Funky fungi for healthy fields

fungus-twitter-englishBy Matt McIntosh for AgInnovation Ontario

St Catharines – Brock University researchers are looking for growth – fungal growth that is – and they are doing it with agriculture in mind.

PhD students Larissa Barelli, Soumya Moonjely, and Shasha Hu are trying to understand the relationship between entomopathogenic fungi – a naturally occurring bug-killer – and plants.

By studying how the ground-based fungi work within the soil, they could develop an effective and more naturally derived method of pest control that also promotes plant growth.

“These fungi exist all over the globe. There are numerous varieties in Ontario alone, and each has its own unique characteristics and target insects,” says Barelli.

“The idea is to be able to control them on a genetic level so farmers can purposely enhance the relationship between plants and the fungi in their soil. If we can determine how nutrient transfer and nutrient levels affect the relationship between plants and fungi, we have the basis of control,” she adds.

Entomopathogenic fungi propagate using spores. Spores land on insects, and the crawling critters are consumed by the fungi over the next five to 11 days. Once the insect dies, the fungi emerge and release further spores.

This rather macabre and horror-film style reproductive system is the basis for the fungi’s usefulness, and according to Barelli, the reason they have been studied as a natural source of pest control for several decades; indeed, such organisms are widely applied on crops in many places around the world, including Australia and Africa.

About 10 years ago, though, Barelli says these fungi were discovered living on plant roots. That proved to be a good thing for both organisms as the fungi receive carbon from the plant, and the plant is able to access more nitrogen.

“At this point we don’t know is whether it’s the fungus or the plant – or both – that is responsible for that relationship,” says Barelli.

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Larissa Barelli and her team

Still in the project’s inaugural year, the first task for Barelli and her colleagues is to map the gene expression profile of the fungi; that means looking at how the organisms’ traits express themselves, send signals, transport, handle stress, and so on. The fungi can then be put into soil, and its physical responses can be measured against varying nutrient levels.

Once they have an understanding of the fungi’s behaviors, Barelli says they will be able to investigate which traits can be controlled to make propagation easier. The fungi could, for instance, be given drought tolerance, or a greater ability to stay fixed within the soil under wet conditions.

Such traits would, says Barelli, be useful for farmers economically and environmentally – the fungi’s staying power and targeted reproduction would mean a lesser need for synthetically produced pesticides.

While the project is only using white beans, soybeans, switchgrass, corn and wheat for trials at this point, Barelli says the technology could be adapted for other plants once the relationship is better understood.

“These fungi are naturally in our soil, so we might as well try and use them,” she says, “They are very easy to find and work with, and they even have green spores; we are literally going green.”

The research is supported by funding from the Natural Sciences and Engineering Research Council of Canada’s Alexander Graham Bell Scholarship, as well as the Queen Elizabeth II Graduate Scholarship in Science and Technology.

Photo source: Larissa Barelli, Brock University