Characterization and engineering of proteins that regulate post-transcriptional gene expression
We are studying the role of RNA-binding proteins that have important roles in the stability, localization and translation of mRNAs in plant cells. The Puf (Pumilio) family of RNA binding proteins function in post-transcriptional control of gene expression in eukaryotic cells. There are up to 26 Puf genes in the genome of the model plant Arabidopsis thaliana, a number far greater than any other species studied to date. This suggests that Puf proteins have an important, broad role in post-transcriptional control in plants. We have studied the activity, structural modeling, and subcellular localization and dynamics of plant Puf family members. Our current efforts are aimed at identifying RNA targets of these proteins in order to determine the functional roles of these proteins. We are also engineering a unique plant Puf protein in an effort to design an advanced Puf that can target specific mRNA species in the cell and regulate the stability, processing or translation of these target mRNAs by coupling the Puf protein to effector domains. We are also using newly described approaches that will identify the in vivo RNA targets of several other plant RNA binding proteins, including metabolic enzymes that 'moonlight' as RNA-binding proteins. The approaches used here involve advanced mass spectrometry and RNA-seq methods.

Molecular and cellular approaches to oil sands tailings remediation and biosensing
We are using novel molecular approaches in an effort to develop plant based technologies for the reclamation and remediation of oil sands tailings ponds. The Athabasca oil sands of Alberta represent the third largest oil reserve in the world, and this industry is an important driver in the Canadian economy. However, the surface mining methods that are used to extract bitumen from the oil sands result in the production of large volumes of liquid tailings that are permanently stored in nearby ponds. Within these tailings are contained recalcitrant organic acids that are toxic to living organisms. We are using the model species Arabidopsis thaliana as a plant biosensor for toxicity and to identify genes that have the ability to degrade toxic organic acids. We have identified several tolerance genes and have developed a novel plant cellular biosensing system using the green fluorescent protein as a reporter of toxicity. Several tree species that can be used in reclamation and remediation projects are in the process of being screened for the expression of these marker genes.