WE STUDY the plant immune system
Some of the oldest and most impressive organisms on Earth are plants. Being able to thrive over hundreds to thousands of years in environments full of potentially harmful microbes requires a strong immune system. Plants have evolved macroscopic traits to combat environmental and biotic stresses, including thick outer layers of bark and waxy leaf cuticles, prickly spikes such as needles and thorns, and unsavoury chemical profiles that can deter herbivores.
Should a microbe or pest breach one of those barriers, they will be met with microscopic defenses at the plant cell or tissue level. Plant cell walls are made up of sugars such as pectin that form a strong mesh that is difficult for pathogens to penetrate. Microbes that do live within plant tissues mostly colonize areas adjacent to plant cells called the apoplast. If a plant cell recognizes a pathogen it often leads to localized cell death in order to save neighbouring tissues. A full immune response like this is costly and involves release of reactive molecules that can also damage the plant if not kept in check. Plant immune responses are therefore tightly controlled: immunity is turned on only when needed, and turned off as soon as the threat has cleared.
The plant anti-microbial immune system is gated by an armada of receptor proteins that bind foreign molecules and activate defence programs. The earliest experimentally-tractable responses following immune receptor activation include a burst of secondary messengers including calcium and reactive oxygen species that amplify the signal. A series of signaling cascades lead to changes in gene expression that result in further defenses being mounted - such as a thickening of the cell wall and the release of systemic signals that protect other areas of the plant.
Cellular signal transduction is largely mediated by protein kinases, enzymes that catalyze the attachment of phosphoryl groups to target proteins in a process called phosphorylation. Phosphorylation regulates protein function by influencing sub-cellular localization, binding partners, and, in the case of many enzymes, activity. Highly regulated phospho-relays pass messages received by proteins at the cell membrane to proteins in the nucleus to temporarily drive immune reprogramming and fight against disease. A lot of our work is aimed at understanding the molecular function of protein kinases in immune signaling pathways.
There are three main classes of intracellular signal transducing protein kinases:
We study proteins from all three superfamilies but recently our work has largely focused on CDPKs and RLCKs.
Located in the BioSciences Complex at beautiful and historic Queen's University, our lab is well-equipped to enable state-of-the-art molecular and cellular biology, plant genomics, large-scale phenotyping, and biochemistry. We have excellent plant growth facilities in our roof-top Phytotron, a microscopy suite with a brand new Zeiss LSM980 Airyscan Confocal Microscope, a Berthold NightShade Imager, a fully outfitted molecular lab, and access to other instruments in the Department of Biology.
We are part of multiple communities on campus including the Plant Sciences Research Group, the Infection, Immunity & Inflammation Research Group, and the Molecular, Cellular and Integrative Biology Research Group, offering inter-disciplinary perspectives on our research and its impact beyond plant biology.
Should a microbe or pest breach one of those barriers, they will be met with microscopic defenses at the plant cell or tissue level. Plant cell walls are made up of sugars such as pectin that form a strong mesh that is difficult for pathogens to penetrate. Microbes that do live within plant tissues mostly colonize areas adjacent to plant cells called the apoplast. If a plant cell recognizes a pathogen it often leads to localized cell death in order to save neighbouring tissues. A full immune response like this is costly and involves release of reactive molecules that can also damage the plant if not kept in check. Plant immune responses are therefore tightly controlled: immunity is turned on only when needed, and turned off as soon as the threat has cleared.
The plant anti-microbial immune system is gated by an armada of receptor proteins that bind foreign molecules and activate defence programs. The earliest experimentally-tractable responses following immune receptor activation include a burst of secondary messengers including calcium and reactive oxygen species that amplify the signal. A series of signaling cascades lead to changes in gene expression that result in further defenses being mounted - such as a thickening of the cell wall and the release of systemic signals that protect other areas of the plant.
Cellular signal transduction is largely mediated by protein kinases, enzymes that catalyze the attachment of phosphoryl groups to target proteins in a process called phosphorylation. Phosphorylation regulates protein function by influencing sub-cellular localization, binding partners, and, in the case of many enzymes, activity. Highly regulated phospho-relays pass messages received by proteins at the cell membrane to proteins in the nucleus to temporarily drive immune reprogramming and fight against disease. A lot of our work is aimed at understanding the molecular function of protein kinases in immune signaling pathways.
There are three main classes of intracellular signal transducing protein kinases:
- Mitogen-activated protein kinases (MAPKs) - similar to ERK and Raf-like kinases in animals
- Receptor-like cytoplasmic kinases (RLCKs) - similar to the RLK/Pelle family in animals
- Calcium-dependent protein kinases (CDPKs) - calcium-binding protein kinase family unique to plants and some protists
We study proteins from all three superfamilies but recently our work has largely focused on CDPKs and RLCKs.
Located in the BioSciences Complex at beautiful and historic Queen's University, our lab is well-equipped to enable state-of-the-art molecular and cellular biology, plant genomics, large-scale phenotyping, and biochemistry. We have excellent plant growth facilities in our roof-top Phytotron, a microscopy suite with a brand new Zeiss LSM980 Airyscan Confocal Microscope, a Berthold NightShade Imager, a fully outfitted molecular lab, and access to other instruments in the Department of Biology.
We are part of multiple communities on campus including the Plant Sciences Research Group, the Infection, Immunity & Inflammation Research Group, and the Molecular, Cellular and Integrative Biology Research Group, offering inter-disciplinary perspectives on our research and its impact beyond plant biology.
