Dr. Jean-Benoit F. Charron
LSCI 204 Genetics
BTEC 306 Experiments in Biotechnology
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.
Chen, F., Li, B., Li, G., Charron, J.B., Dai, M., Shi, X. and Deng, X.W. (2014) Arabidopsis phytochrome A directly targets numerous promoters for individualized modulation of genes in a wide range of pathways. The Plant Cell. Published online: May 1st 2014.
Colton-Gagnon, K., Ali-Benali, M.A., Mayer, B.F., Dionne, R., Bertrand, A., Do Carmo, S. et Charron, J.B. (2014) Comparative analysis of the cold acclimation and freezing tolerance capacities of seven diploid Brachypodium distachyon accessions. Annals of Botany. 113: 681-693.
Ouellet, F. and Charron, J.B. (2013) Cold acclimation and freezing tolerance in plants. eLS, doi: 10.1002/9780470015902.a0020093.pub2
Lau, O.S., Xi, H., Charron, J.B., Li, G. and Deng, X.W. (2011) Interaction of Arabidopsis DET1 with CCA1 and LHY in Mediating Transcriptional Repression in the Plant Circadian Clock. Molecular Cell. 43: 703-712.
Zhou, J., Wang, X., He, K., Charron, J.B., Elling, A.A. and Deng, X.W. (2010) Genomewide profiling of histone H3 lysine 9 acetylation and dimethylation in Arabidopsis reveals correlation between multiple histone marks and gene expression. Plant Molecular Biology. 72: 585-595.
Charron, J.B., He, H., Elling, A.A. and Deng, X.W. (2009) Dynamic landscapes of four histone modifications during de-etiolation in Arabidopsis. The Plant Cell. 21: 3732-3748. IN BRIEF commentary
Charron, J.B., Ouellet, F., Houde, M. and Sarhan, F. (2008) The plant Apolipoprotein D ortholog protects Arabidopsis against oxidative stress. BMC Plant Biology. 8:86.
Guo, L., Zhou, J., Elling, A.A., Charron, J.B. and Deng, X.W. (2008) Histone modifications and expression of light-regulated genes in Arabidopsis are cooperatively influenced by changing light conditions. Plant Physiology. 147: 2070-2083.
Lee, J.H., Terzaghi, W., Gusmaroli, G., Charron, J.B., Yoon, H.J., Chen, H., He, Y.J., Xiong, Y. and Deng, X.W. (2008) Characterization of Arabidopsis and rice DWD proteins and their roles as substrate receptors for CUL4-RING E3 ubiquitin ligases. The Plant Cell. 20:152-167.
Charron, J.B., Ouellet, F., Pelletier, M., Danyluk, J., Chauve, C. and Sarhan, F. (2005) Identification, expression and evolutionary analyses of plant lipocalins. Plant Physiology. 139: 2017-2028.
Breton, G., Danyluk, J., Charron, J.B. and Sarhan, F. (2003) Expression profiling and bioinformatic analyses of a novel stress-regulated multispanning transmembrane protein family from cereals and Arabidopsis. Plant Physiology. 132: 64-74.
Frenette Charron, J.B., Breton, G., Badawi, M. and Sarhan, F. (2002) Molecular and structural analyses of a novel temperature stress-induced lipocalin from wheat and Arabidopsis. FEBS Letters. 517: 129-132.
Charron, J.B., Breton, G., Danyluk, J., Muzac, I., Ibrahim, R.K. and Sarhan, F. (2002) Molecular and biochemical characterization of a cold-regulated phosphoethanolamine N- methyltransferase from wheat. Plant Physiology. 129: 363-373.