Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New 'green' pesticides are first to exploit plant defenses in battle of the fungi

24.03.2009
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 here today 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.

The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With more than 154,000 members, ACS is the world's largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.

Michael Bernstein | EurekAlert!
Further information:
http://www.acs.org

More articles from Life Sciences:

nachricht Cells communicate in a dynamic code
19.02.2018 | California Institute of Technology

nachricht Studying mitosis' structure to understand the inside of cancer cells
19.02.2018 | Biophysical Society

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Contacting the molecular world through graphene nanoribbons

19.02.2018 | Materials Sciences

When Proteins Shake Hands

19.02.2018 | Materials Sciences

Cells communicate in a dynamic code

19.02.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>