Charron, Jean-Benoit

Our lab studies the chromatin regulatory mechanisms that control stress tolerance in plants. Chromatin is a highly organized structure that can be modified in order to modulate the expression of genes. This control can be enacted via DNA methylation and/or through various types of histone modifications and nucleosome remodelling. These modifications can affect gene expression by changing the local chromatin state from either an “open” (transcriptionally active) or “closed” (transcriptionally repressed) configuration and vice versa. To control this process, specialized proteins will craft different combinations of modifications in order to activate or repress gene expression when necessary. The long term goal of our research is to understand how these specialized proteins modulate the dynamic tuning of the plant’s chromatin structure upon perception of environmental stress conditions, and how this translates the stress signals from the cellular environment into orchestrated responses from the DNA.

To study chromatin dynamics we are using the monocot Brachypodium distachyon (purple false brome) as a genetic model system. This plant is a close relative of wheat and barley and is appealing for molecular studies due primarily to its small genome and the relative ease in which it can be transformed. The latter is crucial to our work in the lab as transgenic plants allow us to isolate and analyze the function of specialized chromatin modifying genes involved in the stress response mechanism. Development of over-expression and RNAi-mediated knock-down Brachypodium lines is currently underway in the lab. We employ a number of state-of-the-art molecular techniques (including RT-qPCR, ChIP-qPCR, ChIP-seq and RNA-seq) to identify and functionally characterize these chromatin modifying genes involved in stress response mechanisms in plants. We hope that the elucidation of the chromatin mechanisms involved in stress tolerance will ultimately lead to strategies for the improvement of important cereal monocot crops.

In addition to further developing Brachypodium as a model organism we are also currently working with industrial hemp (Cannabis sativa), a dicot crop of particular economic importance in Canada. The molecular aspects of the stress response mechanisms of this crop are currently being analyzed in the lab. Furthermore, in collaboration with Agriculture and Agrifood Canada and Phytodata inc. we are developing accurate molecular assays for the simultaneous detection and quantification of resistant and sensitive isolates from airborne field fungus samples. These assays are needed for the development of environmentally acceptable crop protection strategies centered on minimum fungicide use.