Research

Rows of plans in soil
Plants in a lab space

The big question

How does internal timekeeping lead to coordination of plant responses to the environment?

In the Greenham lab, we are working to understand how time of day influences a plants response to the environment. 
 
Brassica plant on a blue background

Time of day control of plant physiology and metabolism

Climate change is increasing the severity and duration of stress creating a need for more tolerant crops. Crops grown across latitudinal zones require diverse coping strategies that integrate stress tolerance with growth at a specific time and place. Plants, like humans, have an internal clock that coordinates plant growth and development with daily and seasonal changes in light and temperature. The circadian clock is particularly important under stressful conditions where it times plant physiological and metabolic processes throughout the day to maximize energy use for growth while responding to the stress. The Greenham lab applies transcriptomic, metabolomic, and physiological approaches to uncover the regulatory pathways driving time of day traits associated with tolerant crop varieties. 

 

Close up of protoplasts

Circadian control of tissue specific processes

Physiological and metabolic health relies on the circadian alignment of biological processes with the environment. Since the first documented study of circadian rhythms in the 18th century using a plant system, model organisms have been critical for defining the transcriptional mechanism of the oscillator and revealing the importance of the clock on fitness. Most of this work is based on whole organism or organ level studies leaving many mechanistic questions about how cell specific gene regulation leads to coordination of cellular clocks and a concerted physiological response. We know that gene regulatory networks are effective at modeling gene expression dynamics but resolving cell-type specific networks with time resolution remains a significant challenge. The Greenham lab is using the Arabidopsis model system to dissect how distinct cell type specific circadian regulation controls a physiological response.