# Project 6: Molecular Mechanisms of Heavy Metal Detoxification and Engineering Accumulation in Plants

> **NIH NIH P42** · UNIVERSITY OF CALIFORNIA, SAN DIEGO · 2020 · $198,677

## Abstract

Project Summary/Abstract
Soils and waters with high levels of toxic metal(loid)s such as cadmium, lead, arsenic and mercury are
detrimental to human and environmental health. These 4 heavy metal(loid)s are among the Superfund's top 7
priority hazardous substances. Many human diseases have been attributed to environmental contamination by
heavy metals, including cancers and neurological disorders. Research and applications indicate that uptake of
heavy metals into plant roots and accumulation of heavy metals could provide a cost effective approach for
toxic metal removal and bioremediation of heavy metal-laden soils and waters. In recent research we have
made major advances at understanding key mechanisms that function in heavy metal detoxification, transport
and accumulation in plants. However important genes and pathways that function in heavy metal over-
accumulation in plants remain to be identified. We will combine powerful genomic, genetic, biochemical and
engineering approaches to test new central hypotheses by pursuing the following Specific Aims:
Aim I. The regulatory mechanisms, transcription factors (TFs), and transcriptional network that mediate rapid
heavy metal(loid)-induced transcriptional responses in plants remain largely unknown. Using a luciferase-
based cadmium- and arsenic-induced reporter mutant screening approach we have isolated mutants in rapid
Cd- and As-induced gene expression. New mutants in major Cd-/As-dependent repression and induction loci
will be characterized and the underlying genes isolated and their functions determined. Collaborative research
with Geoffrey Chang (Project 5) will pursue development of cost-effective innovative heavy metal toxicant
nano-reporters in plants.
Aim II. The many genetic redundancies in plant genomes cause major limitations in heavy metal response
gene discovery. To address redundant gene function on a systems biology scale we have designed a genomic
scale artificial microRNA (amiRNA) library for genome-wide knockdown of homologous gene family members
which is leading to discovery of new genes and will be used to characterize key plant genes and network
mechanisms that function in heavy metal accumulation, resistance and remediation.
Aim III: Using genes identified in Specific Aims I and II and previous research, gene-stacking will be used to
generate plants and investigate their enhanced heavy metal accumulation and root sequestration
(phytostabilization) potential. Furthermore, by genomic investigation of plants that are being used for
phytostabilization at semi-arid Superfund sites, the above advances will be used in collaboration with the
University of Arizona Superfund Research Center to uncover mechanisms that render plants suitable for
phytostabilization of toxic metal(loid)s. The proposed research will be leveraged to develop technologies for
avoiding the growing problem of accumulation of heavy metals and arsenic in edible plant tissues.

## Key facts

- **NIH application ID:** 9903345
- **Project number:** 5P42ES010337-19
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN DIEGO
- **Principal Investigator:** JULIAN I SCHROEDER
- **Activity code:** P42 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $198,677
- **Award type:** 5
- **Project period:** — → —

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9903345

## Citation

> US National Institutes of Health, RePORTER application 9903345, Project 6: Molecular Mechanisms of Heavy Metal Detoxification and Engineering Accumulation in Plants (5P42ES010337-19). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9903345. Licensed CC0.

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