Understanding how plants adapt their physiology to overcome severe and often multifactorial stress conditions in nature is vital in light of the climate crisis. This remains a challenge given the complex nature of the underlying molecular mechanisms. To provide a comprehensive picture of stress-mitigation mechanisms, an exhaustive analysis of publicly available stress-related transcriptomic data has been conducted. We combine a meta-analysis with an unsupervised machine-learning algorithm to identify a core of stress-related genes active at 1-6 h and 12-24 h of exposure in Arabidopsis thaliana shoots and roots. To ensure robustness and biological significance of the output, often lacking in meta-analyses, a triple validation is incorporated. We present a 'stress gene core': a set of key genes involved in plant tolerance to ten adverse environmental conditions and ethylene-precursor supplementation rather than individual conditions. Notably, ethylene plays a key regulatory role in this core, influencing gene expression and acting as a critical factor in stress tolerance. Additionally, the analysis provides insights into previously uncharacterized genes, key genes within large families, and gene expression dynamics, which are used to create biologically validated databases that can guide further abiotic stress research. These findings establish a strong framework for advancing multi-stress-resilient crops, paving the way for sustainable agriculture in the face of climate challenges.

• MeSH
• Arabidopsis * genetics   physiology   metabolism   MeSH
• Ethylenes * metabolism   MeSH
• Stress, Physiological * genetics   MeSH
• Plant Roots genetics   metabolism   MeSH
• Arabidopsis Proteins genetics   metabolism   MeSH
• Gene Expression Regulation, Plant MeSH
• Gene Expression Profiling MeSH
• Machine Learning * MeSH
• Transcriptome MeSH
• Plant Shoots genetics   metabolism   MeSH
• Publication type
• Journal Article MeSH
• Meta-Analysis MeSH
• Names of Substances
• ethylene MeSH Browser
• Ethylenes * MeSH
• Arabidopsis Proteins MeSH

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.

• Keywords
• Antioxidants, Reactive oxygen species, Stress imaging, Two-dimensional photon emission imaging, Wounding,
• MeSH
• Arabidopsis * physiology   MeSH
• Photons * MeSH
• Stress, Physiological * MeSH
• Publication type
• Journal Article MeSH
• Review MeSH

Reactive oxygen species (ROS) represent a group of molecules with a signaling role that are involved in regulating human cell proliferation and differentiation. Increased ROS concentrations are often associated with the local nonspecific oxidation of biological macromolecules, especially proteins and lipids. Free radicals, in general, may randomly damage protein molecules through the formation of protein-centered radicals as intermediates that, in turn, decay into several end oxidation products. Malondialdehyde (MDA), a marker of free-radical-mediated lipid oxidation and cell membrane damage, forms adducts with proteins in a nonspecific manner, leading to the loss of their function. In our study, we utilized U-937 cells as a model system to unveil the effect of four selected bioactive compounds (chlorogenic acid, oleuropein, tomatine, and tyrosol) to reduce oxidative stress associated with adduct formation in differentiating cells. The purity of the compounds under study was confirmed by an HPLC analysis. The cellular integrity and changes in the morphology of differentiated U-937 cells were confirmed with confocal microscopy, and no significant toxicity was found in the presence of bioactive compounds. From the Western blot analysis, a reduction in the MDA adduct formation was observed in cells treated with compounds that underlaid the beneficial effects of the compounds tested.

• Keywords
• antioxidants, bioactive compounds, macrophage, malondialdehyde, monocyte, nutraceuticals, phorbol 12-myristate 13-acetate, protein modification, reactive oxygen species, redox reactions,
• MeSH
• Humans MeSH
• Malondialdehyde MeSH
• Oxidation-Reduction MeSH
• Oxidative Stress * MeSH
• Reactive Oxygen Species pharmacology   MeSH
• Free Radicals metabolism   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Malondialdehyde MeSH
• Reactive Oxygen Species MeSH
• Free Radicals MeSH

Photosystem II (PSII) is an intrinsic membrane protein complex that functions as a light-driven water:plastoquinone oxidoreductase in oxygenic photosynthesis. Electron transport in PSII is associated with formation of reactive oxygen species (ROS) responsible for oxidative modifications of PSII proteins. In this study, oxidative modifications of the D1 and D2 proteins by the superoxide anion (O2•-) and the hydroxyl (HO•) radicals were studied in WT and a tocopherol cyclase (vte1) mutant, which is deficient in the lipid-soluble antioxidant α-tocopherol. In the absence of this antioxidant, high-resolution tandem mass spectrometry was used to identify oxidation of D1:130E to hydroxyglutamic acid by O2•- at the PheoD1 site. Additionally, D1:246Y was modified to either tyrosine hydroperoxide or dihydroxyphenylalanine by O2•- and HO•, respectively, in the vicinity of the nonheme iron. We propose that α-tocopherol is localized near PheoD1 and the nonheme iron, with its chromanol head exposed to the lipid-water interface. This helps to prevent oxidative modification of the amino acid's hydrogen that is bonded to PheoD1 and the nonheme iron (via bicarbonate), and thus protects electron transport in PSII from ROS damage.

• Keywords
• EPR, mass spectrometry, photosystem II, reactive oxygen species, tocopherol,
• MeSH
• alpha-Tocopherol chemistry   metabolism   MeSH
• Amino Acids chemistry   metabolism   MeSH
• Arabidopsis enzymology   genetics   radiation effects   MeSH
• Photosynthesis physiology   radiation effects   MeSH
• Photosystem II Protein Complex chemistry   genetics   metabolism   MeSH
• Hydroxyl Radical chemistry   metabolism   MeSH
• Protein Interaction Domains and Motifs MeSH
• Intramolecular Transferases chemistry   genetics   metabolism   MeSH
• Protein Conformation, alpha-Helical MeSH
• Protein Conformation, beta-Strand MeSH
• Oxygen chemistry   metabolism   MeSH
• Models, Molecular MeSH
• Mutation MeSH
• Oxidation-Reduction MeSH
• Superoxides chemistry   metabolism   MeSH
• Light MeSH
• Thermodynamics MeSH
• Thermosynechococcus enzymology   genetics   radiation effects   MeSH
• Thylakoids enzymology   genetics   radiation effects   MeSH
• Protein Binding MeSH
• Binding Sites MeSH
• Iron chemistry   metabolism   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Names of Substances
• alpha-Tocopherol MeSH
• Amino Acids MeSH
• Photosystem II Protein Complex MeSH
• Hydroxyl Radical MeSH
• Intramolecular Transferases MeSH
• Oxygen MeSH
• Superoxides MeSH
• tocopherol cyclase MeSH Browser
• Iron MeSH

It is well established that every living organism spontaneously emits photons referred to as ultra-weak photon emission (synonym biophotons or low-level chemiluminescence) which inherently embodies information about the wellbeing of the source. In recent years, efforts have been made to use this feature as a non-invasive diagnostic tool related to the detection of food quality, agriculture and biomedicine. The current study deals with stress resulting from wounding (mechanical injury) on Arabidopsis thaliana and how it modifies the spontaneous ultra-weak photon emission. The ultra-weak photon emission from control (non-wounded) and stressed (wounded) plants was monitored using different modes of ultra-weak photon emission measurement sensors like charge-coupled device (CCD) cameras and photomultiplier tubes (PMT) and the collected data were analyzed to determine the level of stress generated, photon emission patterns, and underlying biochemical process. It is generally considered that electronically excited species formed during the oxidative metabolic processes are responsible for the ultra-weak photon emission. In the current study, a high-performance cryogenic full-frame CCD camera was employed for two-dimensional in-vivo imaging of ultra-weak photon emission (up to several counts/s) and the spectral analysis was done by using spectral system connected to a PMT. The results show that Arabidopsis subjected to mechanical injury enhances the photon emission and also leads to changes in the spectral pattern of ultra-weak photon emission. Thus, ultra-weak photon emission can be used as a tool for oxidative stress imaging and can pave its way into numerous plant application research.

• Keywords
• Arabidopsis, mechanical injury, oxidative radical reaction, reactive oxygen species, spectral properties, ultra-weak photon emission, wounding,
• Publication type
• Journal Article MeSH