Plenary Lecture – Open to Public

July 4, 8:00-9:00 p.m., N1001

Evolution by Association: Symbiosis in a neo-Darwinian World

Dr. Jan Sapp, Department of Biology, York University

A profound change in our conception of life is emergent today. Organisms are increasingly understood to be symbiotic complexes – tightly intertwined communities of microbes functioning together with their hosts as a collective unit or “symbiome”.  In this presentation we shall see that such a symbiotic conception of life is not new, however. It first emerged from botanical studies 140 years ago, but developed close to the margins of biology in virtual conflict with some of biology’s central doctrines- the neoDarwinian view of life as “red in tooth and claw” and of microbes as disease-causing “germs”.  In this context we will explore why it is that biologists have only recently begun to understand the importance of symbiosis in evolution.

Keynote Speaker Biography: Dr. Sapp completed his PhD in the history of science at l’Université de Montréal and held an Andrew Mellon Fellowship in the laboratory of Nobel laureate Joshua Lederberg at the Rockefeller University before moving to York University in Toronto where he is currently Professor of Biology and History in the Department of Biology. He held the Canada Research Chair in the History of the Biological Sciences at l’Université du Québec à Montréal (2001-03) and he was Visiting Scholar in the Department of History of Science at Harvard University (2012). He is also a Research Associate, and Fellowship award recipient of the Smithsonian Tropical Research Institute, Panama.  His research and writings focus on the history of genetics, molecular biology, research and theory regarding microbial evolution, symbiosis and horizontal gene transfer as modes of evolutionary innovation, as well as tropical ecology, and biodiversity.

 

General Symposium: The Hidden World of Plants

July 5, 8:00 a.m. – 12:30 p.m., N1001

Plants: they whisper, talk, and even move

Roger Hangarter, Distinguished Professor and Chancellor’s Professor of Biology, Indiana University, Bloomington, IN

As a group, plants are among the slowest forms of life. With their barely perceptible movements plants often go unnoticed by humans or are routinely treated as little more than ornamental objects. This presentation will use time-lapse imaging to demonstrate the remarkable dynamics of plant life. We will see how keenly sensitive plants are of their environment throughout their life as they navigate the space around them, respond to various stimuli they encounter, and communicate with other organisms. The sense of intrigue and mystery revealed by time-lapse imaging enhances our own awareness of plant life and provides insight into our relationship to plants and our environment.

Biography: Hangarter received his Ph.D. in Plant Physiology from Michigan State University and is currently a Distinguished Professor and Chancellor’s Professor of Biology at Indiana University. He served on several journal Editorial Boards and grant programs for the NSF, USDA and DOE and was President of the American Society of Plant Biologists (ASPB). He is a Fellow of the American Association for the Advancement of Sciences (AAAS) and the ASPB. His awards include Teaching Awards from the ASPB and the Botanical Society of America. He also received the 2005 Science & Engineering Visualization Award from the NSF and AAAS, and an Emmy Award. His photography and time-lapse movies have been exhibited in numerous museums and galleries. He developed sLowlife and Plant Dance, traveling exhibits to bring a greater awareness of plants to public audiences and developed the Plants-In-Motion website.

 

Darwin’s “abominable mystery” and the search for the first flowering plants

William (Ned) Friedman, Department of Organismic and Evolutionary Biology and The Arnold Arboretum, Harvard University, Boston, MA

Charles Darwin’s “abominable mystery” has come to symbolize just about every question concerning the origin and early evolution of flowering plants.  What did Darwin think was so abominably mysterious?  This mystery will be explored through Darwin’s correspondence with some of the most eminent evolutionists of his time who were also trying to understand where flowering plants came from and how they eventually came to dominate most of Earth’s plant communities.  Debates about the early evolution of angiosperms, in Darwin’s and his correspondents’ hands touched on everything from the completeness of the fossil record to the pace of evolutionary innovation (gradualism or punctualism).  As will be seen, recent botanical discoveries associated with reproductive processes among the most ancient extant flowering plant lineages (Amborella, Nymphaeales, Austrobaileyales) are radically different from the static, if not dogmatic, views that dominated the twentieth century – and a far cry from anything that Darwin and successive generations of evolutionary biologists might have imagined.

Biography: William (Ned) Friedman is the Arnold Professor of Organismic and Evolutionary Biology at Harvard University and the eighth Director of the Arnold Arboretum of Harvard University (in its 144-year history). Friedman’s studies have fundamentally altered century-old views of the earliest phases of the evolution of flowering plants, Darwin’s so-called “abominable mystery.” He is also deeply interested in the history of early (pre-Darwinian) evolutionary thought. He currently teaches a freshman seminar at Harvard called “Getting to Know Darwin,” in which students re-create ten of Charles Darwin’s experiments and read correspondence associated with each topic (yes, the students do visit a pigeon fancier and discover whether earthworms respond to the bassoon). As Director of the Arnold Arboretum, Friedman has worked to expand the Arboretum’s societal impact through diverse initiatives in public programming, enhanced communication between scientists and the public, the embedding of scientific scholarship in the recently opened Weld Hill Research Building, and a reinvigoration of the long-standing relationship between the Arboretum and the biodiversity of Asia.

 

Divergence patterns in the Neotropics: evidence from the palm family (Arecaceae)

Julissa Roncal, Department of Biology, Memorial University of Newfoundland, St. John’s NL

The high species diversity of the Neotropics has attracted evolutionary biologists for centuries. Understanding the patterns and processes underlying the evolution of the high plant species richness requires multiple lines of evidence spatially, temporally and taxonomically. Here I present two case studies in the Arecaceae, a family considered to be a model to study tropical rain forest evolution. A dated molecular phylogenetic tree of the genus Astrocaryum (40 spp.), combined with an ancestral range evolution analysis, supported the constraining role of the aquatic Pebas system on colonization and in situ diversification in western Amazonia, and the role of the Guiana Shield as a source area from which species colonized adjacent regions in South America. Using a phylogeographic and ecological niche modelling approach we analyzed in more detail the evolution of a Western Amazonian clade (15 spp.) and found a phylogeographic break at ca. 5°S between two main clades growing in regions of contrasting geological and climatic characteristics. These results exemplify how geology and climate can shape divergence of Neotropical plants, but the underlying anatomical or morphological adaptations remain unknown.  We use the Geonoma macrostachys species complex as a second case study to capture different stages of speciation with gene flow in Amazonia. Using 29 variable traits we identified morphological entities and explored differentiation amongst them, including genetic variation, soil preference, and pollination biology. We found mixed patterns of population structure, niche breadth, and reproductive isolation within and amongst morphotypes of G. macrostachys, all of which are scale dependent. We conclude that differentiation occurs across our indices at varying scales, representing the complexity of the speciation process.

Biography: Dr. Roncal obtained her PhD in Biology at Florida International University in the U.S.A. She then worked as a Plant Ecologist at Fairchild Tropical Botanic Garden in the U.S.A., and as a post-doc at Aarhus University in Denmark. Subsequently, Dr. Roncal obtained a Marie Curie Intraeuropean Fellowship award to conduct research at the Institut de Recherche pour le Developpement in France. She joined MUN in May of 2013 where she teaches Botany, Systematics and Biogeography, and Evolutionary Genetics. She is also the curator of the Ayre Herbarium, the largest plant collection in Newfoundland. Dr. Roncal is an evolutionary biologist whose research focuses on understanding the patterns and processes underlying the evolution of the high plant species richness in tropical America.

 

The twisted world of arbuscular mycorrhizal fungi

Franck Stefani, Agiculture and Agri-Food Canada, Ottawa, ON

Arbuscular mycorrhiza fungi (AMF) are an ancient lineage of soil microorganisms belonging to the fungal kingdom and living in a mutualistic relation with most of the vascular plants. Mutualism based on AMF is so widespread that the benefits they provide expand far beyond the host plant and account at the ecosystem scale. The role of AMF at the ecosystem scale is still underestimated but their increasing use as biofertilizer raises the awareness of their ecological roles. Since the first description of AMF more than 200 ago, our view on their diversity, taxonomy, genetics and ecological functions has undergone significant changes. The aim of this presentation is to tell the audience the past, present and future research about AMF. We will emphasize how the work of several generations of researchers that started on sporocarpic species of AMF is going to play a significant role in the development of a sustainable agriculture.

Biography: After graduating with a master degree in Environmental sciences from University of Corsica in 2004, Dr. Stefani obtained his PhD from the Department of Forestry at Université Laval (Quebec, Canada) in 2010. As a first postdoctoral experience, he worked at the National Herbarium of Victoria (Melbourne, Australia) where he studied the molecular systematics of Australasian Cortinarius, one of the most diverse group of mushrooms in Australia. In 2012 he joined the laboratory of Prof. Mohamed Hijri in Montreal for developing molecular tests to detect and quantify arbuscular mycorrhizal fungi in soil samples and commercial biofertilizers. He also investigated the impact of oil-polluted sites on soil fungal and bacterial communities using metagenomic approaches. In January 2015, he joined the laboratory of Dr. Armand Séguin at the Canadian Forestry Service (NRCan) in Quebec City for working on soil microbiome and its interactions with poplars in the context of oil-sands reclamation. Since July 2016, Dr. Stefani has joined Ottawa – Research and Development Centre as a researcher in mycology. He is acting as the curator of the in vivo and in vitro collections of arbuscular mycorrhizal fungi and his research directions focus on AMF phenology, ecology and AMF molecular systematics and taxonomy.

 

The mysteries of edge populations: the quintessential Canadian conservation question

Anna Hargreaves, Department of Biology, McGill University, Montreal, QC

Up to 90% of Canadian plant species listed as ‘at risk’ have only the northern edge of their distribution in Canada.  A century of theoretical interest in species distributions yields conflicting predictions about the true conservation importance of such edge populations.  On one hand they are predicted to be small, isolated, unproductive, and of negligible importance to species overall survival.  On the other, they are geographically poised to initiate range shifts under climate change, and may possess adaptations to edge environments that would facilitate such shifts. My research explores the conservation importance of edge populations now and in a warming world, through theory and experiment.  Here I present some of our most recent findings, including evidence that edge populations can be simultaneously poor quality and locally adapted, that local adaptation gives edge individuals an advantage in habitat beyond the current range limit, but that edge populations can lose this ‘edge’ under climate warming.

Biography: Anna Hargreaves (PhD, Queen’s) studies the ecology and evolution of species distributions, with special emphasis on geographic patterns in species interactions, evolution at contracting range limits, and the conservation importance of edge populations.  She has won prestigious national and international awards for both research and communication, including the American Society of Naturalists’ Young Investigator Award, the Governor General’s Gold Medal, and the New Phytologist award for student botanical research.  She conducts science outreach via classroom visits, public lectures, popular science articles, and media interviews.

 

 

Weresub Public Lecture

July 5, 8:00-9:00 p.m., N1001

Some fungi we thought we knew

Greg Thorn, Department of Biology, University of Western Ontario, London, ON

Mushrooms – the macroscopic fruiting bodies of certain fungi – abound in myriad forms and colours. Some of these are well known as wild-harvested edibles, having been first described in Europe in the 18th or 19th centuries and then reported from multiple habitats around the world. But how ubiquitous and well known are they? The honey mushroom, Armillaria mellea, was perhaps the first such widespread and ecologically ubiquitous mushroom to have been studied by a combination of microscopy, mating studies, and eventually molecular phylogeny. Canadian mycologists James B. Anderson and Jean Bérubé featured prominently in dissecting Armillaria to eventually reveal ten species in North America, each with distinctive ecology and distribution. Despite this early lesson, field guides to North American mushrooms remain filled the names of species first described in Europe. Iconic and delicious edible mushrooms such as Boletus edulis, Cantharellus cibarius, Lactarius deliciosus, and Auricularia auricula are all restricted to Eurasia, whereas their North American counterparts deserve separate – and sometimes multiple – species names. This work is ongoing, and gradually improving our knowledge of the North American mycota.

Biography: Dr. Thorn grew up in London and was fortunate to have been introduced to nature through the family garden, long summer vacations across Canada and the northern U.S., and membership in the junior McIlwraith Field Naturalists. In his late teens and early twenties, he spent six summers working in Algonquin Provincial Park as a summer naturalist, leading Algonquin campers and visitors on wildflower hikes, tree hikes, bird hikes, backpacking hikes and even canoe hikes, until one day someone said, “What about mushroom hikes?”  He was mentored by numerous Canadian and international mycologists, to whom he will forever owe a debt of gratitude. Years later, he worked for George Barron of the University of Guelph as a mushroom photographer, did his master’s degree with him; he then enrolled in a PhD with David Malloch at the University of Toronto. He went on to a career as a fungal biologist, culminating with a position in the Department of Biology, back in London at Western University. His research is on the systematics and ecology of fungi, whether nematode-destroying, mycorrhizal, or decomposers, and he still has a love of field biology.

 

 

Ecology Section Symposium (July 6th, 8:30 a.m. – 12:00 p.m., N1001)

Exploring functional space along gradients of species richness

Bill Shipley and Yuanzhi Li, Départment de Biologie, Université de Sherbrooke, Sherbrooke, QC

If we measure n functional traits then this defines an n-dimensional “functional space”.  The values of these traits for a given individual defines its position in this space.  A “functional niche” is the volume of this functional space occupied by the individuals of a given species.  As we look at plant communities containing more and more species, how do these coexisting species occupy this functional space?  Do new species tend to occupy previously unoccupied or previously occupied areas?  Do species in species-rich communities tend to be more functionally specialized (smaller functional niches)?  We explore these questions using two different and complimentary data sets:  First, we combine data sets around the world from boreal to tropical communities.  Second, we present data from an experimental study involving orthogonal gradients of soil fertility and disturbance rates.

 

Modeling convergence and divergence of traits in plant communities

Lauchlan Fraser, Biological Sciences, Thompson Rivers University, Kamloops, BC

Plant traits affect the success or failure of plants to establish, grow and reproduce.  Assembly rules suggest that abiotic filters will restrict the range of viable strategies, thus creating a community of plants that share a similar suite of traits.  In contrast, limiting similarity predicts that segregation of species’ resource use will lead to character displacement.  What is the relative strength of these two processes and do they differ depending on site condition?  Here, we investigate the interaction of these two ecological factors and how they affect plant-trait similarity.  We find support for the hypothesis that trait convergence occurs at low productivity/high disturbance and high productivity/low disturbance, and trait dispersion is most likely at intermediate levels of disturbance and productivity. The relationships among evolution, plant traits, and ecology are multivariate, hierarchical and complex making plant traits at the ecosystem level an exciting and challenging agenda for the future.

 

Developing a framework for Canadian bryophyte and lichen response and effect traits

Nicole J. Fenton1, and André Arsenault2 , 1Forest Research Institute, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, QC; 1Forest Ecologist, Canadian Forest Service, Adjunct Professor of Environmental Science, School of Science and the Environment, Grenfell Campus, Memorial University of Newfoundland

Bryophytes and lichens share a variety of characteristics, such as their poikilohydric nature, small reproductive propagules, and taxa often associated with specific habitat and microenvironment conditions, and have historically been grouped together as “cryptogams”.  While cryptogams are sensitive to different types of disturbance and are therefore frequently used as a “response” group, they also influence ecosystem functions in temperate, boreal and arctic systems where they represent significant proportions of biomass.  Cryptogams  contain a significant amount of intraspecific and interspecific variation with different life forms, reproductive structures, chemistry, and  hydration mechanisms, lending themselves well to the study of  functional traits and how they influence ecosystem processes. Furthermore bryophyte and lichens are among the least documented groups in terms of distribution and ecology in Canada. Considering the importance of cryptogams in Canadian ecosystems, we propose here a project to develop response (to habitat/disturbance) and effect (on ecosystems) functional traits for these colonial, morphologically diverse groups in Canada. Internationally there has been some work on the “moss” or “lichen” effect on ecosystem functions, and preliminary frameworks have been proposed for both response and effect traits for bryophytes and lichens, we will build on this baseline, and in conjunction with the TOPIC database, will propose a framework for future work in Canada.

 

The TOPIC network: collaborative science to make trait data available to Canadian scientists

Laura Boisvert-Marsh1, Isabelle Aubin1, Françoise Cardou2, Alison Munson3, 1Great Lakes Forestry Centre, Canadian Forest Service, Natural Resources Canada, Sault Ste Marie, ON, 2Département de Biologie, Université de Sherbrooke, Sherbrooke, QC, 3Centre d’étude de la forêt, Département des sciences du bois et de la forêt, Université Laval, QC

An important challenge in trait based ecology is the integration of large quantities of ecological knowledge from various sources into a structured, common format that facilitates analysis. The objective of this presentation is to present the collaborative science approach used by the TOPIC (Traits of Plants in Canada) network to meet logistical and data needs of trait-based ecology. TOPIC is a network of scientists from academia and government as well as practitioners that stimulates, promotes and facilitates research in plant ecology and community ecology. The network is principally centred on a structured eco-informatic platform that stimulates the documentation and storage of data on traits on Canadian species, as well as facilitates data sharing among scientists. The network also fosters the application of the trait approach by encouraging the creation of working groups focused on specific ecological issues for which knowledge gaps exist. TOPIC has also increased the availability of trait data in Canada by organizing collaborative trait gathering campaigns targeted at specific data needs to adequately address knowledge gaps at the appropriate scale. Such grassroot networks can serve as a critical link between individual labs and global scale consortia (e.g. TRY) by facilitating groups of researchers with closer geographical ties all while pushing disciplinary boundaries and embracing new data management approaches.

 

Plant Development Section Symposium (July 7th, 8:30 a.m. – 12:00 p.m., N1001)

Function and mechanism of light-dependent chloroplast movements in leaf cells

Roger Hangarter, Department of Biology, Indiana University, Bloomington, IN

Light-dependent chloroplast movements function to optimize light absorption in photosynthetic cells. Under high light intensity leaf cells locate chloroplasts along their sides and in low light the chloroplasts are relocated to the upper and lower sides of cells. This repositioning of chloroplasts is stimulated by the plasma membrane-associated phototropin photoreceptors and appear to be driven by actin re-organization at the plasma membrane. I will discuss how chloroplast movements dynamically affect the optical properties of leaves to fine-tune photosynthesis. In addition, results will be presented showing that the plasma membrane-associated protein, Thrumin1, is required for normal chloroplast movement and functions in reorganization of the cortical actin cytoskeleton during light-dependent chloroplast movements.

 

Dynamic inter-organelle co-operation and networking in plant cells

Jaideep Mathur, Laboratory of Plant Development & Interactions, Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON

While animals tend to move away as they perceive changes in their surroundings plants readily start adjusting to the environmental alterations. The subtle, subcellular adjustments made in plant cells eventually account for their long-term survival as well as successful colonization of seemingly harsh habitats. My lab uses fluorescent protein aided live-imaging to understand the rapid but often transient subcellular responses that occur in plant cells. Our recent work has focused on the behavior of chloroplasts, mitochondria, peroxisomes and the ER. The resultant picture of the co-operation amongst biochemically and functionally unique compartments, that is involved in maintaining cellular homeostasis in living plant cells will be presented.

 

Myosin-driven organelle movements in tip-growing cells

Andreas Nebenfuehr, College of Arts and Sciences, University of Tennessee, Knoxville, TN

Cytoplasmic streaming is a prominent feature that is easily observable in most plant cells. These rapid movements of organelles within the cytoplasm are driven by myosin XI motors that move actively along actin filaments. Reverse genetic approaches in the model species Arabidopsis thaliana have established that myosin motors are required for normal cell expansion. This connection between intracellular movements and cell growth is most evident in root hairs and pollen tubes that require targeted delivery of secretory vesicles to their tip where all growth takes place. For example, we have found reduced organelle motility in myosin mutants that also showed reduced root hair tip growth. Curiously, accumulation of putative secretory vesicles at the root hair tip in one of these mutants was not affected. We also found similar results in pollen tubes where a double mutant of highly similar myosin paralogs resulted in dramatically reduced organelle movements but normal vesicle accumulation at the tip. Interestingly, loss of myosin motors was accompanied by reduced dynamics of actin filaments and, in the case of the pollen double mutant, by a changes in the overall organization of the actin cytoskeleton. These double mutant pollen tubes also elongated significantly more slowly than wild-type pollen which resulted in reduced seed set compared to wild-type, demonstrating a role of myosin motors not only in cytoplasmic streaming and actin organization, but also in cell growth, and ultimately in fertilization.

 

Novel players in plant clathrin-mediated endocytosis

Giovanni Stefano, Luciana Renna, Clarissa Wormsbaecher, J. Gamble, Krzysztof Zienkiewicz, and Federica Brandizzi, MSU-DOE Plant Research Lab and Plant Biology Department, Michigan State University, East Lansing, MI

Eukaryotic cells, through the endocytic process, internalize an equivalent of one to five times per hour their cell surface. In order to support this massive mechanism the endocytic recycling pathway must be precisely and finely regulated to maintain a perfect homeostasis at the plasma membrane. To date it is still unknown, where and how exactly endocytic clathrin-mediated events starts at plasma membrane level. It is well known that clathrin-coated vesicles (CCV) are necessary to start the endocytic process. However, in plant cells little is known about all the molecular mechanisms and accessory proteins involved in this process. Here, I will present the role of two novel proteins in clathrin-mediated endocytosis and propose a new model that describes the establishment of specific areas of the PM where endocytosis events start.