Current Research Projects
Current Projects include
Isolation of differentially expressed genes/proteins during development of the clubroot disease
Characterization of protein functions from the clubroot pathogen Plasmodiophora brassicae
Signaling between plants and pathogens or endophytes
Biocontrol of clubroot
Plant hormones and secondary plant metabolites during the development of pathogenic and symbiotic interactions
Biosynthesis and metabolism of plant hormones and their role during plant development and abiotic stress responses
Secondary metabolites from endophytic fungi
Plasmodiophora brassicae
Pathogenesis
After infection the host root produces tumorous swellings (clubs) which leads to huge losses in agricultural fields. The clubroot symptoms clearly give evidence that plant growth promoting hormones are involved in disease development. We investigate the role of these hormones during pathogenesis, but also with respect to hormone modifying enzymes from the protist. The isolation of genes which play a role during pathogenesis or which may be important for the tolerance of the plants or virulence of the pathogen are also of central importance. Using the Plasmodiophora brassicae genome sequence we look for genes that encode for proteins important for colonization of the host plant including enzymes that are interfering with the plant defense signals.
Disease control
Controlling the disease is a major research focus worldwide. To this end, we have begun to study the interaction between host plants, Plasmodiophora brassicae and other beneficial organisms (endophytes). Here we focus on the fungus Acremonium alternatum and the molecular causes for its effect on disease progression.
Journal titles on the topic
Current research projects
Control of the clubroot disease using biocontrol agents
Acremonium alternatum
Susann Auer
The clubroot disease caused by Plasmodiophora brassicae infects economically important crop species such as canola and causes high yield losses. The disease is difficult to control by chemical and cultural means. In a previous study from our laboratory Acremonium alternatum, a soilborne endopyhtic fungus and known biological control agent in other countries, showed a promising antagonistic effect in clubroot infected plants. The means by which Acremonium controls pathogens is not known so far. Presumably the fungus induces resistance mechanisms in the host plant and thus delays the development of the pathogen. We want to test this theory in the model plant Arabidopsis thaliana as well as the economically important crop species canola (Brassica napus) and Chinese cabbage (B. rapa). To monitor the development of the infection within plants we will use molecular methods as well as phytopathological techniques. The following questions will be addressed: (A) How does Acremonium induce tolerance / resistance in Arabidopsis? (B) In which plant parts can the endophyte be found at different time points after inoculation? (C) Where does the interaction between Acremonium and P. brassicae take place? (D) Which plant signals are involved? The long-term goal is to develop an inoculum from Acremonium spores or spore parts which can be applied easily and constitutes an environmentally friendly and lasting method for the reduction of clubroot infections.
collaboration partners: Feldsaaten Freudenberger, Phytosolution
Funded by AiF
Plant hormones
Plant hormones are important substances for growth and development of plants. We are mainly interested in the role of auxins for plant developmental processes and during abiotic stress situations. Auxins are a class of plant hormones that control in low amounts a plethora of developmental processes, but inhibit plant growth at higher concentrations. Therefore, the regulation of hormone concentration is crucial for proper development of plants. Besides biosynthesis and degradation the formation of auxin conjugates is one of the key regulatory pathways for the activation/inactivation of IAA. Auxin conjugates also play a role during stress responses. We are investigating the role of the auxin homeostasis in different plant species under abiotic stress situations. Heat stress is among the factors analyzed. Also we determine the role of hormones and abiotic stress factors for the adaptation of plants in different microclimate conditions.
Current research projects
Abiotic stress alters microclimate by changing vegetation traits
Willy Petzold
The preservation of biodiversity and endangered habitats is a global priority. A key limitation for this task is the difficulty to identify in advance which goals are currently attainable in a given target area, and what will be the sustainability of our achievements over time in the face of climate change. The assessment of the microclimatic niche of a target vegetation type is a key step, because the microclimate is the actual conditions experienced by the plants (unlike the weather). A major gap in our understanding of microclimate formation is the range to which microclimate is shaped by the vegetation, especially under stressful conditions. Our specific goals are: (1) detecting shifts in traits of dominant species and in the characteristics of the plant community along microclimatic gradients, and in turn, how these shifts alter the microclimate, (2) assessing the thresholds for a change in plant’s resource allocation in response to drought and heat stress in order to anticipate how plant reaction to stress will influence microclimate and species composition in the community, (3) quantifying vegetation’s microclimate modification capacity of a plant community, specifically under drought and heat stress, in field setting and on a broad spatial scale to develop a novel approach for the assessment of community vulnerability to climate change and (4) conduct a synthesis on whether the capacity to mitigate stress is the same as the capacity to alter the microclimate. To achieve these goals we will perform substantial amount of fieldwork in the form of vegetation surveys, manipulation experiments, and physiological measurements of growth and stress parameters while at the same time operating a dense network of sensors to monitor the microclimate in the study plots. Additional climatic and microclimatic variables beyond those measured in the field will be derived through regional datasets, remote sensing and modelling. Collaborative project with Dr. Daniel Gliksman and Prof. Dr. Christian Bernhofer (TU Dresden, Meteorology) and Dr. Sabine Hänel (Hochschule für Technik und Wirtschaft Dresden, HTW).
Funded by the DFG
Bioactive Substances
Plants are not only sources for nutrition, but also supply plenty of compounds of importance for medicinal and pharmaceutical uses. In the continued efforts to identify new substances with useful biological properties plants remain a major source. In addition, we are analyzing the biosynthesis of bioactive cyclic peptides called astins in an endophytic fungus together with the host plant and we use -omics methods to identify further secondary metabolites from the endophytic fungus with bioactive potential.
Current research projects
Novel bioactive compounds from Cyanodermella asteris, an endophytic fungus with high biotechnological potential
Linda Jahn
The fungus Cyanodermella asteris has been isolated recently from dried roots of the plant Aster tataricus, successfully used in traditional Chinese medicine, and described as a new species. The genome has been sequenced and will be used to mine for putative biosynthesis clusters encoding novel secondary metabolites. This biosynthetic potential will be elucidated together with Prof. Dr. Tobias Gulder (Technische Biochemie, TU Dresden) by bioinformatic, biochemical, analytical and molecular methods.
Funded by:
Effect of high temperature on gene expression, phytochemical profile and in vitro bioactivity of seedlings: Case study of broccoli (Brassica oleracea botrytis var. cymosa)
Plants challenged with high temperature undergo many adaptive mechanisms at molecular levels to keep normal physiology function. They can adapt to different temperatures by changing their transcriptome, proteome and metabolome, or even by activating cell death mechanisms. Such adaptability is due to their intensive shifts in biochemical pathways, which, as a consequence, can significantly change their bioactivity as well. In this project our goal is to identify genes and metabolites of brocolli seedlings that have been altered by high temperature, to quantify the intensity of their changes, and to define possible correlations between those parameters and seedlings bioactivity. The chain interactions between temperature shift and plant genes expression and biochemical properties will be assessed employing qRT-PCR analysis, targeted specific metabolomics approach, and statistical data analyses in order to show a tentative pattern of environment temperature effect on plant physiology.
Collaboration with Dr. Ivana Sola (University of Zagreb)
funded by: Deutscher Akademischer Austauschdienst
