Elisa Andresen

HTWG Konstanz - University of Applied Sciences | HTWG · Department of Mechanical Engineering

Carbon fiber-epoxy laminates are used in aerospace manufacturing, e.g. as substrates for solar cells of satellites. Commonly, fibers or fibermats are impregnated with epoxy resin and placed in the required orientation. During subsequent curing, the resin molecules are crosslinked. Cured parts are characterized by their glass transition temperature...

Low Zn availability in soils is a problem in many parts of the world, with tremendous consequences for food and feed production because Zn deficiency affects the yield and quality of plants. In this study we investigated the consequences of Zn-limitation in hydroponically cultivated soybean (Glycine max L.) plants. Parameters of photosynthesis biop...

Soybean (Glycine max (L.) Merr.) plants were exposed to various Cd concentrations from background and low non-toxic (0.5–50 nM) via sublethally toxic (< 550 nM) to highly, ultimately lethally toxic (3 µM) concentrations. Plants were cultivated hydroponically for 10 weeks until pod development stage of the control plants. The threshold and mechanism...

Red mud is a by-product of the production of alumina from bauxite ore. However, less than 2% of red mud produced is currently utilized. Red mud contains a number of residual scarce metals including rare earth elements, some at a considerable concentration, so synchronous cultures of the red microalga Galdieria sulphuraria were tested for their abil...

• METAL TOLERANCE PROTEIN8 (MTP8) of Arabidopsis thaliana is a member of the CATION DIFFUSION FACILITATOR (CDF) family of proteins that transports primarily manganese (Mn), but also iron (Fe). MTP8 mediates Mn allocation to specific cell types in the developing embryo, and Fe re-allocation as well as Mn tolerance during imbibition. We analysed if a...

Solving the global environmental and agricultural problem of chronic low-level Cd exposure requires better mechanistic understanding. Here, soybean (Glycine max) plants were exposed to Cd concentrations ranging from 0.5 nM (background concentration, control) to 3 µM. Plants were cultivated hydroponically under non-nodulating conditions for 10 weeks...

Techniques for metal speciation analysis with sub-nanomolar (ppt) detection limits in complex matrices, with simultaneous quantification of matrix elements, have become a necessity for investigating targets of trace metal binding to macromolecules and pigments at environmentally relevant concentrations. In this work we optimised the analysis of suc...

As many metals are essential for plants, excess or deficiency of them or alteration of their uptake, translocation, sequestration or physiological use can have severe consequences for plant growth and fitness. Therefore, investigating the distribution and speciation of metals in tissues is essential to understand plant physiology. We present a meth...

Chlorophyll fluorescence kinetic analysis has become an important tool in basic and applied research on plant physiology and agronomy. While early systems recorded the integrated kinetics of a selected spot or plant, later systems enabled imaging of at least the slower parts of the kinetics (20-ms time resolution). For faster events, such as the ri...

Many trace metals are essential micronutrients, but also potent toxins. Due to natural and anthropogenic causes, vastly different trace metal concentrations occur in various habitats, ranging from deficient to toxic levels. Therefore, one focus of plant research is on the response to trace metals in terms of uptake, transport, sequestration, specia...

Metal accumulation in seeds is a prerequisite for germination and establishment of plants but also for micronutrient delivery to humans. To investigate metal transport processes and their interactions in seeds, we focused on METAL TOLERANCE PROTEIN 8 (MTP8), a tonoplast transporter of the Mn subclade of cation diffusion facilitators, which in Arabi...

Arsenic (As) pollution is a serious concern worldwide. Recent studies under environmentally relevant conditions revealed that, in the aquatic plant Ceratophyllum demersum, pigments are the first observable target of toxicity, prior to any effect on photosynthetic parameters or to oxidative stress. Lethal toxicity was initiated by a change of As spe...

Essential trace elements (Cu2+, Zn2+, etc) lead to toxic effects above a certain threshold, which is a major environmental problem in many areas of the world. Here, environmentally relevant sub-micromolar concentrations of Cu2+ and simulations of natural light and temperature cycles were applied to the aquatic macrophyte Ceratophyllum demersum as a...

Cadmium (Cd) is an important environmental pollutant and is poisonous to most organisms. We aimed to unravel the mechanisms of Cd toxicity in the model water plant Ceratophyllum demersum exposed to low (nM) concentrations of Cd as are present in nature. Experiments were conducted under environmentally relevant conditions, including nature‐like ligh...

Metal toxicity in plants is still a global problem for the environment, agriculture and ultimately human health. This review initially addresses the current state of the environmental/agricultural problem, and then discusses in detail the occurrence, mechanisms and relevance of toxicity of selected trace metals. When discussing the mechanisms, spec...

Arsenic (As) pollution is a serious concern worldwide. Recent studies under environmentally relevant conditionsrevealed that, in the aquatic plant Ceratophyllum demersum, pigments are the first observable target of toxicity,prior to any effect on photosynthetic parameters or to oxidative stress. Lethal toxicity was initiated by a changeof As specie...

Even essential trace elements are phytotoxic over a certain threshold. In this study, we investigated whether heavy metal concentrations were responsible for the nearly complete lack of submerged macrophytes in an oligotrophic lake in Germany. We cultivated the rootless aquatic model plant Ceratophyllum demersum under environmentally relevant condi...

The heavy metal cadmium (Cd) is highly toxic to plants. To understand the mechanisms of tolerance and resistance to Cd, we treated the rootless, submerged macrophyte Ceratophyllum demersum L. with sub-micromolar concentrations of Cd under environmentally relevant conditions. X-ray fluorescence measurements revealed changing distribution patterns of...

Cadmium is an important pollutant in the environment, toxic to most organisms and a potential threat to human health: Crops and other plants take up Cd from the soil or water and may enrich it in their roots and shoots. In this review, we summarize natural and anthropogenic reasons for the occurrence of Cd toxicity, and evaluate the observed phytot...

As the nonheterocystous diazotrophic cyanobacterium Trichodesmium lives both at the ocean surface and deep in the water column, it has to acclimate to vastly different irradiances. Here, we investigate its strategy of light acclimation in several ways. In this study, we used spectrally resolved fluorescence kinetic microscopy to investigate the bio...

In the non-heterocyst, marine cyanobacterium Trichodesmium nitrogen fixation is confined to the photoperiod and occurs coevally with oxygenic photosynthesis although nitrogenase is irreversibly inactivated by oxygen. In previous studies it was found that regulation of photosynthesis for nitrogen fixation involves Mehler reaction and various activit...