The oxidative damage induced by abiotic stress factors such as salinity, drought, extreme temperatures, heavy metals, pollution, and high irradiance has been studied in Arabidopsis thaliana. Ultra-weak photon emission (UPE) is presented as a signature reflecting the extent of the oxidation process and/or damage. It can be used to predict the physiological state and general health of plants. This study presents an overview of a potential research platform where the technique can be applied. The results presented can aid in providing invaluable information for developing strategies to mitigate abiotic stress in crops by improving plant breeding programs with a focus on enhancing tolerance. This study evaluates the applicability of charged couple device (CCD) imaging in evaluating plant stress and degree of damage and to discuss the advantages and limitations of the claimed non-invasive label-free tool.

• Klíčová slova
• Antioxidants, Reactive oxygen species, Stress imaging, Two-dimensional photon emission imaging, Wounding,
• MeSH
• Arabidopsis * fyziologie   MeSH
• fotony * MeSH
• fyziologický stres * MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Biological systems manifest continuous weak autoluminescence, which is present even in the absence of external stimuli. Since this autoluminescence arises from internal metabolic and physiological processes, several works suggested that it could carry information in the time series of the detected photon counts. However, there is little experimental work which would show any difference of this signal from random Poisson noise and some works were prone to artifacts due to lacking or improper reference signals. Here we apply rigorous statistical methods and advanced reference signals to test the hypothesis whether time series of autoluminescence from germinating mung beans display any intrinsic correlations. Utilizing the fractional Brownian bridge that employs short samples of time series in the method kernel, we suggest that the detected autoluminescence signal from mung beans is not totally random, but it seems to involve a process with a negative memory. Our results contribute to the development of the rigorous methodology of signal analysis of photonic biosignals.

• MeSH
• klíčení fyziologie   MeSH
• luminiscence * MeSH
• vigna růst a vývoj   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: The growth and development of plants is deleteriously affected by various biotic and abiotic stress factors. Wounding in plants is caused by exposure to environmental stress, mechanical stress, and via herbivory. Typically, oxidative burst in response to wounding is associated with the formation of reactive oxygen species, such as the superoxide anion radical (O2•-), hydrogen peroxide (H2O2) and singlet oxygen; however, few experimental studies have provided direct evidence of their detection in plants. Detection of O2•- formation in plant tissues have been performed using various techniques including electron paramagnetic resonance spin-trap spectroscopy, epinephrine-adrenochrome acceptor methods, staining with dyes such as tetrazolium dye and nitro blue tetrazolium (NBT); however, kinetic measurements have not been performed. In the current study, we provide evidence of O2•- generation and its kinetics in the leaves of spinach (Spinacia oleracea) subjected to wounding. METHODS: Real-time monitoring of O2•- generation was performed using catalytic amperometry. Changes in oxidation current for O2•- was monitored using polymeric iron-porphyrin-based modified carbon electrodes (φ = 1 mm) as working electrode with Ag/AgCl as the reference electrode. RESULT: The results obtained show continuous generation of O2•- for minutes after wounding, followed by a decline. The exogenous addition of superoxide dismutase, which is known to dismutate O2•- to H2O2, significantly suppressed the oxidation current. CONCLUSION: Catalytic amperometric measurements were performed using polymeric iron-porphyrin based modified carbon electrode. We claim it to be a useful tool and a direct method for real-time monitoring and precise detection of O2•- in biological samples, with the potential for wide application in plant research for specific and sensitive detection of O2•-.

• Klíčová slova
• Electrochemical detection, Polymeric iron-porphyrin-based modified carbon electrode, Superoxide anion radical, Wounding,
• Publikační typ
• časopisecké články MeSH

Hydrogen peroxide (H2O2) is known to be generated in Photosystem II (PSII) via enzymatic and non-enzymatic pathways. Detection of H2O2 by different spectroscopic techniques has been explored, however its sensitive detection has always been a challenge in photosynthetic research. During the recent past, fluorescence probes such as Amplex Red (AR) has been used but is known to either lack specificity or limitation with respect to the minimum detection limit of H2O2. We have employed an electrochemical biosensor for real time monitoring of H2O2 generation at the level of sub-cellular organelles. The electrochemical biosensor comprises of counter electrode and working electrodes. The counter electrode is a platinum plate, while the working electrode is a mediator based catalytic amperometric biosensor device developed by the coating of a carbon electrode with osmium-horseradish peroxidase which acts as H2O2 detection sensor. In the current study, generation and kinetic behavior of H2O2 in PSII membranes have been studied under light illumination. Electrochemical detection of H2O2 using the catalytic amperometric biosensor device is claimed to serve as a promising technique for detection of H2O2 in photosynthetic cells and subcellular structures including PSII or thylakoid membranes. It can also provide a precise information on qualitative determination of H2O2 and thus can be widely used in photosynthetic research.

• Klíčová slova
• EPR-spin trapping, amperometric biosensor, hydrogen peroxide, photosystem II, reactive oxygen species, superoxide anion radical,
• Publikační typ
• časopisecké články MeSH

Two-dimensional imaging of spontaneous ultra-weak photon emission was measured in the yeast cells, Arabidopsis plant and the human hand using highly sensitive charge coupled device (CCD) camera. For the first time, the detail analysis of measuring parameters such as accumulation time and binning is provided with the aim to achieve two-dimensional images of spontaneous ultra-weak photon emission of good quality. We present data showing that using a hardware binning with binning factor 4 × 4, the accumulation time decreases in the following order: yeast cells (30 min) > the human hand (20 min) > Arabidopsis plant (10 min). Analysis of measuring parameters provides a detailed description of standard condition to be used for two-dimensional spontaneous ultra-weak photon imaging in microbes, plants and animals. Thus, CCD imaging can be employed as a unique tool to examine the oxidative state of the living organism with the application in microbiological, plant and medical research.

• MeSH
• Arabidopsis fyziologie   MeSH
• časové faktory MeSH
• fotony * MeSH
• lidé MeSH
• oxidace-redukce MeSH
• ruka fyziologie   MeSH
• Saccharomyces cerevisiae fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH