A5045340363- Plant Stress Responses and Tolerance
- Plant Micronutrient Interactions and Effects
- Photosynthetic Processes and Mechanisms
- Heavy metals in environment
- Aluminum toxicity and tolerance in plants and animals
- Marine and coastal ecosystems
- Geochemistry and Elemental Analysis
- Microbial Community Ecology and Physiology
- Legume Nitrogen Fixing Symbiosis
- Algal biology and biofuel production
- Heavy Metals in Plants
- Plant responses to water stress
- Protist diversity and phylogeny
- Geology and Paleoclimatology Research
- Arsenic contamination and mitigation
- Oral microbiology and periodontitis research
- Plant-Microbe Interactions and Immunity
- Antioxidant Activity and Oxidative Stress
- Plant nutrient uptake and metabolism
- Light effects on plants
- Analytical chemistry methods development
- Hereditary Neurological Disorders
- Oral health in cancer treatment
- Electrochemical Analysis and Applications
- Bacteriophages and microbial interactions
Institute of Plant Molecular Biology
2016-2025
Czech Academy of Sciences, Biology Centre
2016-2025
Czech Academy of Sciences
2016-2025
University of South Bohemia in České Budějovice
2016-2025
Universitätsklinikum Tübingen
2019-2025
University of Konstanz
2006-2017
Sewanee: The University of the South
2002-2013
In-Q-Tel
2013
Ludwig-Maximilians-Universität München
1998-2013
Deutsches Elektronen-Synchrotron DESY
2004-2009
Abstract Despite recent progress in our understanding of carotenogenesis plants, the mechanisms that govern overall carotenoid accumulation remain largely unknown. The Orange (Or) gene mutation cauliflower (Brassica oleracea var botrytis) confers high levels β-carotene various tissues normally devoid carotenoids. Using positional cloning, we isolated representing Or and verified it by functional complementation wild-type cauliflower. encodes a plastid-associated protein containing DnaJ...
Following experiments which studied the substitution of central ion isolated chlorophylls by heavy metal ions in vitro, vivo with submersed water plants were carried out. It was discovered that atom chlorophyll, magnesium, metals (mercury, copper, cadmium, nickel, zinc, lead) is an important damage mechanism stressed plants. This prevents photosynthetic light-harvesting affected chlorophyll molecules, resulting a breakdown photosynthesis. The reaction varies light intensity. In low...
Cellular compartmentation of Zn in the leaves hyperaccumulator Thlaspi caerulescens was investigated using energy-dispersive x-ray microanalysis and single-cell sap extraction. Energy-dispersive frozen, hydrated leaf tissues showed greatly enhanced accumulation epidermis compared with mesophyll cells. The relative concentration epidermal cells correlated linearly cell length both young mature leaves, suggesting that vacuolation may promote preferential accumulation. results from sampling...
• Acclimation of hyperaccumulators to heavy metal-induced stress is crucial for phytoremediation and was investigated using the hyperaccumulator Thlaspi caerulescens nonaccumulators T. fendleri ochroleucum. Spatially spectrally resolved kinetics in vivo absorbance fluorescence were measured with a novel kinetic microscope. At beginning growth on cadmium (Cd), all species suffered from toxicity, but subsequently recovered completely. During stress, few mesophyll cells became more inhibited...
In the modern ocean, a significant amount of nitrogen fixation is attributed to filamentous, nonheterocystous cyanobacteria genus Trichodesmium. these organisms, confined photoperiod and occurs simultaneously with oxygenic photosynthesis. Nitrogenase, enzyme responsible for biological N 2 fixation, irreversibly inhibited by oxygen in vitro. How nitrogenase protected from damage photosynthetically produced O was once an enigma. Using fast repetition rate fluorometry fluorescence kinetic...
Nickel uptake and cellular compartmentation were investigated in three Ni hyperaccumulators: Alyssum bertolonii (Desv), lesbiacum (Candargy) Thlaspi goesingense (Hálácsy). The species showed similar hyperaccumulation of Ni, but T. was less tolerant to than the two species. An addition 500 mg kg(-1) a nutrient-rich growth medium significantly increased shoot biomass all species, suggesting that hyperaccumulators have higher requirement for normal plants. Energy-dispersive X-ray microanalysis...
The targets of heavy metal (here Cu 2 + and Zn ) attack on the photosynthetic apparatus algae belonging to different phyla were investigated. Experiments with green alga Scenedesmus quadricauda confirmed previous findings that according irradiance level two phenomena occur, which further characterized by specific changes in several parameters. reaction occurring under low ( shade is substitution Mg chl molecules bound predominantly light harvesting complex II Chlorophyta (LHC II). Under high...
Abstract Extended x-ray absorption fine structure measurements were performed on frozen hydrated samples of the cadmium (Cd)/zinc (Zn) hyperaccumulator Thlaspi caerulescens (Ganges ecotype) after 6 months Zn2+ treatment with and without addition Cd2+. Ligands depended metal function age plant tissue. In mature senescent leaves, oxygen ligands dominated. This result combined earlier knowledge about compartmentation indicates that plants prefer to detoxify hyperaccumulated metals by pumping...
We investigated changes in mineral nutrient uptake and cellular expression levels for metal transporter genes the cadmium (Cd)/zinc (Zn) hyperaccumulator, Thlaspi caerulescens during whole plant leaf ontogenesis under different long-term treatments with Zn Cd. Quantitative mRNA situ hybridization (QISH) revealed that gene not only dependent on nutrition/toxicity, but even more so development. The main abundances found were: ZNT1, mature leaves of young plants; ZNT5, MTP1 (= ZTP1 = ZAT), both...
Abstract The amphibious water plant Crassula helmsii is an invasive copper (Cu)-tolerant neophyte in Europe. It now turned out to accumulate Cu up more than 9,000 ppm its shoots at 10 μ m (=0.6 ppm) Cu2+ the nutrient solution, indicating that it a hyperaccumulator. We investigated uptake, binding environment, and toxicity of this under emerged submerged conditions. Extended x-ray absorption fine structure measurements on frozen-hydrated samples revealed was bound almost exclusively by oxygen...
Metal accumulation in seeds is a prerequisite for germination and establishment of plants but also micronutrient delivery to humans. To investigate metal transport processes their interactions seeds, we focused on METAL TOLERANCE PROTEIN8 (MTP8), tonoplast transporter the manganese (Mn) subclade cation diffusion facilitators, which Arabidopsis (Arabidopsis thaliana) expressed embryos seeds. The x-ray fluorescence imaging showed that expression MTP8 was responsible Mn localization...
Chlorophyll fluorescence kinetic analysis has become an important tool in basic and applied research on plant physiology agronomy. While early systems recorded the integrated kinetics of a selected spot or plant, later enabled imaging at least slower parts (20-ms time resolution). For faster events, such as rise from dark-adapted yield to maximum (OJIP transient), decrease during reoxidation plastoquinone A after saturating flash, integrative are used because limiting speed available...
Arsenic (As) pollution is a serious concern worldwide. Recent studies under environmentally relevant conditions revealed that, in the aquatic plant Ceratophyllum demersum , pigments are first observable target of toxicity, prior to any effect on photosynthetic parameters or oxidative stress. Lethal toxicity was initiated by change As species and their distribution pattern various tissues. Here, localization investigated at subcellular level through X-ray fluorescence using submicron beam...
Quantification of pigments in complex mixtures is an important task the physiology photosynthetic organisms, because pigment composition differs depending on species, tissue, and physiological state. Currently available methods, however, are either limited to very few (classical UV/vis spectroscopic methods), or they time-consuming, labor intensive, costly (e.g., HPLC). Here we describe a spectrophotometric method that capable rapid (∼1 min/sample) inexpensive (<1 euro/sample) quantification...
Abstract The cadmium/zinc hyperaccumulator Thlaspi caerulescens is sensitive toward copper (Cu) toxicity, which a problem for phytoremediation of soils with mixed contamination. Cu levels in T. grown 10 μ m Cu2+ remained the nonaccumulator range (&lt;50 ppm), and most individuals were as related fendleri. Obviously, hyperaccumulation metal resistance are highly specific. Cu-induced inhibition photosynthesis followed “sun reaction” type damage, photosystem II reaction center charge...
Summary Cadmium (Cd) is an important environmental pollutant and poisonous to most organisms. We aimed unravel the mechanisms of Cd toxicity in model water plant Ceratophyllum demersum exposed low (nM) concentrations as are present nature. Experiments were conducted under environmentally relevant conditions, including nature‐like light temperature cycles, a biomass ratio. measured chlorophyll (Chl) fluorescence kinetics, oxygen exchange, reactive species pigments, metal binding proteins,...
Summary Like pathogens, beneficial endophytic fungi secrete effector proteins to promote plant colonization, for example, through perturbation of host immunity. The genome the root endophyte Serendipita indica encodes a novel family highly similar, small alanine‐ and histidine‐rich proteins, whose functions remain unknown. Members this protein carry an N‐terminal signal peptide conserved C‐terminal DELD motif. Here we report on functional characterization plant‐responsive Dld1 using...
The in vivo substitution of Mg2+ chlorophyll by heavy metals is an important damage mechanism metal-stressed plants that leads to inhibition photosynthesis. In photosynthetic organisms with LHC II antennae, the Cu2+ occurs particularly readily under low irradiance a dark phase - phenomenon referred as 'shade reaction'. present study limiting steps shade reaction were investigated synchronised cultures chlorococcal green alga Scenedesmus quadricauda (Turp.) Bréb. rate copper formation during...