Featured Research

from universities, journals, and other organizations

New 'Green' Pesticides Are First To Exploit Plant Defenses In Battle Of The Fungi

Date:
March 24, 2009
Source:
American Chemical Society
Summary:
Exploiting a little-known punch/counterpunch strategy in the ongoing battle between disease-causing fungi and crop plants, scientists in Canada are reporting development of a new class of "green" fungicides that could provide a safer, more environmentally-friendly alternative to conventional fungicides.

Scientists in Canada are reporting development of a new type of "green" fungicide that could provide a safer, more environmentally-friendly alternative to conventional fungicides. Shown is a leaf infected with a fungus.
Credit: Canola Council of Canada

Exploiting a little-known punch/counterpunch strategy in the ongoing battle between disease-causing fungi and crop plants, scientists in Canada are reporting development of a new class of "green" fungicides that could provide a safer, more environmentally-friendly alternative to conventional fungicides.

They will report on the first pesticides to capitalize on this unique defensive strategy March 23 in Salt Lake City, Utah, at the 237th National Meeting of the American Chemical Society.

Developed with sustainable agriculture in mind, the new fungicides — called "paldoxins" — could still do the work of conventional pesticides, helping to protect corn, wheat and other crops. These crops increasingly are used not just for food, but to make biofuels. The new fungicides also could help fight the growing problem of resistance, in which plant pests shrug off fungicides, the researchers suggest.

Most fungicides today are made based on chemicals that can kill potentially beneficial organisms and have other adverse environmental effects. The new materials are more selective, stopping fungi that cause plant diseases without harming other organisms. They work in a unique way, disrupting a key chemical signalling pathway that the fungi use to breakdown a plant's normal defenses. As a result, the plants boost their natural defenses and overcome fungal attack without harming people and the environment, the researchers say.

"Conventional fungicides kill constantly," explains study leader Soledade Pedras, Ph.D., a professor of chemistry at the University of Saskatchewan in Canada. "Our products only attack the fungus when it's misbehaving or attacking the plant. And for that reason, they're much safer."

Researchers have known for years that many plants have a defense mechanism that involves production of natural chemicals, called phytoalexins, to kill disease-causing fungi. The fungus, however, fights back. It releases enzymes that detoxify, or destroy, the phytoalexin, leaving the plant vulnerable to the fungi's attack.

To take advantage of that punch-counterpunch strategy, Pedras and her colleagues proposed the development of new anti-fungal agents to block the fungi's destruction of phytoalexins. They termed these new agents paldoxins, short for phytoalexin detoxification inhibitors.

Pedras discovered those agents after screening broccoli, cauliflower, mustard greens and other plants in the so-called "crucifer family." They discovered the most powerful phytoalexin in a flowering plant called camelina or "false flax." In laboratory tests, camelina phytoalexins blocked detoxifying enzymes produced by a wide variety of fungi.

"We found that many fungi couldn't degrade this chemical," says Pedras. "So that's what we used to design synthetic versions that were even stronger than the original."

The researchers now have developed six different synthetic versions of the paldoxins, which are essentially potent inhibitors of fungal enzymes.

The researchers have successfully tested the synthetic paldoxins in the lab on several crucifer plants, including rapeseed plants and mustard greens. Pedras' group plan field tests of their new fungicides on other important crop varieties. In the future, a similar strategy will be applied to grasses such as wheat, rye, and oat. These grassy plants tend to be more difficult to protect with fungicides than broccoli and related veggies, the researchers say.

If studies continue to show promise, the paldoxins could be marketed quickly, within a few years, Pedras says. The new fungicides could be applied like conventional pesticides.

The Natural Sciences and Engineering Research Council of Canada and the University of Saskatchewan funded the study.


Story Source:

The above story is based on materials provided by American Chemical Society. Note: Materials may be edited for content and length.


Cite This Page:

American Chemical Society. "New 'Green' Pesticides Are First To Exploit Plant Defenses In Battle Of The Fungi." ScienceDaily. ScienceDaily, 24 March 2009. <www.sciencedaily.com/releases/2009/03/090323110447.htm>.
American Chemical Society. (2009, March 24). New 'Green' Pesticides Are First To Exploit Plant Defenses In Battle Of The Fungi. ScienceDaily. Retrieved April 24, 2014 from www.sciencedaily.com/releases/2009/03/090323110447.htm
American Chemical Society. "New 'Green' Pesticides Are First To Exploit Plant Defenses In Battle Of The Fungi." ScienceDaily. www.sciencedaily.com/releases/2009/03/090323110447.htm (accessed April 24, 2014).

Share This



More Plants & Animals News

Thursday, April 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Monkeys Are Better At Math Than We Thought, Study Shows

Monkeys Are Better At Math Than We Thought, Study Shows

Newsy (Apr. 23, 2014) A Harvard University study suggests monkeys can use symbols to perform basic math calculations. Video provided by Newsy
Powered by NewsLook.com
Raw: Leopard Bites Man in India

Raw: Leopard Bites Man in India

AP (Apr. 22, 2014) A leopard caused panic in the city of Chandrapur on Monday when it sprung from the roof of a house and charged at rescue workers. (April 22) Video provided by AP
Powered by NewsLook.com
Iowa College Finds Beauty in Bulldogs

Iowa College Finds Beauty in Bulldogs

AP (Apr. 22, 2014) Drake University hosts 35th annual Beautiful Bulldog Contest. (April 21) Video provided by AP
Powered by NewsLook.com
805-Pound Shark Caught Off The Coast Of Florida

805-Pound Shark Caught Off The Coast Of Florida

Newsy (Apr. 22, 2014) One Florida fisherman caught a 805-pound shark off the coast of Florida earlier this month. Video provided by Newsy
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