Featured Research

from universities, journals, and other organizations

Fern's evolution gives arsenic tolerance that may clean toxic land

Date:
June 14, 2010
Source:
Purdue University
Summary:
Isolating a gene that allows a type of fern to tolerate high levels of arsenic, researchers hope to use the finding to create plants that can clean up soils and waters contaminated by the toxic metal.

Researchers have discovered mechanisms of arsenic hyperaccumulation and tolerance using the fern Pteris vittata.
Credit: Image courtesy of American Society of Plant Biologists

Isolating a gene that allows a type of fern to tolerate high levels of arsenic, Purdue University researchers hope to use the finding to create plants that can clean up soils and waters contaminated by the toxic metal.

The fern Pteris vittata can tolerate 100 to 1,000 times more arsenic than other plants. Jody Banks, a professor of botany and plant pathology, and David Salt, a professor of horticulture, uncovered what may have been an evolutionary genetic event that creates an arsenic pump of sorts in the fern.

"It actually sucks the arsenic out of the soil and puts it in the fronds," Banks said. "It's the only multi-cellular organism that can do this."

Without a genome sequenced for Pteris vittata, Banks and Salt used a method of gene identification called yeast functional complementation. They combined thousands of different Pteris vittata genes into thousands of yeast cells that were missing a gene that makes them tolerant to arsenic.

The yeast was exposed to arsenic, with most of it dying. The yeast strains that lived had picked up the genes from Pteris vittata that convey arsenic resistance.

To confirm that this was the correct gene, its function was knocked down and the plant was exposed to arsenic. Without the gene functioning properly, the plant could not tolerate arsenic.

"It tells us that this gene is necessary for the plant to function on arsenic," said Banks, whose findings were published in the early online version of the journal Plant Cell. "We looked for a similar gene in the plant Arabidopsis. We couldn't find it. It can't be found in any flowering plant."

Banks and Salt found that the protein encoded by this gene ends up in the membrane of the plant cell's vacuole. Salt said the protein acts as a pump, moving arsenic into the cell's equivalent of a trashcan.

"It stores it away from the cytoplasm so that it can't have an effect on the plant," Salt said.

Banks said understanding how the Pteris vittata functions with arsenic could lead to ways to clean up arsenic-contaminated land.

"Potentially you could take these genes and put them in any organism that could suck the arsenic out of the soil," Banks said.

Salt said rice plants could be modified with the gene to store arsenic in the roots of plants -- instead of rice grains -- in contaminated paddies.

Banks and Salt found another gene in Pteris vittata that looks almost exactly the same as the one that controls arsenic tolerance. When the fern was exposed to arsenic, the confirmed arsenic-tolerance gene increased its expression while the similar gene did not.

Salt said the gene that regulates arsenic tolerance could be a duplicate of the other that has changed slightly to give itself a new function.

"The fact that it has these two genes could be a sign of evolution," Salt said. "One of the thoughts of gene evolution is that one copy could continue to do what it has always done, while the duplicate can develop another function."

The plant might have evolved to accumulate arsenic, Banks and Salt theorized, as a defense against animals or insects eating them.

Banks hopes findings such as this will lead to more research emphasis on non-flowering plants. She said there are characteristics in plants such as Pteris vittata that cannot be found in other organisms.

The next step in their research is to put the arsenic-tolerance gene from Pteris vittata into Arabidopsis to see whether it gives the new plant the same characteristics.

The National Science Foundation funded the research.


Story Source:

The above story is based on materials provided by Purdue University. The original article was written by Brian Wallheimer. Note: Materials may be edited for content and length.


Journal Reference:

  1. E. Indriolo, G. Na, D. Ellis, D. E. Salt, J. A. Banks. A Vacuolar Arsenite Transporter Necessary for Arsenic Tolerance in the Arsenic Hyperaccumulating Fern Pteris vittata Is Missing in Flowering Plants. The Plant Cell, 2010; DOI: 10.1105/tpc.109.069773

Cite This Page:

Purdue University. "Fern's evolution gives arsenic tolerance that may clean toxic land." ScienceDaily. ScienceDaily, 14 June 2010. <www.sciencedaily.com/releases/2010/06/100608183044.htm>.
Purdue University. (2010, June 14). Fern's evolution gives arsenic tolerance that may clean toxic land. ScienceDaily. Retrieved August 28, 2014 from www.sciencedaily.com/releases/2010/06/100608183044.htm
Purdue University. "Fern's evolution gives arsenic tolerance that may clean toxic land." ScienceDaily. www.sciencedaily.com/releases/2010/06/100608183044.htm (accessed August 28, 2014).

Share This




More Plants & Animals News

Thursday, August 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
Powered by NewsLook.com
Raw: Australian Sheep Gets Long Overdue Haircut

Raw: Australian Sheep Gets Long Overdue Haircut

AP (Aug. 28, 2014) Hoping to break the record for world's wooliest, Shaun the sheep came up 10 pounds shy with his fleece weighing over 50 pounds after being shorn for the first time in years. (Aug. 28) Video provided by AP
Powered by NewsLook.com
Minds Blown: Scientists Develop Fish That Walk On Land

Minds Blown: Scientists Develop Fish That Walk On Land

Newsy (Aug. 28, 2014) Canadian scientists looking into the very first land animals took a fish out of water and forced it to walk. Video provided by Newsy
Powered by NewsLook.com
Fake Dogs Scare Real Geese from Wis. Park

Fake Dogs Scare Real Geese from Wis. Park

AP (Aug. 28, 2014) Parks officials in Stevens Point, Wisconsin had a fowl problem. Canadian Geese were making a mess of a park, so officials enlisted cardboard versions of man's best friend. (Aug. 28) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins