May, Alexander N.


Research Associate

B.Sc., McMaster University, 2010

Research Interests:

Cooperation and signaling in microbes and plants; the evolution, maintenance, and breakdown of endosymbiosis in legumes and other species; experimental evolution and biological trade-offs.


My undergraduate thesis involved studying the plastic behaviour of plants when surrounded by genetically variable neighbors. In particular, I looked at the ability of plants to recognize their kin and 'talk' to one another (using chemical or volatile cues).

However, my interests now lie in the complex mutualism between legume plants and their facultative bacteria symbionts, rhizobia.

While most research has concentrated on the mechanistic processes behind root nodule formation and nitrogen-fixation, I'm more interested in the biological trade-offs that sustain rhizobial populations over the long term. Legumes are capable of sanctioning poorly-performing rhizobia in their nodules, and in the soil, rhizobia are capable of entering a type of quiescent, persister state. These traits may affect processes as diverse as aging, soil predation or herbivory, antibiotic resistance, and crop yield, among others.

Currently, my goal is to understand the bacterial processes involved in root nodule senescence; specifically, how the rhizobia within a decaying nodule are capable of propagating future generations. This has implications for agriculture as well as medicine – while a farmer would like to maintain strong populations of helpful bacteria in his soil, a doctor would want to completely eradicate antibiotic-resistant bacteria from a patient. I hope to shed some light on these subjects.

© micropop 2012