Charles Seller

Graduate Program Affiliations

• Biological Sciences (BISI): Molecular and Cell Biology (MOCB)

Research Interests

How do plants sense and respond to a changing environment? How do environmental signals regulate the structure and activity of the plant genome? These and other related questions animate the research in our lab. Our aim is to uncover the molecular mechanisms that enable environmentally responsive plants genomes. In pursuit of this goal, we utilize both modern techniques including cell-type specific genomics and proteomics as well as more traditional genetic and plant physiological approaches. We believe that this research will have significance to basic plant science and at the same time have relevance to the development of new strategies to overcome the challenges faced by agriculture due to global climate change.

In the Seller lab we often use the stomatal guard cell of the plant Arabidopsis thaliana as a model cell system in our research. Guard cells are specialized cells located on the leaf epidermis that are critical to plant survival. Guard cells must integrate multiple environmental cues to optimally control the size of microscopic pores on the leaf surface known as stomata (Figure 1). Stomatal regulation minimizes transpirational water loss while allowing carbon dioxide (CO2) uptake from the atmosphere for photosynthesis. For example, changes in the concentration of the plant hormone abscisic acid (ABA), a key regulator of plant drought stress responses, and changes in atmospheric CO2 concentration are well known signals that trigger stomatal movements (Figure 1). Closure of the stomatal aperture is critical for plant survival during periods of drought because it minimizes the loss of water through these small pores.

Using genomic approaches we have uncovered cell-type specific genome regulatory programs deployed in guard cells by the hormone ABA. During drought stress, ABA triggers extensive remodeling of chromatin structure in guard cells. Our goal is to discover the molecular mechanisms that enable ABA hormone signaling to reshape chromatin structure. Furthermore, we want to understand how these changes to chromatin structure contribute to the long-term optimization of stomatal responses during drought stress. Finally, we hope to understand why different plant cell-types exhibit distinct gene regulatory responses to ABA.

Separately, we have found that ABA and changes to atmospheric CO2 concentration engage distinct gene regulatory programs in guard cells. Given the continuing increase in atmospheric CO2 levels we are interested in understanding how CO2 concentration controls gene expression in plants. Because stomatal guard cells respond to both ABA and CO2 we hope to understand how this cell-type integrates these and other diverse environmental cues, especially at the level of genome activity.

Finally, we hope to understand the principles that control the 3-dimensional folding of the genome in the guard cell nucleus and its relationship to stomatal function. Within the nucleus, genomes fold into specific 3-dimensional structures and this folding can contribute to gene regulation, but in plants we know little about the forces that control this process. 

Education

• Postdoc, UC San Diego, 2019-2024
• Ph.D., UC San Francisco, 2012-2018