ultraviolet-B Light Research Articles

Keratinocyte derived extracellular vesicles mediated crosstalk between epidermis and dermis in UVB-induced skin inflammation.

Ultraviolet-B (UVB) light induces dermal inflammation, although it is mostly absorbed in the epidermis. Recent reports suggest extracellular vesicles (EVs) act as a mediator of photodamage signaling. Melatonin is reported to be a protective factor against UV-induced damage. We hypothesized that EVs derived from UVB-irradiated keratinocytes might trigger proinflammatory responses in dermal cells and tested whether melatonin can ameliorate UVB-induced inflammation. We used UVB-irradiated HaCaT cells, primary keratinocytes and STING knock-out mice to model production of EVs under photodamaging conditions and performed immunoblotting and ELISA to measure their effect on dermal macrophages. UVB-irradiated keratinocytes produce an increased number of EVs that contain higher concentrations of DNA and protein compared with controls. KC-derived EVs (KEVs) induced a STING- and inflammasome-mediated proinflammatory response in macrophages in vitro, and a pronounced inflammatory infiltrate in mouse dermis in vivo. Melatonin ameliorated KEVs inflammatory effect both in vitro and in vivo. This data suggests EVs are mediators in a crosstalk that takes place between keratinocytes and their neighboring cells as a result of photodamage. Further studies exploring EVs induced by damaging doses of UVB, and their impact on other cells will provide insight into photodamage and may help develop targeted therapeutic approaches.

Effects of UV-B and UV-C Spectrum Supplementation on the Antioxidant Properties and Photosynthetic Activity of Lettuce Cultivars.

Indoor farming systems enable plant production in precisely controlled environments. However, implementing stable growth conditions and the absence of stress stimulants can weaken plants' defense responses and limit the accumulation of bioactive, health-beneficial phytochemicals. A potential solution is the controlled application of stressors, such as supplemental ultraviolet (UV) light. To this end, we analyzed the efficiency of short-term pre-harvest supplementation of the red-green-blue (RGB, LED) spectrum with ultraviolet B (UV-B) or C (UV-C) light to boost phytochemical synthesis. Additionally, given the biological harm of UV radiation due to high-energy photons, we monitored plants' photosynthetic activity during treatment and their morphology as well as sensory attributes after the treatment. Our analyses showed that UV-B radiation did not negatively impact photosynthetic activity while significantly increasing the overall antioxidant potential of lettuce through enhanced levels of secondary metabolites (total phenolics, flavonoids, anthocyanins), carotenoids, and ascorbic acid. On the contrary, UV-C radiation-induced anthocyanin accumulation in the green leaf cultivar significantly harmed the photosynthetic apparatus and limited plant growth. Taken together, we showed that short-term UV-B light supplementation is an efficient method for lettuce biofortification with healthy phytochemicals, while UV-C treatment is not recommended due to the negative impact on the quality (morphology, sensory properties) of the obtained leafy products. These results are crucial for understanding the potential of UV light supplementation for producing functional plants.

Effect of the Addition of an Ultraviolet B Light Bulb for 6 Months to the Enclosure of Client-Owned Cockatiels (Nymphicus hollandicus) on Serum 25-Hydroxyvitamin D Concentrations

BackgroundThe objective of this study was to determine the effects of ultraviolet B (UVB) radiation on the serum concentration of 25-hydroxyvitamin D [25(OH)D] in pet cockatiels (Nymphicus hollandicus) living in their home environments. MethodsThirty client-owned cockatiels were allocated to an intervention group, consisting of exposure to a commercial coil fluorescent bulb, or a control group, with no exposure to supplemental lighting. Blood samples were collected at baseline (Day 0) and 6 months after simple randomization for measurement of 25(OH)D (Day 180). A linear mixed model was used to determine if serum 25(OH)D concentrations were influenced by time, group, age, or sex. ResultsAt baseline, median 25(OH)D concentration for the whole study population was 13nmol/L (range, 0.0-15.0nmol/L). At the end of the study, median 25(OH)D concentration for the whole study population was 6.5 nmol/L (0.0-15.0nmol/L), for the UVB group was 3 nmol/L (0.0-8.0nmol/L) and for the control group was 7.5nmol/L (6.0-11.0nmol/L). There was a statistically significant 50% reduction in 25(OH)D concentrations from the baseline to the final sampling period for the overall population, but no differences by group, age, or sex. Conclusion and clinical relevanceThe addition of a UVB bulb for 6 months to the enclosures of cockatiels did not increase their serum 25(OH)D concentrations. There was an unexplained decrease in both groups when comparing Day 0 to the Day 180 sampling period. The 50% attenuation in the UVB lighting group, although not statistically significant, may be clinically relevant and deserves further investigation.

Nuclear accumulation of rice UV-B photoreceptors is UV-B- and OsCOP1-independent for UV-B responses

In plants, the conserved plant-specific photoreceptor UV RESISTANCE LOCUS 8 (UVR8) perceives ultraviolet-B (UV-B) light and mediates UV-B-induced photomorphogenesis and stress acclimation. In this study, we reveal that UV-B light treatment shortens seedlings, increases stem thickness, and enhances UV-B stress tolerance in rice (Oryza sativa) via its two UV-B photoreceptors OsUVR8a and OsUVR8b. Although the rice and Arabidopsis (Arabidopsis thaliana) UVR8 (AtUVR8) photoreceptors all form monomers in response to UV-B light, OsUVR8a, and OsUVR8b function is only partially conserved with respect to AtUVR8 in UV-B-induced photomorphogenesis and stress acclimation. UV-B light and CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1) promote the nuclear accumulation of AtUVR8; by contrast, OsUVR8a and OsUVR8b constitutively localize to the nucleus via their own nuclear localization signals, independently of UV-B light and the RING-finger mutation of OsCOP1. We show that OsCOP1 negatively regulates UV-B responses, and shows weak interaction with OsUVR8s, which is ascribed to the N terminus of OsCOP1, which is conserved in several monocots. Furthermore, transcriptome analysis demonstrates that UV-B-responsive gene expression differs globally between Arabidopsis and rice, illuminating the evolutionary divergence of UV-B light signaling pathways between monocot and dicot plants.

The effect of betel nut extract on melanin pigment levels in rats' skin exposed to Ultraviolet B radiation

This study aims to analyze the effect of areca nut extract on the amount of melanin pigment in the skin of Wistar rats exposed to ultraviolet-B light. The research method used was post-test with control group design. The total sample of white rats used was 20 rats, which were divided into 4 groups with each group consisting of 5 rats. The cream preparation was made using cold cream base. The rats were then exposed to UVB with a certain intensity for 5 days, characterized by erythema as a result of UVB absorption into the epidermis. Each group of treated rats received base cream, 10% areca nut extract cream, and 15% areca nut extract cream topically for 14 days before termination on day 15. The collected data were then tabulated and analyzed. To determine significant differences or influences between the test groups, analysis was carried out with t-test or Independent Samples T-Test approach at 95% confidence level (p < 0.05). The results of the analysis showed that the administration of areca nut extract was effective in reducing the amount of melanin pigment in the skin of Wistar rats exposed to Ultraviolet-B light. From histopathological observations, the administration of areca nut extract with a concentration of 15% is effective in removing or fading melanin pigments in the skin exposed to Ultraviolet-B light and the results of damaged skin melanin pigments appear in the epidermis of rat skin barely visible grain.

Advantages of AlGaN Tunnel Junction in N-Polar 284 nm Ultraviolet-B Light Emitting Diode

Smart, low cost and environmentally safe aluminum gallium nitride (AlGaN)-based ultraviolet-B light-emitting diodes (UV-B LEDs) are promising in real-world applications including medical as well as agricultural sciences. Higher efficiency droops, low hole injection efficiency, and high operating voltage are the key problems that AlGaN-based UV-B LEDs are facing. In this work, a smart and clean AlGaN-based UV-B LED at 284 nm emission wavelength has been studied. Here an approach is presented to electrically operate the quantum tunnelling probability by exploiting the transported carriers at the interface of p-AlGaN/n-AlGaN/n++-AlGaN tunnel junction (TJ) with moderate Si and Mg-doping levels and optimized thickness with the help of simulation study. The simulation results show that the Augur recombination rate is successfully suppressed and quite a high radiative recombination rate is achieved in the 284 nm N-polar AlGaN-based TJ UV-B LEDs, which is attributed to the improved hole injection toward the MQWs when compared to C-LED (conventional-LED). It is found that C-LED has a maximum IQE (internal quantum efficiency) of 40% under 200 A cm−2 injection current with an efficiency drop of 15%, while the TJ-LED has a maximum IQE of 93% with an efficiency droop of 0%. In addition, TJ-based AlGaN LED emitted power has been improved by 6 times compared to the C-LED structure. The emitted powers of TJ-LED increase linearly under varying current densities, whereas in the case of C-LED, the emitted power changes nonlinearly under varying current densities. This is attributed to the lower Augur recombination rate in the MQWs of N-AlGaN-based TJ UV-B LED. The operating voltages were reduced from 5.2 V to 4.1 V under 200 mA operation, which is attributed to the thickness and doping optimization in TJ and better selection of relatively lower Al-content in the contact layer. N-polar AlGaN-based TJ is explored for UV-B LEDs and the demonstrated work opens the door to epitaxial growth of high-performance UV emitters in MOCVD and MBE for a plethora of biomedical applications.

Response surface methodology of subcritical water-reactive extraction of gingerol to shogaol ginger dregs through ultraviolet light pretreatment

The increase of shogaol production through reactive extraction of subcritical water depends on the stages of the pretreatment process in destroying the cellular cells of ginger pulp. Pretreatment using ultraviolet B (UVB) is predicted to be able to damage cellular cell walls and outer cell membranes (plasmalemma). In addition, to initiate the degradation of gingerols to shogaols, the reaction conversion and selectivity of shogaols are increased. This study aimed to examine the optimum process conditions for the subcritical water-reactive extraction of gingerol to shogaol from the ginger pulp by utilizing UVB pretreatment: reactive extraction temperature (110 – 130oC), ratio solvent/feed (22:1 – 32:1 b/b), and time (10 – 30 minutes). The extract of shogaol in solvent was separated from the raffinate with a separator funnel and analysed using HPLC-MS. Interpretation of experimental data to optimize the reactive extraction process used the Response Surface Methodology (RSM). The study results show that at 120°C, solvent:inlet ratio 27:1 for 20 minutes through ultraviolet B-light pretreatment for 10 minutes, the yield of shogaol increased from 177 µg/L (without UV) to 18646 µg/L. Moreover, the RSM model was very good at predicting shogaol acquisition responses with a determination coefficient of R2 to be 0.8554. The optimum condition for reactive extraction through UV-B light pretreatment was reached at a temperature of 121.46°C and an inlet solvent ratio of 27.96 at 18.36 minutes, with a shogaol concentration of 18567.1 µg /L.

The synergistic bactericidal effect of simultaneous 222 nm krypton-chlorine excilamp and 307 nm UVB light treatment on sliced cheese and its mechanisms

In this study, we investigated the combined effect of 222 nm krypton-chlorine excilamp (EX) and 307 nm ultraviolet-B (UVB) light on the inactivation of Salmonella Typhimurium and Listeria monocytogenes on sliced cheese. The data confirmed that simultaneous exposure to EX and UVB irradiation for 80 s reduced S. Typhimurium and L. monocytogenes population by 3.50 and 3.20 log CFU/g, respectively, on sliced cheese. The synergistic cell count reductions in S. Typhimurium and L. monocytogenes in the combined treatment group were 0.88 and 0.59 log units, respectively. The inactivation mechanism underlying the EX and UVB combination treatment was evaluated using fluorescent staining. The combination of EX and UVB light induced the inactivation of reactive oxygen species (ROS) defense enzymes (superoxide dismutase) and synergistic ROS generation, resulting in synergistic lipid peroxidation and destruction of the cell membrane. There were no significant (P > 0.05) differences in the color, texture, or sensory attributes of sliced cheese between the combination treatment and control groups. These results demonstrate that combined treatment with EX and UVB light is a potential alternative strategy for inactivating foodborne pathogens in dairy products without affecting their quality.

Effects of Supplemental Lighting on Flavonoid and Anthocyanin Biosynthesis in Strawberry Flesh Revealed via Metabolome and Transcriptome Co-Analysis.

The spectral composition of light influences the biosynthesis of flavonoids in many plants. However, the detailed composition of flavonoids and anthocyanins and the molecular basis for their biosynthesis in strawberry fruits under two light-quality treatments, red light supplemented with blue light (RB) and ultraviolet B (UVB) irradiation, remain unclear. In this study, the content of flavonoids and anthocyanins was significantly increased in strawberry fruits under RB light and UVB, respectively. The content of flavonoids and anthocyanins in strawberry fruits under UVB light was dramatically higher than that in strawberry fruits irradiated with RB light, and a total of 518 metabolites were detected by means of LC-MS/MS analysis. Among them, 18 phenolic acids, 23 flavonoids, and 8 anthocyanins were differentially accumulated in the strawberry fruits irradiated with red/blue (RB) light compared to 30 phenolic acids, 46 flavonoids, and 9 anthocyanins in fruits irradiated with UVB. The major genes associated with the biosynthesis of flavonoids and anthocyanins, including structural genes and transcription factors (TFs), were differentially expressed in the strawberry fruits under RB and UVB irradiation, as determined through RNA-seq data analysis. A correlation test of transcriptome and metabolite profiling showed that the expression patterns of most genes in the biosynthesis pathway of flavonoids and anthocyanins were closely correlated with the differential accumulation of flavonoids and anthocyanins. Two TFs, bZIP (FvH4_2g36400) and AP2 (FvH4_1g21210), induced by RB and UVB irradiation, respectively, exhibited similar expression patterns to most structural genes, which were closely correlated with six and eight flavonoids, respectively. These results indicated that these two TFs regulated the biosynthesis of flavonoids and anthocyanins in strawberry fruit under RB light and UVB, respectively. These results provide a systematic and comprehensive understanding of the accumulation of flavonoids and anthocyanins and the molecular basis for their biosynthesis in strawberry fruits under RB light and UVB.

Study of Demographic Patterns and Treatment Approaches of Ocular Surface Squamous Neoplasia in a Tertiary Care Centre

Abstract Background: Ocular surface squamous neoplasia (OSSN) includes a wide spectrum of conjunctival and corneal intraepithelial neoplasia, which can manifest as mild, moderate, severe dysplasia, carcinoma-in-situ and invasive squamous cell carcinoma. OSSN can mimic many common indolent lesions like pterygium and have a potential for causing ocular and systemic morbidity and mortality. OSSN is more common in elderly males. ultraviolet-B light, human immune deficiency, and human papilloma virus have been proposed as major risk factors in aetiopathogenesis. Though diagnosis of OSSN is mainly based on clinical suspicion, definitive diagnosis needs histopathological evaluation. Anterior segment optical coherence tomography, ultrasonic bio microscopy, and impression cytology are nonsurgical tools used for diagnosis and management, of which anterior segment optical coherence tomography has brought about a paradigm shift in the diagnosis of OSSN. Aim: The aim of the study was to demonstrate the demographics, clinical profile, types of OSSN, management approaches, histopathology and the effectiveness of different approaches in patients with OSSN in a tertiary care centre in Tamil Nadu. Materials and Methods: It was a hospital-based prospective interventional study where 51 eyes of 50 patients with clinically suspicious OSSN were studied between July 2021 and January 2023 (over 18 months) with a minimum follow-up of 6 months. Results: The age group for the patients ranged between 30 and 79 years. Out of 50 patients, 26 were men and 24 were women with no sex predilection in our study. Unilateral involvement was seen in 49 patients and only one patient had bilateral involvement. Twenty-nine patients presented with gelatinous-like lesions, six with leukoplakic lesions, five with papilliform like lesion, nine with pigmented lesions and one with nodulo ulcerative type lesion. On histopathological examination, majority (21 patients) were severe dysplasia. Majority (78.4%) underwent surgical clearance with no recurrence. Adjunctive therapy to reduce recurrence included intraoperative cryotherapy and postoperative topical chemotherapy using mitomycin C. Conclusion: In our series, the most common morphological type of lesion was gelatinous, and surgical management using Shield’s technique was commonly used as the management option for unifocal lesions less than 5 mm with less than 4 clock hours involvement. The demographic profile was comparable with other studies on OSSN. Being a potentially malignant condition, a study on OSSN helps us in understanding the disease better and helps in early detection, leading to timely intervention and improved treatment outcomes. Furthermore, research on OSSN contributes to enhancing our knowledge on ocular oncology.

The Addition of Astaxanthin 0.5% in Sunscreen SPF 50 Inhibits the Increase of Sunburn Cells in Rats Induced By Ultraviolet Light B

Long-term exposure to ultraviolet light can cause chronic inflammation that can damage collagen and increase sunburn cells known as photoaging. There is a prevalence of up to 69% in female students in Jakarta aged 18–21 years who experience aging of the skin due to not using sunscreen. One of the signs of photoaging measured in this study is sunburn cells. This study wants to prove that the addition of astaxanthin 0.5% contained in SPF 50 sunscreen can inhibit the increase in sunburn cells in mice induced by ultraviolet B-light. Sunscreen also has protection limits, for example, SPF 30 has 97% protection, which means there is still 3% of radiation entering the skin so there is still a small portion that can cause free radicals. Additional ingredients are needed so that sunscreen can optimally protect the skin. An experimental study with a post-test-only design was used in this study comparing rats given SPF 50 sunscreen containing no astaxanthin (P1) and rats given SPF 50 sunscreen containing 0.5% astaxanthin (P2) to assess the inhibition of increased sunburn cells. 36 rats (Rattus Norvegicus) were divided into 2 groups and then shaved and exposed to UVB light with a total of 3100 mJ for 5 weeks. After the last exposure in the fifth week, skin tissue was taken fixed and stained using Hematoxylin Eosin to count sunburn cells. Sunburn Cells in group P1 had a value of 0.47 Å} 0.27 cells per high power field (hpf), and group P2 had a value of 0.16 Å} 0.18 cells per hpf. According to the Mann-Whitney test, there is a significant difference in the number of sunburn cells between groups (p < 0.05). From the results of this study, it can be concluded that astaxanthin 0.5% added to SPF 50 sunscreen products can inhibit the increase in sunburn cells.

Comparison of UVA vs UVB Photoaging Rat Models in Short-term Exposure.

Prolonged exposure to sunlight is known to induce photoaging of the skin, leading to various skin changes and disorders, such as dryness, wrinkles, irregular pigmentation, and even cancer. Ultraviolet A (UVA) and ultraviolet B (UVB) radiation are particularly responsible for causing photoaging. This study aims to identify and compare photoaging rat models exposed to UVA and UVB. This research method compared macroscopic (scoring degree of wrinkling) and microscopic (histology) signs and symptoms on skin samples of rat exposed to UVA and UVB for 4 weeks at a radiation dose of 840mJ/cm2. The results of this study indicated that the degree of wrinkling was highest in rat skin exposed to UVB rays by 51% (p<0.05). UVB histological results showed that the epidermis layer (40 µm, p<0.05) was thickened and the dermis layer (283 µm, p<0.05) was thinned in the skin of mice exposed to UVB light. The UVB group, showed the density of collagen in the dermis with a mean value of 55% (p<0.05). Our results suggest that short-term exposure to UVB radiation (in the acute, subacute or subchronic phase) induces more rapid and pronounced damage to rat skin when compared to UVA radiation exposure.

Induced Resistance of Shallot (Allium cepa L. var aggregatum) against Twisted Disease Using Ultraviolet-B Light

Ultraviolet-B (UV-B) light is known to induce plant resistance in suppressing disease infection. Its ability to induce plant resistance has been widely used as an inducer of plant resistance. This study aims to determine the ability of UV-B light in suppressing shallot twisted disease, potency of plant resistance induction through accumulation of peroxidase enzymes, salicylic acid, chlorophyl content and to observe shallot growth after treatment. This study applied UV-B light with a duration of 65 mW/m2 for 4 hours each day for 3, 5 and 7 days, for inoculated and non-inoculated plants. Fungicide (Benomyl) was used as a comparison for inoculated plants. The results showed that UV-B irradiation of 4 hours/day for 7 days was able to reduce the incidence of shallot twisted disease, but the incubation period among treatments was not significantly different. UV-B irradiation of 4 hours/day, for 7 days was able to increase salicylic acid content, and maintain the same chlorophyll content as the negative control, however the peroxidase enzyme content was not significantly different. Treatment of UV-B 4 hours/day for 7 days irradiation did not inhibit the growth and production of shallot plants.

Effect of Serum Breadfruit Leaf Extract (Artocarpus Altilis) on TNF-Α and Sod Levels (Experimental Study on Guinea Pigs Exposed to UVB Light)

Continuous exposure to ultraviolet B (UVB) light can increase the amount of melanin, causing hyperpigmentation on the skin. This process involves the important role of Tumor Necrosis Factor-α (TNF-α) and Superoxide Dismutase (SOD). Artocarpus Altilis contain flavonoids that have anti-inflammatory potential, can reduce TNF-α levels and increase SOD which affects the melanogenesis process. To determine the effect of administering Artocarpus Altilis extract serum on TNF-α and SOD levels in guinea pigs exposed to UVB. This research is an in vivo experimental study with Post Test Only Group design, which was conducted at the IBL FK Laboratory (Integrated Biomedical Laboratory Faculty of Medicine) Unissula. A total of 30 male guinea pigs were divided into 5 groups, namely: Group 1 sham, group 2 negative control, group 3 treated with 2% Artocarpus Altilis extract serum, group 4 treated with 4% serum and group 5 treated with 6% serum. Then analyzed using the One-way ANOVA test to determine differences between groups. The lowest mean TNF-α levels were found in group P2 (4.958), other values were P1 (5.820), P3 (5.964), KS (6.069) and KN (5.811). Meanwhile, the average SOD levels in all groups were not much different, P2 (5.802), P1 (5.975), P3 (5.906), KS (6.054) and KN (6.000). In the One-way ANOVA test on TNF-α and SOD there was no significant difference, p&gt;0.05. Administration Artocarpus Altilis extract serum, especially 4%, caused a decrease in TNF-α levels but was not significant, and there was no increase in SOD levels, in guinea pigs exposed to UVB light.

Effectiveness of Applying Anti-Aging Cream with Lemon Peel Extract (Citrus Limon) in Inhibiting the Skin Aging Process of Wistar Rats (Rattus Norvegicus) Exposed to Ultra Violet-B Rays

Aging is a gradual physiological change in an organism that results in senescence or a reduction in biological function and the ability of the organism to respond to metabolic stress. Aging occurs in cells, organs, or the entire organism over time; the study of the aging process seeks to understand and regulate all elements that contribute to an individual's life constraints. The predominant acute consequence of UV radiation on normal human skin is sunburn-induced inflammation (erythema). The overall goal of this study is to examine and test the efficacy of applying an anti-aging cream containing lemon peel extract (Citrus limon) in preventing the aging process of mouse skin. Wistar strain (Rattus norvegicus) exposed to ultraviolet-B light. The specific goal of this study is to investigate the efficacy of applying lemon peel extract (Citrus limon) cream at 5%, 10%, and 15% concentrations in preventing the aging process of rat skin exposed to UV-B radiation.

Exposure to artificial ultraviolet-B light mediates alterations on the hepatic transcriptome and vitamin D metabolism in pigs

In the currently prevailing pig husbandry systems, the vitamin D status is almost exclusively dependent on dietary supply. Additional endogenous vitamin D production after exposure to ultraviolet-B (UVB) light might allow the animals to utilize minerals in a more efficient manner, as well as enable the production of functional vitamin D-enriched meat for human consumption. In this study, growing pigs (n = 16) were subjected to a control group or to a daily narrowband UVB exposure of 1 standard erythema dose (SED) for a period of 9 weeks until slaughter at a body weight of 105 kg. Transcriptomic profiling of liver with emphasis on the associated effects on vitamin D metabolism due to UVB exposure were evaluated via RNA sequencing. Serum was analyzed for vitamin D status and health parameters such as minerals and biochemical markers. The serum concentration of calcidiol, but not calcitriol, was significantly elevated in response to UVB exposure after 17 days on trial. No effects of UVB exposure were observed on growth performance and blood test results. At slaughter, the RNA sequencing analyses following daily UVB exposure revealed 703 differentially expressed genes (DEGs) in liver tissue (adjusted p-value < 0.01). Results showed that molecular pathways for vitamin D synthesis (CYP2R1) rather than cholesterol synthesis (DHCR7) were preferentially initiated in liver. Gene enrichment (p < 0.05) was observed for reduced cholesterol/steroid biosynthesis, SNARE interactions in vesicular transport, and CDC42 signaling. Taken together, dietary vitamin D supply can be complemented via endogenous production after UVB exposure in pig husbandry, which could be considered in the development of functional foods.

The Effects of UV Light and Methyl Salicylate on Phytochemical Constituents and Nutritional Traits in Common Bean (Phaseolus vulgaris L.)

Background: Mutagenesis has also been used to improve many desirable traits such as earliness, darkness, resistance or tolerance to biotic and abiotic stress, seed yield and oil quality. There are numerous mutagen agents, both chemical and physical, available to create and obtain valuable mutations in crop plants. Methods: The experiment was done at the laboratory of the Faculty of Applied Sciences, Ton Duc Thang University in Vietnam from September 2021 to December 2022. This study examined the effects of ultraviolet B-light (UV-B) and methyl salicylate (MeSA) treatment on phytochemical constituents (total phenols and flavonoids) and nutritional characteristics (protein and fat content) in a common bean cultivar, GRIS2. Result: The results show that UV irradiation for 3 hours increased the phenolic content in M1 seeds when compared to the control and other treatments. Furthermore, compared to the control and other treatments, UV-B irradiation for up to 5 hours increased the phenolic, protein and lipid content in the pod (in the immature pod, mature pod and seed). Alternatively, treatment with MeSA considerably decreased the levels of these same compounds. Treating the seed with 0.05 mM MeSA did increase the flavonoid content. These findings demonstrate the potential of UV-B treatment for improving bean nutritional quality. On the other hand, the negative general implications of the higher MeSA treatment suggest exogenous treatments should be kept at lower concentrations to ensure the minimization of nutritional losses.

Shoot-to-root communication via GmUVR8-GmSTF3 photosignaling and flavonoid biosynthesis fine-tunes soybean nodulation under UV-B light.

Legume nodulation requires light perception by plant shoots and precise long-distance communication between shoot and root. Recent studies have revealed that TGACG-motif binding factors (GmSTFs) integrate light signals to promote root nodulation; however, the regulatory mechanisms underlying nodule formation in changing light conditions remain elusive. Here, we applied genetic engineering, metabolite measurement, and transcriptional analysis to study soybean (Glycine max) nodules. We clarify a fine-tuning mechanism in response to ultraviolet B (UV-B) irradiation and rhizobia infection, involving GmUVR8-dependent UV-B perception and GmSTF3/4-GmMYB12-GmCHS-mediated (iso)flavonoid biosynthesis for soybean nodule formation. GmUVR8 receptor-perceived UV-B signal triggered R2R3-MYB transcription factors GmMYB12-dependent flavonoid biosynthesis separately in shoot and root. In shoot, UV-B-triggered flavonoid biosynthesis relied on GmUVR8a, b, c receptor-dependent activation of GmMYB12L-GmCHS8 (chalcone synthase) module. In root, UV-B signaling distinctly promotes the accumulation of the isoflavones, daidzein, and its derivative coumestrol, via GmMYB12B2-GmCHS9 module, resulting in hypernodulation. The mobile transcription factors, GmSTF3/4, bind to cis-regulatory elements in the GmMYB12L, GmMYB12B2, and GmCHS9 promoters, to coordinate UV-B light perception in shoot and (iso)flavonoid biosynthesis in root. Our findings establish a novel shoot-to-root communication module involved in soybean nodulation and reveal an adaptive strategy employed by soybean roots in response to UV-B light.

Effect of dietary vitamin D3 and ultraviolet-B light on the behaviour and growth of broilers challenged with social isolation stress

Within intensive poultry production systems, broilers are reared indoors, at fast growth rates in controlled environments with little access to natural light, which together impacts the expression of natural behaviours. Birds can see into the ultraviolet spectrum and the provision of ultraviolet-B (UVB) light may support the expression of natural behaviour and endogenous synthesis of vitamin D3 (vitD3). Commercially, chickens regularly encounter stressors, and both the environment and diet can influence their response to stressors. This study was designed to compare the impacts of providing dietary vitD3 at 4000 IU/kg (VitD) compared with provision via UVB light on the behaviour of broilers challenged with periodic social isolation stress. One-day-old Ross 308 broiler chicks (n = 192) were randomly allocated to non-isolated (control) and periodically isolated groups and were provided with either, additional dietary vitD3, or UVB light, in a 2 × 2 factorial design. UVB lamps were provided in all pens (12% UVB D3 of 55 cm length, 24-Watt, 280–315 nm wavelength and 28.12 µW/cm2 intensity) but in the VitD treatment, there were filters to remove UVB. Behaviour was recorded from video footage using instantaneous scans measuring the number of birds engaged in each behaviour six times per day on 12 days spread across days 2–39, resulting in 72 scan samples per pen. Body weight was measured weekly and analysed to provide context for understanding the activity of broilers. Body weight was modelled using growth curves and poisson models were used to analyse behaviour, controlling for the number of birds visible in scans. Chickens performed less active behaviour when they had been periodically isolated. Chickens spent more time sitting inactive (and less sitting active) and sleeping when they received UVB light but were not isolated. Sunbathing was lower in isolation treatments compared to controls, but this effect was reduced when they received UVB lighting. The growth rate of chickens was highest in the isolation and VitD treatment and higher for VitD compared to UVB treatments. Higher activity on days 2 and 39 was associated with a lower growth rate. These results indicate some benefits of supplementation of UVB light in terms of observing natural behaviour when chickens are exposed to stressors. However, we did not observe large differences in behaviour in chickens receiving UVB light compared to those provided with VitD. Further research is needed to investigate the benefits and optimal level of UVB light to support the behaviour and welfare of broilers.

ZnO quantum dots-diacetylenes-zinc(II) nanocomposites for colorimetric detection of ultraviolet-B light: the size effects

Polydiacetylenes (PDAs) are color-responsive materials that have shown potential as colorimetric sensors for detecting various classes of analytes. However, the utilization of PDAs for sensing ultraviolet-B light (UVB) is rare. This contribution introduces a facile method for enhancing the UVB-responsive property of PDAs by incorporating zinc oxide (ZnO) quantum dots (QDs). We explore the size effects of ZnO QDs/nanoparticles and diacetylene (DA) monomers on the sensitivity of the resultant nanocomposites to UVB light. Interestingly, the sensitivity of nanocomposites to UV light with different wavelengths can be controlled by adjusting the size of ZnO nanoparticles. We have found that the incorporation of ZnO QDs with diameters ranging from 2.2 to 3.8 nm drastically increases the sensitivity to UVB light. In addition, fine-tuning of the UVB sensitivity can be achieved by varying alkyl chain lengths of the DA monomers. The colorimetric response of nanocomposites to specific UVB regions can be obtained by adjusting the band gap of ZnO QDs. This property allows their utilization as colorimetric sensors for detecting UVB doses in sunlight and other sources. Colorimetric UVB sensors can be fabricated in different forms including smart ink sensors, free-standing flexible sensors, paper-based sensors, and hydrogel-based sensors.