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1
Kumar, Sunil, e Priyanka Kumari. "High intensity ultraviolet radiation induced changes in aquatic arthropod with retene and riboflavin". Environment Conservation Journal 12, n. 3 (22 dicembre 2011): 83–87. http://dx.doi.org/10.36953/ecj.2011.120316.
Testo completoAbstract (sommario):
Ozone depletion is resulting into increase in ultraviolet radiation level in the world. Exposure to UV radiation has been found to have negative effects on aquatic and terrestrial organisms. Adverse effect of natural solar and artificial ultraviolet-B and UV-A radiations was observed in crustacean species Daphnia magna in presence of retene and riboflavin. Daphnia magna exposed to artificial ultraviolet-B with retene causes maximum physiological changes and mortality, indicating that enhanced solar UV-B exposure could be lethal to aquatic fauna. Artificial UV-B had a stronger damaging effect than solar radiation and become highly toxic in presence of retene. Riboflavin is slightly phototoxic in presence of solar and artificial UV radiation. Results on mortality rate indicated highest mortality in retene + ultraviolet-B exposed group followed by riboflavin + artificial ultraviolet - B radiation. A dose and intensity dependent change in mortality rate was observed. Retene and riboflavin photoproducts with ultraviolet radiation generate reactive oxygen species leading to cell injury and mortality thus are threat to aquatic biodiversity.
2
Zelenkov, Valery N., Anatoly A. Lapin, Vyacheslav V. Latushkin e Vladimir V. Karpachev. "Effect of ultraviolet radiation on plant biochemical properties". Butlerov Communications 63, n. 8 (31 agosto 2020): 134–40. http://dx.doi.org/10.37952/roi-jbc-01/20-63-8-134.
Testo completoAbstract (sommario):
Depletion of the ozone layer leads to increased ultraviolet radiation, which affects the growth and functioning of plants and leads to their various physiological, biochemical, morphological and ultrastructural changes. When studying the effect of ultraviolet radiation on seed sowing qualities and biometric indicators of morphological organs of plants of various cultures, scientists did not come to a consensus on the optimal parameters of its effects. For seeds of each plant variety, there is an optimal amount of energy absorbed, resulting in a maximum effect. Ecologically significant low ultraviolet radiation changes the metabolism of reactive oxygen species and plant antioxidant systems by increasing enzyme regulation. The relevance of studies in this direction is obvious, as it allows you to stimulate the germination of seeds with physical influences, increasing their laboratory and field germination. The authors obtained and published new data on comparison of sown, crop and antioxidant properties of seeds and seedlings, seed viability, microzelenium biomass formation and change of total antioxidant activity of vegetable crops after thermodehydration. As a continuation of these studies, the purpose of this work was to study the effect of ultraviolet radiation on the biochemical properties of plants. The total antioxidant activity of sugar beet and nougat sprouts in the experiment increased under the influence of stress ultraviolet radiation. Compared to control samples (germination according to GOST in the dark), under the influence of ultraviolet radiation, antioxidant activity increases by 11.4-17.4% otn. Ultraviolet radiation is damaging factors of plant growth and development, which is manifested at different stages of ontogenesis. Thus, sowing properties are reduced (germination of sugar beet seeds is less than control by 18%, in nougat seeds by 12%), above-ground biomass at the end of the germination period is less by 49.0% in sugar beet and by 16.5% in Abyssinian nougat. Resistance to the damaging effects of ultraviolet radiation depends on the genetic nature of the plant: in the experiment, the sprouts of the Abyssinian nuga turned out to be more resistant.
3
Gulin, A. V., e V. I. Donskaya. "Comparative assessment of the nature of the impact of ultraviolet radiation on watermelon seeds in time mode". Vegetable crops of Russia, n. 6 (18 dicembre 2019): 155–58. http://dx.doi.org/10.18619/2072-9146-2019-6-155-158.
Testo completoAbstract (sommario):
Relevance. One of the main components of the spectrum of sunlight is ultraviolet rays – invisible to the human eye short-wave radiation. The influence of these rays on plant life was considered insignificant until recently, but recent studies have shown the fallacy of such conclusions. Ultraviolet has a beneficial effect not only on the human body and animals, but also on plants, including – crops. The destruction of the ozone layer is currently continuing under the influence of anthropogenic factors. In this regard, the study of the effect of ultraviolet radiation on living organisms, including plants, is very relevant from both theoretical and practical points of view. The epidermis of plant leaves and seed shells are permeable to medium-and long-wave UV radiation, so of particular interest is the ultraviolet radiation of the Sun and artificial sources of ultraviolet radiation in the range of 400...180 nm.Purpose of work: to assess the nature of the impact of ultraviolet radiation in the time mode on watermelon seeds using cytogenetic analysis.Methods. The material for research was the seeds of the watermelon variety "Astrakhan". The studies were conducted in 2017-2018.Results. The results of studies have shown that long-term exposure to ultraviolet radiation can affect the physiological processes and anatomical structure of plants, as well as have serious genetic changes: aneuploidy, cytotomy, pyknosis and various chromosomal aberrations that lead to mutations or death of plants. However, plants acquire useful mutations with short-term exposure-0.5-2 hours, which can be used later in selection.
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Balouchi, H. R., S. A. M. M. Sanavy, Y. Emam e A. Dolatabadian. "UV radiation, elevated CO2 and water stress effect on growth and photosynthetic characteristics in durum wheat". Plant, Soil and Environment 55, No. 10 (21 ottobre 2009): 443–53. http://dx.doi.org/10.17221/1024-pse.
Testo completoAbstract (sommario):
Climate change studies are of considerable interest in agriculture and environmental science. The objective of this research was to investigate the changes in photosynthetic pigments and other physiological and biochemical traits of durum wheat exposed to ultraviolet A, B and C radiation, elevated CO<sub>2</sub> and water stress. The results showed that carotenoids, anthocyanins, flavonoids and proline content increased significantly by decreasing ultraviolet wavelength compared to control. Elevated CO<sub>2</sub> increased only height and specific leaf area. Water stress induced a significant increase in carotenoids, anthocyanins, flavonoids, proline and protein content. Interaction of UV-C and water stress in ambient CO<sub>2</sub> increased UV screen pigments and proline content, while under elevated CO<sub>2</sub> these increments were alleviated. Interaction among UV-C radiation, elevated CO<sub>2</sub> and water stress demonstrated a significant decrease in Fv/Fm, chlorophyll, protein, carbohydrates and specific leaf area compared to control. The results of this experiment illustrate that increased UV radiation and water stress induces an increase of screen pigments and elevated CO<sub>2</sub> prevents accumulation of these pigments.
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Ferreyra, G. A., S. Demers, P. A. del Giorgio e J. P. Chanut. "Physiological responses of natural plankton communities to ultraviolet-B radiation in Redberry Lake (Saskatchewan, Canada)". Canadian Journal of Fisheries and Aquatic Sciences 54, n. 3 (1 marzo 1997): 705–14. http://dx.doi.org/10.1139/f96-322.
Testo completoAbstract (sommario):
Damaging effects of ultraviolet radiation on the aquatic biota, related to anthropogenic modifications in the ozone layer, have been extensively described. However, most of the research has focused on marine environments, and information about the effects of ultraviolet radiation on saline prairie lakes of Canada is lacking. To test the deleterious effects of ultraviolet-B (UV-B) radiation on the planktonic community, two exposure experiments were performed in Redberry Lake, Saskatchewan. The responses of primary productivity, phytoplankton chlorophyll a and size, bacterial changes, and the electron transport system to natural UV-B fluxes reaching the surface of the lake were studied. No clear effects of UV-B on phytoplankton carbon assimilation and chlorophyll a were observed. However, significant responses were found for the two phytoplankton size fractions studied (0.7-2 and >2 µm), which were more related to the experimental conditions than to UV-B effects. Bacteria presented a clear decrease in cell number under the highest UV-B doses, whereas the opposite was observed for the electron transport system activity.
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Albi, Elisabetta, Samuela Cataldi, Maristella Villani e Giuseppina Perrella. "Nuclear Phosphatidylcholine and Sphingomyelin Metabolism of Thyroid Cells Changes during Stratospheric Balloon Flight". Journal of Biomedicine and Biotechnology 2009 (2009): 1–5. http://dx.doi.org/10.1155/2009/125412.
Testo completoAbstract (sommario):
Nuclear sphingomyelin and phosphatidylcholine metabolism is involved in the response to ultraviolet radiation treatment in different ways related to the physiological state of cells. To evaluate the effects of low levels of radiation from the stratosphere on thyroid cells, proliferating and quiescent FRTL-5 cells were flown in a stratospheric balloon (BIRBA mission). After recovery, the activity of neutral sphingomyelinase, phosphatidylcholine-specific phospholipase C, sphingomyelin synthase, and reverse sphingomyelin synthase was assayed in purified nuclei and the nuclei-free fraction. In proliferating FRTL-5, space radiation stimulate nuclear neutral sphingomyelinase and reverse sphingomyelin synthase activity, whereas phosphatidylcholine-specific phospholipase C and sphingomyelin synthase were inhibited, thus inducing sphingomyelin degradation and phosphatidylcholine synthesis. This effect was lower in quiescent cells. The possible role of nuclear lipid metabolism in the thyroid damage induced by space radiations is discussed.
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Nassour, Rana, e Abdulkarim Ayash. "Effects of Ultraviolet-B Radiation in Plant Physiology". Agriculture (Pol'nohospodárstvo) 67, n. 1 (1 aprile 2021): 1–15. http://dx.doi.org/10.2478/agri-2021-0001.
Testo completoAbstract (sommario):
Abstract Over the past few decades, anthropogenic activities contributed to the depletion of the ozone layer, which increased the levels of solar ultraviolet-B (UV-B) radiation reaching the Earth`s surface. Generally, UV-B is harmful to all living organisms. It damages the cell`s Deoxyribonucleic acid (DNA), proteins, and lipids, and as a consequence, it affects the bio-membranes negatively. In this review, we summarize the major effects of UV-B in the plant`s main molecules and physiological reactions, in addition to the possible defence mechanisms against UV-B including accumulating UV-B absorbing pigments to alleviate the harmful impact of UV-B.
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Cechin, Inês, Terezinha de Fátima Fumis e Anne Ligia Dokkedal. "Growth and physiological responses of sunflower plants exposed to ultraviolet-B radiation". Ciência Rural 37, n. 1 (febbraio 2007): 85–90. http://dx.doi.org/10.1590/s0103-84782007000100014.
Testo completoAbstract (sommario):
The effects of UV-B radiation were studied in sunflower plants (Helianthus annuus L. cv. Catissol-01) growning in greenhouse under natural photoperiod conditions. The plants received approximately 0.60Wm-2 (control) or 4.0Wm-2 (+UV-B) of UV-B radiation for 7h d-1, centered around solar noon from 15 days after sowing. Compared to the control, plants exposed to high UV-B radiation for 12 or 21 days did not show any difference in shoot dry matter, specific leaf weight or UV-B absorbing compounds. Enhanced UV-B radiation caused a significant inhibition of photosynthesis (A) only in the first sampling and this was accompained by reduction in stomatal conductance (g s) and transpiration rate. The inhibition in A can not be fully explained by reduction in g s since intercellular CO2 concentration was not affected by UV-B radiation. In both samplings, the total chlorophyll content was not affected by enhanced UV-B radiation whereas in the first sampling, the chlorophyll a and the ratio of chlorophyll a/b were reduced. Enhanced UV-B radiation increased the minimal fluorescence yield, but did not alter the ratio of variable to maximal fluorescence yield of dark adapted leaves. Overall, this study suggests that the present level of solar UV-B radiation affects sunflower plants performance even though the shoot dry biomass may not be affected.
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Fischer, Gerhard, Fernando Ramírez e Fánor Casierra-Posada. "Ecophysiological aspects of fruit crops in the era of climate change. A review". Agronomía Colombiana 34, n. 2 (1 maggio 2016): 190–99. http://dx.doi.org/10.15446/agron.colomb.v34n2.56799.
Testo completoAbstract (sommario):
The increased concentration of carbon dioxide (CO2) and other greenhouse effect gases has led to global warming, which has resulted in climate change, increased levels of ultraviolet (UV) radiation and changes in the hydrological cycle, affecting the growth, development, production and quality of fruit crops, which undoubtedly will be difficult to predict and generalize because the physiological processes of plants are multidimensional. This review outlines how the effects of high/low solar radiation, temperature, water stress from droughts, flooding and rising levels of CO2 in the atmosphere affect fruit crops and their growth and physiology.
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Craver, Joshua K., Chad T. Miller, Kimberly A. Williams e Nora M. Bello. "Ultraviolet Radiation Affects Intumescence Development in Ornamental Sweetpotato (Ipomoea batatas)". HortScience 49, n. 10 (ottobre 2014): 1277–83. http://dx.doi.org/10.21273/hortsci.49.10.1277.
Testo completoAbstract (sommario):
Intumescences are a physiological disorder characterized by hypertrophy and possibly hyperplasia of plant tissue cells. Ultimately, this disorder results in the death of the affected cells. Previous observations and research suggest that the quality and quantity of light to which plants are exposed may be a factor in development of the disorder. The purpose of this study was to assess the preventive effect of ultraviolet-B (UVB) radiation on intumescence development in ornamental sweetpotato (Ipomoea batatas). Two sweetpotato cultivars, Sidekick Black and Ace of Spades, were grown under light treatments consisting of 1) normal greenhouse production conditions; 2) supplemental UVB lighting; 3) supplemental UVB lighting with Mylar® sleeves over the lamps to block UVB radiation; and 4) control lighting with full spectrum lamps. Treatments were administered for 2 weeks, and the experiment was repeated twice. ‘Ace of Spades’ was highly susceptible to intumescence development, whereas ‘Sidekick Black’ was much less susceptible to the disorder. For ‘Ace of Spades’, the addition of UVB radiation significantly reduced the number of leaves affected with intumescences when compared with plants grown under the other light treatments; this UVB effect was not apparent for ‘Sidekick Black’. Furthermore, there was no evidence for reduced plant growth under UVB light in either cultivar, but side effects from the radiation included leaf discoloration and deformities. This study indicates a cultivar-specific effect of UVB light in preventing intumescence development on ornamental sweetpotato, therefore suggesting a potential genetic component in intumescence susceptibility. These results provide further insight in better understanding intumescence development and how to prevent the disorder.
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Neven, Lisa G. "Physiological Effects of Physical Postharvest Treatments on Insects". HortTechnology 13, n. 2 (gennaio 2003): 272–75. http://dx.doi.org/10.21273/horttech.13.2.0272.
Testo completoAbstract (sommario):
As concerns about the safety of our food supply increase along with concerns about the impact of agricultural chemicals on our environment, the development of nonchemical quarantine treatments to meet export requirements become increasingly necessary. The types of physical treatments used have been largely determined by commodity tolerances and processing practices. The most common physical treatments use temperature extremes such as heat [>40 °C (104.0 °F)] and cold [<10 °C (50.0 °F)]. Other physical treatments commonly include the use of controlled or modified atmospheres (low oxygen, elevated carbon dioxide). Current technology has led to investigations in the application of energy to control infesting insects. These treatments include ionizing radiation, microwaves, ultraviolet radiation, infrared radiation, radio frequency, electron beam, X-rays, and electricity. Although the effects of these physical treatments can impact commodity quality, the goal of the treatments is to kill infesting (real or in certain instances, potential) insects to meet quarantine requirements. The effects of physical treatments on insect mortality and fecundity are discussed.
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Ambasht, Navin Kumar, e Madhoolika Agrawal. "Physiological and biochemical responses of Sorghum vulgare plants to supplemental ultraviolet-B radiation". Canadian Journal of Botany 76, n. 7 (1 luglio 1998): 1290–94. http://dx.doi.org/10.1139/b98-137.
Testo completoAbstract (sommario):
Sorghum (Sorghum vulgare (Pers.) cv. MSH 51) plants were grown in the field under ambient and supplemental levels of ultraviolet-B radiation (UV-B; supplemental daily dose corresponding to a 20% reduction in the stratospheric ozone column). Gas exchange characteristics, biomass, and levels of photosynthetic pigments, flavonoids, catalase, peroxidase activity, and ascorbic acid were determined to evaluate the changes induced by enhanced levels of UV-B irradiation. Gas exchange analysis indicated that one of the reasons for the decline in photosynthesis is stomatal limitation. Enhanced UV-B also caused reductions in chlorophyll and carotenoid pigments after 60 days of exposure. Concentrations of UV-B absorbing pigments increased linearly with age. UV-B irradiation also increased phenolic compounds. Catalase activity decreased, while peroxidase activity increased in response to elevated UV-B. There was a decrease in total plant biomass and ascorbic acid content of plants exposed to UV-B. Thus, an enhanced level of UV-B irradiation over a long period has a cumulative unfavourable effect on a number of physiological and biochemical processes, leading to a reduction in dry matter production.Key words: UV-B radiation, Sorghum vulgare, photosynthesis, stomatal resistance, flavonoids, peroxidase.
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Lombardi, Lisa, Marina Zoppo, Cosmeri Rizzato, Colin Gerard Egan, Roberto Scarpato e Arianna Tavanti. "Use of Amplification Fragment Length Polymorphism to Genotype Pseudomonas stutzeri Strains Following Exposure to Ultraviolet Light A". Polish Journal of Microbiology 66, n. 1 (30 marzo 2017): 107–11. http://dx.doi.org/10.5604/17331331.1234998.
Testo completoAbstract (sommario):
Changes in ultraviolet light radiation can act as a selective force on the genetic and physiological traits of a microbial community. Two strains of the common soil bacterium Pseudomonas stutzeri, isolated from aquifer cores and from human spinal fluid were exposed to ultraviolet light. Amplification length polymorphism analysis (AFLP) was used to genotype this bacterial species and evaluate the effect of UVA-exposure on genomic DNA extracted from 18 survival colonies of the two strains compared to unexposed controls. AFLP showed a high discriminatory power, confirming the existence of different genotypes within the species and presence of DNA polymorphisms in UVA-exposed colonies.
14
Lin, Xiaokai, Feng Liu, Haizhi Liao, Jingjia Du, Junjie Peng e Kaibing Zhou. "Effect of Enhanced Ultraviolet-B Radiation on Fruit Maturity and Quality and Leaf Photosynthesis in ‘Guifei’ Mango". HortScience 57, n. 9 (settembre 2022): 1167–72. http://dx.doi.org/10.21273/hortsci16738-22.
Testo completoAbstract (sommario):
To investigate the characteristics of photosynthetic physiological changes in leaves of Mangifera indica L. cv. Guifei under enhanced ultraviolet (UV)-B radiation, natural light-exposed trees were used as controls and 96 kJ·m−2·d−1 enhanced UV-B radiation was artificially simulated in the field. The changes in fruit maturity and quality, the leaf net photosynthetic rate (Pn), photosynthetic pigment contents, photochemical reactions, the activities of photosynthetic enzymes and related gene expression levels were determined. Compared with the control, the percentage of mature fruits under the treatment significantly increased, and fruit quality improved. The net photosynthetic rate (Pn), photosynthetic pigment content, Hill reaction activity, and photochemical quenching coefficient (qP) of the treated leaves showed significantly higher values than those of the control leaves. The activities of Rubisco and Rubisco activating enzyme (RCA) and the expression levels of the Rubisco large subunit and Rubisco small subunit were significantly increased. Treatment with 96 kJ·m−2·d−1 enhanced ultraviolet-B radiation improved Rubisco activity by increasing the expression of the Rubisco large and small subunit genes, thereby enhancing the CO2-fixing capacity and dark reaction capacity of leaves. Thus, the net photosynthetic rate of leaves increased, which promoted the early maturity of ‘Guifei’ mango by the rapid accumulation of photosynthetic products.
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Morillas, Lourdes, Javier Roales, Cristina Cruz e Silvana Munzi. "Resilience of Epiphytic Lichens to Combined Effects of Increasing Nitrogen and Solar Radiation". Journal of Fungi 7, n. 5 (26 aprile 2021): 333. http://dx.doi.org/10.3390/jof7050333.
Testo completoAbstract (sommario):
Lichens are classified into different functional groups depending on their ecological and physiological response to a given environmental stressor. However, knowledge on lichen response to the synergistic effect of multiple environmental factors is extremely scarce, although vital to get a comprehensive understanding of the effects of global change. We exposed six lichen species belonging to different functional groups to the combined effects of two nitrogen (N) doses and direct sunlight involving both high temperatures and ultraviolet (UV) radiation for 58 days. Irrespective of their functional group, all species showed a homogenous response to N with cumulative, detrimental effects and an inability to recover following sunlight, UV exposure. Moreover, solar radiation made a tolerant species more prone to N pollution’s effects. Our results draw attention to the combined effects of global change and other environmental drivers on canopy defoliation and tree death, with consequences for the protection of ecosystems.
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Wang, Wenlong, Chenglong Gao, Lili Ren e Youqing Luo. "The Effect of Longwave Ultraviolet Light Radiation on Dendrolimus tabulaeformis Antioxidant and Detoxifying Enzymes". Insects 11, n. 1 (18 dicembre 2019): 1. http://dx.doi.org/10.3390/insects11010001.
Testo completoAbstract (sommario):
Longwave ultraviolet (UVA) light, in the range of 315–400 nm, has been widely used as a light source in the light trapping of insect pests. Previous studies have demonstrated the oxidative stress and lethal effect of UV radiation on insects. In this study, we evaluated the influence of UVA radiation on the antioxidant and detoxifying enzymes of Dendrolimus tabulaeformis. We tested the contents of malondialdehyde (MDA), hydroxyl radical (·OH), hydrogen peroxide (H2O2), reduced glutathione (GSH), and oxidized glutathione (GSSH) following different exposure time periods of UVA light irradiation on D. tabulaeformis adults. In addition, we investigated how the activities of antioxidant and detoxifying enzymes responded to UVA radiation by determining the activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), polyphenol oxidase (PPO), glutathione S-transferase (GST), glutathione reductase (GR), acetylcholinesterase (AChE), carboxylesterase (CarE), alkaline phosphatase (ALP), and acid phosphatase (ACP). Adults were exposed to UVA light for different time periods (0, 5, 15, 30, 60, and 120 min). We found that exposure to UVA light for 5 min resulted in rapid variation in the activities of the antioxidant and detoxification enzyme systems. However, the antioxidant capacity of females was incongruous with that of males following UVA irradiation. Our results confirmed that UVA light irradiation increased the level of oxidative stress and disturbed physiological detoxification in D. tabulaeformis adults. Based on the above results, we anticipated that further research of the mechanism of UVA irradiation on the antioxidant and detoxifying enzymes of D. tabulaeformis would gain more importance, allowing to develop and use new, less toxic and environmentally friendly pesticides.
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Vincent, Warwick F., e Suzanne Roy. "Solar ultraviolet-B radiation and aquatic primary production: damage, protection, and recovery". Environmental Reviews 1, n. 1 (1 gennaio 1993): 1–12. http://dx.doi.org/10.1139/a93-001.
Testo completoAbstract (sommario):
The continuing degradation of the Earth's ozone layer by atmospheric pollutants has generated concern about the impact of increased solar ultraviolet-B radiation (UV-B) on aquatic ecosystems. UV-B is a small (less than 1% of total energy) but highly active component of the solar spectrum that can penetrate to biologically significant depths in lakes and oceans. It has the potential to cause wide-ranging effects, including mutagenesis, chronic depression of key physiological processes, and acute physiological stress that may result in death. There are major uncertainties at present about the appropriate time scales and bioassay protocols for assessing such effects. Algal and cyanobacterial cells have four lines of defence against the toxic effects of UV-B. Some species avoid UV exposure by their choice of habitat or by migration strategies. Many species produce sunscreening pigments that filter out UV wavelengths; mycosporine-like amino acids are an especially important and ubiquitous class of such compounds. Most cells have a variety of defences against the toxic end products of UV radiation, such as radical scavenging by carotenoid pigments and superoxide dismutase. Finally, most cells have at least some ability to identify and repair the UV damage of DNA and other biomolecules. There is a large interspecific variability in the extent of each of these defence strategies. Continuing ozone depletion is not likely to cause an abrupt collapse of photosynthetic production, but may result in subtle, community-level responses that could ultimately impact on higher trophic levels.Key words: Arctic, Antarctic, photosynthesis, UV radiation, UV-B, ozone, atmospheric pollutants.
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Lu, Yanwei, Baoli Duan e Chunyang Li. "Physiological responses to drought and enhanced UV-B radiation in two contrasting Picea asperata populations". Canadian Journal of Forest Research 37, n. 7 (luglio 2007): 1253–62. http://dx.doi.org/10.1139/x07-006.
Testo completoAbstract (sommario):
The responses of two Picea asperata Mast. populations to enhanced ultraviolet B (UV-B) radiation under well-watered and drought conditions were investigated to further elucidate the effect of UV-B radiation on drought tolerance. Two P. asperata populations originating from wet- and dry-climate regions in China were employed. Drought significantly decreased the CO2 assimilation rate, stomatal conductance, and effective photosystem II quantum yield, while it significantly increased nonphotochemical quenching and the activity of superoxide dismutase in both populations. Compared with the wet-climate population, the dry-climate population was more acclimated to drought stress and showed much higher superoxide dismutase and ascorbate peroxidase activities and much lower levels of malondialdehyde and electrolyte leakage. Enhanced UV-B radiation also induced a significant decrease in chlorophyll content in both populations under well-watered conditions and a significant increase in UV-absorbing compounds in the wet-climate population. After exposure to different UV-B radiation levels and watering regimes over one growing season, the increases in malondialdehyde and electrolyte leakage, which are indicators of damage to the cellular membrane induced by drought, were less pronounced under the combination of enhanced UV-B radiation and drought than they were under well-watered conditions without enhanced UV-B radiation. In addition, an additive effect of drought and UV-B radiation on the CO2 assimilation rate and stomatal conductance was observed in the wet-climate population and on the activity of ascorbate peroxidase and nonphotochemical quenching in the dry-climate population. These results suggest that the UV-B exposure may have alleviated some of the damage induced by drought.
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Cai, Heng Jiang, Zhi Hua Zhang, Chang Fa Liu, Hai Feng Wei e Jun Xin Zhang. "Effects of UV-B Radiation on the Growth, Physiological and Biochemical Characteristics of Chondrus ocellatus Holm (Rhodophyta)". Advanced Materials Research 955-959 (giugno 2014): 222–26. http://dx.doi.org/10.4028/www.scientific.net/amr.955-959.222.
Testo completoAbstract (sommario):
Effects of enhanced ultraviolet B (UV-B, 280-320 nm) on macroalgae have gained particular attention in recent years. We investigated the changes in the growth, physiological and biochemical characteristics of C. ocellatus under UV-B radiation in this study. The results showed that UV-B could inhibit the growth of C. ocellatus (p<0.01) and the growth inhibition was more significant with increased doses of UV-B radiation. The effects of UV-B radiation on Chl-a content in C. ocellatus were not obvious. The soluble proteins content and MDA content in C. ocellatus were increased by UV-B radiation, and the increase of MDA content was extraordinary significant. The SOD activity and CAT activity were increased when the intensity of UV-B radiation was 7.2 J/m2, while the SOD activity and CAT activity were decreased when the intensity of UV-B radiation was 21.6 J/m2.
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Huovinen, Pirjo, Pablo Leal e Iván Gómez. "Interacting effects of copper, nitrogen and ultraviolet radiation on the physiology of three south Pacific kelps". Marine and Freshwater Research 61, n. 3 (2010): 330. http://dx.doi.org/10.1071/mf09054.
Testo completoAbstract (sommario):
Coastal ecosystems currently face multiple environmental impacts, such as nutrient loading, chemical contamination and enhanced ultraviolet (UV) radiation. Large kelps dominate many rocky shores worldwide and their capacity to handle environmental stress could have major consequences for these systems. The impacts of the interaction of copper (150 μg L–1), nitrate (350 μM) and short-term UV radiation on the physiological responses (photosynthetic activity, contents and anti-oxidant activity of phlorotannins) of three large kelps, Macrocystis pyrifera, Lessonia nigrescens and Durvillaea antarctica, from the coast of Chile were studied during a 2-week laboratory exposure. Macrocystis accumulated the most copper in its tissues, which decreased under nitrate-enriched conditions. Inhibition of photosynthetic activity by copper was observed in all three species (11–30%) after 12 days of incubation, with the strongest response in Lessonia. Nitrate enrichment mitigated the inhibitory effect of copper on photosynthesis in all three species. Soluble phlorotannin content decreased under copper and/or nitrate-enriched conditions with additional short-term UV exposure, particularly in Durvillaea, in which the strongest increase in the anti-oxidant activity of soluble phlorotannins was observed. Overall, the observed physiological responses reflect differences in morpho-functional processes and habitat characteristics of the three kelps and the importance of the interactions of multiple environmental factors.
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Kolokolova, A. Y., N. V. Ilyuhina, M. V. Trishkaneva e A. A. Korolev. "The effect of combining microwave and ultraviolet methods of plant materials processing on Salmonella culture inhibition". Proceedings of the Voronezh State University of Engineering Technologies 82, n. 1 (15 maggio 2020): 76–81. http://dx.doi.org/10.20914/2310-1202-2020-1-76-81.
Testo completoAbstract (sommario):
The research results concerning the application of physical methods of plant raw materials influencing - fresh beetroot - to inhibit microorganisms of Salmonella genus were presented in the work. Pathogenic microorganisms of Salmonella genus pose a threat to humans, being causative agents of typhoid fever, paratyphoid fever and other salmonellosis. The use of effective and available physical methods of influence in the fruit and vegetable processing technology allows us to ensure the maximum conservation of physiologically valuable components of the raw material and its safety. Microwave (microwave field) and ultraviolet radiation were chosen as physical methods for research. The sterilizing effect of the microwave field was clearly expressed - the bacteria survival after such a treatment was 2 or more times less than during heat treatment. Treatment with ultraviolet radiation has a bactericidal effect and is characterized by a minimal effect on the plant materials organoleptic properties. A comparative assessment of the effectiveness of the inhibition of the Salmonella test culture on diced fresh beets after treatment with the selected physical methods was carried out during the study. The samples temperature rose up to 43–46 °C under the influence of a microwave field in the selected mode with a power of 400 W, a duration of 40 s, and a flux density of 0.44 W / cm2. Treatment with ultraviolet (UV) radiation in the C-band (wavelength 253.7 nm) was carried out for 15 min with a dose of 50 kJ / m2 with a total power of ultraviolet lamps equal to 60 V. Processing of fresh chopped beets with UV radiation reduced the number of microorganisms by 5 orders of magnitude from the initial amount. Processing in a microwave field allowed to reduce the initial seed contamination of raw materials by 7 orders of magnitude. Sequential processing in a microwave field and subsequent ultraviolet radiation allowed us to reduce the initial beets seedling by 8 orders of magnitude. The combination of processing methods (microwave + UV) showed the effectiveness of their application to reduce pathogenic microflora.
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CALDERINI, D. F., X. C. LIZANA, S. HESS, C. R. JOBET e J. A. ZÚÑIGA. "Grain yield and quality of wheat under increased ultraviolet radiation (UV-B) at later stages of the crop cycle". Journal of Agricultural Science 146, n. 1 (6 settembre 2007): 57–64. http://dx.doi.org/10.1017/s0021859607007447.
Testo completoAbstract (sommario):
SUMMARYThe increase of ultraviolet (UV-B) radiation could be a challenge for wheat production systems in Southern Chile, as in other areas. Previous reports have shown that increased UV-B radiation decreases wheat yield by affecting both grain number and grain weight. However, contrasting results have also been published showing no effect on wheat biomass and grain yield. In addition, little is known about the effect of higher UV-B radiation at particular periods of the crop cycle on grain quality traits. The objective of the present study was to evaluate grain yield, yield components and grain quality in response to increased UV-B radiation during key periods of yield component determination. Two experiments were carried out under field conditions in the Universidad Austral de Chile (latitude 39°62′S). Two spring wheat cultivars were exposed to two periods of supplemented UV-B radiation (280–320 nm): (i) between booting and anthesis, c. 20 days, and (ii) from 10 days after anthesis until physiological maturity, c. 40 days. Ultraviolet radiation was increased to levels of 3·8 and 4·9 kJ/m2/day in experimental years 1 and 2, respectively, by using UV-B lamps. At harvest, plants were sampled to quantify aboveground biomass, grain yield, grain number and average grain weight. In addition, protein and gluten concentration of grains were measured. Grain yield was not affected (P>0·05) by the UV-B increase at pre- or at post-anthesis treatments. Similar results were found for each yield component. In addition, grain protein and gluten concentration showed similar values in the increased UV-B and control treatments. Therefore, if increases in UV-B radiation take place during the latter stages of the crop cycle as is expected, the present results do not support the speculation that increases of UV-B radiation in Southern Chile will compromise wheat production systems.
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Watson, Megan K., Mark A. Mitchell, Adam W. Stern, Amber L. Labelle, Stephen Joslyn, Timothy M. Fan, Melissa Cavaretta, Micah Kohles e Kemba Marshall. "EVALUATING THE CLINICAL AND PHYSIOLOGICAL EFFECTS OF LONG-TERM ULTRAVIOLET B RADIATION ON RABBITS (ORYCTOLAGUS CUNICULUS)". Journal of Exotic Pet Medicine 28 (gennaio 2019): 43–55. http://dx.doi.org/10.1053/j.jepm.2018.04.016.
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Yoon, Hyo In, Hyun Young Kim, Jaewoo Kim, Myung-Min Oh e Jung Eek Son. "Quantitative Analysis of UV-B Radiation Interception in 3D Plant Structures and Intraindividual Distribution of Phenolic Contents". International Journal of Molecular Sciences 22, n. 5 (7 marzo 2021): 2701. http://dx.doi.org/10.3390/ijms22052701.
Testo completoAbstract (sommario):
Ultraviolet-B (UV-B) acts as a regulatory stimulus, inducing the dose-dependent biosynthesis of phenolic compounds such as flavonoids at the leaf level. However, the heterogeneity of biosynthesis activation generated within a whole plant is not fully understood until now and cannot be interpreted without quantification of UV-B radiation interception. In this study, we analyzed the spatial UV-B radiation interception of kales (Brassica oleracea L. var. Acephala) grown under supplemental UV-B LED using ray-tracing simulation with 3-dimension-scanned models and leaf optical properties. The UV-B-induced phenolic compounds and flavonoids accumulated more, with higher UV-B interception and younger leaves. To distinguish the effects of UV-B energy and leaf developmental age, the contents were regressed separately and simultaneously. The effect of intercepted UV-B on flavonoid content was 4.9-fold that of leaf age, but the effects on phenolic compound biosynthesis were similar. This study confirmed the feasibility and relevance of UV-B radiation interception analysis and paves the way to explore the physical and physiological base determining the intraindividual distribution of phenolic compound in controlled environments.
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Revin, Victor, Nelli Atykyan, Ekaterina Lyovina, Yuliya Dragunova e Victoriya Ushkina. "Effect of ultraviolet radiation on physiological and biochemical properties of yeast Saccharomyces cerevisiae during fermentation of ultradispersed starch raw material". Electronic Journal of Biotechnology 31 (gennaio 2018): 61–66. http://dx.doi.org/10.1016/j.ejbt.2017.11.004.
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Watson, Megan K., Adam W. Stern, Amber L. Labelle, Stephen Joslyn, Timothy M. Fan, Katie Leister, Micah Kohles, Kemba Marshall e Mark A. Mitchell. "Evaluating the Clinical and Physiological Effects of Long Term Ultraviolet B Radiation on Guinea Pigs (Cavia porcellus)". PLoS ONE 9, n. 12 (17 dicembre 2014): e114413. http://dx.doi.org/10.1371/journal.pone.0114413.
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Li, Chunchun, Weining Yuan, Yuping Gou, Kexin Zhang, Qiangyan Zhang, Jing-Jiang Zhou e Changzhong Liu. "The Impact of Ultraviolet-B Radiation on the Sugar Contents and Protective Enzymes in Acyrthosiphon pisum". Insects 12, n. 12 (25 novembre 2021): 1053. http://dx.doi.org/10.3390/insects12121053.
Testo completoAbstract (sommario):
Natural and anthropogenic changes have been altering many environmental factors. These include the amount of solar radiation reaching the Earth’s surface. However, the effects of solar radiation on insect physiology have received little attention. As a pest for agriculture and horticulture, aphids are one of the most difficult pest groups to control due to their small size, high fecundity, and non-sexual reproduction. Study of the effects of UV-B radiation on aphid physiology may provide alternative control strategies in pest management. In this study, we examined the effects of UV-B radiation on protein and sugar contents, as well as the activities of protective enzymes, of the red and green morphs of the pea aphid over eight generations. The results indicated a significant interaction between UV-B radiation and aphid generations. Exposure of the pea aphids to UV-B radiation caused a significant decrease in the protein content and a significant increase in the glycogen and trehalose contents at each generation as measured in whole aphid bioassays. The enzyme activity of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) of the pea aphids changed significantly at each generation with UV-B treatments. The SOD activity increased over eight generations to the highest level at G7 generation. However, the enzyme activity of CAT first increased and then decreased with UV-B treatments, and POD mostly gradually decreased over the eight generations. Therefore, UV-B radiation is an environmental factor that could result in physiological changes of the pea aphid. Moreover, our study discovered that red and green aphids did not display a significant consistent difference in the response to the UV-B treatments. These results may prove useful in future studies especially for assessing their significance in the adaptation and management against UV-B radiation.
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Dzierżyńska, Anna. "„Good” and „Bad” Ozone - Evaluation on the Basis of Plant Reaction to Ozone / „Dobry” I „Zły” Ozon - Ocena Na Podstawie Reakcji Roślin Na Ozon". Chemistry-Didactics-Ecology-Metrology 17, n. 1-2 (1 dicembre 2012): 97–112. http://dx.doi.org/10.2478/cdem-2013-0009.
Testo completoAbstract (sommario):
Abstract Ozone is a natural and artificial chemical compound of Earth’s atmosphere. O3 is an absorbent of ultraviolet and infrared radiation and has strong oxidative properties. In the stratosphere the ozone layer protects the planet’s surface from dangerous UV radiation, its indirect effect on plant organisms is positive so stratospheric ozone can be called “good” ozone. The depletion of the ozone layer, as a result of atmosphere pollution, described as an ozone “hole” is causing UVB radiation enhanced level on Earth’s surface. The genetic, cytological, physiological and morphological reaction of prolonged UVB exposure in plants is twofold: it damages plants and simultaneously plants protect themselves and repair their injuries. The ozone in the troposphere originates from natural sources and is also a secondary pollutant, formed in photochemical reactions, leading to “smog” and ozone “spots” occurrence. As a strong oxidant, O3 is directly toxic to plants and can be recognized as “bad” ozone. Ozone is also classified as a “greenhouse” gas, participating in global warming. It is difficult to value the impact of O3 as a “greenhouse” gas on plants. The combined effect of O3 changes in the stratosphere and troposphere on plants can be estimated as loss in crop yield and in productivity of natural ecosystems
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Hock, Maria, Carolin Plos, Maria Sporbert e Alexandra Erfmeier. "Combined Effects of UV-B and Drought on Native and Exotic Populations of Verbascum thapsus L." Plants 9, n. 2 (18 febbraio 2020): 269. http://dx.doi.org/10.3390/plants9020269.
Testo completoAbstract (sommario):
During plant invasions, exotic species have to face new environmental challenges and are affected by interacting components of global change, which may include more stressful environmental conditions. We investigated an invasive species of New Zealand grasslands, commonly exposed to two concomitant and limiting abiotic factors—high levels of ultraviolet-B radiation and drought. The extent to which Verbascum thapsus may respond to these interacting stress factors via adaptive responses was assessed in a greenhouse experiment comprising native German plants and plants of exotic New Zealand origins. Plants from both origins were grown within four treatments resulting from the crossed combinations of two levels of UV-B and drought. Over twelve weeks, we recorded growth, morphological characteristics, physiological responses and productivity. The results showed that drought stress had the strongest effect on biomass, morphology and physiology. Significant effects of UV-B radiation were restricted to variables of leaf morphology and physiology. We found neither evidence for additive effects of UV-B and drought nor origin-dependent stress responses that would indicate local adaptation of native or exotic populations. We conclude that drought-resistant plant species might be predisposed to handle high UV-B levels, but emphasize the importance of setting comparable magnitudes in stress levels when testing experimentally for antagonistic interaction effects between two manipulated factors.
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Jacobo-Velázquez, Daniel A., Melissa Moreira-Rodríguez e Jorge Benavides. "UVA and UVB Radiation as Innovative Tools to Biofortify Horticultural Crops with Nutraceuticals". Horticulturae 8, n. 5 (28 aprile 2022): 387. http://dx.doi.org/10.3390/horticulturae8050387.
Testo completoAbstract (sommario):
The consumption of fruits and vegetables is related to the prevention and treatment of chronic–degenerative diseases due to the presence of secondary metabolites with pharmaceutical activity. Most of these secondary metabolites, also known as nutraceuticals, are present in low concentrations in the plant tissue. Therefore, to improve the health benefits of horticultural crops, it is necessary to increase their nutraceutical content before reaching consumers. Applying ultraviolet radiation (UVR) to fruits and vegetables has been a simple and effective technology to biofortify plant tissue with secondary metabolites. This review article describes the physiological and molecular basis of stress response in plants. Likewise, current literature on the mechanisms and effects of UVA and UVB radiation on the accumulation of different bioactive phytochemicals are reviewed. The literature shows that UVR is an effective tool to biofortify horticultural crops to enhance their nutraceutical content.
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de Almeida, Sérgio L., Éder C. Schmidt, Debora Tomazi Pereira, Marianne Kreusch, Marthiellen R. de L. Felix, Luz K. P. Osorio, Roberta de Paula Martins et al. "Effect of ultraviolet-B radiation in laboratory on morphological and ultrastructural characteristics and physiological parameters of selected cultivar of Oryza sativa L." Protoplasma 250, n. 6 (25 maggio 2013): 1303–13. http://dx.doi.org/10.1007/s00709-013-0512-0.
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Fang, Yujie, e Minato Wakisaka. "A Review on the Modified Atmosphere Preservation of Fruits and Vegetables with Cutting-Edge Technologies". Agriculture 11, n. 10 (12 ottobre 2021): 992. http://dx.doi.org/10.3390/agriculture11100992.
Testo completoAbstract (sommario):
Respiration and microbial infection are important causes of postharvest spoilage of fruits and vegetables (F&V). Atmosphere storage technology can significantly reduce postharvest losses. This comprehensive review aims to cover recent progress in the application of atmosphere storage to F&V preservation, not only focusing on the effect of gas conditions but also evaluating combination applications involving newer preservation technologies, including ethylene scavengers, high-pressure and decompression technology, ozone, ultraviolet radiation, active packaging, high-voltage electrostatic field, plasma treatment, and pulse-controlled atmosphere. Appropriate choice of storage conditions optimal for each F&V is essential since the physiological properties and sensory qualities are affected by them. The combination of atmosphere storage with these emerging technologies could contribute to significant reductions in food loss during storage.
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Lucas, José A., Ana García-Villaraco, Beatriz Ramos-Solano, Khalid Akdi e Francisco Javier Gutierrez-Mañero. "Lipo-Chitooligosaccharides (LCOs) as Elicitors of the Enzymatic Activities Related to ROS Scavenging to Alleviate Oxidative Stress Generated in Tomato Plants under Stress by UV-B Radiation". Plants 11, n. 9 (5 maggio 2022): 1246. http://dx.doi.org/10.3390/plants11091246.
Testo completoAbstract (sommario):
Exposure to ultraviolet-B (UV-B) radiation can lead to oxidative damage in plants, increasing reactive oxygen species (ROS) production. To overcome ROS burst, plants have antioxidant mechanisms related to ROS scavenging which can be improved by elicitation with biological agents or derived molecules (elicitors), as they can trigger a physiological alert state called “priming”. This work describes the effects of lipo-chitooligosaccharides (LCOs) treatment applied to tomato plants under UV-B stress. The LCOs used in the study are produced by three species of the genus Ensifer (formerly Sinorhizobium) (SinCEU-1, SinCEU-2, and SinCEU-3) were assayed on tomato plants under UV-B stress. LCOs were able to significantly increase most of the enzymatic activities related to ROS scavenging while non-enzymatic antioxidants were not modified. This response was associated with a lower oxidative stress, according to malondialdehyde (MDA) levels and the higher antioxidant capacity of the plants. Furthermore, the photosynthetic efficiency of LCOs-treated plants indicated a better physiological state than the control plants. Therefore, although more studies and deepening of certain aspects are necessary, LCOs have shown great potential to protect plants from high UV-B radiation conditions.
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Katsoulas, Nikolaos, Anastasia Bari e Chryssoula Papaioannou. "Plant Responses to UV Blocking Greenhouse Covering Materials: A Review". Agronomy 10, n. 7 (15 luglio 2020): 1021. http://dx.doi.org/10.3390/agronomy10071021.
Testo completoAbstract (sommario):
Pure polyethylene (PE) is enriched with several additives to make it a smart application material in protected cultivation, as a cover material for either greenhouses or screenhouses. When this material completely or partially absorbs ultraviolet (UV) solar radiation, then it is called UV blocking material. The current work presents a review on the effects of the UV blocking covering materials on crop growth and development. Despite the passage of several years and the evolution of the design technology of plastic greenhouse covers, UV blocking materials have not ceased to be a rather interesting technique for the protection of several vegetable and ornamental species. Much of the research on UV blocking materials focuses on their indisputable effect on reducing the activity of pests and viral-related diseases, rather than on the effects on the crop physiology itself. In the present paper, representative studies dealing with the effect of the UV blocking materials on the agronomic factors of different crops are presented and discussed. The results reveal that UV blocking materials have mainly positive effects on the different plant physiological functions, such as photosynthesis and transpiration rate, and on growth characteristics, while they might have a negative effect on the production and content of secondary compounds, as anthocyanins and total phenolics.
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Silva, Isabel, Marta Alves, Catarina Malheiro, Ana Rita R. Silva, Susana Loureiro, Isabel Henriques e M. Nazaret González-Alcaraz. "Short-Term Responses of Soil Microbial Communities to Changes in Air Temperature, Soil Moisture and UV Radiation". Genes 13, n. 5 (10 maggio 2022): 850. http://dx.doi.org/10.3390/genes13050850.
Testo completoAbstract (sommario):
We analyzed the effects on a soil microbial community of short-term alterations in air temperature, soil moisture and ultraviolet radiation and assessed the role of invertebrates (species Enchytraeus crypticus) in modulating the community’s response to these factors. The reference soil, Lufa 2.2, was incubated for 48 h, with and without invertebrates, under the following conditions: standard (20 °C + 50% water holding capacity (WHC)); increased air temperature (15–25 °C or 20–30 °C + 50% WHC); flood (20 °C + 75% WHC); drought (20 °C + 25% WHC); and ultraviolet radiation (UV) (20 °C + 50% WHC + UV). BIOLOG EcoPlates and 16S rDNA sequencing (Illumina) were used to assess the microbial community’s physiological profile and the bacterial community’s structure, respectively. The bacterial abundance (estimated by 16S rDNA qPCR) did not change. Most of the conditions led to an increase in microbial activity and a decrease in diversity. The structure of the bacterial community was particularly affected by higher air temperatures (20–30 °C, without E. crypticus) and floods (with E. crypticus). Effects were observed at the class, genera and OTU levels. The presence of invertebrates mostly resulted in the attenuation of the observed effects, highlighting the importance of considering microbiome–invertebrate interactions. Considering future climate changes, the effects described here raise concern. This study provides fundamental knowledge to develop effective strategies to mitigate these negative outcomes. However, long-term studies integrating biotic and abiotic factors are needed.
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Kyyak, N. Ya, O. V. Lobachevska e Ya D. Khorkavtsiv. "Morpho-physiological reactions of gravisensitivity and adaptation to UV-radiation of the moss Bryum Caespiticiumhedw. from Antarctica". Kosmìčna nauka ì tehnologìâ 27, n. 5 (2021): 47–59. http://dx.doi.org/10.15407/knit2021.05.047.
Testo completoAbstract (sommario):
The adaptive physiological reactions of the moss Bryum caespiticium Hedw. from Antarctica to the influence of UV radiation and gravimorphoses as a factor of adaptive plasticity, associated with environmental conditions, were studied. As a control, B. caespiticium plants were collected in the Nature Reserve “Roztochchia” (Lviv region). In investigations, we used a sterile laboratory culture of mosses grown under controlled conditions in a phytotron. Moss shoots were irradiated with UV rays generated by an ultraviolet lamp OSRAM with an intensity of 4 kW/m2, which caused 50 % inhibition of plant regeneration (ED50). Physiological parameters were determined 24 h after exposure to UV radiation. The influence of gravity on the morphological form of B. caespiticium gametophyte turf and the interaction of light and gravity in gravi-/phototropism as a manifestation of gravimorphoses adaptability were analyzed. One of the objectives was to investigate the formation of gravimorphoses as a result of the initiation of cells’ branching processes and the formation of gametophore buds and to evaluate their role in the life cycle of B. caespiticium under extreme conditions. For this, we determined the branching coefficient of the gravitropic protonema, the inclination angle of the branches and the buds’ development depending on the interaction of photo- and gravitropism, under the influence of red and blue light, and the effect of UV on gravisensitivity. The influence of physiologically active red and blue light on the branching activity and bud formation on the gravitropic protonema of the Antarctic moss B. caespiticium was investigated. It was found that red light mainly inhibited graviperception and gravitropic growth of protonemata cells, resulting in a change of the response to gravity, but initiated high branching activity and, accordingly, another morphological form of turf. After the influence of the blue light, intensive bud formation and gametophore development were observed. Thus, gravitation promoted morphological variability and changes in the functional activity of cells at the juvenile stage of the protonemata development, which is important for the survival of the moss under extreme environmental conditions. After UV irradiation the gravisensitivity of the B. caespiticium protonemata decreased. However, due to the resistance of the moss sample from Antarctica to the prolonged influence of UV rays, gravitropic growth was not completely blocked, as in plants from the Lviv region. The effect of the ultraviolet irradiation on the antioxidant activity, the content of soluble (vacuolar) and cell wall-bound fractions of UV-absorbing phenolic components, flavonoids content and their absorption spectra, as well as the amount of carotenoids and anthocyanins in B. caespiticium shoots, were determined. It was established that B. caespiticium plants from Antarctica have 1.5 times higher antioxidant activity compared to plants from the Lviv region, which confirms the high level of protection against oxidative damage. UV irradiation activates the synthesis of UV-absorbing phenolic compounds in mosses. The shoots of B. caespiticium from Antarctica defined a higher content of phenols compared to samples from the Lviv region and their significant increase under the influence of UV radiation. The content of UV-absorbing compounds bound with the cell wall was higher than the concentration of soluble phenolic compounds, both in plants from Antarctica and in samples from the Lviv region, which indicates their participation in the mechanisms of cells protection from UV radiation. It was shown that the influence of UV irradiation induced an increase of flavonoids’ content in the shoots of both samples of B. caespiticium, but for plants from Antarctica, the concentration of flavonoids after stress was 1.7 times higher than in plants from the Lviv region. The absorption spectra of flavonoids revealed flavonols rutin and quercetin and flavone luteolin in both samples of B. caespiticium, which provide effective cells absorption of UV rays. The higher content of anthocyanins and carotenoids in moss shoots from Antarctica both in the control sample and after the exposure to UV radiation promotes the protection against damage and formation of the adaptive potential.
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Retana-Cordero, Marlon, Samson Humphrey e Celina Gómez. "Effect of Radiation Quality and Relative Humidity on Intumescence Injury and Growth of Tomato Seedlings". HortScience 57, n. 10 (ottobre 2022): 1257–66. http://dx.doi.org/10.21273/hortsci16712-22.
Testo completoAbstract (sommario):
Intumescence is a physiological disorder that affects some tomato (Solanum lycopersicum) cultivars grown in environments lacking ultraviolet radiation. Both far-red (FR) radiation and blue light have been shown to help mitigate this disorder. Thus, the objectives of this study were to characterize and compare intumescence injury and growth of various tomato cultivars propagated under different radiation qualities (Expt. 1) and to evaluate plant responses to the interactive effect of radiation quality and relative humidity (RH) (Expt. 2). Seedlings of six cultivars in Expt. 1 were grown under broad band white light (W), W and blue with (WBFR) or without (WB) FR radiation, and blue and red light with FR radiation (BRFR). Seedlings of four cultivars in Expt. 2 were grown under W or WBFR and a low (≈50%) or high (≈95%) RH. In both experiments, seedlings were grown under a daily light integral of ≈13 mol·m‒2·d‒1 (200 ± 4 μmol·m‒2·s‒1 for 18 h·d−1). FR radiation was provided using 20 ± 2 μmol·m−2·s−1 delivered throughout the entire photoperiod or at the end-of-day (EOD) in Expts. 1 or 2, respectively. Intumescence was generally suppressed when seedlings in Expt. 1 were grown under BRFR and WBFR, which also corresponded with the general response to stomatal conductance (gs). In contrast, seedlings grown under W had the highest incidence of intumescence, ranging from 23% to 69% across cultivars. The high blue photon flux (PF) ratio in WB was not effective at suppressing intumescence injury without FR radiation, although incidence and severity were lower compared with W. In Expt. 2, intumescence incidence was generally lower in seedlings grown under WBFR, and RH had small effects on intumescence. In both experiments, younger leaves were relatively less affected by intumescence, suggesting that a developmental factor is associated with the disorder. As expected, providing FR radiation resulted in a general increase in stem height across cultivars and in both experiments. The high RH provided in Expt. 2 also resulted in an increase in stem height. However, seedlings under low RH produced larger leaves, lower specific leaf area, and more shoot dry mass than those under high RH. Overall, our findings show that applying FR radiation helps suppress intumescence, but strategies are needed to minimize issues with excessive stem elongation.
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Mishra, Anu, Himansu Shekhar Mohapatra e B. S. Butola. "Imparting Protection against UV Radiations Using <i>In Situ</i> Coating of Titanium Dioxide on Textiles". International Letters of Chemistry, Physics and Astronomy 82 (12 marzo 2019): 14–20. http://dx.doi.org/10.56431/p-26i977.
Testo completoAbstract (sommario):
Protection against ultraviolet radiation is one of the areas, in which considerable attention is being paid. Application of a wash durable finish on cotton fabric to protect the wearer from these radiations remains a challenge. The harmful effects of UV radiations result in the form of eye disorders, accelerated ageing of skin, DNA damage and cause of cancer. The current study focuses upon the use of TiO2 on cotton fabric to impart UV protection. TiO2 is deposited on cotton fabric using its pre-cursor. Sol-gel method has been used to convert pre-cursor into titanium oxide directly on fabric surface. The deposition was further stabilized on fabric surface by various heat treatments such as curing, hydrothermal and solvothermal treatments. It has been found that the TiO2 remains wash durable with a reasonably high degree of UV protection after hydrothermal and solvothermal treatments. EDX and ICP-MS techniques were used to examine the add-on % of TiO2 on cotton fabrics. The morphology of the TiO2 coated cotton fabric was studied using Field emission scanning electron microscopy. The measurement of UV protection property of the fabric has been carried out using UV-visible spectrophotometer (UV-2000F, Labsphere, USA).
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Ren, Lingxiao, Jing Huang, Huagang Zhu, Wei Jiang, Haoyu Wu, Yuyang Pan, Yinghui Mao, Minghan Luo e Taeseop Jeong. "Effects of Algal Utilization of Dissolved Organic Phosphorus by Microcystis Aeruginosa on Its Adaptation Capability to Ambient Ultraviolet Radiation". Journal of Marine Science and Engineering 10, n. 9 (6 settembre 2022): 1257. http://dx.doi.org/10.3390/jmse10091257.
Testo completoAbstract (sommario):
Phosphorus (P) plays an important role in eutrophication and algal adaptation to environmental stresses; therefore, a better understanding of the impact of P is essential to control cyanobacterial bloom. In this study, Microcystis aeruginosa is treated with 5 h of ambient irradiation in the culture medium with different availabilities of dissolved organic P (DOP) and dissolved organic matter (DOM) to explore algal physiological responses. Compared to photosynthetically active radiation (PAR), ambient UV-A and UV-B radiation exerted oxidative stresses and has inhibitive effects on the growth and photosynthesis of M. aeruginosa. However, M. aeruginosa had a strong adaptation capability, and the negative effects of UV radiation can be alleviated with DOM addition in the DOP-rich medium. The adaptation of M. aeruginosa to UV radiation in the DOP-rich waters can be mainly achieved through hydrolysis of DOP and metabolism of dissolved inorganic P (DIP), and the DOP utilization behaviors of M. aeruginosa might greatly affect algal UV adaptation capability. In the DOP-rich medium without DOM, the great inactivation of algal alkaline phosphatase (APase) after UV radiation could result in worse affinity for DOP, slower DOP uptake and lower cellular P quota. Consequently, the P demand of M. aeruginosa could not be satisfied for UV adaptation processes, including decreasing UV-induced damages and promoting self-repair. However, DOM could act as an antioxidant and significantly decrease APase inactivation of UV-radiated M. aeruginosa. In the DOP-rich medium with DOM, DOP utilization by M.aeruginosa in the UV-A and UV-B treatments is promoted and algal demand for P is satisfied for its adaptation, such as enhanced production of photosynthetic pigments, increased superoxide dismutase (SOD) activity, recovery of photosynthetic efficiency, etc. Overall, our findings indicate the close relationship between algal DOP utilization and the adaptation to ambient UV radiation of typical cyanobacteria in DIP-limited and DOP-enriched natural waters.
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Francini e Sebastiani. "Abiotic Stress Effects on Performance of Horticultural Crops". Horticulturae 5, n. 4 (26 settembre 2019): 67. http://dx.doi.org/10.3390/horticulturae5040067.
Testo completoAbstract (sommario):
The yield and quality of horticultural crops mainly depend on genotype, environmental conditions, and cultivation management. Abiotic stresses, such as adverse environmental conditions, can strongly reduce crop performance, with crop yield losses ranging from 50% to 70%. The most common abiotic stresses are represented by cold, heat, drought, flooding, salinity, nutrient deficiency, and high and low light intensities, including ultraviolet radiation. These abiotic stresses affect multiple physiological and biochemical processes in plants. The ability of plants to face these stresses depends on their adaptation aptitude, and tolerant plants may express different strategies to adapt to or avoid the negative effects of abiotic stresses. At the physiological level, photosynthetic activity and light-use efficiency of plants may be modulated to enhance tolerance against the stress. At the biochemical level, several antioxidant systems can be activated, and many enzymes may produce stress-related metabolites to help avoid cellular damage, including such compounds as proline, glycine betaine, amino acids, etc. This special issue gathers eight papers; three are reviews and five are research papers. Two reviews are focused on the application of appropriate agronomic strategies for counteracting the negative effects of abiotic stresses. The third review is based on ornamental plant production under drought stress conditions and the effect on their ornamental quality. The research papers report the effect of climate change on crop development, yield, and quality. Abiotic stresses have been proven to reduce crop performance and yield. Research studies are essential for understanding the key adaptation strategies of plants that can be exploited for improving the crop stress tolerance.
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LAI, Yong-Zhong, e Kun-Shan GAO. "EFFECTS OF SOLAR ULTRAVIOLET RADIATION ON PHYSIOLOGICAL CHARACTERISTICS OF THE AQUATIC-LIVING COLONIES OF NOSTOC FLAGELLIFORME CULTURED INDOOR". Acta Hydrobiologica Sinica 33, n. 3 (10 giugno 2009): 435–41. http://dx.doi.org/10.3724/sp.j.1035.2009.00435.
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MANEK, ADITYA K., MAUD C. O. FERRARI, JEFF M. SEREDA, SOM NIYOGI e DOUGLAS P. CHIVERS. "The effects of ultraviolet radiation on a freshwater prey fish: physiological stress response, club cell investment, and alarm cue production". Biological Journal of the Linnean Society 105, n. 4 (24 febbraio 2012): 832–41. http://dx.doi.org/10.1111/j.1095-8312.2011.01829.x.
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Qaderi, Mirwais M., Navjeet K. Basraon, C. C. Chinnappa e David M. Reid. "Combined Effects of Temperature, Ultraviolet‐B Radiation, and Watering Regime on Growth and Physiological Processes in Canola (Brassica napus) Seedlings". International Journal of Plant Sciences 171, n. 5 (giugno 2010): 466–81. http://dx.doi.org/10.1086/652389.
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Ramamoorthy, Purushothaman, Raju Bheemanahalli, Stephen L. Meyers, Mark W. Shankle e Kambham Raja Reddy. "Drought, Low Nitrogen Stress, and Ultraviolet-B Radiation Effects on Growth, Development, and Physiology of Sweetpotato Cultivars during Early Season". Genes 13, n. 1 (16 gennaio 2022): 156. http://dx.doi.org/10.3390/genes13010156.
Testo completoAbstract (sommario):
Drought, ultraviolet-B (UV-B), and nitrogen stress are significant constraints for sweetpotato productivity. Their impact on plant growth and development can be acute, resulting in low productivity. Identifying phenotypes that govern stress tolerance in sweetpotatoes is highly desirable to develop elite cultivars with better yield. Ten sweetpotato cultivars were grown under nonstress (100% replacement of evapotranspiration (ET)), drought-stress (50% replacement of ET), UV-B (10 kJ), and low-nitrogen (20% LN) conditions. Various shoot and root morphological, physiological, and gas-exchange traits were measured at the early stage of the crop growth to assess its performance and association with the storage root number. All three stress factors caused significant changes in the physiological and root- and shoot-related traits. Drought stress reduced most shoot developmental traits (29%) to maintain root growth. UV-B stress increased the accumulation of plant pigments and decreased the photosynthetic rate. Low-nitrogen treatment decreased shoot growth (11%) and increased the root traits (18%). The highly stable and productive cultivars under all four treatments were identified using multitrait stability index analysis and weighted average of absolute scores (WAASB) analyses. Further, based on the total stress response indices, ‘Evangeline’, ‘O’Henry’, and ‘Beauregard B-14’ were identified as vigorous under drought; ‘Evangeline’, ‘Orleans’, and ‘Covington’ under UV-B; and ‘Bonita’, ‘Orleans’, and ‘Beauregard B-14’ cultivars showed greater tolerance to low nitrogen. The cultivars ‘Vardaman’ and ‘NC05-198’ recorded a low tolerance index across stress treatments. This information could help determine which plant phenotypes are desirable under stress treatment for better productivity. The cultivars identified as tolerant, sensitive, and well-adapted within and across stress treatments can be used as source materials for abiotic stress tolerance breeding programs.
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Ortega-Hernández, Nair, Welti-Chanes, Cisneros-Zevallos e Jacobo-Velázquez. "Wounding and UVB Light Synergistically Induce the Biosynthesis of Phenolic Compounds and Ascorbic Acid in Red Prickly Pears (Opuntia ficus-indica cv. Rojo Vigor)". International Journal of Molecular Sciences 20, n. 21 (25 ottobre 2019): 5327. http://dx.doi.org/10.3390/ijms20215327.
Testo completoAbstract (sommario):
The present study evaluated the effects of ultraviolet B (UVB) radiation and wounding stress, applied alone or combined, on the biosynthesis of phenolic compounds and ascorbic acid in the peel and pulp of red prickly pear (Opuntia ficus-indica cv. Rojo Vigor). Whole and wounded-fruit samples were treated with UVB radiation (6.4 W·m−2) for 0 and 15 min, and stored for 24 h at 16 °C. Phytochemical analyses were performed separately in the peel and pulp. The highest phenolic accumulation occurred after storage of the whole tissue treated with UVB, where the main phenolic compounds accumulated in the peel and pulp were quercetin, sinapic acid, kaempferol, rosmarinic acid, and sinapoyl malate, showing increases of 709.8%, 570.2%, 442.8%, 439.9%, and 186.2%, respectively, as compared with the control before storage. Phenylalanine ammonia-lyase (PAL) activity was increased after storage of the whole and wounded tissue treated with UVB light, and this increase in PAL activity was associated to phenolic accumulation. On the other hand, l-galactono-γ-lactone dehydrogenase (GalLDH) activity and ascorbic acid biosynthesis was enhanced due to UVB radiation, and the effect was increased when UVB was applied in the wounded tissue showing 125.1% and 94.1% higher vitamin C content after storage when compared with the control. Respiration rate was increased due to wounding stress, whereas ethylene production was increased by wounding and UVB radiation in prickly pears. Results allowed the generation of a physiological model explaining the UVB and wound-induced accumulation of phenolic compounds and ascorbic acid in prickly pears, where wounding facilitates UVB to access the underlying tissue and enhances an apparent synergistic response.
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Khotimah, Husnul, Dina Dewi Lestari Ismail, Dhelya Widasmara, Wibi Riawan, Ekowati Retnaningtyas, Raditya Weka Nugraheni, Oktavia Eka Puspita, Oktavia Rahayu Adianingsih, Mardiyah Mardiyah e Andri Setiawan. "Ameliorative effect of gel combination of Centella asiatica extract transfersomes and rosemary essential oil nanoemulsion against UVB-induced skin aging in Balb/c mice". F1000Research 11 (8 marzo 2022): 288. http://dx.doi.org/10.12688/f1000research.109318.1.
Testo completoAbstract (sommario):
Background: Ultraviolet B (UVB) radiation induces physiological and morphological photoaging of the skin resulting in wrinkles, and loss of elasticity. This study analyzed nanoencapsulation of a gel combination of Centella asiatica (CA) transfersomes and rosemary essential oil (REO) nanoemulsion with lipid-based nanocarriers for the ability of both biological compounds to synergistically prevent UVB radiation, along with ameliorative and anti-aging effects. Methods: To ensure the quality, lipid-based nanocarriers of transfersomes and nanoemulsion were characterized based on physicochemical properties such as particle size distribution, polydispersity index, zeta potential. In vivo studies were used to determine the biological effects of a gel combination of CA transfersomes, and REO nanoemulsion applied topically two weeks before UVB radiation (840 mJ/cm2) in BALB/c hairless mice. Results: Results showed that the optimum lipid-based nanocarriers had a particle size of 43.97 ± 5.6 nm, a polydispersity index of 0.64 ± 0.01, and a zeta potential of -10.91 ± 1.99 mV. In vivo experiments revealed that topical application of a gel combination of CA transfersomes and REO nanoemulsion significantly ameliorated wrinkle formation, epidermal hyperplasia, and collagen fiber arrangement caused by UVB exposure. Further, the gel combining CA transfersomes and REO nanoemulsion suppressed lipid peroxidation by decreasing the expression of malondialdehyde (MDA) and collagen destruction by inhibiting matrix metalloproteinase-9 (MMP-9) expression. Moreover, the gel combination of CA transfersomes and REO nanoemulsion upregulated type I collagen through activation of the transforming growth factor-β (TGF-β)/Smad pathway, thereby recovering the density of collagen fiber reduced by UVB radiation. Conclusions: Overall, these data indicate that topical application of a gel combination of CA transfersomes and REO nanoemulsion could act synergistically and potentially prevents oxidative stress and collagen degradation in the skin from UVB-induced photoaging.
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Li, Zheng-Ke, Guo-Zheng Dai, Philippe Juneau e Bao-Sheng Qiu. "Different physiological responses of cyanobacteria to ultraviolet-B radiation under iron-replete and iron-deficient conditions: Implications for underestimating the negative effects of UV-B radiation". Journal of Phycology 53, n. 2 (7 marzo 2017): 425–36. http://dx.doi.org/10.1111/jpy.12517.
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SCHOEDL, K., R. SCHUHMACHER e A. FORNECK. "Correlating physiological parameters with biomarkers for UV-B stress indicators in leaves of grapevine cultivars Pinot noir and Riesling". Journal of Agricultural Science 151, n. 2 (24 luglio 2012): 189–200. http://dx.doi.org/10.1017/s0021859612000536.
Testo completoAbstract (sommario):
SummaryThe robustness of seven physiological parameters together with two potential biomarkers for ultraviolet (UV)-B stress assessment was tested in greenhouse assays on the Vitis vinifera L. cultivars Pinot noir and Riesling. Effects of year, UV-B treatment, cultivar and clone were studied in four individual experiments. Grapevine plants were exposed to three dosed UV-B stress treatments (−UV-B: no UV-B radiation; +UV-B: daily dose of 4856·3 J/m2 UV-BBE; ++UV-B: daily dose of 7025·3 J/m2 UV-BBE) to detect changes of chlorophyll fluorescence and gas exchange parameters. Significant correlations between the leaf polyphenols quercetin-3-O-glucoside and kaempferol-3-O-glucoside with the maximum fluorescence (Fm), the variable fluorescence (Fv) and the maximum quantum yield for photosystem (PS) II (Fv/Fm) were found, which confirmed the biomarkers’ relevance, additionally validated by cultivar- and year-independency.
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Feitosa, Valéria de Albuquerque Sousa, Elvira Marques Luz Dias e Drauzio Eduardo Naretto Rangel. "Zinc-elicited stress tolerance in fungi". Research, Society and Development 12, n. 2 (26 gennaio 2023): e12012240044. http://dx.doi.org/10.33448/rsd-v12i2.40044.
Testo completoAbstract (sommario):
Fungi for industrial and agricultural uses must endure a variety of physical and chemical challenges, collectively referred to as stresses. The fungal response to stress conditions may be due to impaired growth and metabolism. Understanding the physiology of stress responses can help alleviate the detrimental effects when the fungus is applied agricultural and industrial uses. The present study aims to review the physiological and morphological effects of zinc ions on fungi. Zinc is essential for the activity of zinc metalloenzymes, such as alcohol dehydrogenase and aldehyde dehydrogenase. It can activate riboflavin synthesis and increase protein content in fermenting yeast. However, excess zinc is toxic to the cell, and the cellular level must be finely controlled within an adequate range between 0.1 and 0.5 mM. In conclusion, a relationship between zinc and yeasts is observed but has not yet been fully defined in the fermentation process. Thus, studies are still needed to evaluate the physiological and morphological effects of zinc ions in fungi used in agriculture, such as tolerance of conidia produced in culture media with zinc or to conditions of oxidative stress, osmotic stress, ultraviolet radiation, and heat.
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Schmidt, Éder C., Marianne Kreusch, Marthiellen R. de L. Felix, Debora T. Pereira, Giulia B. Costa, Carmen Simioni, Luciane C. Ouriques et al. "Effects of Ultraviolet Radiation (UVA+UVB) and Copper on the Morphology, Ultrastructural Organization and Physiological Responses of the Red AlgaPterocladiella capillacea". Photochemistry and Photobiology 91, n. 2 (8 gennaio 2015): 359–70. http://dx.doi.org/10.1111/php.12396.
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