O/T Looking At Pharmaceutical, Agricultural Uses For T. virens

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Looking At Pharmaceutical, Agricultural Uses For T. virens

Main Category: Infectious Diseases / Bacteria / Viruses

Also Included In: Water - Air Quality / Agriculture; Pharma Industry / Biotech

Industry; Cancer / Oncology

Article Date: 04 Mar 2011 - 0:00 PST

http://www.medicalnewstoday.com/articles/218046.php

Researchers have come closer to understanding how a common fungus " makes its

living in the soil, " which could lead to its possible " career change " as a

therapeutic agent for plant and human health.

That's according to Dr. Kenerley, Texas AgriLife Research plant

pathologist, and a team of scientists from the U.S., India and France, whose

study on Trichoderma virens is in February's Journal of Biological Chemistry.

T. virens already enjoy a good reputation in the plant world. The fungi is found

throughout the world in all types of soil, Kenerley explained.

" We started working with this organism because it has what we would call

biological control activity, " he added. " They are used either as seed treatment,

as a foliar spray, or in the mixtures of potting soil at nurseries (to help

control disease). "

Because they are mycoparasites, T. virens attack other, less desirable fungi

that can harm roots and foliage of plants, he added. Colonization of plant roots

by T. virens also prompts the plant to produce defense responses to fight off

pathogenic fungi.

As a bonus, when no pathogens are loitering, T. virens enhance the growth of

plants, he added. " These fungi are very diversified organisms that have various

roles in ecology, " Kenerley said, " so agriculture has adopted them for use in

biocontrol or growth promotion. T. virens will colonize most agricultural crops

including corn, cotton, sorghum and alfalfa, as well as woody plants and

numerous other nursery plants. "

Anything good enough to fight off disease and encourage growth might have more

to offer, the scientists reasoned, so they looked deeper.

Sure enough, Kenerley noted, T. virens also produce antibiotics and short chains

of amino acids called peptaibols. Amino acids - because they string together to

form protein - are like the cinder blocks of all living things.

In this study, the researchers found two classes of peptaibols that contain more

than 70 components that had never been described.

" What is also exciting is that the 11- and 14-amino acid peptaibols have great

diversity. The chemists I work with have been able to identify 52 different

forms of this 11-amino acid peptaibol, " Kenerley said. " When you have so many

different forms, you have now a suite of compounds that you can test (for

potential uses). "

Sorting out that diversity to determine any specific uses for each of the 52

forms is something the team continues to pursue.

" Some might be interesting for use in plant science and some might be looked at

by the pharmaceutical industry for human uses, " he said.

The researcher said finding potential uses for the compounds will not be easy.

" The biggest challenge is not only in selection of the most appropriate form,

but then how do you gear the organism to produce more of what you want rather

than the whole suite of its compounds, " Kenerley said. " There's probably an

ecological reason the fungus produces a diversity of these compounds. I'm sure

it has to do with survival in the soil, and its interaction with other organisms

and plant roots.

" The compounds are not necessarily there for our benefit, but we would like to

use these compounds in different applications, " he added.

While Kenerley's team is considering agricultural uses for the peptaibols,

others are considering pharmaceutical uses for treating tumors in humans or

perhaps their ability to work against harmful bacteria, fungi and viruses, he

said.

" You can see that they would have great potential if they have therapeutic value

but are not harmful to the hosts - the hosts being humans, " Kenerley added.

The scientist said once researchers understand how the peptaibols are produced

by the fungus, the fungus could be potentially modified to produce only the part

needed for a specific use.

" If we can demonstrate a cheap way to make these, the specific form desired

could be synthesized, " he said. " The problem right now is there are so many

forms of these peptaibols, you really don't know which one to go after. We need

to figure out 'do I need a combination of these things? or really do I only need

to make one or two? "

Kenerley's team is working with chemists in France to determine which peptaibols

to select for continued work.

Source:

Kathleen

Texas A & M AgriLife Communications