R.M. Parsons Laboratory
Environmental Science and Engineering


We are particularly interested in an important parameter called Water Use Efficiency (WUE), which reflects the balance between CO2 assimilation and water use. We identified a natural genetic variant affecting WUE using a combination of high-throughput phenotyping, population genetics, linkage mapping, and transgenics in Arabidopsis thaliana (Des Marais et al. 2014. PNAS).

Response to environmental cues is a genome-wide phenomenon; much of this response is coordinated at the level of gene transcription. We are interested in characterizing both the trans-acting (Des Marais et al. 2015 MBE) and cis-acting (Lasky et al. 2014 MBE) variants which drive natural variation in transcriptional responses. With collaborators, the Des Maras Lab is using tools from network theory to understand how topological features of gene regulatory networks shape the evolution of environmental response (Des Marais et al. 2017.

Plants integrate a spectacular amount of environmental data on time scales bridging minutes (e.g. passing clouds can alter available light) to seasons (temperature and water availability) to decades (climate trends, including anthropogenic change). A plant’s life history – its lifespan and when and how often it reproduces -- dictates the extent to which it must respond to cues at these different temporal scales. Life history variation represents compromises between biomass allocation, survivorship risks, and subsequent fitness benefits.

Understanding how and why individuals and species respond differently to environmental cues is paramount for predicting how natural and agricultural systems will be impacted by climate change.