Dr. Soledade Pedras
Canada Research Chair in Bioorganic and Agricultural Chemistry
When disease attacks a plant, it starts a complex cascade of defense and counterattack processes as the disease tries to invade and the plant strives to repel the onslaught.
Soledade Pedras works to understand this molecular struggle and perhaps in the process lay the foundations for the next generation of crop protection products – products that will work by bolstering plants' natural defenses.
The Pedras’ lab is one of very few in the world working to intimately understand both the signaling and defense mechanisms involved in fighting off disease. In particular, she is interested in the enzymes that fungi use to “trick” plants into lowering their guard and allowing invasion.
“I think we are the only group in the world doing this type of work – that is extracting the enzymes, characterizing the enzymes, seeing what are the possible inhibitors of these enzymes.”
The group has already coined a term for one type of these designer chemicals – paldoxins, for “phytoalexin detoxification inhibitors”. Phytoalexins are the substances plants use to fight off fungal infection, but some fungi – the ones that cause disease – have learned how to neutralize or detoxify these defenses.
Working to augment an organism’s own defenses is not a new idea – some of the latest drugs to treat human diseases use this approach. But while much is known about human enzyme systems, in the plant world, this branch of inquiry is still in its infancy.
It marks an important step in the evolution of pesticides, driven both by consumer demand and an increasing desire to protect the environment.
“I think the consumer is better informed of what is happening, and also of the consequences of some of these pesticides – and I underline some,” she says. “There have been crop protection agents that have been extremely helpful, but some of the older types, they have definitely shown terrible environmental impact.”
Pedras is not against the concept of pesticides – quite the contrary. Civilization cannot exist without agriculture, and while consumers in the developed world can demand that their farmers produce foods without pesticides, this is a luxury not available to the world’s poor.
“Right now, if the industry withdrew all the pesticides, there would be famine, especially in certain parts of the world. It would be impossible,” she says.
“I have no questions, no doubts, that we have to have some sort of control. I just think that one has to be smarter and try to bring new ideas into research so that that eventually these things can go out and have some positive impact.”
Pedras envisions her group as the leading edge of this positive wave. She hopes the products of her lab, once proven effective, will be taken forward and developed by industrial partners into new, safer, more effective crop protection products.
“We are going to be looking at designing drugs for treating the plant when it’s infected,” she says.“It would be extremely expensive for any ag industry player to do it. But once we have the molecules, they can take them and develop them into treatments – a pharmacy for the plant.”