The evolution of annual and perennial life strategies
The distinction between annual and perennial plants is underlined by several traits that were modified during evolution to give rise to the annual or perennial forms. To get a better understanding of the molecular mechanisms contributing to life strategy evolution in plants our group studies the control of developmental traits that differ between annuals and perennials.
Our research group studies the cellular reaction of algal cells to the environment. Major research topic is the regulation of water homeostasis in various systems. Using classical cell biological (video microscopy, fluorescence microscopy, protein biochemistry) and forward and reverse genetic approaches we are investigating the role of the contractile vacuole in osmoregulation in Chlamydomonas. Furthermore, using omics approaches we investigate desiccation tolerance but also the effect of light and temperature stress in lab experiments and natural alpine and polar habitats
Cell Wall Integrity and Growth Control in Pollen Tubes
Growing plant cells direct the deposition of the primary cell wall (CW), a rigid extracellular matrix that yet is flexible enough to allow expansion. To achieve such a remarkable dynamic balance between flexibility and rigidity, the growing cell must be kept informed about any environmental changes modifying its CW properties so as to avoid growth arrest or rupture. Our main interest is to elucidate how this relatively unexplored, complex and fascinating coordination occurs. Our goal is to unravel how the redundant receptor-like kinases ANXUR1 (ANX1) and ANX2 coordinate CW performance and PT growth (see Boisson-Dernier et al., 2009, 2011, 2013).
Mechanisms of Mineral Nutrient Acquisition in Plants
The Bucher Lab studies the molecular basis of symbiotic plant-microbe interactions. Most of our work focuses on the arbuscular mycorrhizal symbiosis (AMS) which is based on an intimate interaction between most vascular plants and soil fungi from the phylum Glomeromycota.
Adaptive molecular variation in plant systems
Our research seeks to reconstruct the recent history of adaptive molecular variation in plant systems. In other terms, we aim at dissecting the molecular mechanisms of Darwinian evolution in complex natural systems. We work with the weedy annual and model plant species Arabidopsis thaliana and its close relatives A. lyrata and A. halleri. Our work focuses on understanding links between life history strategies and fitness. We further intend to develop new methods to track the action of natural selection at the molecular level.
Molecular mechanisms of microbe - plant interactions
Our research aims to identify and understand molecular mechanisms of microbe-plant interactions. Focus is on effector proteins of biotrophic microbes, which suppress host immunity and plant metabolism.
Within CEPLAS, we are interested to i) study the role of plant cysteine proteases in immunity and how they are modulated by microbial effectors and ii)elucidate how organ-specific factors of both plant and colonizing microbe contribute to interaction outcomes.
Transcriptional control of Glucosinolate metabolism
Transcriptional control involves the formation of complexes between a discrete number of transcription factors (TFs) and regulatory proteins and their subsequent interactions with gene regulatory DNA regions to convey signals to RNA Polymerase-II. Our group aims to understand how the information encoded by DNA is transformed into specific cellular responses and to study the mechanisms that underlie the formation of TF complexes in response to specific intra- or extracellular signals. We are particularly interested to address how the activity of proteins belonging to the MYB–bHLH regulatory complexes in Arabidopsis and related organisms is modulated in response to metabolic products and signalling molecules of this pathway. To understand the metabolite signalling in plants we use the example of particular class of plant secondary metabolites known as glucosinolates (GSLs). While studying the assembly and disassembly of regulatory complexes in response to specific signals, we will reveal mechanisms that explain the ability of TFs to activate specific cellular responses by regulating a selected set of genes.
Protein Degradation in Light-controlled Plant Development
We are studying the role of protein degradation in light-controlled plant development. To unravel this process, we are using the model species Arabidopsis thaliana and a combination of genetic, molecular and biochemical methods.
Cryptophytes are microscopic flagellated algae containing four genomes of different evolutionary origin in their cells. My research focuses on the molecular phylogeny, systematics, classification and DNA taxonomy of the cryptophytes and on the evolutionary history of their phenotypic and molecular characters. In my work I combine classical (differential interference contrast light microscopy, spectrophotometry, transmission electron microscopy) with molecular methods.
Molecular Cell Biology and Developmental Genetics
We use Arabidopsis trichomes as a model system to study cell-cell communication, cell differentiation and morphogenesis. Genetic screens have revealed a large number of mutants affecting distinct steps of trichome development enabling a further molecular and cell biological analysis. The beauty of this system is that virtually all trichome genes turned out to be relevant for other cell types as well because they are involved in various general mechanisms of plant development
Plant mineral nutrition
The long term goal of our research is to understand how plants integrate the uptake and utilization of key mineral nutrients with their needs, demand, and changes in environment. We use a combination of biochemical, genetic and physiological approaches and exploit natural variation in the model species Arabidopsis thaliana. We defined the transcriptional mechanisms controlling sulfate uptake and assimilation and showed how this is linked to uptake of other nutrients such as nitrate (reviewed in Takahashi et al., 2011).
Compartmentation of Plant Metabolism
Similar to other higher organisms’ plants consist of different organs comprising different cell types. The metabolic requirements of a particular cell depend on its function and therefore, the metabolic environment of these cells differs. Although knowledge about the function and regulation of metabolic pathways rises, the cell-specific adaptation of metabolism is still a neglected field in plant research. Our current research focusses on serine biosynthesis in plants. Serine can be synthesised by two pathways in plants: the photorespiratory pathway in autotrophic cells and the phosphorylated serine biosynthesis (PS) pathway in heterotrophic cells (Benstein et al., 2013; Ros et al., 2014). Our main interest is to understand how the function of both pathways is coordinated and to what extend both pathways are interacting.
Immunity and cell-death
Over the past decades, growing evidence has highlighted remarkable similarities between the innate immune systems of the plant and animal kingdoms. These ‘shared’ innate immune systems include intracellular receptors as exemplified by nucleotide-binding leucine-rich repeat proteins (NLRs). Our group aims to unravel the underlying mechanistic parallels between plant and animal immune components using plants as a model. Our research programme encompasses a diverse array of experimental systems including genetics, genomics and cellular and structural biology with an emphasis on immunity and cell death.
Our research focuses on the molecular mechanisms underlying the interaction of pathogenic microbes with their plant hosts. We particularly focus on understanding how molecules (so-called AVRa effectors) from the powdery fungus facilitate successful infection of the barley host and the development of fungal diseases on cereals. Our research aims to contribute to the control fungal phytopathogens on economically important crops.
Our research group is interested in plant adaptation and evolution. We use the domestication of crops as model to study how plants respond to changing environments. Our models are, the incomplete domestication of the South American pseudo-cereal amaranth, and the domestication and cultivation history of maize. We use population and quantitative genetic methods to understand how wild plants became crops and how these crops spread across the globe.
Evolutionary microbiology: fungal plant pathogens
Our research aims to identify mechanisms that underly pathogenicity of fungi on plant hosts. To this end, we study the soil-borne broad host-range vascular wilt fungus Verticillium dahliae and try to understand molecular processes that mediate adaptation to plant hosts by studying the evolution of “effector activities” that are exerted by fungal secreted molecules to mediate host colonization. The functional analysis of the most relevant effector proteins leads to the discovery of crucial processes that are targeted by the fungus to subvert host immunity and support host colonization. One of the most recent discoveries concerns the identification of Verticillium dahliae effector proteins secreted during host colonization that manipulate the host microbiome to particularly repress microbial antagonists.
Functional genomics and molecular biology of symbiotic fungi
Research in our group focus on the mechanisms that enable symbiotic fungi to colonize plants successfully and on the processes accounting for variations in host preferences and fungal lifestyles. The prime models for our studies are the root endophyte Piriformospora indica (Basidiomycota, Sebacinales), and the orchid mycorrhizal Sebacina vermifera, two biotrophic symbiont that colonizes the root epidermal and cortex cells of a broad range of plant species, including the dicot model plant Arabidopsis thaliana and the agriculturally important monocot Hordeum vulgare.