Research in the Xu laboratory focuses on plant and microalgal lipid metabolism. By applying state-of-the-art approaches in genetics, biochemistry, cellular biology, synthetic biology and biotechnology, we aim to address both fundamental and applied questions in the field. The major research objectives in our research group are to improve our understanding of the mechanisms underlying acyl lipid assembly (e.g. triacylglycerols/oils, galactolipids/photosynthetic membrane lipids, phospholipids/membrane lipids) in photosynthetic organisms and to design lipid biosynthetic pathways to improve agriculture production and produce value-added oils for food, feed, fuel, and materials applications.Learn More
Research Area: Plant biology
The ultimate goal of my research is to understand viruses and viral diseases for the betterment of agriculture. Our research involves a number of important viruses that infect plants, which include Grapevine rupestris stem pitting-associated virus (GRSPaV), a ubiquitous and important pathogen of grapes worldwide. Current research directions include: Processing and subcellular localization of polyproteins; structure and cellular localization of viral replication complexes; evolution and bio-informatics of grapevine viruses; development of virus-induced gene-silencing vectors ; and, development and application of technologies for the diagnosis of grapevine viruses.Learn More
My research group investigates biotic and abiotic stress on plants at the cellular and sub-cellular biochemical and molecular levels. The objective is to identify what changes occur in plant cells upon exposure to stress and which of these changes aid the plant to increase its tolerance to the stress.A major focus currently is the investigation of freezing stress tolerance in grapevines. Winters in Ontario can cause substantial damage to the cultivated grapes used in the Wine Industry, whereas wild grapes have no problems. We try to find out what the molecular basis is for this phenomenon. The ultimate goal is to use this knowledge to improve freezing and drought stress tolerance in the cultivated grapes.Learn More
My research explores biodiversity from different perspectives and scales. We have develop molecular diagnostic tools for plant identification, including herbal product authentication and certification. Also, we contribute to the Plant Barcode of Life, investigating intra and interspecific variation in plants, and incorporate both Indigenous knowledge and DNA-based approaches to understanding diversity. In addition, I have extensively researched the effects of ecosystem management on community structure. Lastly, I am engaged in the scholarship of teaching and learning and have recently looked at 1) learning objects as mechanisms of engagement, 2) active learning within large first year biology classes, and 3) ancient pedagogies.Learn More
Our lab works on three major areas of plant biology:
1) Cytoskeleton & Cell Morphogenesis: We study the pivotal role played by the cytoskeleton in cell shape development in higher plants.
2) Live Cell Visualization & Organelle Dynamics: We dissect the response hierarchy and localized co-operation between plastids, mitochondria and peroxisomes and also between the actin and microtubule components of the cytoskeleton during differential growth in higher plant cells.
3) Plant Interactions: We document the earliest intracellular responses of plant cells to diverse environmental stimuli.
My research focuses on three main areas of plant cell biology:
1) Characterization of enzymes involved in seed oil biosynthesis.
2) Understanding various aspects of the biogenesis of peroxisomes, including how membrane proteins are targeted to this organelle, and what role the endoplasmic reticulum (ER) serves in the formation of peroxisomes.
3) Identification and characterization of a unique class of integral membrane proteins known as "Tail-Anchored" (TA) proteins.
We study the evolution of plant function and its mechanistic links to the ecological functioning of populations, communities and ecosystems. We study how and why plant functional traits evolve, and how these traits influence the outcome of ecological interactions that are known to shape community assembly, such as competition and mutualism. To do this work, we use several approaches, including comparative analyses among populations and species, observations of natural selection in the wild, and experimental studies that manipulate the identity of selective agents experienced by populations. We explore how traits influence community assembly and ecosystem function by carrying out experimental studies in controlled environments and in the field.Learn More
My primary research interest concerns the splendid array of compounds that are made by plants and the underlying molecular and biochemical basis of their synthesis. My lab focuses on natural products that are of medicinal, industrial or pharmacological relevance and on specialized metabolites that help plants cope with their dynamic environment. As an example, we investigate the biosynthesis, composition and structure of plant-derived polyisoprenoids. We also work closely with collaborators in various fields such as organic chemistry, food science, neurobiology, and ecology with the overall goal to shed light on the processes that operate at the interface of plant primary and secondary metabolism.Learn More
As they are literally rooted in place, plants possess remarkable mechanisms that perceive, interpret, and respond to internal and external cues so as to optimise plant growth and development relative to prevailing environment conditions. Despite the incredible diversity in plant forms, the molecular mechanisms that control plant responses to internal and external cues are highly conserved across diverse genera. The timing and localisation of these mechanisms shape plant and development. Our research team aims to gain greater insights into molecular mechanisms that plants employ to convert internal cues and external signals into appropriate adjustments in resource acquisition and allocation, focusing on the role of gene regulation in conditioning these adjustments.Learn More
One of the fundamental questions in plant biology concerns the nature of the signals that bring about the transition from vegetative to reproductive growth. My research is aimed at characterizing the developmental signals that cause plants to flower. The primary focus of this work is the maize indeterminate gene (id1). Maize plants that lack id1 function flower extremely late, or not at all, and they exhibit abnormal flower development. The ID1 protein contains zinc-finger motifs, suggesting that it regulates the expression of other genes. Expression analysis reveals that id1 mRNA is expressed only in leaf tissue, suggesting that ID1 acts by controlling the production of leaf-derived signals that mediate the transition to flowering.Learn More
Much of our current effort is focused on understanding the regulation of starch synthesis in storage tissues such as the developing seeds of cereals. Starch is the major determinant of yield in such crops, and has wide application in both the food and non-food industries, yet there remain a huge number of unknowns in what limits the production and structure of this important glucan polymer. There is also an increasing realization that different types of starch provide benefits for human health. Our research covers cereals such as maize, barley, rice, and wheat, as well as the model organism Arabidopsis thaliana. I lead a large, interdisciplinary team whose expertise includes plant biochemistry, genetics, molecular biology, microbiology, human physiology, and nutrition.Learn More
My lab examines the control mechanisms underpinning starch biosynthesis in leaf chloroplasts (which make starch during the daytime, and degrade it at night) of the model plant Arabidopsis thaliana, and non-photosynthetic amyloplasts of cereal endosperms such as maize, wheat, barley and rice which make storage starches. More specifically, we are interested in the biochemical control mechanisms governing the many enzymes and enzyme classes which make up the core pathway of starch biosynthesis. This involves investigating the role of protein-protein interactions and protein phosphorylation in coordinating the proteins involved in starch synthesis and degradation within the plastid to produce the highly ordered and complex structure of the starch granule.Learn More
Dr. Heyland's laboratory uses novel functional genomics approaches to study the endocrine and neuroendocrine systems of aquatic invertebrates. Specifically he investigates the function and evolution of hormonal and neurotransmitter signaling systems in the regulation of development and metamorphosis. His research includes evolutionary development studies of marine invertebrate metamorphosis, eco-toxicogenomic approached to understand endocrine disruption in aquatic ecosystems and water remediation technologies. These projects are integrated with several national and international collaborations ranging form basic scientific work to industry partnerships.Learn More
My research program investigates the ecological and evolutionary processes operating in plant populations, both wild and domesticated. Much of our work is conducted through the lens of plant reproductive systems, which control the quantity and quality of sperm and eggs, patterns of mating, and ultimately the transmission of genetic variation from one generation to the next. Current research projects include: 1) mating system variation and evolution, 2) polyploid speciation, 3) genetic and phenotypic consequences of whole genome duplication; 4) biology of small populations, and 5) impacts of hybridization between introduced species and endangered congeners. We work on a variety of study systems, including Arabidopsis, apple, strawberry, fireweed, American chestnut, and mulberry.Learn More
The main goal of our research program is to understand how the intrinsically disordered late embryogenesis abundant (LEA) proteins are able to protect plants from damage caused by cold, drought and high salinity. Our main focus has been on dehydrins, a group of abiotic stress response proteins that have been shown to protect plants from damage caused by drought and cold. Dehydrins are interesting in that they are composed of a variable number of conserved motifs that appear to have roles in protection of proteins, membranes and DNA from abiotic damage, as well as roles in localization.Learn More