Effects Of ultraviolet-B Radiation Research Articles

Effects of Ultraviolet B Radiation on the Function of the Testicles, Expression of Caspase-3 and NOS-2, and the Protective Role of Naringin in Mice.

In today's evolving global environment, reproductive dysfunctions brought on by various environmental toxins are of greatest concern. Radiation is a constant threat to living things, causing both genetic and cellular changes that result in mutations and cell death. It is thought that ultraviolet B (UVB) radiation we are exposed to daily has biological effects on rats and humans that are both short and long term. Due to the damaging effects of UVB radiation on the living system, this study explores the automatic mechanism by which a certain level of radiation induces oxidative stress, which is further controlled by the antioxidant activity of naringin (NG). In our study, male Swiss albino mice were exposed to UVB irradiation, which altered mice's body and testes weight, hormonal imbalance, biochemical parameters, and histo-morphometric parameter. In addition, we chose naringin's UVB irradiation deterrent effect. Twenty-four healthy adult male Swiss albino mice weighing 25-35 g were chosen at random. For 15 days of exposure, they were divided into four groups at random: group I-control, group II-UVB exposure (2 h per day), group III-UVB exposure with naringin (NG) (80 mg/kg, bw), and group IV-naringin (NG) (80 mg/kg, bw). Compared to the control group, UVB irradiation causes alterations in the animal body weight, testes weight, hormones, enzymatic and non-enzymatic assays, and histological parameters. It was seen that NG retrieved the alterations in parameters caused by UVB irradiation. The UVB radiation exposure on mice caused the testicular dysfunction drastically, while the naringin recapitulates testis functioning.

Effects of UV-B radiation on pollen germination and tube growth: A global meta-analysis

Despite widespread recognition of pollen's potential sensitivity to ultraviolet-B (UV-B) radiation (280–315 nm), there remains ongoing debate surrounding the extent and mechanisms of this effect. In this study, using published data on pollen germination and tube growth including 377 pair-wise comparisons from 77 species in 30 families, we present the first global quantification of the effects of UV-B radiation on pollen germination and tube growth, along with its underlying mechanisms. Our results showed a substantial reduction in both pollen germination and tube growth in response to UV-B radiation, affecting 90.9 % and 84.2 % of species, respectively. Notably, these reductions exhibited phylogenetic constraints, highlighting the role of evolutionary history in shaping the sensitivity of pollen germination and tube growth to UV-B radiation. A negative correlation between elevation and the sensitivity of pollen tube growth was detected, suggesting that pollens from plants at higher elevations exhibit greater resistance to UV-B radiation. Our investigation also revealed that the effects of UV-B radiation on pollen germination and tube growth were influenced by a range of abiotic and biotic factors. Nevertheless, the intensity and duration of UV-B radiation exposure exhibited the highest explanatory power for the effects on both pollen germination and tube growth. This suggests that the responses of pollens to UV-B radiation are profoundly influenced by its dose, a critical consideration within the context of global change. In conclusion, our study provides valuable insights into the diverse responses of pollen germination and tube growth to UV-B radiation, highlighting the environment and species-dependent nature of pollen's susceptibility to UV-B radiation, with substantial implications for our understanding of the ecological and agricultural consequences of ongoing changes in UV-B radiation.

UV-A and UV-B combined with photosynthetically active radiation change plant growth, antioxidant capacity and essential oil composition of Pelargonium graveolens

BackgroundThe different wavelengths of solar radiation incident on earth [herein: Photosynthetically Active Radiation (PAR) , Ultra Violet-A (UV-A) and Ultra Violet-B (UV-B)] and their spectral balance not only have an impact on plants’ growth, morphology and physiology, but also are important for the quality and quantity of plant secondary metabolites.Material and methodsIn an outdoor study we addressed the effects of PAR intensity and UV-A and UV-B on the growth, yield, phenolic and flavonoid content, antioxidant activity and essential oil composition of Pelargonium graveolens L’Hér. The experiment was performed with split plots in a randomized complete block design with three replications. During the growth, two PAR intensities (ambient PAR and reduced PAR) and four UV treatments (ambient UV, enhanced UV-A, enhanced UV-B and enhanced UVA + B) were applied.ResultsHigh PAR intensity decreased the length and width of leaf, the height of plant and fresh weight of aerial parts, and increased the dry weight of aerial parts. Enhanced UV-B irradiation was associated with reduced plant height, leaf expansion and fresh and dry weight of aerial parts. Interestingly, the negative effect of UV-B radiation on morphology and growth of plant was largely alleviated by high PAR intensity. The amount of total phenols and flavonoids, antioxidant activity and essential oil production of P. graveolens strongly increased with the increase of UV-B irradiation and PAR. On the other hand, UV-A radiation did not significantly influence total phenol and flavonoid content, antioxidant activity and essential oil composition. Moreover, the combination of high PAR intensity and UV-B led to further increases in total flavonoid content and antioxidant capacity. Both high PAR intensity and enhanced UV-B increased the percentage of geraniol in essential oil, leading to a slight reduction of citronellol/geraniol ratio which is a marker of quality for rose geranium essential oil.ConclusionsOverall, we conclude that UV-B irradiation was associated to reduction of plant growth and yield, while, the adverse effect of UV-B irradiation on the plant was mitigated by high PAR intensity. On the other hand, both high PAR and enhanced UV-B boosted the production of phenols, flavonoids and essential oil. Considering that the lower citronellol/geraniol ratio is the most important indicator for the economic value of rose geranium essential oil, reducing citronellol/geraniol ratio under enhanced UV-B radiation and/or high PAR is likely to be favorable.

Exposure to ultraviolet-B radiation increases the susceptibility of mosquitoes to infection with dengue virus.

By 2100, greenhouse gases are predicted to reduce ozone and cloud cover over the tropics causing increased exposure of organisms to harmful ultraviolet-B radiation (UVBR). UVBR damages DNA and is an important modulator of immune function and disease susceptibility in humans and other vertebrates. The effect of UVBR on invertebrate immune function is largely unknown, but UVBR together with ultraviolet-A radiation impairs an insect immune response that utilizes melanin, a pigment that also protects against UVBR-induced DNA damage. If UVBR weakens insect immunity, then it may make insect disease vectors more susceptible to infection with pathogens of socioeconomic and public health importance. In the tropics, where UVBR is predicted to increase, the mosquito-borne dengue virus (DENV), is prevalent and a growing threat to humans. We therefore examined the effect of UVBR on the mosquito Aedes aegypti, the primary vector for DENV, to better understand the potential implications of increased tropical UVBR for mosquito-borne disease risk. We found that exposure to a UVBR dose that caused significant larval mortality approximately doubled the probability that surviving females would become infected with DENV, despite this UVBR dose having no effect on the expression of an effector gene involved in antiviral immunity. We also found that females exposed to a lower UVBR dose were more likely to have low fecundity even though this UVBR dose had no effect on larval size or activity, pupal cuticular melanin content, or adult mass, metabolic rate, or flight capacity. We conclude that future increases in tropical UVBR associated with anthropogenic global change may have the benefit of reducing mosquito-borne disease risk for humans by reducing mosquito fitness, but this benefit may be eroded if it also makes mosquitoes more likely to be infected with deadly pathogens.

Postharvest UV-B exposure drives changes in primary metabolism, phenolic concentration, and volatilome profile in berries of different grape (Vitis vinifera L.) varieties.

The ultraviolet-B (UV-B) radiation can alter grape metabolism during berry development, but little is known on the effect of postharvest UV-B exposure. In this study, we evaluated the effect of postharvest UV-B exposure on berry primary and secondary metabolites in four grapevine varieties (Aleatico, Moscato bianco, Sangiovese, and Vermentino) in order to evaluate the possibility to increase the grape quality and its nutraceutical properties. The treatment did not significantly affect the berry primary metabolism in terms of organic acids, carbohydrates, and amino acids profile, regardless of the variety. UV-B exposure reduced the total anthocyanin content, particularly the tri-substituted and di-substituted forms in Aleatico and Sangiovese, respectively. An overall negative effect of UV-B irradiation on the flavonols profile of Aleatico, Moscato bianco, and Vermentino berries was found, whereas it enhanced the quercetin, myricetin and kaempferol concentration in Sangiovese. The free fraction of berry volatile organic compounds increased in UV-B-treated Aleatico and Moscato bianco berries, especially C13 -norisoprenoids and volatile phenols, as well as key monoterpenes, such as the linalool derivatives. However, higher concentrations of glycosylated monoterpenes and C13 -norisoprenoids were measured in Sangiovese and Vermentino berries treated with UV-B. This study provides new insights on the effect of postharvest UV-B radiation on berry secondary metabolism, highlighting a different modulation between varieties and suggesting the potential use of this technique to increase some nutraceutical and quality characteristics of grape berry. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Inhibition of melanogenesis by 3-(1′-methyltetrahydropyridinyl)-2,4-6-trihydroxy acetophenone via suppressing the activity of cAMP response element-binding protein (CREB) and nuclear exclusion of CREB-regulated transcription coactivator 1 (CRTC1)

Exposure to Ultraviolet radiation or α-melanocyte-stimulating hormone (α-MSH) stimulates the Cyclic Adenosine Monophosphate/Protein Kinase A signalling pathway, which leads to the synthesis and deposition of melanin granules in the epidermis. Skin pigmentation is the major physiological defence against inimical effects of sunlight. However, excessive melanin production and accumulation can cause various skin hyperpigmentation disorders. The present study involved the identification of 3-(1′-methyltetrahydropyridinyl)-2,4-6-trihydroxy acetophenone (IIIM-8) as an inhibitor of melanogenesis, IIIM-8 significantly inhibited pigment production both in vitro and in vivo without incurring any cytotoxicity in Human Adult Epidermal Melanocytes (HAEM). IIIM-8 repressed melanin synthesis and secretion both at basal levels and in α-MSH stimulated cultured HAEM cells by decreasing the levels of Cyclic Adenosine Monophosphate (cAMP) and inhibiting the phosphorylation of cAMP response element-binding (CREB) protein, coupled with restoring the phosphorylation of CREB-regulated transcription coactivator 1 (CRTC1) and its nuclear exclusion in HAEM cells. This impeding effect correlates with diminished expression of master melanogenic proteins including microphthalmia-associated transcription factor (MITF), Tyrosinase (TYR), Tyrosinase related protein 1 (TRP1), and Tyrosinase related protein 2 (TRP2). Additionally, topical application of IIIM-8 induced tail depigmentation in C57BL/6J mice. Furthermore, IIIM-8 efficiently mitigated the effect of ultraviolet-B radiation on melanin synthesis in the auricles of C57BL/6J mice. This study demonstrates that IIIM-8 is an active anti-melanogenic agent against ultraviolet radiation-induced melanogenesis and other hyperpigmentation disorders.

Long-term adaptation to elevated temperature but not CO2 alleviates the negative effects of ultraviolet-B radiation in a marine diatom

Multifaceted changes in marine environments as a result of anthropogenic activities are likely to have a compounding impact on the physiology of marine phytoplankton. Most studies on the combined effects of rising pCO2, sea surface temperature, and UVB radiation on marine phytoplankton were only conducted in the short-term, which does not allow to test the adaptive capacity of phytoplankton and associated potential trade-offs. Here, we investigated populations of the diatom Phaeodactylum tricornutum that were long-term (∼3.5 years, ∼3000 generations) adapted to elevated CO2 and/or elevated temperatures, and their physiological responses to short-term (∼2 weeks) exposure of two levels of ultraviolet-B (UVB) radiation. Our results showed that while elevated UVB radiation showed predominantly negative effects on the physiological performance of P. tricornutum regardless of adaptation regimes. Elevated temperature alleviated these effects on most of the measured physiological parameters (e.g., photosynthesis). We also found that elevated CO2 can modulate these antagonistic interactions, and conclude that long-term adaptation to sea surface warming and rising CO2 may alter this diatom's sensitivity to elevated UVB radiation in the environment. Our study provides new insights into marine phytoplankton's long-term responses to the interplay of multiple environmental changes driven by climate change.

Long-term variability of human health-related solar ultraviolet-B radiation doses for the 1980s to the end of the 21st century.

Solar ultraviolet-B (UV-B) radiation has played a crucial role in the evolution of life on Earth, and potential changes in its levels could affect the health and functionality of humans and the ecosystems. UV exposure presents both risks and benefits to humans. However, optimal UV-B radiation exposure depends on several environmental and physiological factors and cannot be easily determined. The present document provides a review of the current state of knowledge relative to the effects of UV-B radiation on human health. A brief description of the physical mechanisms that control the levels of solar UV-B radiation at the Earth's surface is provided, with special emphasis on the role of ozone and the importance of the Montreal Protocol. A comprehensive review of studies reporting current trends in levels of surface solar UV-B radiation and projections of future levels reveals the dominant role of climatic changes in the long-term variability of UV-B radiation and its impact on the development of melanomas as well as eye disorders. The review provides strong evidence that despite the success of the Montreal Protocol and the expected ozone recovery, the future evolution of the levels of solar UV-B radiation at the Earth's surface is not certain.

Effects of Ultraviolet-B Radiation on the Regulation of Ascorbic Acid Accumulation and Metabolism in Lettuce

To understand the effect of ultraviolet (UV)-B irradiation on the antioxidant capacity and growth of lettuce (Lactuca sativa), we subjected lettuce plants to UV-B irradiation (15.55 kJ m−2 d−1) for 7 days and measured yield, photosynthetic performance, hydrogen peroxide (H2O2), reduced glutathione (GSH), and ascorbic acid (AsA) contents, and the enzyme activity and expression of genes involving AsA recycling. UV-B exposure did not significantly decrease the fresh/dry weight of the lettuce shoots. The net photosynthesis rate, internal CO2 concentration, transpiration rate, and stomatal conductance decreased during the first 4 days of irradiation and light but recovered at day 7. In UV-B-treated plants, the levels of AsA, GSH, and H2O2 increased significantly and simultaneously, with a positive correlation found between H2O2 and AsA or GSH levels. UV-B exposure upregulated the expression level of most genes encoding the enzymes involving AsA recycling but downregulated the associated enzymatic activities. The increase of AsA content in UV-B-exposed lettuce might contribute to the AsA–GSH cycle, leading to downregulation of ascorbate oxidase (AO) enzymatic activity and gene expression. UV-B irradiation had a greater impact on metabolite levels than time of UV-B treatment. These results suggest that AsA homeostasis in UV-B-treated lettuce is regulated through a feedback loop between the expression and activity of enzymes associated with AsA recycling. Short-term UV-B supplementation (24 h) could be a promising approach to enhance AsA content in lettuce.

Responses to Solar UV-B Exclusion and Drought Stress in Two Cultivars of Chestnut Rose with Different Leaf Thickness

Plants adopt a series of strategies to tolerate solar UV-B radiation (with the side effects of growth reduction), but the positive effects of solar UV-B radiation have not been yet clarified. In this study, two cultivars with different leaf thickness for Chestnut rose (Rosa roxburghii Tratt), a pioneering species for ecological restoration in Karst region of Southwest China, were employed to investigate its responses to ultraviolet-B (UV-B) exclusion, moderate drought, and their combination in an outdoor experiment. Thin-leaf cultivars (Gui 2) adopt an opportunistic growth strategy, growing better than Gui 7 under UV-B exclusion combined with well-watered conditions. To avoid the penetration of solar UV-B wavelengths into the underlying leaf tissues, Gui 2 exhibited higher enhancements in leaf thickness, palisade/spongy tissue ratio, antioxidant responses such as the leaf concentration of flavonols compounds catalyse activity under solar UV-B exposure. Moreover, ambient solar UV-B radiation alleviated the adverse impact caused by drought in both cultivars, improving total biomass and reducing membrane penetration. This alleviation may be related with two potential explanations. First, solar UV-B radiation primes chestnut rose plants with increased antioxidative capacity against drought stress, shown in both antioxidative enzyme activity and non-enzyme antioxidants (in particular, with total flavonols and flavonol ratio [(quercetin+myricetin)/kaempferol]). Second, to avoid nutrition insufficiency, solar UV-B radiation and drought endows chestnut rose plants with complementary effects on nutrition balance. Overall, solar UV-B radiation helps the chestnut tolerate drought stress that occurs frequently in the Karst region by modulating its antioxidative capacity and nutrition balance.

How does UV‐B stress affect secondary metabolites of Scutellaria baicalensis in vitro shoots grown at different 6‐benzyl aminopurine concentrations?

Ultraviolet-B (UV-B) radiation is one of the abiotic stresses that can significantly affect the secondary metabolite accumulation in in vitro tissue cultures of medicinal plants. The present study investigated the effects of UV-B radiation on the secondary metabolites and antioxidant activities of Scutellaria baicalensis in vitro shoots grown at different concentrations of 6-benzyl aminopurine (6-BA), which is the cytokinin most widely used in plant tissue culture. The UV-B radiation caused significant increases in lipid peroxidation, total phenolic, and flavonoid contents, and antioxidant activities in the in vitro shoots grown at lower 6-BA concentrations (0 and 1mg L-1 ), while it did not cause any significant changes in those grown at higher 6-BA concentrations (2 and 3mg L-1 ). However, the UV-B radiation significantly altered the contents of main individual flavonoids at both lower and higher 6-BA concentrations. Upon UV-B radiation, aglycones (including baicalein, wogonin, and scutellarein) increased, while glucuronides such as baicalin and wogonoside decreased; this was more evident at higher 6-BA concentrations. This study demonstrated that the effects of UV-B radiation on the secondary metabolites of S. baicalensis in vitro shoots highly depended on the 6-BA concentration in the culture medium.

Does a Moderately Warming Climate Compensate for the Negative Effects of UV-B Radiation on Amphibians at High Altitudes? A Test of Rana kukunoris Living on the Qinghai-Tibetan Plateau.

Simple SummaryBoth the warming climate and ultraviolet-B radiation are notable environmental factors affecting tadpole development. However, the phenotypes of tadpoles living at high altitudes may be improved by moderately warming temperatures, reducing or eliminating the negative effects of oxidative damage caused by cool temperatures or strong ultraviolet-B radiation. To verify this hypothesis, Rana kukunoris tadpoles, which live at high altitudes, were exposed to ultraviolet-B radiation and ultraviolet-B radiation-free environments at 14 (cool temperature) and 22 °C (warm temperature), respectively. Ultraviolet-B radiation and a warm temperature had opposite influences on several traits of the tadpoles, and the moderate temperature could compensate for or override the negative effects of ultraviolet-B radiation by increasing the tadpoles’ preferred body temperature and critical tolerance temperature, thus enhancing the locomotion ability and thermal sensitivity of their antioxidant systems. The dark skin coloration and aggregation behavior of R. kukunoris tadpoles may also be effective strategies for allowing them to resist ultraviolet-B radiation and helping them to better adapt to a warming environment with stronger ultraviolet-B radiation. Thus, a moderate degree of warming may increase the capacity of living organisms to adapt to environmental changes and thus have positive effects on the development of tadpoles living at high altitudes.Both the warming climate and ultraviolet-B radiation (UVBR) are considered to be notable environmental factors affecting amphibian population decline, with particular effects on tadpole development. However, the phenotypes of tadpoles living at high altitudes may be improved by moderately warming temperatures, reducing or eliminating the negative effects of oxidative damage caused by cool temperatures or strong UVBR at high altitudes. To verify this hypothesis, Rana kukunoris tadpoles, which live at high altitudes, were used to test the effect of the interaction of temperature and UVBR on their development and antioxidant systems in a fully factorial design. The tadpoles were exposed to UVBR and UVBR-free environments at 14 (cool temperature) and 22 °C (warm temperature), respectively. UVBR and a warm temperature had opposite influences on several traits of the tadpoles, including their survival, developmental rate, individual size, preferred body temperature, thermal tolerance temperature, oxidative damage, and enzymatic and nonenzymatic antioxidant systems. The moderate temperature could compensate for or override the negative effects of UVBR by increasing the tadpoles’ preferred body temperature and critical tolerance temperature, thus enhancing the locomotion ability and thermal sensitivity of their antioxidant systems. Furthermore, the dark skin coloration and aggregation behavior of R. kukunoris tadpoles may also be effective strategies for allowing them to resist UVBR and helping them to better adapt to a warming environment with stronger UVBR. Thus, it is possible that a moderate degree of warming may increase the capacity of living organisms to adapt to environmental changes and thus have positive effects on the development of tadpoles living at high altitudes.

Evaluation of UV-B Ameliorating Properties of Indigenous Plants Ashwagandha Withania somnifera (Dunal), Amla Emblica officinalis (Gaertn), and Prickly Chaff Flower Achyranthes aspera (L.) Supplemented Diets in Prior UV-B Exposed Catla catla

Ultraviolet B (UV-B) radiation is a potent environmental stressor and it severely affects the survival, growth, and physiology of aquatic organisms. The UV-B protective properties of three herbal ingredients enriched diets were evaluated in pre-exposedCatla catla. Fish (70.38 ± 1.18 g) were divided into five sets with three replicates each. Four sets were exposed to UV-B (80 µW/cm2) for an initial 10 days (20 min/day), and the fifth one remained unexposed (control). On day 11, feeding with enriched diets started. These diets were: diet 1 (D1) containingWithania somnifera(0.5%) root powder, diet 2 (D2) containingEmblica officinalis(1.25%) fruit powder, diet 3 (D3) containing seeds ofAchyranthes aspera(0.5%), and diet 4 (D4) control. There were two batches of D4 diet-fed fish, D4a, UV-B exposed, and D4b unexposed. Blood and tissue samples were collected on days 0, 7, 14, and 21 of feeding. The average weight reduced 26.32% in UV-B exposed catla compared to the unexposed one on day 0. Among the exposed fish, average weight was significantly higher in D3 compared to others throughout the study period. Significantly lower nitric oxide synthase (NOS) and higher thiobarbituric acid reactive substances (TBARS), carbonyl protein, superoxide dismutase (SOD), and heat shock proteins (Hsp) 70 and 90 were observed in D4a compared to the enriched diet fed catla. The NOS level was significantly higher in D3 on day 21. The TBARS level was significantly lower in D3 on days 7 and 14 and in D2 and D3 on day 21. The carbonyl protein, SOD, and Hsp70 levels were always significantly lower in D3 compared to others, and D2 followed D3 treatment. Hsp 90 was significantly lower in D2 compared to others on day 7 and in D3 on days 14 and 21. All three enriched diets helped the fish overcome the harmful effect of UV-B radiation, and the D3 diet-fed fish showed the best performance.

SWATH-based quantitative proteomic analysis of Morus alba L. leaves after exposure to ultraviolet-B radiation and incubation in the dark

Morus alba is a woody shrub of the family Moraceae and used as traditional Chinese medicine for a long history. Ultraviolet-B (UV-B) radiation, as a kind of abiotic stress factor, affected the growth and secondary metabolism in M. alba. Previous studies indicated that the contents of several secondary metabolites such as moracin N, chalcomaricin were significantly increased under high level UV-B radiation and dark incubation in M. alba leaves. To reveal the response mechanism under UV-B radiation and dark incubation in M. alba leaves, SWATH-based quantitative proteomic analysis was performed. Totally, 716 proteins were identified and quantified in the control, UVB, and UVD groups. Among them, 123 proteins and 96 proteins were identified as differentially abundant proteins in UVB group and UVD groups, respectively. Proteins related to photosynthesis, amino acid biosynthesis, and tocopherol biosynthesis were significantly altered in UVB group, while proteins related to the biosynthesis of phenolic compounds were significantly altered in UVD group. In addition, the abundances of proteins involved in the ubiquitin-proteasome system (UPS) were significantly increased in both UVB and UVD groups, indicating that UPS combined with secondary mechanism participated in the resistance to UV-B radiation and dark incubation. The obtained results provide novel insight into the effects of high level UV-B radiation on M. alba leaves and on the strategies used for maximizing the chemical constituents and the medicinal value of the M. alba leaves.

Drought, Low Nitrogen Stress, and Ultraviolet-B Radiation Effects on Growth, Development, and Physiology of Sweetpotato Cultivars during Early Season.

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.

Effects of Ultraviolet-B Radiation on Behaviour, Reproductive Performance, Serum Vitamin D Status and Gene Expression in Female Rabbits

Effects of Ultraviolet-B Radiation on Behaviour, Reproductive Performance, Serum Vitamin D Status and Gene Expression in Female Rabbits

Transcriptomics Integrated With Metabolomics Reveal the Effects of Ultraviolet-B Radiation on Flavonoid Biosynthesis in Antarctic Moss

Bryophytes are the dominant vegetation in the Antarctic continent. They have suffered more unpleasant ultraviolet radiation due to the Antarctic ozone layer destruction. However, it remains unclear about the molecular mechanism of Antarctic moss acclimation to UV-B light. Here, the transcriptomics and metabolomics approaches were conducted to uncover transcriptional and metabolic profiling of the Antarctic moss Leptobryum pyriforme under UV-B radiation. Totally, 67,290 unigenes with N50 length of 2,055 bp were assembled. Of them, 1,594 unigenes were significantly up-regulated and 3353 unigenes were markedly down-regulated under UV-B radiation. These differentially expressed genes (DEGs) involved in UV-B signaling, flavonoid biosynthesis, ROS scavenging, and DNA repair. In addition, a total of 531 metabolites were detected, while flavonoids and anthocyanins accounted for 10.36% of the total compounds. There were 49 upregulated metabolites and 41 downregulated metabolites under UV-B radiation. Flavonoids were the most significantly changed metabolites. qPCR analysis showed that UVR8-COP1-HY5 signaling pathway genes and photolyase genes (i.e., LpUVR3, LpPHR1, and LpDPL) were significantly up-regulated under UV-B light. In addition, the expression levels of JA signaling pathway-related genes (i.e., OPR and JAZ) and flavonoid biosynthesis-related genes were also significantly increased under UV-B radiation. The integrative data analysis showed that UVR8-mediated signaling, jasmonate signaling, flavonoid biosynthesis pathway and DNA repair system might contribute to L. pyriforme acclimating to UV-B radiation. Therefore, these findings present a novel knowledge for understanding the adaption of Antarctic moss to polar environments and provide a foundation for assessing the impact of global climate change on Antarctic land plants.

Subsequent treatment of leafy vegetables with low doses of UVB-radiation does not provoke cytotoxicity, genotoxicity, or oxidative stress in a human liver cell model

Ultraviolet B (UVB) radiation in low but ecological-relevant doses acts as a regulator in the plant's secondary metabolism. This study investigates the effect of UVB radiation from light-emitting diodes (LEDs) [peak wavelength of (290 ± 2) nm] on the biosynthesis of health-promoting secondary plant metabolites (carotenoids, phenolic compounds, and glucosinolates) of green and red leafy vegetables of Lactuca sativa, Brassica campestris, and Brassica juncea followed by evaluation of potential adverse effects in a human liver cell model.UVB radiation led to a significant increase in individual secondary plant metabolites, especially of phenolic compounds and glucosinolates, e.g. alkenyl glucosinolate content. Kaempferol und quercetin glycoside concentrations were also significantly increased compared to untreated plants.The plant extracts from Lactuca sativa, Brassica campestris, and Brassica juncea were used to assess cytotoxicity (WST-1 assay and trypan blue staining), genotoxicity (Comet assay), and production of reactive oxygen species (EPR) using metabolically competent human-derived HepG2 liver cells. No adverse effects in terms of cytotoxicity, genotoxicity, or oxidative stress were detected in an extract concentration ranging from 3.125 to 100 μg ml−1. Notably, only at very high concentrations were marginal cytostatic effects observed in extracts from UVB-treated as well as untreated plants.In conclusion, the application of UVB radiation from LEDs changes structure-specific health-promoting secondary plant metabolites without damaging the plants. The treatment did not result in adverse effects at the human cell level. Based on these findings, UVB LEDs are a future alternative, promising light source to replace currently commonly used high-pressure sodium lamps in greenhouses.

Postharvest UV-B radiation increases enzyme activity, polysaccharide and secondary metabolites in honeysuckle (Lonicera japonica Thunb.)

Postharvest ultraviolet-B (UV-B) radiation can modulate the accumulation of bioactive compounds with many pharmacological effects in plants. Honeysuckle (Lonicera japonica Thunb.) is a UV-B tolerant crop which has a high medical value. The effects of UV-B on bioactive compounds in its flowers have been reported, while very few studies focused on the leaves and stems. Therefore, the effects of postharvest UV-B radiation on basic physiological traits and bioactive compounds (polysaccharides and secondary metabolites) in the leaves, stems and flowers of honeysuckle were investigated in this study. In this study, the leaves, stems and flowers of honeysuckle were exposed to UV-B radiation (0, 8.4 and 22.4 μW cm−2) for different times (2, 4, 6 and 8 h), and variables were detected after 24 h after they were able to get a repair time. The results showed that the contents of chlorophyll, carotenoid, soluble sugar, and the activities of catalase (CAT) and superoxide dismutase (SOD) in postharvest leaves were increased after UV-B treatment. But the malonaldehyde (MDA) content in leaves decreased when the duration of UV-B treatment lasted for 4 h. Besides, the contents of polysaccharide, total polyphenols, total flavonoid, and chlorogenic acid in different organs all increased significantly and reached a peak under the UV-B1 (8.4μW cm−2) treatment for 2 h, whereas they reached the lowest point under the 6 h of UV-B2 (22.4μW cm−2) exposure according to the heat map analysis. Interestingly, the Pearson correlation analysis revealed that the total flavonoid content was positively correlated with the chlorogenic acid content in the flowers of honeysuckle, and the total flavonoid content was negatively correlated with the contents of chlorophyll, CAT and carotenoid in plant leaves. In a word, the secondary metabolites and polysaccharide of honeysuckle can be increased by postharvest UV-B, and the quality can be improved by adjusting its physiological traits. In addition, the content of bioactive substances is correlated with the physiological traits. The results will provide a basis for improving the medicinal values of honeysuckle by postharvest UV-B treatment.

Accumulation of phenolics and growth of dioecious Populus tremula (L.) seedlings over three growing seasons under elevated temperature and UVB radiation

Accumulation of secondary metabolites may exhibit developmentally regulated variation in different plant organs. Moreover, prevailing environmental conditions may interact with development-related variations in plant traits. In this study, we examined developmentally regulated variation in phenolic accumulation in the twigs of dioecious Populus tremula (L.) and how the effects of elevated temperature and ultraviolet B (UVB) radiation on growth and phenolics accumulation varied as the plants get older. In an open-field experiment, six female and six male genotypes were exposed to single and combined elevated temperature and UVB radiation treatments for three consecutive growing seasons. The concentrations of low molecular weight phenolics and condensed tannins did not show age-dependent variation in the twigs. In temperature-treated plants, diameter growth rate decreased, and concentration of condensed tannins increased as plants aged; there were no cumulative effects of elevated UVB radiation on growth and phenolic accumulation. Females maintained a higher concentration of low molecular weight phenolics throughout the experimental period; however, growth and phenolic concentration did not vary over time in females and males. Our results suggest that phenolic accumulation in perennial plants may not necessarily always exhibit age-dependent variation and the effects of elevated temperature on growth and phenolic may diminish as plants get older.