My primary research interests are in the physiological and molecular mechanisms of plant interactions with the physical environment. Past research subjects have included air pollutant injury, root cell plasticity in response to nutrient deficiency, plant behavioral movements in response to light and temperature, and plant response to global change (elevated CO2).
Currently my program is focused on the regulation of seasonal dormancy in perennials. One emphasis is the regulation of growth cessation and bud formation in perennials as part of the developmental program that prepares plants to survive potentially damaging winter conditions. Despite being one of the most dramatic landscape and ecosystem events of the annual cycle, very little is known about the physiological and genetic regulation of dormancy in perennial species. Ultimately, a goal is to contribute to assembling a pathway of events from perception of the signal(s) for dormancy induction through to the developmental events associated with bud formation and endodormancy development. A second emphasis is on the molecular and physiological mechanisms of the quantitative chilling requirement for spring bud break. Chilling requirement is a fascinating example of biological 'counting' of the time of cold exposure and is of significant interest to horticulturalists and ecologists alike.