Toxicity and Uptake of Chlordane in Plants
Afrachanna D. Butler, US Army Corps of Engineer-Engineer Research and Development Center, 3909 Halls Ferry Road, Vicksburg, MS 39180, Tel: 601-634-3575, Fax: 601-634-3518, Email:  afrachanna.d.butler@usace.army.mil.
Victor F. Medina, Ph.D., U.S. Army Corps of Engineer-Engineer Research and Development Center, 3909 Halls Ferry Road, Vicksburg, MS 39180, Tel: 601-634-4283, Fax: 601-634-3518, Email:  victor.f.medina@erdc.usace.army.mil.
Agnes B. Morrow, US Army Corps of Engineer-Engineer Research and Development Center, 3909 Halls Ferry Road, Vicksburg, MS 39180, Tel: 601-634-2392, Fax: 601-634-3518, Email:  agnes.b.morrow@usace.army.mil.
Scott A Waisner, US Army Corps of Engineer-Engineer Research and Development Center, 3909 Halls Ferry Road, Vicksburg, MS 39180, Tel: 601-634-2286, Fax: 601-634-3518, Email:  scott.a.waisner@usace.army.mil.
David R. Johnson, Ph.D., US Army Corps of Engineer-Engineer Research and Development Center, 3909 Halls Ferry Road, Vicksburg, MS 39180, Tel: 601-634-2910, Fax: 601-634-3518, Email:  david.r.johnson@usace.army.mil.    

Chlordane is an organochlorinated pesticide that was banned in 1988 due to its health risks to humans and animals.  It still persists in soils and sediments and is an environmental concern.  The United States Air Force used chlordane to control termites around residential housing. This has resulted in soil contamination in many cases.  The Army Engineer Research and Development Center teamed with the Air Force Center of Environmental Excellence to study the fate and bioavailability of the chlordane in the environment.  One aspect of this study is plant interactions with the contaminant.

A phytotoxicity and uptake study is currently being conducted to address low chlordane concentrations.  This study consists of soils from contaminated chlordane sites.  Two grass species Poa pratensis L. (Kentucky Bluegrass) and Lolium perenne L. (Perennial Ryegrass) and one sedge Cyperus esculentus L. (Yellow Nutsedge) have been planted and are growing in contaminated and uncontaminated soils using methods specified in the ASTM standard guide E 1963-98.  Two soils are being tested, one from a base in the Northeast United States and one from the Southwest.  At the termination of the test, phytotoxicity endpoints such as germination percentages, root and shoot heights, and total plant biomasses are going to be measured.  Also plant tissue removal and final soil analyses will be measured to investigate the ability of grasses to remove chlordane from the soil.  These results will be presented at the conference. 

Understanding the Physiological and Molecular Mechanisms of Persistant Organic Pollutants (POPs) Uptake and detoxification in Cucurbit species (Zucchini and Squash)
Sudesh Chhikara, Bibin Paulose, and Om Parkash Dhankher, Dept. of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, MA-01003, USA, Tel: 413-545-5231; email: parkash@psis.umass.edu
Jason White, The Connecticut Agricultural Experiment Station, 123 Huntington St. Box 1106, New Haven CT- 06504, email: Jason.White@po.state.ct.us

Persistent organic pollutants (POPs) are of great environmental concern because of their toxicity, global distribution, and resistance to remediation.  Most plants, including many species traditionally utilized in phytoremediation approaches, have proven ineffective for weathered POPs. However, Cucurbita pepo ssp pepo (zucchini, pumpkin) roots phytoextract significant amounts of contaminant from soil, followed by effective translocation to aboveground tissues.  The pollutants accumulated by C. pepo ssp pepo include DDT/DDE, chlordane, and PCBs.  The amount of contaminant removed from the soil is dependent both on the pollutant characteristics and on the specific plant cultivar used.  For DDE, the stem-to-soil bioconcentration factors (dry weight ratio of contaminant in the stems to that in soil) approach 15, with up to 5% contaminant extraction in a single growing season.  Interestingly, other closely related species, including C. pepo ssp ovifera, do not have the ability to accumulate hydrophobic organic pollutants.

In a batch hydroponic trial, cultivars of C. pepo ssp pepo (cultivar variety Costata) and ssp ovifera (cultivar variety Zephyr) were exposed to DDE at 120 ppb for 96 hours.  The stem DDE content of exposed Zephyr cultivars was equivalent to that of non-exposed controls.  Conversely, the DDE content in Costata stems approached 1 ppm and was nearly 6-fold that of Zephyr. In batch hydroponic trials, the impact of DDE (2-20ppm) on the transpiration and biomass of C. pepo ssp pepo (Costata) and ssp ovifera (Zephyr) cultivars was evaluated over 31 days.  Zephyr was significantly more sensitive to DDE exposure.  For Zephyr, 4ppm DDE significantly reduced Zephyr biomass (14%) after 17 days; for Costata, significant biomass reductions were observed only after 20 days of exposure at 20 ppm (20%).  Similarly, exposure to 2 ppm DDE for 3 days reduced the transpiration volume of Zephyr by 35%; for Costata, exposure to 4 ppm DDE for 3 days significantly reduced transpiration volume (30%).

In order to identify differentially expressed genes in DDE treated Zucchini (C. pepo ssp pepo) as compared to DDE treated Squash (C. pepo ssp ovifera), PCR select Suppression subtraction hybridization was used. The subtracted library was subjected to differential screening in order to eliminate false positives. After differential screening, 46 cDNAs clones (40 cDNAs isolated from shoot and 6 cDNAs isolated from roots) were sequenced. Out of 40 shoot cDNA sequences, 34 cDNAs are similar to different parts of Phloem filament protein 1 (PP1) and few novel unknown genes, whereas, in root, out of 6 cDNAs, 2 are similar to Cytochrome P450 like proteins, one as putative senescence associated protein and rest are novel unknown genes. Currently, we are in the process of analyzing the regulation of these genes by RT-PCR in response to DDE exposure. These candidate genes will be further characterized by both forward and reverse genetic approach for their role in uptake of DDEs in plants.

Long-term Maintenance and Monitoring of a Phytoremediation Site and its Associated Reduction of Groundwater Contaminants
George Prince, U.S. EPA Environmental Response Team, 2890 Woodbridge Ave., Edison, NJ 08837, Tel: 732-321-6649, Fax: 732-321-6724 
Christopher Gussman, Lockheed Martin/REAC, 2890 Woodbridge Ave., Edison, NJ 08837, Tel: 732-321-4237, Fax: 732-494-4021
Jianwei Huang, PhD., Lockheed Martin/REAC, 2890 Woodbridge Ave., Edison, NJ 08837, Tel: 732-321-4233, Fax: 732-494-4021
Stephen (Brett) Sovick, Lockheed Martin/REAC, 2890 Woodbridge Ave., Edison, NJ 08837, Tel: 732-321-4279, Fax: 732-494-4021

The United States Environmental Protection Agency/ Emergency Response Team (U.S.EPA/ERT) has encouraged the use of phytoremediation technology at several applicable sites.   For some of these  locations there now exists an unusually complete data set, encompassing more than a decade of maintenance and monitoring efforts.  The Edward Sears Property Site, located in the coastal plain of southern New Jersey, has demonstrated a considerable reduction in groundwater contaminants over time.

The former owner of the Edward Sears Property Site stored drums of off-specification paints, solvents, varnish, lubrication oils, tar, epoxy resin, and other varied waste at his residential property from the mid-1960s until 1992.  In 1994 to 1995, the EPA Region II Removal Program removed and disposed of approximately 4,000 containers ranging in size from pints to 55-gallon drums.   In addition, 450 cubic yards of contaminated soil was removed to a depth of 5 feet, where a tight clay was encountered and reduced further penetration of contaminants.  Ground water contamination was then evaluated at the site, and sampling of the groundwater revealed  470,000 ug/L dichloromethane, 510 ug/L trimethylbenzene, 1890 ug/L trimethylbenzene, 510 ug/L TCE, 545 ug/L xylene, and a number of other VOCs in smaller amounts.  The site was determined to be ideal for phytoremediation, and one hundred hybrid poplars were planted in December of 1996.  Monitoring  at the site has included extensive groundwater sampling data as well as sap flow and annual growth measurement of the phytoremediation trees. Maintenance occurred at the site on an annual basis which included fertilizing, spraying, and pruning the trees and maintaining the site wells.   Today, many of the VOCs are no longer detectable or present in very low concentrations.  Recently, temporal visualization has been developed to represent dispersion and movement of contaminants of concern (COCs) over a 10-year plus time frame.  Geostatistical methodology selected for temporal analysis was directed by the geospatial distribution of the sampling locations and the range of samples in each data set.    Although many phytoremediation efforts are initiated, very few are monitored long enough to visualize the technology taking effect. 

Assessing the Potential of Phytoremediation Techniques at the Superfund Site
Julia Kuzovkina, Tom Morris, Dawn Pettinelli, Cristian Schulthess, Olena Zhivotovsky, University of Connecticut, 1376 Storrs Rd Unit 4067, Storrs CT 06269-4067, Tel: 860-486-3438, Email: jkuzovkina@uconn.edu

The high costs of traditional remediation methods for lead contamination of the skeet range in the Town of Sprague, CT, make soil removal an unrealistic option for the Town. The goal of this study is to recommend the most effective, environmentally safe and cost-effective re-use of the land through testing of 2 different phytoremediation strategies that could be deployed at this unusual site.

Strategy I. The objective was to investigate the efficacy of phytoextraction technology, defined as the removal of organic contaminants from soil due to the plants’ uptake and translocation into aboveground organs such as leaves and twigs, to remediate soil below regulatory limits.

Strategy II.  In parallel, we tested an alternative technology - phytostabilization - based on the use of plant covers, or buffer strips to stabilize the site. Plant covers act as hydraulic barriers that aim to prevent leaching or runoff of contaminants from the site, reduce soil erosion and decrease airborne dust and particulate matter. The project will investigate the possibility of phytostabilization of the site and the achievement of its re-use through the production of biomass for biofuel crops. Benefits of this strategy for the site include the preservation of green space while providing fuel for energy. 

Piptatherum miliaceum: A Good Alternative for Phytostabilization of Mine Soils in SE Spain
A. Zanuzzi, Sustainable Use, Management and Remediation of Soil and Water Research Group, Agrarian Science and Technology Department, Technical University of Cartagena, Paseo Alfonso XIII, 52, 30203 Cartagena, Murcia, Spain, Tel: +34968327072, Fax: +34968327046, Email: andrea.zanuzzi@upct.es.
A. Faz, Sustainable Use, Management and Remediation of Soil and Water Research Group, Agrarian Science and Technology Department, Technical University of Cartagena, Paseo Alfonso XIII, 52, 30203 Cartagena, Murcia, Spain, Tel: +34968325764, Fax: +34968327046, Email: angel.fazcano@upct.es
S. Lutts, Unité de Biologie végétale, Université catholique de Louvain, 5 (Bte 13) Place Croix du Sud, 1348 Louvain-la-Neuve, Belgium, Tel: +3210472037, Fax: +3210473435, Email: lutts@bota.ucl.ac.be
T. Lambrechts, Unité de Biologie végétale, Université catholique de Louvain, 5 (Bte 13) Place Croix du Sud, 1348 Louvain-la-Neuve, Belgium, Tel: +3210472037, Fax: +3210473435, Email: thomas.lambrechts@uclouvain.be

The intense mining activity carried out in Cartagena-La Unión Mining District, Southeast Spain, caused extremely high accumulation of heavy metals in soils. These lands show great risks for the surrounding environment due to the strong wind and water erosion processes, and, as a consequence, remediation measures are urgently required. The use of a plant cover is a cost-effective and environmentally sustainable method for reclaiming mine lands. Even though the natural plant species of this area are adapted to the shortage of water and scarcity of nutrients, it is necessary to reduce the availability of heavy metals, and also to neutralize soil acidity to achieve the objective of revegetation. For this purpose, chemical stabilization of heavy metals, by adding carbonates and organic wastes, combined with phytostabilization were used as a remediation technique in the polluted area. Anthropogenic wastes (pig manure, sewage sludge and marble wastes) were applied in experimental plots constructed in a representative mining zone. Amendments addition provided plant nutrients and reduced acid drainage and also heavy metal availability. As a consequence, there was an improvement of plant colonization and growth. Among the species that grew successfully on the plots, Piptatherum miliaceum was selected as a good candidate for phytostabilization because of its adaptation to the semi-arid climate conditions, its tolerance to heavy metals, its potential to reduce erosion and its ability to colonize these mining lands, as was observed in the field experiments. Laboratory studies also showed that soil compactness and nutrient stress are the main factors that limit plant growth. Therefore, the use of Piptatherum miliaceum in a ploughed mine soil, combined with the addition of organic amendments and lime, for reducing heavy metal availability, could be employed for reclaiming polluted mining areas from Southeast Spain.

Isolation and Characterization of Chromium-Induced Genes from Crambe abyssinica for Phytoremediation of Chromium Contamination
Student Presenter
Asma Zulfiqar , Dept. of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, MA-01003, USA, Tel: 413-545-5231; email: asmazulfiqar@hotmail.com
Bibin Paulose, Dept. of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, MA-01003, USA, Tel: 413-545-5231; bpaulose@psis.umass.edu
Om Parkash Dhankher, Dept. of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, MA-01003, USA, Tel: 413-545-0062; email: parkash@psis.umass.edu

Chromium (Cr) is a serious environmental pollutant due to its widespread use in industries such as tanning, corrosion, plating, pigment manufacturing and nuclear weapons production. Cr (VI) is generally considered to pose the greatest human health risk because of it being toxic, mutagenic and carcinogenic. There is no cost-effective environmental-friendly Cr remediation strategy available so far. Plants can be used to cleanup the Cr pollution by accumulating, stabilizing or transforming into less toxic form Cr(III). Previously, we have analyzed the uptake of Cr and other toxic metals in Crambe abyssinica and other Brassica species. Crambe accumulated high levels of Cr and As in the shoot tissues and thus has potential to be utilized as an ideal non-food crop for phytoremediation of heavy metals and metalloids. The present study was undertaken with an aim to isolate and characterize the genes induced in response to Cr stress in Crambe using a PCR-Select Subtractive cDNA Hybridization approach. After subtraction and differential screening, 71 positive cDNA clones from the subtracted library were sequenced. The sequences were categorized based on their similarity with reported sequences in the databases. Forty-five genes were found to be induced in response to Cr stress. Among these were Transcription factors, Chitinases, Thi-J like protein, Peroxidases, Glutathionases-S-Transferases, Aquaporins, Oxidoreductases, Harpins, Zn and Fe-binding proteins and many novel sequences with some unknown functions. Currently, we are analyzing these genes for expression analysis and functional characterization using both forward and reverse genetic approaches. The homologues of some selective genes i.e Harpins, Lipocaline and Thi-j like proteins have been identified in Arabidopsis and they have been cloned into vectors overexpression in plants. These transgenic plants will be analyzed for metal resistance and uptake studies. Further, studies to understand the physiological response (i.e photosynthesis, lipid peroxidation and levels of sugars and thiols) of plants under Cr stress are underway. The candidate genes will be used to engineer non-food high biomass C. abyssinica plants for phytoremediation of Cr contaminated soil and sediments.

Top