh grasses growing in
hydroponic conditions was studied in relation to the chemical form and
concentration of As added to nutrient solution. A 4x3x2 factorial exp
eriment was conducted with treatments consisting of four As chemical f
orms [arsenite, As(III); arsenate, As(V); monomethyl arsonic acid, MMA
A; and dimethyl arsinic acid, DMAA], three As concentrations (0.2, 0.8
, and 2.0 mg As L-1) and two plant species (Spartina patens and Sparti
na alterniflora). Arsenic phytoavailability and phytotoxicity were pri
marily determined by the As chemical form present in the nutrient solu
tion, though As concentration also influenced both As availability and
toxicity. Application of As(V) increased root, shoot and total dry ma
tter production; this positive plant growth response may be linked wit
h P nutrition. Organic arsenicals and As(III) were the most phytotoxic
species to both marsh grasses when plant growth was considered. Arsen
ic uptake and transport in plant were species-specific. Phytoavailabil
ity of As followed the trend DMAA << MMAA congruent to As(V) < As(III)
. Root and shoot As concentrations significantly increased with increa
sing As application rates to the rooting medium, regardless of the As
chemical form. Upon absorption, inorganic arsenicals and MMAA were mai
nly accumulated in the root system, while DMAA was readily translocate
d to the shoot.