Developing a Molecular System for Phytoremediation

EPA Grant Number: X832201
Center: Donald Danforth Plant Science Center
Center Director: Beachy, Roger N.
Title: Developing a Molecular System for Phytoremediation
Investigators: Beachy, Roger N. , Jez, Joseph M. , Smith, Thomas , Xia, Yiji
Institution: Donald Danforth Plant Science Center
Current Institution: Donald Danforth Plant Science Center , Donald Danforth Plant Science Center
EPA Project Officer: Lasat, Mitch
Project Period: February 1, 2005 through January 31, 2007 (Extended to January 31, 2008)
Project Amount: $484,700
RFA: Targeted Research Center (2004) Recipients Lists
Research Category: Targeted Research , Hazardous Waste/Remediation


Although the engineering of plants for improved phytoremediation properties shows promise, concerns about the risks of releasing genetically-modified organisms into the environment have focused attention on pollen/seed dispersal and control of gene expression as major issues in the assessment of transgenic crop plants. This proposal addresses these challenges by developing environmentally safe technologies that enhance cadmium and zinc accumulation in plants and control transgene flow into nature. Our aims are as follows: 1) to engineer glutathione biosynthesis by directed evolution for enhancing cadmium tolerance; 2) to test the effect of expressing a zinc-binding protein for improving zinc accumulation; 3) to develop a fertility control system to eliminate transgene flow; and 4) to demonstrate the utility of a chemical gene switch system to control transgene expression in Brassica juncea.


Our proposal employs a team of researchers with expertise in structural, molecular, and plant biology to develop the components of a system for phytoremediation. Half of this project focuses on improving the mechanisms plants use to protect themselves from metal toxicity by engineering enhanced glutathione biosynthesis for cadmium tolerance and by introducing a zinc-binding protein into plants to enhance zinc accumulation. The second half of the project focuses on molecular systems for controlling gene flow and expression, including the development of a new fertility control technology and testing chemical gene switch technology in a plant (B. juncea) suited for phytoremediation.

Expected Results:

This research will provide fundamental information on the mechanisms by which plants tolerate and accumulate cadmium and zinc and will develop new systems to control transgene flow and transgene expression. By the project’s end the individual components for improving metal tolerance and for controlling gene flow will be completed and tested in Arabidopsis as proof-of-principle. In addition, the chemical gene switch technology will be validated in B. juncea. These experiments will set the stage to incorporate these pieces of molecular technology into B. juncea to engineer a plant tailored for cadmium or zinc accumulation that is environmentally safe. Since heavy metal contamination poses health and environmental challenges with a price tag for remediation using existing technology estimated at $200 billion in this country alone, understanding how plants protect themselves from metal toxicity and manipulating these processes are crucial for optimizing plants as agents for phytoremediation.

Journal Articles: 2 Displayed | Download in RIS Format

Other center views: All 4 publications 2 publications in selected types All 2 journal articles
Type Citation Sub Project Document Sources
Journal Article Romanyuk ND, Rigden DJ, Vatamaniuk OK, Lang A, Cahoon RE, Jez JM, Rea PA. Mutagenic definition of a papain-like catalytic triad, sufficiency of the N-terminal domain for single-site core catalytic enzyme acylation, and C-terminal domain for augmentative metal activation of a eukaryotic phytochelatin synthase. Plant Physiology 2006;141(3):858-869. X832201 (2006)
X832201 (Final)
  • Abstract from PubMed
  • Full-text: Plant Physiology Full Text
  • Other: Plant Physiology PDF
  • Journal Article Wei B, Randich AM, Bhattacharyya-Pakrasi M, Pakrasi HB, Smith TJ. Possible regulatory role for the histidine-rich loop in the zinc transport protein, ZnuA. Biochemistry 2007;46(30):8734-8743. X832201 (Final)
  • Abstract from PubMed
  • Supplemental Keywords:

    chemistry, structural biology, soil, heavy metals, contaminants in soil, plant-based remediation, zinc transport, transgene containment, transcription factor, transgenic plant, chemical gene switch, RFA, Scientific Discipline, Waste, TREATMENT/CONTROL, Ecosystem Protection/Environmental Exposure & Risk, Aquatic Ecosystems & Estuarine Research, Treatment Technologies, Aquatic Ecosystem, Bioremediation, Ecological Risk Assessment, Ecology and Ecosystems, Agricultural Engineering, plant-based remediation, gene expression patterns, fertility control technology, glutahione biosynthesis, genetically engineered plants, plant uptake studies, gene transfer, remediation, genetic engineering, ecological consequences, plant biotechnology, water quality, biochemistry, cadmium, phytoremediation, plant mediated contaminants

    Progress and Final Reports:

  • 2005
  • 2006 Progress Report
  • Final Report