The balance between growth and defense in response to nearby or canopy shading in heliotropic plants has been deeply understood. However, the adaptive traits developed by shade-tolerant plants through long-term evolution remain unclear. In this study, the typical shade-tolerant medicinal plant Anoectochilus roxburghii was used as the experimental material.(1) Different planting densities were set, including 8 cm(row spacing) × 8 cm(plant spacing), 6 cm × 6 cm, 4 cm × 4 cm, and 2 cm × 2 cm, to monitor the individual plant responses to nearby shading.(2) Different light environments, including blue light∶red light=3∶2(B3R2), blue light∶red light∶far-red light=3∶2∶1(B3R2FR1), blue light∶red light∶far-red light=3∶2∶2(B3R2FR2), and blue light∶red light∶far-red light=3∶2∶4(B3R2FR4), were set to monitor the morphological and physiological changes in plants in response to actual shading conditions. The results showed that:(1) Moderate increases in planting density helped optimize morphological traits such as stem diameter and leaf area. This not only slightly increased biomass but also significantly improved SOD activity in both leaves and stems, as well as lignin content in stems, thereby enhancing the plant's defense capabilities.(2) Increasing the far-red light in the light environment negatively regulated the plant height of A. roxburghii, which was contrary to the typical shade-avoidance response observed in heliotropic plants. However, it significantly enhanced SOD and POD activity in both stems and leaves, as well as lignin content in stems. Furthermore, it reduced the incidence and disease index of stalk rot, effectively defending against biotic stress. Therefore, the shade-tolerant plant A. roxburghii has specific adaptive strategies for shading conditions. Reasonable dense planting or light environment modulation can synergistically improve yield, medicinal quality, and resistance of A. roxburghii. This study provides a theoretical foundation and technical support for optimizing the regional deployment and cultivation strategies of ecological planting for Chinese medicinal materials.
Orchidaceae/genetics* ; Light ; Plant Leaves/physiology* ; Sunlight ; Adaptation, Physiological/radiation effects* ; Plant Proteins/genetics*

Microbial denitrification is a major pathway for nitrogen removal from water bodies. However, denitrification is often difficult to continue when there is a lack of microbially available organic matter in the water body to serve as electron donors. In recent years, studies have shown that some denitrifying bacteria can directly utilize photoelectrons generated by sunlight-excited semiconductor minerals or natural organic matter for denitrification without the need for bioavailable organic matter as electron donors. This process is defined as microbial photoelectrotrophic denitrification. The discovery of microbial photoelectrotrophic denitrification phenomenon reshapes the previous knowledge about the chemoheterotrophic mode of denitrifying bacteria and broadens the pathway of nitrogen removal by the new photoelectrotrophic metabolism, which is of great significance to our understanding and exploration of sunlight-driven nitrogen cycling process. In this paper, we comprehensively sort out the existing research reports in the field of microbial photoelectrotrophic denitrification, systematically summarize the principle and the current research progress of microbial photoelectrotrophic denitrification, deeply analyze the problems and challenges faced by this technology, and make an outlook on the future research directions and application prospects of this technology, providing a reference for the further research and application of this technology.
Denitrification/physiology* ; Nitrogen/isolation & purification* ; Bacteria/metabolism* ; Sunlight ; Phototrophic Processes

Background. Prolonged sun exposure without adequate sun protection places outdoor workers such as traffic enforcers at risk for skin cancer. Data on knowledge, attitude, and practices amongst traffic enforcers are currently unavailable, hence the need for research on this matter.

Objectives. 1) To evaluate the knowledge, attitude, and practices of traffic enforcers on sun exposure and sun protection, 2) To identify any association with sociodemographic characteristics, and 3) To determine whether knowledge and attitude are correlated with sun-protective practices.

Method. An analytical cross-sectional study was conducted from January to February 2019 among traffic enforcers in Pasig City, Philippines thru a self-administered questionnaire. Descriptive statistics were used to summarize the sociodemographic profile of the respondents while the Fisher's exact/Chi-square test was used to determine the association between sociodemographic variables and adequacy of knowledge, attitude, and practices. Pearson's rho was used to determine the degree of association between knowledge, attitude, and practices.

Results. A total of 178 traffic enforcers with a 100% response rate participated in the study. 94.4% had adequate knowledge and 93.8% had a desirable attitude as opposed to 46.1% who had adequate sun-protective practices. Adequate knowledge was found to be significant when obtained from television (51.19% at p=0.018), with the respondents being least knowledgeable about proper sunscreen use. Only a few had the desired positive attitude that sunscreen is not an added expense at 39.89%. The most common methods of sun protection were the wearing of sunglasses (82.02%), long-sleeved clothing (68.54%), and the wearing of a wide-brimmed hat (65.17%). Reapplication of sunscreen was the least common at 32.02%. Those with an adequate sun-protective practice obtained their knowledge from social media (48.78% at p=0.003). Adequacy of knowledge when compared to actual practice noted that there were more respondents with poor knowledge translating to poor practice (9.38% at p=0.019). There was insufficient evidence to state associations between the sociodemographic profile and knowledge, attitude, or practice. Correlations between knowledge, attitude, and practices on sun exposure and sun-protective practices were found to be weak.

Conclusion. Most of the traffic enforcers who partici pated in this study had adequate knowledge and a desirable attitude on sun exposure and sun protection but had inadequate sun-protective practices, emphasizing the need to investigate other factors that hinder translation of adequate knowledge and attitude to adequate practice. Occupational health policies need to be implemented to reduce the harmful effects of UV radiation in high-risk populations such as traffic enforcers.

BACKGROUND: Lack of sunlight exposure is the primary reason for the worldwide epidemic of vitamin D deficiency. Although recommended sunlight exposure guidelines exist, there is no evidence regarding whether current guidelines are optimal for increasing vitamin D levels among individuals with vitamin D deficiency.METHODS: Sixty Korean adults aged 20–49 years with serum 25-hydroxyvitamin D (25[OH]D) levels of < 20 ng/mL were randomly assigned to three groups: sunlight exposure (n = 20), vitamin D supplementation groups (n = 20), and daily living (n = 20) for 1 month. The sunlight exposure group had sunlight exposure on 20% to 30% of their body surface areas for 30–60 minutes per day, 3 times a week during the summer season. Vitamin D supplementation was prescribed with 800 IU/day of vitamin D. The serum levels of 25(OH)D were measured at baseline and at 1-month follow-up examinations.RESULTS: The largest change in serum 25(OH)D was observed among the vitamin D supplementation group (+3.5 ng/mL, P < 0.001). The sunlight exposure group showed a slight increase in serum 25(OH)D level, but the absolute increase was less than one-third that of the vitamin D supplementation group (+0.9 ng/mL, P = 0.043). Only two participants in the sunlight exposure reached serum concentrations of 25(OH)D ≥ 20 ng/mL at follow-up. The daily living group showed no difference in vitamin D levels (−0.7 ng/mL, P = 0.516).CONCLUSION: Sunlight exposure was not sufficient to overcome vitamin D insufficiency or deficiency in the current study subjects. Effectiveness of current sunlight exposure guidelines among various populations should be reassessed in larger clinical studies.TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0002671
Adult ; Body Surface Area ; Follow-Up Studies ; Humans ; Information Services ; Seasons ; Solar System ; Sunlight ; Vitamin D Deficiency ; Vitamin D ; Vitamins

PURPOSE: We determined whether elevated serum alkaline phosphatase (ALP) was related to prevalence, location, type, length, and recurrence of pterygium in a population from the Republic of Korea.METHODS: A nationwide cross-sectional dataset, the Korean National Health and Nutrition Examination Survey (2008–2011), was used in this study. All participants were > 30 years of age and underwent the ALP test and ophthalmic evaluation (n = 22,359). One-way analysis of variance, the chi-square test, and Fisher's exact test were used to compare characteristics and outcomes among participants. Multivariable logistic regression was used to examine the possible associations between serum ALP levels and various types of pterygium. Data were adjusted for known risk factors for development of pterygium and ALP elevation (age, sex, residence, sunlight exposure, drinking, smoking, hypertension, diabetes, BMI, AST, ALT, vitamin D, and HDL).RESULTS: The overall prevalence of pterygium was 8.1%, and participants with pterygium had higher levels of serum ALP (p < 0.001). Participants with higher serum ALP had a significantly higher prevalence of all types of pterygium than those in the lower serum ALP quartiles. After adjusting for potential confounding factors, multivariate logistic regression analysis revealed that ALP was associated with the prevalence of pterygium (odds ratio [OR], 1.001; p = 0.038). Trend analysis between the OR and ALP quartiles revealed a linear trend in overall prevalence and in the intermediate type of pterygium. Subgroup analysis revealed a stronger correlation in participants > 50 years of age. One-way analysis of variance revealed an association between the size of pterygium and serum ALP quartile levels. Serum ALP was not associated with recurrence of pterygium.CONCLUSIONS: Increased serum ALP was associated with the prevalence and size of pterygium.
Alkaline Phosphatase ; Cross-Sectional Studies ; Dataset ; Drinking ; Hypertension ; Korea ; Logistic Models ; Nutrition Surveys ; Prevalence ; Pterygium ; Recurrence ; Republic of Korea ; Risk Factors ; Smoke ; Smoking ; Sunlight ; Vitamin D

In this paper, the correlation between the chemical constituents of Chinese herbal medicines Daphnes Cortex and the ecological factors and soil factors was studied, which provided a reference for the selection of suitable areas for artificial cultivation of Daphne giraldii and wild tending. The geographic information system(GIS) was applied to obtain the ecological factor information of 23 collection sites of Daphnes Cortex, and the soil factor information was determined by the standard procedure in the soil test standard manual. Combining the information of 93 chemical constituents of Daphnes Cortex in 23 collection sites the correlation between components and ecological factors and soil factors was analyzed by statistical methods. The correlation analysis showed that the longitude, annual average rainfall, annual sunshine intensity, annual average temperature in the ecological factors, soil type, effective copper and pH value were the dominant factors affecting the chemical composition of Daphnes Cortex.
China ; Copper ; Daphne/chemistry* ; Drugs, Chinese Herbal ; Geographic Information Systems ; Hydrogen-Ion Concentration ; Plants, Medicinal/chemistry* ; Rain ; Soil/chemistry* ; Sunlight ; Temperature

Pinellia ternata is a medicinal herb of Araceae, and its tubers are used as medicines. It is a common Chinese herbal medicine in China and has a large market demand. When exposing to strong light intensity and high temperature during the growth process, P. ternata withers in a phenomenon known as "sprout tumble", which largely limits tuber production. Shade can effectively delay sprout tumble formation and increase its yield, however the relevant regulation mechanism is unclear. DNA methylation, as a self-modifying response to environmental changes, is often involved in the regulation of plant growth and development. In this study, P. ternata grown under natural light and 90% shading were selected as the control group and the experimental group for genomic DNA methylation analysis by using methylate sensitive amplification polymorphism(MSAP). The results showed that a total of 617 loci were detected with 20 pairs of primers, of which 311 were in the natural light group and 306 in the shading group. The methylation sites in the light and shading groups accounted for 58.2% and 71.57%, respectively, and the methylation ratios in the methylation sites were 27.65% and 29.41%, respectively, indicating that shading significantly induced the genome DNA methylation of P. ternata. Compared to the natural light group, shading promoted 32.51% of the genes methylation, while inducing 16.25% gene demethylation. This study reveals the DNA methylation variation of P. ternata under shading conditions, which lays a preliminary theoretical foundation for further analysis of the mechanism of shading regulation of P. ternata growth from epigenetic level.
China ; DNA Methylation ; Darkness ; Epigenesis, Genetic ; Pinellia/radiation effects* ; Plants, Medicinal/radiation effects* ; Sunlight

Chlorophyll content,leaf mass to per area,net photosynthetic rate and bioactive ingredients of Asarum heterotropoides var. mandshuricum,a skiophyte grown in four levels of solar irradiance were measured and analyzed in order to investigate the response of photosynthetic capability to light irradiance and other environmental factors. It suggested that the leaf mass to per area of plant was greatest value of four kinds of light irradiance and decreasing intensity of solar irradiance resulted in the decrease of leaf mass to per area at every phenological stage. At expanding leaf stage,the rate of Chla and Chlb was 3. 11 when A. heterotropoides var. mandshuricum grew in full light irradiance which is similar to the rate of heliophytes,however,the rate of Chla and Chlb was below to 3. 0 when they grew in shading environment. The content of Chla,Chlb and Chl( a+b) was the greatest value of four kinds of light irradiance and decreasing intensity of solar irradiance resulted in its decreasing remarkably( P<0. 05). The rate of Chla and Chlb decreased but the content of Chla,Chlb and Chl( a+b) increased gradually with continued shading. The maximum value of photosynthetically active radiation appeared at 10: 00-12: 00 am in a day. The maximum value of net photosynthetic rate appeared at 8: 30-9: 00 am and the minimum value appeared at 14: 00-14: 30 pm at each phenological stage if plants grew in full sunlight. However,when plants grew in shading,the maximum value of net photosynthetic rate appeared at about 10: 30 am and the minimum value appeared at 12: 20-12: 50 pm at each phenological stage. At expanding leaf stage and flowering stage,the average of net photosynthetic rate of leaves in full sunlight was remarkably higher than those in shading and it decreased greatly with decreasing of irradiance gradually( P < 0. 05). However,at fruiting stage,the average of net photosynthetic rate of leaves in full sunlight was lower than those in 50% and 28% full sunlight but higher than those in 12% full sunlight. All photosynthetic diurnal variation parameters of plants measured in four kinds of different irradiance at three stages were used in correlation analysis. The results suggested that no significant correlation was observed between net photosynthetic rate and photosynthetically active radiation,and significant negative correlation was observed between net photosynthetic rate and environmental temperature as well as vapor pressure deficit expect for 12% full sunlight. Positive correlation was observed between net photosynthestic rate and relative humidity expect for 12% full sunlight. Significant positive correlation was observed between net photosynthetic rate and stomatal conductance in the four light treatments. Only,in 12% full sunlight,the net photosynthetic rate was significantly related to photosynthetically active radiation rather than related to environmental temperature,vapor pressure deficit and relative humidity. In each light treatment,a significant positive correlation was observed between environmental temperature and vapor pressure deficit,relative humidity as well as stomatal conductance. Volatile oil content was 1. 46%,2. 16%,1. 56%,1. 30% respectively. ethanol extracts was 23. 44%,22. 45%,22. 18%,21. 12% respectively. Asarinin content was 0. 281%,0. 291%,0. 279% and 0. 252% respectively. The characteristic components of Asarum volatile oil of plant in different light treatments did not change significantly among different groups.
Asarum ; physiology ; radiation effects ; Chlorophyll ; analysis ; Photosynthesis ; Plant Leaves ; radiation effects ; Sunlight

The study is aimed to investigate the effects of light intensities on growth,photosynthetic physiology,antioxidant systems and chemical composition of Viola yedoensis and provide cultivation references for V.yedoensis.Five groups of V.yedoensis were planted under five light intensities conditions,namely 100%,80%,50%,35%,5%of full sunlight,and then morphological index,growth,chlorophyll fluorescence parameters,photosynthetic parameters and antioxidant enzyme system indexes were measured during harvest.The results showed that there was no significant difference in the biomass of V.yedoensis among 35% -100%full sunlight,but the biomass of those were significantly higher than that in the 5%full sunlight treatment(P<0.05).The net photosynthetic rate,transpiration rate,stomatal conductance,intercellular CO_2 concentration and water use efficiency increased firstly and then decreased with the decrease of light intensity;F_m,F_v/F_mand Yield in 5% full sunlight treatment were significantly lower than those in the other four groups(P<0.05).The structure of chloroplast was normal under light intensity ranged from 50%to 100% full sunlight.The lamellar concentration of chloroplast matrix decreased and the starch granules decreased in 35% full sunlight treatment,and the margin of lamellar layer of chloroplast and substrate were blurred,and the starch granules were small and the number of starch granules decreased significantly under 5% full sunlight.MDA content in 5%full sunlight treatment was significantly higher than those in the other four groups(P<0.05).The total coumarin content and total flavonoid content decreased with the decrease of light intensity.In summary,the light in-tensity range suitable for the growth of V.yedoensis is wide(ranging from 35% to 100% full sunlight).The content of flavonoids and coumarins is positively correlated with light intensity.
Biomass ; Chlorophyll ; Chloroplasts ; Photosynthesis ; Plant Leaves ; Sunlight ; Viola

BACKGROUND: The risk factors for renal cancer include smoking, obesity, hypertension, and exposure to trichloroethylene. Recent studies have shown that low sunlight exposure increases the risk of developing a range of cancers, including renal cancer. Given that most of the daytime is spent at work, a lack of occupational sunlight exposure can be a risk factor for renal cancer. Therefore, this study examined the relationship between occupational sunlight exposure and the incidence of renal cancer. METHODS: This was a university hospital-based case-control study on renal cancer. Of the 706 newly diagnosed patients with renal cell carcinoma (RCC), 633 cases were selected; 73 who had no occupational history were excluded. In addition, 633 controls were selected from the general population after 1:1 matching with respect to sex, age (within 5 years), and residential area (constituency-level). Information on sunlight exposure by the occupational group was referred to data from France. To estimate the association between occupational sunlight exposure and the RCC risk, the odds ratios (ORs) were calculated using conditional logistic regression analysis. RESULTS: Sunlight exposure was divided into quartiles and the risk of RCC was analyzed. The adjusted OR of RCC (OR: 0.664, 95% confidence interval: 0.449–0.983) was significantly lower for the Q4 group than Q1 group but the Q2 and Q3 groups did not show significant results. The risk of RCC tended to decrease with increasing exposure to sunlight (p for trend < 0.028). CONCLUSIONS: Higher occupational sunlight exposure reduces the risk of RCC.
Carcinoma, Renal Cell ; Case-Control Studies ; France ; Humans ; Hypertension ; Incidence ; Kidney Neoplasms ; Logistic Models ; Obesity ; Occupational Groups ; Odds Ratio ; Risk Factors ; Smoke ; Smoking ; Sunlight ; Trichloroethylene