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Determination of the Effect of Organic Matter Addition to Mineral Soil on Nickel Detoxification in Radish, Its Yield, Nitrogen Metabolism and Chloroplast Pigments
Understanding soil properties that govern physicochemical and biological processes is essential for achieving high crop quality and yield. Organic matter is an important element of soil fertility and fertility in vegetable cultivation. In the process of decomposition of organic matter in the soil, humus of various quality is formed. The quality of humus depends on the content of individual acids (fulvic, humic and hymatomalanic acids) in it, which can affect the binding–chelation of heavy metals, limiting their availability to plants. The conducted studies determined the effect of adding organic matter (high peat, brown coal and wheat straw) to mineral soil on nickel detoxification in radish, its yield, nitrogen management and chloroplast pigments. The studies were conducted for three years in a greenhouse in a container system. The tested substrates were contaminated with nickel in the amount of 50, 75 and 100 mg dm−3. It was found that introducing organic matter into mineral soil can affect the reduction as well as the increase in nickel content in edible parts of radish. The type of organic material introduced into mineral soil as a source of organic matter has a significant impact on nickel content in radish. It was shown that nitrate reductase activity (NR) depends to a large extent on the substrate in which the plants are grown as well as on the applied dose of nickel. A similar relationship was demonstrated in the case of changes in the level of chloroplast pigments (chlorophyll a, chlorophyll b and carotenoids).
In Memoriam: Professor Philippe Jeandet – an outstanding scientist and his legacy in natural product chemistry and bioactivity
Professor Philippe Jeandet was one of the world’s leading biologists and plant biochemists, best known for his research on the chemical structure of natural products and their bioactivity, particularly that of stilbenoids. His scientific interests primarily focused on resveratrol (trans-3,5,4'-trihydroxystilbene), a stilbene with a wide range of biological activities. Additionally, his work highlighted the potential of combining pharmacological treatments with the use of natural products of plant origin, which have made significant contributions to the treatment of various diseases. He leaves behind a legacy of groundbreaking research and a lasting influence in the field. He was also involved in research on sugar signaling during plant responses to abiotic and biotic stress factors, as well as the role of signaling molecules in fruit development. His scientific achievements demonstrate that he was, first and foremost, a dedicated scientist – but also a honourable colleague who understood and respected the work of others.
Nitrogen Metabolism and Antioxidant Capacity of Selected Vegetables from Organic and Conventional Crops
The study aimed to determine the level of selected indicators of nitrogen metabolism in vegetables from organic (organic food store) and conventional (supermarket and local market) crops. Nitrates, total chlorophyll content, and the activity of the nitrate biosynthesis pathway enzymes—nitrate reductase (NR) and glutamine synthetase (GS)—were determined in the leaves of selected species from different plant families. The research material consisted of dill, carrot, celery, beet, onion, Chinese and white cabbage, and rocket. The nitrate content was within the permissible limits, except for vegetables bought at a local market. In most cases, no significant differences in the level of nitrates between organic and conventional farming were observed. The analyses revealed the highest nitrate content in dill [2.16 mg × g−1] and the lowest in onions [0.06 mg × g−1] from conventional crops. The enzyme activities were related to the level of nitrates. The analysed species differed in phenolic compounds, ascorbate levels, and total antioxidant capacity (TCA). Positive correlations were found between TCA and antioxidants.
Udział cząsteczek sygnałowych w odpowiedzi obronnej łubinu na patogena grzybowego Colletotrichum gloeosporioides - sprawcę antraknozy
Adaptive significance of age- and light-related variation in needle structure, photochemistry, and pigments in evergreen coniferous trees
Enhancing Lettuce Drought Tolerance: The Role of Organic Acids in Photosynthesis and Oxidative Defense
The aim of this study was to investigate the effects of maleic acid (MA), salicylic acid (SA), and citric acid (CA) on alleviating the drought stress of a lettuce (Lactuca sativa L.) hydroponic culture. The effect of these organic acids was tested under stress conditions induced by polyethene glycol (PEG 6000) at 5% and 7.5% concentrations. Drought stress reduced the fresh and dry matter yields of plants. The acid treatment caused increasing tendencies in the fresh weight yield:control (SA, MA), PEG 7.5% (SA, MA, CA)) and dry weight yield (control (SA, MA), PEG 5% (MA), PEG 7.5% (SA, MA)). The acid treatment also enhanced the nutrient uptake of stressed plants: SA: N (PEG 7.5%), K (PEG 5 and 7.5%); MA: N, P, K, Ca (PEG 5 and 7.5%). This work found that chlorophyll a and b amounts did not change under applied experimental conditions. Most parameters of chlorophyll fluorescence did not depend on either the level of applied water stress (PEG level) or the type of spraying. Drought stress increased leaf superoxide anion (O2•−) and malondialdehyde (MDA) levels but decreased H2O2. Proline (Pro) and phenolic compounds (TFC), including flavonols (Fla), accumulated more in stressed plants. Drought stress also affected the chlorophyll fluorescence. Our results suggest that acids can improve plant tolerance to drought stress by boosting the antioxidant defence system and reducing the oxidative damage caused by reactive oxygen species.
The Role of Sugars in Plant Responses to Stress and Their Regulatory Function during Development
Due to their role as energy and carbon sources and their regulatory functions, sugars influence all phases of the plant life cycle, interact with other signaling molecules, including phytohormones, and control plant growth and development [...]