Stopping plants from getting sick

Fungi-infected plants often cause dramatic symptoms such as the formation of colourful masses of fungal spores instead of seeds. Some fungi can even make infected plants smell like rotting fish. In general, these infections cause major headaches for farmers who are counting on their crops, such as wheat and barley, to survive through the growing season.

Natural Sciences and Engineering Research Council (NSERC) grantee James Kronstad has spent almost his entire life looking for the "Achilles' heel" of these infections and to develop fungicides to stop fungi in their tracks. He spent his childhood on Oregon wheat farms and witnessed first-hand the damage that fungi can do to crops. He then went to university to learn the tools for dealing with fungal infections of both plants and animals.

Thirty years later, after a lifetime of work in both farmer's fields and the scientific field of fungal biology, Kronstad is being honoured for his work by the American Association for the Advancement of Science (AAAS). He will be inducted as an AAAS Fellow during the association's annual conference that is being held in San Francisco from February 15 to 19.

"This is a great honour, but it's also a reflection of the hard work my trainees and students and post-docs put in as they worked with me during their careers," says Kronstad, a biologist at the University of British Columbia. "There are about 40 other people who I wish could share this fellowship with me."

Kronstad's NSERC-funded research focuses on the smut fungi, a group of pathogens with an unusual name that comes from the sooty black masses of spores that they form on infected plants. The smut fungi represent particularly useful models to study how pathogens infect crop plants. These fungi depend on the infection of a plant to complete part of their life cycle. But once that part of their life is over, they can be removed from the plant to be studied in the laboratory.

What Kronstad discovered was the method that these fungi use to invade plants and shut down seed production, replacing it with their own spores and causing the black masses of spores on wheat crops – as he saw when he was a child. The fungi also sense lipids and phosphorous in the plant, meaning the right kind of fungicide might be developed to target that ability and block infection.

"These pathogens provide us with the best of both worlds in terms of research – we can study them in the field, but we can also bring them to the laboratory and isolate the genes that allow them to infect the plant," says Kronstad. "In fact, genomics and computers have made this a lot easier during the last five to 10 years. Before it would take a graduate student all of his or her research time to sequence and characterize one gene. Now that we have sequenced the genome of a smut fungus, I can look through thousands of genes on my desktop computer."

Kronstad is now using his NSERC-funded research as a foundation to fight an outbreak of the yeast fungus Cryptococcus on Vancouver Island, applying his research on plants to help investigate how this yeast causes pneumonia, meningitis and other illnesses in humans and animals. Still, he says he expects to be kept busy studying fungi for a long time – keeping the sooty black smut and the smell of rotting fish from Canada's wheat fields.

Source : Natural Sciences and Engineering Research Council