Effect of dimethylarsenic acid (DMAA) on growth, tissue arsenic, and photosynthesis of rice plants

Abstract

The effect of dimethylarsenic acid (DMAA) applied to the root on arsenic (As) uptake and concentration, net photosynthesis (Pn), and growth parameters of rice (Oryza sativa L. cv. 'Mercury') plants was studied. The experiment consisted of four treatments (0, 0.2, 0.8, and 1.6 mg As/L) with four replications in a completely randomized design. The DMAA was applied in nutrient solution as its sodium salt. The solution culture was changed every four days to avoid changes in the As chemical form. Arsenic uptake and concentration in shoot and root increased upon increased DMAA concentration in solution. Upon uptake, DMAA was readily translocated to the shoot. At the two higher rates of DMAA application (0.8 and 1.6 mg As/L), Pn and photosynthetic capacity were significantly decreased in response to tissue As concentration. Leaf area and dry matter production were also significantly reduced at the two higher rates of DMAA. At the lower rate (0.2 mg As/L) of DMAA application, there was no significant reduction in Pn or growth. Dimethylarsenic acid application did not affect nutrient allocation within the rice plant at concentration levels used in this study.

Anthocyanins, thiols, and antioxidant scavenging enzymes are involved in Lemna gibba tolerance to arsenic

“…Arsenic uptake and its effect on the growth of L. gibba Plants were washed with deionized water and placed into a conventional oven at 80 8C until constant dry weight was achieved. Plants were then mineralized (Marin et al 1993), and the As concentration was analyzed using an hydride generation atomic absorption spectrophotometer (Shimadzu † , AA6701F). The relative growth rate (RGR) of the plants was calculated using the equation proposed by Hunt (1978).…”

Toxicity of arsenate in Silene vulgaris, accumulation and degradation of arsenate‐induced phytochelatins

“…which the As is transported is unknown. There is some indication that dimethylarsenic acid is transported to the shoots (Marin et al, 1993).…”

“…Increased As levels may cause toxic symptoms in plants, such as a decrease in plant growth and fruit yield (Carbonell-Barrachina et al, 1995), root discoloration and root plasmolysis, wilting and necrosis of leaf tips and leaf margins (Machlis, 1941), and a decrease in photosynthetic capacity (Marin et al, 1993).…”

“…which the As is transported is unknown. There is some indication that dimethylarsenic acid is transported to the shoots (Marin et al, 1993).Increased As levels may cause toxic symptoms in plants, such as a decrease in plant growth and fruit yield (Carbonell-Barrachina et al, 1995), root discoloration and root plasmolysis, wilting and necrosis of leaf tips and leaf margins (Machlis, 1941), and a decrease in photosynthetic capacity (Marin et al, 1993).Some authors have reported the accumulation of heavy metal-binding, thiol-rich phytochelatins (PCs) on exposure to As (Grill et al, 1986a(Grill et al, ,b, 1987Maitani et al, 1996). Phytochelatins have the structure (γ-glu-cys) n -gly, where n l 2-11 (Grill et al, 1985), and are produced in plants on exposure to a variety of heavy metals and metalloids (Gekeler et al, 1989).…”

Effect of arsenic on photosynthesis, growth and yield of five widely cultivated rice (Oryza sativa L.) varieties in Bangladesh

“…It interferes with metabolic processes and inhibit plant growth and development through arsenic induced phytotoxicity (Marin et al, 1993).…”