Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers discover way to transport environmental arsenic to plant leaves in new clean-up strategy

13.04.2006


Environmental arsenic pollution is a serious and growing environmental problem, especially on the Indian subcontinent. Researchers at the University of Georgia had, several years ago, used genetic techniques to create "arsenic-eating" plants that could be planted on polluted sites.



There was a problem, however. The arsenic sequestered from soil remained largely in the roots of the plant, making it difficult to harvest for safe disposal. Now, the research team, led by geneticist Richard Meagher, has discovered a way to move the arsenic from roots to shoots. The payoff could be a new and effective tool in cleaning up thousands of sites where arsenic presents serious dangers to human health.

The research was just published in the Proceedings of the National Academy of Sciences (PNAS). Other authors of the paper include Om Parkash Dhankher and Elizabeth McKinney from the department of genetics at UGA and Barry Rosen of Wayne State University.


"High levels of arsenic in soil and drinking water have been reported around the world," said Meagher, "but the situation is worst in India and Bangladesh, where around 400 million people are at risk of arsenic poisoning. Unfortunately, the high cost of using excavation and reburial at these sites makes these technologies unacceptable for cleaning up the vast areas of the planet that need arsenic remediation. As a result, the overwhelming majority of arsenic-contaminated sites are not being cleaned up."

The problem is vast. The World Health Organization (WHO) predicts that long-term exposure to arsenic could reach epidemic proportions, the PNAS paper reports. The WHO says a staggering 1 in 10 people in northern India and Bangladesh may ultimately die of diseases resulting from arsenic-related poisoning.

The new strategy is part of what researchers call phytoremediation--the cleaning of polluted soils through the use of plants that sequester poisons, make them less harmful, and which can then be harvested--and has the potential to be of use on millions of acres of arsenic-polluted lands worldwide.

In research reported in 2002 in Nature Biotechnology, Meagher’s team inserted two unrelated genes from the bacterium E. coli called arsC and ECS into Arabidopsis, a model lab plant and small member of the mustard family. This allowed the plants to resist the toxic effects of arsenic and sequester three-fold more arsenic in their shoots than normal plants. Still this was too ineffective to allow planting of the transgenic plants on arsenic-polluted sites, since far more arsenic needed to be moved into the plant leaves for safe harvesting and disposal.

In the just-reported research, the team identified a single gene, ACR2, in the Arabidopsis genome as one that allows the plants to move sequestered arsenic in roots. By engineering plant lines with a silenced ACR2 gene, they discovered they could get 16-fold more arsenic in shoots than in natural wild-type Arabidopsis. This experiment identified the active mechanism for sequestering arsenic in roots.

"We want a 35- to 50-fold increase in these plants’ ability to sequester arsenic," said Meagher, "and now that we understand the mechanism, we believe that is possible." Indeed, it appears possible to create arsenic-eaters among tree, shrub and even grass species, using the new knowledge.

The problem of arsenic pollution is especially severe all over the Ganges River basin in India. During the so-called "Green Revolution" of the ’60s and ’70s, the cultivation of rice in flooded fields became pervasive, and workers dug open wells all over India through soil and rocks with naturally occurring arsenic. The result was widespread arsenic pollution from contaminated water. The problem is thus extremely widespread and not the result of industrial accidents or practices.

Kim Carlyle | EurekAlert!
Further information:
http://www.uga.edu

More articles from Ecology, The Environment and Conservation:

nachricht Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen

nachricht A new indicator for marine ecosystem changes: the diatom/dinoflagellate index
21.08.2017 | Leibniz-Institut für Ostseeforschung Warnemünde

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>