Uptake and modeling of pesticides by roots and shoots of parrotfeather (Myriophyllum aquaticum).
BACKGROUND
Aquatic plants have a great potential to function as in situ, on-site biosinks and biofilters of pollutants. They are used for phytoremediation and phytotoxicity studies. Pesticide uptake studies are very important to predict contaminant accumulation, translocation, and transformation. There are a lot of models which have been developed for emergent plants, but there are not any existing models for submerged aquatic plants for assessing pesticide uptake.


OBJECTIVE
In this study, uptake of selected pesticides in parrotfeather (Myriophyllum aquaticum) were studied and the results were modeled with the aid of Log Kow and the concentration of pesticides. At the end, the developed model was compared to other existing models.


METHODS
The test was conducted with parrotfeather as a model plant. The bioassay and cultivation of this plant were examined. Pesticide uptake by roots and shoots was determined using 14C-radiolabeled materials.


CONCLUSIONS
The results were fitted with an equation that showed a relationship between uptake and lipophilicity of pesticides. The model was compared with other pesticide uptake models developed for other plants. Atrazine and cycloxidim were taken up more by roots than by shoots in comparison to other pesticides used. The total uptake, both in shoots and roots, was lower than for terbutryn and trifluralin. The best appropriate model was developed from the results against the other models seen in the literature. The concentration factors (Root Concentration Factor (RCF) and Submerged Shoot Concentration Factor (SSCF)) increased with a higher Kow of the substances. The Submerged Shoot Concentration Factor (SSCF) revealed a better relationship of the chemicals than did the Root Concentration Factor (RCF).


CONCLUSIONS
In this study, an uptake model was developed for rooted, submerged aquatic plants. Further studies are necessary to develop and compare models with different plants and pesticides.


CONCLUSIONS
Such studies as this one may be extended to other environmental pollutants in the aquatic ecosystem and may be employed to evaluate the possibility of using different plants in phytoremediation studies.
Turgut
Cafer
C
Adnan Menderes University, Faculty of Agriculture, Aydin, Turkey. cturgut@adu.edu.tr
D001280:Atrazine / Q000032:analysis / Q000378:metabolism; D001673:Biodegradation, Environmental; D002250:Carbon Radioisotopes; D003510:Cyclohexanes / Q000032:analysis / Q000378:metabolism; D006540:Herbicides / Q000032:analysis / Q000378:metabolism*; D019684:Magnoliopsida / Q000378:metabolism*; D008954:Models, Biological; D000442:Octanols / Q000737:chemistry; D018517:Plant Roots / Q000378:metabolism*; D018520:Plant Shoots / Q000378:metabolism*; D011714:Pyrans / Q000032:analysis / Q000378:metabolism; D014227:Triazines / Q000032:analysis / Q000378:metabolism; D014274:Trifluralin / Q000032:analysis / Q000378:metabolism; D014867:Water / Q000737:chemistry
D002250:Carbon Radioisotopes; D003510:Cyclohexanes; D006540:Herbicides; D000442:Octanols; D011714:Pyrans; D014227:Triazines; D014867:Water; C401281:cycloxydim; D014274:Trifluralin; D001280:Atrazine; C010347:terbutryne