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Ultraviolet‐B light (UV‐B) is a major cause of skin photoaging, inducing cell death and extracellular matrix collapse by generating reactive oxygen species (ROS). Belamcandae Rhizoma (BR), the rhizome of Belamcanda chinensis Leman, exhibits antioxidant properties, but it remains unknown whether BR extract ameliorates UV‐B‐induced skin damage. In this study, we evaluated the effects of a standardized BR extract on UV‐B‐induced apoptosis and collagen degradation in HaCaT cells. BR was extracted using four different methods. We used radical‐scavenging assays to compare the antioxidative activities of the four extracts. Cells were irradiated with UV‐B and treated with BR boiled in 70% (vol/vol) ethanol (BBE). We measured cell viability, intracellular ROS levels, the expression levels of antioxidative enzymes, and apoptosis‐related and collagen degradation‐related proteins. The irisflorentin and tectorigenin levels were measured via high‐performance liquid chromatography. BBE exhibited the best radical‐scavenging and cell protective effects of the four BR extracts. BBE inhibited intracellular ROS generation and induced the synthesis of antioxidative enzymes such as catalase and glutathione. BBE attenuated apoptosis by reducing the level of caspase‐3 and increasing the Bcl‐2/Bax ratio. BBE reduced the level of matrix metalloproteinase‐1 and increased that of type I collagen. The irisflorentin and tectorigenin contents were 0.23% and 0.015%, respectively. From these results, BBE ameliorated UV‐B‐induced apoptosis and collagen degradation by enhancing the expression of antioxidative enzymes. It may be a useful treatment for UV‐B‐induced skin damage. [ABSTRACT FROM AUTHOR]

Ultraviolet-B (UVB) irradiation causes skin damage via deleterious effects including oxidative stress, inflammation, and collagen degradation. The photoprotective effects of a hyperoside-enriched fraction obtained from Houttuynia cordata Thunb. (H. cordata) on the attenuation of UVB-induced skin aging in human fibroblasts were investigated. The solvent-partition technique was used to establish the hyperoside-enriched fraction of H. cordata (HcEA). The active compounds identified in the H. cordata extracts were hyperoside, quercitrin, chlorogenic acid, and rutin. With regard to the photoprotective effects of H. cordata on UVB-irradiated dermal fibroblasts, HcEA and hyperoside inhibited intracellular ROS production and inflammatory cytokine secretions (IL-6 and IL-8), while increasing collagen type I synthesis along with downregulating MMP-1 gene and protein expressions. Mechanistically, the hyperoside-enriched fraction obtained from H. cordata inhibited UVB-irradiated skin aging through regulation of the MAPK signaling pathway by attenuating the activation of JNK/ERK/c-Jun in human dermal fibroblasts. The hyperoside-enriched fraction of H. cordata exerted potent anti-skin aging properties against UVB exposure. The findings of this study can be applied in the cosmetics industry, as H. cordata extract can potentially be used in pharmaceutical or cosmetic formulations as a photoprotective or anti-skin aging agent.

The depletion of the stratospheric ozone layer is a major environmental issue and has increased the dosage of ultraviolet-B (UV-B) radiation reaching the Earth’s surface. Organisms are negatively affected by enhanced UV-B radiation, and especially in crop plants this may lead to severe yield losses. Soybean (Glycine max L.), a major legume crop, is sensitive to UV-B radiation, and therefore, it is required to breed the UV-B-resistant soybean cultivar. In this study, 688 soybean germplasms were phenotyped for two categories, Damage of Leaf Chlorosis (DLC) and Damage of Leaf Shape (DLS), after supplementary UV-B irradiation for 14 days. About 5% of the germplasms showed strong UV-B resistance, and GCS731 was the most resistant genotype. Their phenotypic distributions showed similar patterns to the normal, suggesting UV-B resistance as a quantitative trait governed by polygenes. A total of 688 soybean germplasms were genotyped using the Axiom® Soya 180K SNP array, and a genome-wide association study (GWAS) was conducted to identify SNPs significantly associated with the two traits, DLC and DLS. Five peaks on chromosomes 2, 6, 10, and 11 were significantly associated with either DLC or DLS, and the five adjacent genes were selected as candidate genes responsible for UV-B resistance. Among those candidate genes, Glyma.02g017500 and Glyma.06g103200 encode cryptochrome (CRY) and cryptochrome 1 (CRY1), respectively, and are known to play a role in DNA repair during photoreactivation. Real-time quantitative RT-PCR (qRT-PCR) results revealed that CRY1 was expressed significantly higher in the UV-B-resistant soybean compared to the susceptible soybean after 6 h of UV-B irradiation. This study is the first GWAS report on UV-B resistance in soybean, and the results will provide valuable information for breeding UV-B-resistant soybeans in preparation for climate change.

AIM: To study the effects of curcumin on the secretion of interleukin (IL) -6 and IL-8 by corneal limbus epithelial cells. METHODS: Human corneal limbus epithelial cells were isolated and cultured from donor eyes and irradiated by UVB at different dosages with or without curcumin. MTT test was used for studying the effects of UVB and curcumin on the cell viability. The role of mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) pathways on the UVB-induced secretion of IL-6 and IL-8 were tested by addition of their inhibitors to the culture with or without UVB-radiation. Levels of various signal pathways, IL-6 and IL-8 in the cells and in the conditioned culture medium were measured by ELISA analysis. RESULTS: UVB at 20 mJ/cm2 or less and curcumin at 20 μmol/L or less did not affect the cell viability of cultured limbus epithelial cells (P>0.05). UVB irradiation at 10 and 20 mJ/cm2 induced a significant increase of secretion of IL-6 and IL-8 and upregulated NF-κB and phosphorylated MAPK pathways of cultured limbus epithelial cells (P

Ultraviolet radiation can cause many serious problems for all living organisms. With a growing population, the UV sensitivity of crop plants presents a particular problem. To evaluate the suitability of growing in areas under UV irradiance, the influence of different doses of UV-B (3.042, 6.084 and 9.126 kJm−2d−1) on the sugar beet (Beta vulgaris L) plants was studied. UV-B induced a significant decrease in growth displayed as reduced height and fresh and dry weight. This reduction is not dose dependent and was associated with diminishing photosynthetic O2 evolution, relative chlorophyll content, photosynthetic pigments and chlorophyll fluorescence. On the other hand, antioxidant enzyme activities, total protein content, compatible solutes, total free amino acids and total betalain content were increased under 9.126 kJm−2d−1 UV-B treatments, representing mechanisms by which the plants coped with the stress. The oxidative stress upon UV-B treatment was evident by increased malondialdehyde (MDA) content, however, hydrogen peroxide (H2O2) was not affected in UV-B exposed plants. Thus, the studied sugar beet variety BR1seems to be suitable particularly for areas with high doses of UV-B irradiation.

Ultraviolet-B (UV-B) radiation is an elicitor of secondary metabolites in plant tissue culture, but the effects on 20-hydroxyecdysone (20E) are still unclear. The 20E may show biotechnological, pharmacological, medical, and agrochemical applicability. Here, we use Pfaffia glomerata, a medically important species, to understand the impacts of UV-B radiation on their physiological performance, the expression of key genes involved in the 20E biosynthesis, and the 20E content. Two accessions (A22 and A43) of plants 20 days old grown in vitro were exposed to 0 (control), 2 (6.84 kJ m−2), and 4 (13.84 kJ m−2) h UV-B radiation for 20 consecutive days. Our data showed that UV-B reduced glucose concentration in A22 and A43 under 4 h of exposure (29 and 30%, respectively), while sucrose concentration increased (32 and 57%, respectively). UV-B also differentially impacted the accessions (A22 and A43), where the A22 under 4 h of UV-B had reduced total dry weight (8%) and electron transport rate (31%); in contrast, A43 did not change. Also, only A22 had increased POD activity under 4 h of UV-B (66%), as well as increased gene expression of the 20E pathway and the 20E content under 2 and 4 h of UV-B in leaves (28 and 21%, respectively) and roots (16 and 13%, respectively). This differential performance to UV-B can be explained by the contrasting anthocyanin contents. Notably, A43 displayed 56% more anthocyanin to the former, a possible defense against UV-B. In conclusion, UV-B radiation is a potential elicitor for increasing 20E content in P. glomerata grown in vitro. [ABSTRACT FROM AUTHOR]

Background/Aims: Excessive exposure to UV radiation negatively affects the human skin, characterized by photo-damage (premature aging & carcinogenesis). UV-B radiation causes about 90% of non-melanoma skin cancers by damaging de-oxy ribonucleic acids (DNA). We have previously reported that UV-B radiation induces skin photodamage through oxidative & Endoplasmic Reticulum (ER) stresses and Glycyrrhizic acid (GA), a natural triterpene, protects skin cells against such stresses. UV-B radiation elicits signalling cascade by activation of proteins involved in sensing, signalling, and repair process of DNA damage. In this study, we explored the effects & mechanisms of Glycyrrhizic acid (GA) against UV-B –induced photodamage using a well established cellular model. Methods: We used primary human dermal fibroblasts as a cellular model. The cells were cultured in the presence or absence of GA for 3,6, & 24 h. Effect of UV-B was assessed by examining cell viability, cell morphology, oxidative stress, ER stress, DNA damage & cellular autophagy levels through biochemical assays, microscopy & protein expression studies. Results: In this study, we have determined the effect of GA on autophagy mediated DNA damage response system as the main mechanism in preventing photodamage due to UV-B -irradiation to primary human dermal fibroblasts (HDFs). GA treatment to UV-B exposed HDFs, significantly inhibited cell death, oxidative & ER stress responses, prevented Cyclobutane Pyrimidine dimer (CPD) DNA adduct formation, and DNA fragmentation via modulation of UV-B induced autophagic flux. Present results showed that GA treatment quenched reactive oxygen species (ROS), relieved ER stress response, improved autophagy (6 hr‘s post-UV-B -irradiation) and prevented UV-B induced DNA damage. Conclusion: The present study links autophagy induction by GA as the main mechanism in the prevention of DNA damage and provides a mechanistic basis for the photoprotective effect of GA and suggests that GA can be potentially developed as a promising agent against UV-B induced skin photo-damage. [ABSTRACT FROM AUTHOR]

Abstract Increases in nitrogen (N) deposition and ultraviolet-B (UV-B) radiation play an important role in global climate change. Because coarse woody debris (CWD) represents a sizeable proportion of total carbon (C) pool in forest ecosystems, understanding the response of CWD decomposition to increased UV-B and N deposition become necessary for evaluating forest C storage under global climate change. In this study, we investigated the respiration of CWD (R CWD) in response to increased UV-B and N deposition over a two-year period for two tree species in subtropical Chinese forests: Cunninghamia lanceolata (Lamb.) Hook. (CL) and Cinnamomum camphora (L.) Presl (CC). We found that N and UV-B treatment, alone or in combination, significantly promoted R CWD , which was further magnified by increased temperature. Moreover, the combined treatment (UV-B + N) far exceeded the sum of the individual effects of N and UV-B treatments. Our results indicated that the three components of global climate change (increased UV-B, N deposition, and warming) worked interactively to accelerate CWD decomposition in forest ecosystems, suggesting that the biogeochemical cycling of subtropical forests could be altered greatly in the future, and this alteration must be considered in modelling the effects of global climate change. Graphical abstract Unlabelled Image Highlights • Both UV-B and N treatment significantly accelerated the R CWD. • The combined treatment effect exceeded the sum of the individual treatment effects. • UV-B, N, UV-B + N treatment effects were further amplified by increasing temperature. • Ozone depletion, N, warming may work synergistically to accelerate CWD decomposition. [ABSTRACT FROM AUTHOR]

Ultraviolet radiation can cause many serious problems for all living organisms. With a growing population, the UV sensitivity of crop plants presents a particular problem. To evaluate the suitability of growing in areas under UV irradiance, the influence of different doses of UV-B (3.042, 6.084 and 9.126 kJm−2d−1) on the sugar beet (Beta vulgaris L) plants was studied. UV-B induced a significant decrease in growth displayed as reduced height and fresh and dry weight. This reduction is not dose dependent and was associated with diminishing photosynthetic O2 evolution, relative chlorophyll content, photosynthetic pigments and chlorophyll fluorescence. On the other hand, antioxidant enzyme activities, total protein content, compatible solutes, total free amino acids and total betalain content were increased under 9.126 kJm−2d−1 UV-B treatments, representing mechanisms by which the plants coped with the stress. The oxidative stress upon UV-B treatment was evident by increased malondialdehyde (MDA) content, however, hydrogen peroxide (H2O2) was not affected in UV-B exposed plants. Thus, the studied sugar beet variety BR1seems to be suitable particularly for areas with high doses of UV-B irradiation. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Solar ultraviolet-B radiation (UVB) has severe adverse effects on the structure and functions of the skin. Although, UVB (290–320 nm) represents only 5–10% of UV light reaching earth's surface, its contribution towards photoaging is tremendous. In this present study was investigate the photoprotective effect of methanolic extract of the male flower of J. regia L. (MEJR) against UVB induced photoaging in human epidermal keratinocytes (HaCaT). Cells were exposed to UVB-irradiation at a dose of 20 mJ/cm2, induces the activation of several signaling pathways which are associated with oxidative stress and photoaging. A single dose of UVB irradiation increased the protein and mRNA expression of MAPKs, AP-1, MMPs, Smad7 and decreased expression of TIMP-1/2, TGF-β1, Smad3, procollagen type-1 in HaCaT cells. In contrast, pretreatment of MEJR (80 μg/ml) prior to UVB-irradiation significantly prevented the overexpression of MAPKs, AP-1, MMPs, Smad7 and decreased expression of TIMP-1/2, TGF-β1, Smad3 and procollagen type-1 in HaCaT cells. Moreover, pretreatment of MEJR (80 μg/ml) prior to UVB-irradiation significantly prevents apoptosis in sub G o -phase. Thus, MEJR protects UVB-mediated photoaging in human skin cells, by modulating the expression of photoaging markers. The protection might be because of the presence of the good amount of bioactive compounds in MEJR. [ABSTRACT FROM AUTHOR]

Mirabilis himalaica is an important Tibetan medicinal plant in China. However, it has become a rare and class I endangered Tibetan medicine plant. Therefore, the use of callus to propagate germplasm resources is of great significance. We found that the flavonoid content of M. himalaica callus increased continuously with the extension of UV-B treatment. Multi-omics profiles were used to reveal the co-expression patterns of gene networks of flavonoid metabolism in M. himalaica callus during UV-B radiation. Results showed that five medicinal metabolics, including geranin, eriodictyol, astragalin, isoquercetin, pyrotechnic acid, and one anthocyanin malvide-3-O-glucoside were identified. The transcriptome data were divided into 46 modules according to the expression pattern by WGCNA (weighted gene co-expression network analysis), of which the module Turquoise had the strongest correlation with six target metabolites. We found that seven structural genes and twenty-five transcription factors were related to the metabolism of flavonoid synthesis, among which the structural genes CHI , C4H and UGT79B6 had strong co-expression relationships with the 6 target metabolites. WRKY42, WRKY7, bHLH128 and other transcription factors had strong co-expression relationships with multiple structural genes. Consequently, these findings suggest callus grown under UV-B treatment could be an effective alternative medical resource of M. himalaica , which is valuable for conservation and usage of this wild and endangered plant. • Six key medicinal metabolic were identified in M. himalaica callus by UV-B radiation. • WGCNA was used to analyze the relationship between gene modules and metabolites. • CHI , C4H and UGT79B6 had strong co-expression relationship with 6 target metabolites. • WRKY42, WRKY7, bHLH128 had strong co-expression relationships with structural genes. [ABSTRACT FROM AUTHOR]

Due to changes in human lifestyle (expanded sunbathing, the use of solaria, etc.) and, most importantly, increasing lifetime and thus higher cumulative exposure to solar radiation, skin aging and skin cancer have become major health issues. As a consequence effective photoprotection is of outmost importance to humans. In this regard a lot has been learned in the past about the cellular and molecular basis underlying ultraviolet (UV) radiation-induced skin damage and, based on this knowledge, numerous skin protective approaches including organic and inorganic UV-filters, but also topically applicable antioxidants, DNA repair enzymes and compatible solutes as well as oral photoprotective strategies based on nutritional supplements have been developed. A new aspect is here that sun protection of human skin might even be possible after solar radiation-induced skin damage has occurred. A second, very important development was prompted by the discovery that also wavelengths beyond the UV spectrum can damage human skin. These include the blue light region of visible light (VIS) as well as the near infrared range (IRA) and corresponding sunprotection strategies have thus recently been or are still being developed. In this article we will provide a state of the art summary of these two novel developments and, at the end, we will also critically discuss strengths and weaknesses of the current attempts, which mainly focus on the prevention of skin damage by selected wavelengths but greatly ignore the possibility that wavelengths might interfere with each other. Such combined effects, however, need to be taken into account if photoprotection of human skin is intended to be global in nature.

Recently, the consumption of greenhouse-grown peaches has declined because of their poor flavor, which makes them unappealing to consumers. In this study, an optimum intensity of 1.44 kJ·m −2 ·d −1 of ultraviolet B (UV-B) radiation increased the sugar accumulation and the total soluble solid/total acidity in ‘Tainongtianmi’ fruit. In the Lumi 1 peach tree variety, 1.44 kJ·m −2 ·d −1 of UV-B radiation increased the anthocyanin contents twofold in fruit compared with the control. Additionally, the sucrose level increased before the second fruit-expansion stage, while it tended to decrease after the slow-growth period in ‘Lumi 1’ peach trees. The fundamental mechanism in response to the increased sucrose level prior to the second fruit-expansion stage was the increased transport of sucrose to fruit caused by an enhanced tonoplastic monosaccharide transporter function in leaves. The sorbitol content increased in mature fruit owing to the slight increase in sorbitol transporter activity in leaves. Our study indicates that exposure to 1.44 kJ·m −2 ·d −1 UV-B radiation before the second fruit-expansion period can transiently increase the sucrose and total sugar contents of peach, while prolonged irradiation with UV-B inhibited the accumulation of sugars. [ABSTRACT FROM AUTHOR]

The current study was designed to test the concerning strategy of water hyacinth (Eichhornia crassipes (Mart.) Solms) to UV-B. In this study, we evaluated the short-term effect of UV-B radiation (short-term UV-B radiation, S-UV-B) on water hyacinth under the natural conditions of Nanjing, China (118°46′E, 32°24′N, 30 m above sea level) with supplemental ultraviolet-B (12 W m−2 above ambient). The growth characteristics and the photosynthetic performance of water hyacinth leaves exposed to UV-B were assessed by measuring net photosynthetic rate, the specific fluorescence parameters including maximal fluorescence (Fm), efficiency of photosystem II (Fv/Fm), and JIP-test parameters. Water hyacinth was tolerant to 1-h UV-B doses over 25 days, maintaining a stable dry weight after treatment. Conversely, plants showed elongation of roots and a decrease in ramet numbers. These changes in growth were closely related to a physiological protection strategy consisting of a higher ability to dissipate extra light energy, strong antioxidative abilities, higher phosphoenolpyruvate carboxylase (PEPC) activity, and stable ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity, as indicated by the stable net photosynthetic rate and reduced inhibition of reactive oxygen species content. After the 3-h dose of UV-B, dry weight decreased significantly, as the above-mentioned protective strategy could not cope with the oxidative damage arising from these treatments. The study concludes that S-UV-B is a potent stimulating factor in increasing the concentrations of defense compounds and antioxidants in water hyacinth to optimize its performance under stress. [ABSTRACT FROM AUTHOR]

Tropical frogs experience damaging effects from exposure to UV-B radiation, and some diurnally active, conspicuous species exhibit avoidance behaviours to high levels of UV-B. To determine if similar behaviours are present in other diurnal frogs, we experimentally compared UV-B avoidance in two common species of neotropical diurnal frogs – Oophaga pumilio , an aposematic poison frog and Craugastor bransfordii , a cryptic leaf-litter frog – in response to different levels of UV-B. Wild-caught frogs were tested in experimental arenas fitted with filters that permitted two different levels of UV-B (low: 14% vs. high: 84% UV-B). Both species spent significantly more time under the low UV-B filter, suggesting that behavioural preferences for lower levels of UV-B are common to different diurnal species. Furthermore, male O. pumilio significantly preferred lower levels of UV-B, whereas females did not exhibit a preference for lower UV-B, which may suggest differences in UV-B exposure or sensitivity and/or alternative mechanism(s) to avoid UV-B between sexes. Although limited in scope, the findings of our study suggest that UV-B avoidance may be a behavioural adaptation common to all diurnal frogs. [ABSTRACT FROM AUTHOR]

A simulation experiment was conducted to explore the influence of enhanced ultraviolet-B (UV-B) radiation, water deficit, and their combination on UV-absorbing compounds and osmotic adjustment substances of mosses Bryum argenteum and Didymodon vinealis isolated from biological soil crusts (BSCs) growing in a revegetated area of the Tengger Desert, China. Four levels of UV-B radiation and two gradients of water regime were employed. Compared with their controls, amounts of total flavonoids, chlorophyll, carotenoids, soluble sugars, and soluble proteins significantly decreased (p < 0.05), but proline content significantly increased (p < 0.05), when exposed to either enhanced UV-B or water deficit. The negative effects of enhanced UV-B were alleviated when water deficit was applied. There were increases in UV-absorbing compounds and osmotic adjustment substances when exposed to a combination of enhanced UV-B and water deficit compared with single stresses, except for the proline content in D. vinealis. In addition, our results also indicated interspecific differences in response to enhanced UV-B, water deficit, and their combination. Compared with B. argenteum, D. vinealis was more resistant to enhanced UV-B and water deficit singly and in combination. These results suggest that the damage of enhanced UV-B on both species might be alleviated by water deficit. This alleviation is important for understanding the response of BSCs to UV-B radiation in future global climate change. This also provides novel insights into assessment damages of UV-B to BSC stability in arid and semiarid regions. [ABSTRACT FROM AUTHOR]

The signal to noise ratio (SNR) is an important consideration for any scientific image sensor application, particularly the relatively low light involved with observations of the solar disc at a discrete ultraviolet-B (UVB) wavelength using an unmodified smartphone image sensor. In particular, the SNR of each of the primary image sensor colour channels (red, green and blue) is a critical step in determining which colour channel signal to analyse for any characterisation research. In each image, the solar disc appears as a very small pale-magenta dot. In this paper, the SNR of each colour channel response for solar UVB, alongside their chromatic transforms were analysed for a stacked, mosaic filtered, backside illuminated complementary metal oxide semiconductor (CMOS) image sensor. Using data visualisation techniques, it has become clear that specific colour channels, in this case – the red channel, provide the strongest SNR for use in characterisation and other analytical research. The effects of a straightforward adaptive threshold and de-noising algorithm (median filter) on each colour channel’s SNR are also analysed. The variation of the colour channels’ SNR with external factors, including irradiance, is modelled. The effects of the prevalence of noise features, such as hot pixels and dark noise, are also observed. It has been found that before the median filter is applied, most of the signal, particularly for the green colour channel, is from these noise features in some image sensors – representing a ‘false positive’ in these low-light conditions. A chrominance model using a weighted proportion of the red and blue colour channels that provides the best SNR when sensing in the UVB waveband for the sensor has been developed and evaluated. [ABSTRACT FROM AUTHOR]

The flavonoids in the extracts of Ginkgo leaves have been shown to have great medical value: thus, a method to increase the flavonoid contents in these extracts is of significant importance for human health. In the present study, we investigated the changes in flavonoid contents and the corresponding gene expression levels in post-harvest Ginkgo leaves after various treatments. We found that both ultraviolet-B and NaCl treatment induced flavonoid accumulation. However, gene expression analysis showed that the increases in flavonoid contents were achieved by different pathways. Furthermore, post-harvest Ginkgo leaves responded differently to NaCl treatment compared with naturally grown leaves in both flavonoid contents and corresponding gene expression. In addition, combined treatment with ultraviolet-B and NaCl did not further increase the flavonoid contents compared with ultraviolet-B or NaCl treatment alone. Our results indicate the existence of a novel mechanism in response to NaCl treatment in post-harvest Ginkgo leaves, and provide a technique to increase flavonoid content in the pharmaceutical industry.

Developmental age is an important determinant of plant stress responses. In this study the importance of “within-individual-heterogeneity” of developmental age for plant UV-B responses was quantified. Arabidopsis thaliana rosettes were raised under indoor conditions, and the responses of leaves at different developmental stages were compared following exposure to supplemental UV-B radiation. Exposure to a low dose of UV-B had positive effects on concentrations of UV-absorbing pigments, quercetins and kaempferols as well as total antioxidant activity measured. Unlike UV-B, developmental age had a substantial effect on photochemistry, and especially energy dissipation. Younger leaves display relatively strong regulated dissipation, while older leaves show more non-regulated, non-photochemical energy dissipation. Developmental age also impacted on concentrations of UV-absorbing compounds, and antioxidant activity. In fact, developmental variation matched, or even exceeded the UV-induced response for these two parameters. Thus, pooling of rosette leaves is not necessarily a good strategy to visualise plant UV-responses. Rather, to fully understand plant UV-responses in a developmental context it is important to advance reporter technologies for physiological studies, including spin-trap technology to visualise in planta ROS and ROS-defences, and fluorescence excitation screening technology and chromogenic assays for in planta visualisation of specific UV-absorbing pigments. [ABSTRACT FROM AUTHOR]

Objectives Low ultraviolet-B ( UVB) radiation causes hypovitaminosis D, which is a known risk factor for multiple sclerosis ( MS) and associated with MS disease activity. Our objective is to test whether vitamin D supplementation is most effective in lowering disease activity during the period of the year with low UVB radiation and consequently low serum 25-hydroxyvitamin D3 (25( OH)D3) concentration. Methods Retrospective analysis of medical records from our outpatient department identified 40 MS patients with available data of at least 6 months before and during oral vitamin D supplementation. Serum 25( OH)D3 concentration was analyzed using immunoassay. UVB radiation data were provided by the local government. Annualized and quarterly relapse rates before and during vitamin D supplementation served as outcome parameters. Results During vitamin D supplementation (18,950 international units/week (mean, SD 3,397)), serum 25( OH)D3 concentration increased by 51 nmol/L and the UVB-related seasonal variability in 25( OH)D3 levels ceased (rho = −0.13, p > .05). Furthermore, the annualized relapse rate decreased by approximately 50%. This was almost solely driven by the prominent reduction in the quarterly relapse rate in late winter/early spring, when 25( OH)D3 levels of nonsupplemented patients were the lowest. Conclusions Our study demonstrated the modulation of seasonal MS disease activity through vitamin D supplementation. Given the prominent reduction in the quarterly relapse rate in late winter/early spring, our data indicate a beneficial effect of supplementing MS patients with vitamin D, especially during this period of the year. [ABSTRACT FROM AUTHOR]

The Arabidopsis UV-B photoreceptor UV RESISTANCE LOCUS 8 (UVR8) orchestrates the expression of hundreds of genes, many of which can be associated with UV-B tolerance. UV-B does not efficiently penetrate into tissues, yet UV-B regulates complex growth and developmental responses. To unravel to what extent and how UVR8 located in different tissues contributes to UV-B-induced responses, we expressed UVR8 fused to the YELLOW FLUORESCENT PROTEIN (YFP) under the control of tissue-specific promoters in a uvr8 null mutant background. We show that (1) UVR8 localized in the epidermis plays a major role in regulating cotyledon expansion, and (2) expression of UVR8 in the mesophyll is important to protect adult plants from the damaging effects of UV-B. We found that UV-B induces transcription of selected genes, including the key transcriptional regulator ELONGATED HYPOCOTYL 5 ( HY5), only in tissues that express UVR8. Thus, we suggest that tissue-autonomous and simultaneous UVR8 signalling in different tissues mediates, at least partly, developmental and defence responses to UV-B. [ABSTRACT FROM AUTHOR]

Global cancer incidence and mortality rates are high and increasing. Thus, it is imperative to find novel solutions to preventing cancer incidence and treating it at an affordable yet efficacious manner. The solar UVB-vitamin D-cancer hypothesis was first proposed in 1980 based on a geographical ecological study. Since then, numerous ecological and observational studies as well as studies of mechanisms have provided support for the hypothesis. However, observational studies have not provided consistent support, in part due to using a single blood draw from any season to use for serum 25-hydroxyvitamin D [25(OH)D] concentration in prospective studies with long follow-up times. Case-controls studies, in which blood is drawn near time of diagnosis, and prospective studies in which blood is drawn in the sunnier half of the year, are more likely to find significant inverse relations between 25(OH)D and cancer incidence. Three vitamin D plus calcium clinical trials have found significant reduction in all-cancer incidence. This paper reviews the evidence for vitamin D in reducing incidence of and increasing survival from breast, colorectal, lung, ovarian, pancreatic, and prostate cancer. The epidemiological evidence provides strong support for all of these types of cancer except for non-aggressive prostate cancer. Studies of the cellular mechanisms of vitamin D action in different cancer cell types, strongly indicate that vitamin D can exert protective and anti-tumorigenic activities that would retard cellular transformation, hyperplasia and cancer progression. Based on the scientific evidence reviewed in this paper, individuals and health providers can consider increasing 25(OH)D concentrations through sensible sun exposure and/or vitamin D supplementation to reduce risk of and, in conjunction with standard care, treat cancer. Public health acceptance of vitamin D for cancer prevention and treatment requires stronger support from vitamin D clinical trials. [ABSTRACT FROM AUTHOR]

Sporopollenin, which forms the outer wall of pollen and spores, contains a chemical signature of ultraviolet-B flux via concentrations of UV-B absorbing compounds (UACs), providing a proxy for reconstructing UV irradiance through time. Although Fourier transform infrared (FTIR) spectroscopy provides an efficient means of measuring UAC concentrations, nitrogen-containing compounds have the potential to bias the aromatic and hydroxyl bands used to quantify and standardise UAC abundances. Here, we explore the presence and possible influence of nitrogen in UV reconstruction via an FTIR study of Lycopodium spores from a natural shading gradient. We show that the UV-sensitive aromatic peak at 1510 cm − 1 is clearly distinguishable from the amide II peak at 1550 cm − 1 , and the decrease in aromatic content with increased shading can be reconstructed using standardisation approaches that do not rely on the 3300 cm − 1 hydroxyl band. Isolation of the sporopollenin results in the loss of nitrogen-related peaks from the FTIR spectra, while the aromatic gradient remains. This confirms the lack of nitrogen in sporopollenin and its limited potential for impacting on palaeo-UV reconstructions. FTIR is therefore an appropriate tool for quantifying UACs in spores and pollen, and information on UV flux should be obtainable from fossil or processed samples. [ABSTRACT FROM AUTHOR]

Phospholipid hydroperoxide glutathione peroxidase (PHGPX) is an antioxidant enzyme that plays a crucial role in metabolizing phospholipid hydroperoxides in membrane against oxidative damage. Here, two PHGPX genes from the predatory mite Neoseiulus barkeri were identified and characterized ( NbPHGPX1 and NbPHGPX2 ). Alignment analysis of NbPHGPX1 and NbPHGPX2 showed a great deal of similarity with other known PHGPX s from databases. The well-conserved regions, NVASXCGXT, FPCNQFXXQEP, and IKWNFXKFLV, were surrounded by reactive cysteine, glutamine, and tryptophan residues, respectively. The results of quantitative polymerase chain reaction at different stages of the N. barkeri life cycle showed both NbPHGPX1 and NbPHGPX2 genes were highly expressed in male adults, and their levels of expression were determined upon challenge by different triggers. The data showed that the expression of NbPHGPX1 could be induced by low (4 °C) and high (42 °C) temperatures, UV-B, pyridaben and fenpropathrin, whereas NbPHGPX2 could be only up-regulated by high (42 °C) temperature and fenpropathrin. These results suggested that NbPHGPX1 and NbPHGPX2 genes might participate in protection of the organism from the oxidative damage challenge by oxidative stresses. [ABSTRACT FROM AUTHOR]

One of the abiotic stress factors affecting plant metabolism is ultraviolet-B (UV-B) radiation. 5-Aminolevulinic acid (ALA), a key precursor of porphyrin biosynthesis, promotes plant growth and crop yields. To investigate the alleviating effects of exogenous ALA on the damages caused by UV-B exposure, two different concentrations [10 ppm (ALA1) and 25 ppm (ALA2)] of ALA were applied to lettuce seedlings for 24 h and then they were exposed to 3.3 W m UV-B. Results showed that UV-B treatment significantly decreased chlorophyll a and b (Chl a and b) concentration, enhanced the activity of antioxidant enzymes, total phenolic concentration, soluble sugar contents, expression of phenylalanine ammonia lyase (PAL) and γ-tocopherol methyltransferase (γ-TMT) genes, the concentration of malondialdehyde (MDA), hydrogen peroxide (HO), and the rate of superoxide radical ( $${\text{O}}_{2}^{ - }$$ ) generation in the lettuce seedlings when compared to the control. Pre-treatment with exogenous ALA significantly enhanced UV-B stress tolerance in lettuce seedlings by decreasing the reactive oxygen species. On the other hand, ALA application caused more increases in the PAL and γ-TMT gene expression, antioxidant enzymes activities, Chl a and b concentration, total phenolic content, antioxidant capacity and the concentrations of soluble sugars. Obtained results indicated that UV-B radiation exerts an adverse effect on lettuce seedlings, and some of the negative effects of UV-B radiation can be alleviated by exogenous ALA. [ABSTRACT FROM AUTHOR]

The goal of this study was to elucidate the role of Fas, TNF-R1, FADD and cytochrome c in UVB-induced K + channel activation, an early step in UVB-induced apoptosis, in human corneal limbal epithelial (HCLE) cells. HCLE cells were treated with Fas, TNF-R1 or FADD siRNA and exposed to 80 or 150 mJ/cm 2 UVB. K + channel activation and loss of intracellular K + were measured using whole-cell patch-clamp recording and ion chromatography, respectively. Cytochrome c was measured with an ELISA kit. Cells in which Fas was knocked down exhibited identical UVB-induced K + channel activation and loss of intracellular K + to control cells. Cells in which TNF-R1 or FADD were knocked down demonstrated reduced K + channel activation and decreased loss of intracellular K + following UVB, relative to control cells. Application of TNF-α, the natural ligand of TNF-R1, to HCLE cells induced K + channel activation and loss of intracellular K + . Cytochrome c was translocated to the cytosol by 2 h after exposure to 150 mJ/cm 2 UVB. However, there was no release by 10 min post-UVB. The data suggest that UVB activates TNF-R1, which in turn may activate K + channels via FADD. This conclusion is supported by the observation that TNF-α also causes loss of intracellular K + . This signaling pathway appears to be integral to UVB-induced K + efflux, since knockdown of TNF-R1 or FADD inhibits the UVB-induced K + efflux. The lack of rapid cytochrome c translocation indicates cytochrome c does not play a role in UVB-induced K + channel activation. [ABSTRACT FROM AUTHOR]

Our previous study evaluated the antioxidant activities of sulfated polysaccharides from Celluclast-assisted extract of Hizikia fusiforme (HFPS) in vitro in Vero cells and in vivo in zebrafish. The results showed that HFPS possesses strong antioxidant activity and suggested the potential photo-protective activities of HFPS. Hence, in the present study, we investigated the protective effects of HFPS against ultraviolet (UV) B-induced skin damage in vitro in human dermal fibroblasts (HDF cells). The results indicate that HFPS significantly reduced intracellular reactive oxygen species (ROS) level and improved the viability of UVB-irradiated HDF cells in a dose-dependent manner. Furthermore, HFPS significantly inhibited intracellular collagenase and elastase activities, remarkably protected collagen synthesis, and reduced matrix metalloproteinases (MMPs) expression by regulating nuclear factor kappa B (NF-κB), activator protein 1 (AP-1), and mitogen-activated protein kinases (MAPKs) signaling pathways in UVB-irradiated HDF cells. These results suggest that HFPS possesses strong UV protective effect, and can be a potential ingredient in the pharmaceutical and cosmetic industries.

Ultraviolet-B (UVB) exposure on the skin triggers apoptosis, oxidative stress and acute inflammatory responses, which eventually increases the risk of various skin disorders. Hemin, an iron-binding porphyrin, has been clinically used for porphyria treatment. However, whether hemin contributes to the skin protection against UVB injury remains to be elucidated. Here, we found that hemin treatment (10 and 20 mg/kg) by intraperitoneal administration could dramatically relieve UVB irradiation-induced skin damage featured by erythema, edema, epidermal hyperplasia and collagen loss in C57BL/6 J mice. Importantly, hemin treatment attenuated UVB irradiation-triggered cell apoptosis in skin epidermis. Consistently, hemin (10, 20 μM) treatment decreased Caspase-3 activation and protected against UVB-induced apoptosis in HaCaT cells. Besides, hemin treatment reduced the infiltration of neutrophils in skin under UVB irradiation, thus restrained neutrophil extracellular traps (NET) formation and myeloperoxidase (MPO) release. We further revealed that hemin inhibited the expression of inflammation associated cytokines and chemokines in UVB-induced HaCaT cells and blocked the chemotaxis of dHL-60 cells to preconditioned media from HaCaT culture upon UVB irradiation. Furthermore, hemin inhibited the excessive maturation and mobilization of bone marrow neutrophils and rectified the proportion of abnormally elevated neutrophils in the blood under UVB irradiation. In conclusion, our study showed that hemin treatment protects against UVB-induced skin damage through inhibiting keratinocytes apoptosis, and suppressing neutrophils infiltration in the skin via externally restraining the keratinocyte attraction and internally regulating bone marrow neutrophil maturation and mobilization, suggesting that hemin is an effective drug candidate for the therapy of UVB damage. [Display omitted] • Hemin treatment protected against UVB-induced skin damage. • Hemin attenuated keratinocytes apoptosis under UVB irradiation. • Hemin reduced neutrophils infiltration in skin under UVB irradiation. •.Hemin restrained the chemotaxis of neutrophil to keratinocyte, and inhibited BM neutrophil maturation and mobilization. [ABSTRACT FROM AUTHOR]

Ultraviolet (UV)-B irradiation leads to DNA damage, cell cycle arrest, growth inhibition, and cell death. To evaluate the UV-B stress–induced changes in plant cells, we developed a model system based on tobacco Bright Yellow-2 (BY-2) cells. Both low-dose UV-B (low UV-B: 740 J m−2) and high-dose UV-B (high UV-B: 2960 J m−2) inhibited cell proliferation and induced cell death; these effects were more pronounced at high UV-B. Flow cytometry showed cell cycle arrest within 1 day after UV-B irradiation; neither low- nor high-UV-B–irradiated cells entered mitosis within 12 h. Cell cycle progression was gradually restored in low-UV-B–irradiated cells but not in high-UV-B–irradiated cells. UV-A irradiation, which activates cyclobutane pyrimidine dimer (CPD) photolyase, reduced inhibition of cell proliferation by low but not high UV-B and suppressed high-UV-B–induced cell death. UV-B induced CPD formation in a dose-dependent manner. The amounts of CPDs decreased gradually within 3 days in low-UV-B–irradiated cells, but remained elevated after 3 days in high-UV-B–irradiated cells. Low UV-B slightly increased the number of DNA single-strand breaks detected by the comet assay at 1 day after irradiation, and then decreased at 2 and 3 days after irradiation. High UV-B increased DNA fragmentation detected by the terminal deoxynucleotidyl transferase dUTP nick end labeling assay 1 and 3 days after irradiation. Caffeine, an inhibitor of ataxia telangiectasia mutated (ATM) and ataxia telangiectasia and Rad3-related (ATR) checkpoint kinases, reduced the rate of cell death in high-UV-B–irradiated cells. Our data suggest that low-UV-B–induced CPDs and/or DNA strand-breaks inhibit DNA replication and proliferation of BY-2 cells, whereas larger contents of high-UV-B–induced CPDs and/or DNA strand-breaks lead to cell death.

Ultraviolet-B (UV-B) stress appears to be more striking than other research works because of the thin ozone layer. The protective influence of an exogenous nitric oxide donor and sodium nitroprusside (SNP) on the growth properties of Larix gmelinii seedlings was investigated under ultraviolet-B radiation conditions. The results indicated that 0.1 mM SNP could effectively alleviate the damage caused by ultraviolet-B radiation, and improved the seedling growth properties, the relative water content, and photosynthetic pigment content in leaves. Additionally, the photosynthetic capacity and antioxidant enzyme activity were increased during the exposure. On the contrary, the damage caused by active oxygen was decreased in SNP-treated seedling leaves. The damage caused by ultraviolet-B radiation was slightly reduced after treating with 0.01 mM SNP. Nevertheless, treatment with 0.5 mM SNP had a negative effect under ultraviolet-B radiation. Furthermore, supplementing NO (nitric oxide) improved the photosynthetic capacity and antioxidant enzyme activity and alleviated the damage of caused by active oxygen. The best effective concentration of SNP was 0.1 mM. Therefore, a suitable amount of exogenous NO can protect the Larix gmelinii seedlings and increase their tolerance to ultraviolet-B radiation. [ABSTRACT FROM AUTHOR]

Purpose: The immediate aim of this study was to investigate alterations in peroxiredoxin (Prdx) 6 at posttranslational levels, and the levels of protein oxidation, lipid peroxidation, and reactive oxygen species (ROS) in lens epithelial cells (LECs) after exposure to severe oxidative stress, such as ultraviolet-B (UV-B). Our ultimate aim was to provide new information on antioxidant defenses in the lens and their regulation, thereby broadening existing knowledge of the role of Prdx6 in lens physiology and pathophysiology. Methods: The expression of the hyperoxidized form of Prdx6 and oxidation of protein were analyzed by western blotting and the OxyBlot assay in human LECs (hLECs). ROS levels were quantified using DCFH-DA dye, and cell viability was quantified by the MTS and TUNEL assays. To evaluate the protective effect of Prdx6, we cultured lenses with or without the TAT transduction domain (TAT-HA-Prdx6) and observed (and photographed) the cultures at specified time-points after the exposure to UV-B for the development of opacity. Results: Prdx6 in hLECs was hyperoxidized after exposure to high amounts of UV-B. UV-B treatment of hLECs increased the levels of cell death, protein oxidation, and ROS. hLECs exposed to UV-B showed higher levels of ROS, which could be reduced by the application of extrinsic TAT-HA-Prdx6, attenuating UV-B-induced lens opacity and apoptotic cell death. Conclusion: Excessive oxidative stress induces the hyperoxidation of Prdx6 and may reduce the ability of Prdx6 to protect LECs against ROS or stresses. Because extrinsic Prdx6 could attenuate UV-B-induced abuse, this molecule may have a potential in preventing cataractogenesis. [ABSTRACT FROM AUTHOR]

Main conclusion : Paper-bagging treatment can transform non-transcribed MdMYB1 - 2 and MdMYB1 - 3 alleles into transcribed alleles through epigenetic regulations, resulting in the red pigmentation of a normally non-red apple cultivar 'Mutsu.' Anthocyanin biosynthesis in apples is regulated by MdMYB1/ A/ 10, an R2R3-Type MYB gene. 'Mutsu,' a triploid apple cultivar harboring non-transcribed MdMYB1- 2 and MdMYB1- 3 alleles, retains green skin color under field conditions. However, it can show red/pink pigmentation under natural or artificial ultraviolet-B (UV-B) light exposure after paper-bagging and bag removal treatment. In the present study, we found that in 'Mutsu,' paper bagging-induced red pigmentation was due to the activation of non-transcribed MdMYB1- 2/- 3 alleles, which triggered the expression of downstream anthocyanin biosynthesis genes in a UV-B-dependent manner. By monitoring the epigenetic changes during UV-B-induced pigmentation, no significant differences in DNA methylation and histone modifications in the 5′ upstream region of MdMYB1- 2/-3 were recorded between the UV-B-treated fruit skin (red) and the fruit skin treated only by white light (green). In contrast, bag treatment lowered the DNA methylation in this region of MdMYB1- 2/- 3 alleles. Similarly, higher levels of histone H3 acetylation and trimethylation of H3 tail at lysine 4, and lower level of trimethylation of H3 tail at lysine 27 were observed in the 5′ upstream region of MdMYB1- 2/-3 in the skin of the fruit immediately after bag removal. These results suggest that bagging treatment can induce epigenetic changes, facilitating the binding of trans factor(s) to MdMYB1- 2/- 3 alleles, resulting in the activation of these MYBs after bag removal. [ABSTRACT FROM AUTHOR]

Background and Aims Atmospheric carbon dioxide ( CO2) levels and temperature are expected to increase in the next decades. In addition, changes in climate as well as the stratospheric ozone concentration may affect the exposure of viticultural regions to UV- B. The aim of the present study was to investigate the effect of combined elevated CO2 and increased temperature (+ CO2/+T) regimes and UV- B radiation on anthocyanin and flavonol biosynthesis in grape berries. Methods and Results Three UV- B doses [0, 5.98 and 9.66 kJ/(m2·d)] and two CO2-day/night temperature regimes (390 μmol/mol CO2-24/14°C and 700 μmol/mol CO2-28/18°C) were imposed on V itis vinifera cv. Tempranillo fruit-bearing cuttings from fruitset to maturity. Berry mass, composition and expression of selected genes were monitored. The time to reach veraison and maturity was reduced under + CO2/+ T. Anthocyanin concentration under + CO2/+ T was higher 2 weeks after veraison, but lower at maturity. Ultraviolet- B radiation slowed berry development and upregulated flavonol and anthocyanin biosynthesis. Conclusions The effect of UV- B, which modulates the accumulation of sugars and upregulates anthocyanin biosynthesis, compensated the deleterious effect of elevated CO2 and increased temperature on berry anthocyanin concentration. Significance of the Study Certain viticultural practices, such as leaf removal, that modify the exposure of grapes to UV- B and the leaf surface to fruit mass ratio, may alleviate the effect of elevated CO2 and increased temperature on grape anthocyanin concentration. [ABSTRACT FROM AUTHOR]

Ultraviolet-B (UV-B) radiation is one of the most important abiotic stress factors that could influence plant growth, development, and productivity. Nitric oxide (NO) is an important plant growth regulator involved in a wide variety of physiological processes. In the present study, the possibility of enhancing UV-B stress tolerance of lettuce seedlings by the exogenous application of sodium nitroprusside (SNP) was investigated. UV-B radiation increased the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD) and total phenolic concentrations, antioxidant capacity, and expression of phenylalanine ammonia lyase (PAL) gene in seedlings, but the combination of SNP pretreatment and UV-B enhanced antioxidant enzyme activities, total phenolic concentrations, antioxidant capacity, and PAL gene expression even more. Moreover, UV-B radiation significantly inhibited chlorophylls, carotenoid, gibberellic acid (GA), and indole-3-acetic acid (IAA) contents and increased the contents of abscisic acid (ABA), salicylic acid (SA), malondialdehyde (MDA), hydrogen peroxide (HO), and superoxide radical (O•) in lettuce seedlings. When SNP pretreatment was combined with the UV-B radiation, we observed alleviated chlorophylls, carotenoid, GA, and IAA inhibition and decreased content of ABA, SA, MDA, HO, and O• in comparison to non-pretreated stressed seedlings. [ABSTRACT FROM AUTHOR]

This work presents broad-band ultraviolet-B (UVB) to visible photodetection with a high responsivity and detectivity values based on a simple metal-Zn 2 SnO 4 (ZTO) thin film-metal structure. Al-ZTO-Al based metal-semiconductor-metal planar structure shows high responsivity values of 9.25 A/W, 3.64 A/W, 0.71 A/W, and 0.44 A/W under 280 nm, 300 nm, 460 nm, and 550 nm illuminations at + 5 V bias with detectivity values of 4.06 × 1012 Jones, 1.6 × 1012 Jones, 3.1 × 1011 Jones, and 1.93 × 1011 Jones, respectively. The sensitivity values of ∼103 , 4.7 × 102, 3.2 × 102, and 2.25 × 102 have been achieved under 280 nm, 300 nm, 460 nm, and 550 nm illuminations with external quantum efficiency values of 4.1 × 103%, 1.5 × 103%, 1.9 × 102%, and 9.9 ×101%, respectively. Unprecedentedly, from the successive responsivity measurements, an ionization transition level of an in-gap defect in ZTO has been proposed to be peaking at ∼2.3 eV below the conduction band causing the visible light sensitivity. This simple ZTO thin film-based UVB to visible broad-band photodetection is very promising for future optoelectronic applications. [Display omitted] • Zn 2 SnO 4 thin film-based UVB to visible broad-band photodetection reported. • High responsivity of 9.25 and 0.71 A/W obtained under 280 and 460 nm illuminations. • Position of defect states proposed from the successive responsivity measurements. [ABSTRACT FROM AUTHOR]

Anthocyanin plays critical role in plant secondary metabolism. Although many transcription factors (TFs) that participate in the anthocyanin biosynthesis pathway have been characterized, many have yet to be reported. In the study, we cloned a WRKY Group IIc TF in apple (Malus × domestica), MdWRKY71-L, which localized to the nucleus. The overexpression of MdWRKY71-L promoted the accumulation of anthocyanin in apple calli. MdWRKY71-L mainly stimulated this accumulation through interacting with the promoters of MdMYB1 and MdUFGT. In addition to plant genotype, the synthesis of anthocyanin is also affected by external factors, such as ultraviolet-B radiation. Ultraviolet-B exposure induced MdWRKY71-L expression and MdWRKY71-L promoted the expression of MdHY5 by interacting with its promoter. Our research provided new insights into how WRKY TFs participated in the ultraviolet-B signaling pathway to regulate the accumulation of anthocyanin in apple. • Transgenic MdWRKY71-L regulated apple anthocyanin synthesis. • MdWRKY71-L mainly promoted anthocyanin accumulation by binding to the promoters of MdMYB1 and MdUFGT. • MdWRKY71-L could participate in UV-induced anthocyanin synthesis in apple. • MdWRKY71-L regulated the biosynthesis of anthocyanin through MdHY5-MdMYB1 transcriptional regulatory cascade. [ABSTRACT FROM AUTHOR]