Plant Tolerance of Herbivory


Why have some plants evolved to resist herbivory while others are less defended, but able to tolerate larger amounts of damage? Do these two components of defense, resistance (avoiding being eaten) and tolerance (enduring being eaten), differ in their relationships to growth and reproduction, and when are they likely to co-occur? Do herbivores select for tolerant plants or is tolerance a by-product of selection from plant competitors? Does tolerance fundamentally differ from resistance in its impacts on herbivore population dynamics and effects on higher trophic levels?

I am intrigued by tolerance as a strategy of defense in plants not only because there are still key gaps in our knowledge of the ecology and evolution of tolerance traits, but also because exploiting herbivory tolerant plants in agricultural settings is an underutilized approach in pest management. We have been examining tolerance and tolerance traits in a variety of systems, including tomato and with invasive Chinese tallow tree, and seek to identify a tolerance mechanism that could be the target of plant improvement. We are also directly examining the evolution of tolerance and resistance using common mustard, Brassica rapa (pictured below in a competition assay), and experimental evolution.