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Globally, the widespread use of antibiotics in intensive animal farming has contributed to their increased environmental burden. Notably, data and knowledge on these contaminants in farmlands are lacking in India, despite being a major agricultural producer worldwide. To date, no studies have explored whether antibiotics are an intractable environmental issue in Indian agroecosystems. Specifically, information on the prevalence and spread of common antibiotics in long-term animal manure-laden organic farmlands of India is non-existent. Here, we examined samples of manure, soil and vegetables collected from 24 different organic farmlands in India to assess the presence of residues from 15 typical veterinary antibiotics (VAs). Our findings revealed that nine VAs, including three tetracyclines (TCs), three sulfonamides (SAs), one macrolide (ML), and two quinolones (QNs), were recorded in almost all the manure and soil samples. The residual levels of antibiotics (µg kg‒1) decreased in the following order: TCs (manure: 22.10‒161.10; soil: 8.30‒61) > SAs (manure: 0.90‒73; soil: 0.20‒48.40) > QNs (manure: nd‒3.60; soil: nd‒1.80) > MLs (manure: nd‒1.50; soil: nd‒0.90). Poultry manure-applied farmlands exhibited the highest antibiotic contamination levels, with total antibiotic concentrations surpassing the ecotoxicological effect trigger value of 100 μg kg−1 set by the Steering Committee of the Veterinary International Committee on Harmonization, highlighting the potential hazard of VAs to the soil ecosystem. The translocation of VAs in vegetables was in the order: leaf > root > fruit, and bioaccumulation of 0.10‒3.90 μg kg−1 was recorded. Notably, the calculated risk quotients of antibiotics in vegetables were ˂1, indicating the negligible risk to human health. Overall, our study unveils a concerning state of VAs pollution in organic farmlands in India that warrants special attention, as it may contribute to the proliferation of antibiotic resistance.

In tropical forests, the shade provided by tree canopies and extreme climate causes inhibition of plant seedling growth due to the lack of light. However, the plants can acclimate to such environmental stress by generating specific responses. The present study aimed to investigate the effects of shading conditions on ecophysiological performance of Narra seedlings (Pterocarpus indicus L.) via a mesocosm experiment. A pot experiment was conducted for 20 weeks in a greenhouse with different shading treatments, 75% (control), 25%, and 4% of full sunlight (FS). As a result, the photosynthetic rate (PN), Rubisco enzyme activity, maximum carboxylation rate (VCmax), and maximum electron transport rate (Jmax) in 25% FS treatment were higher or similar to those in control after three weeks of the beginning of shade treatment, whereas the highest values after ten weeks were observed in control. In contrast, the photosynthetic pigments were highest in control after three weeks, while the values were highest in 25% FS treatment after ten weeks. The growth parameters, such as biomass and leaf area, were highest in 75% FS treatment. The expression of Rubisco, phosphoglycerate kinase, glyceraldehyde-3-phosphate dehydrogenase, and fructose-1,6-bisphosphatase were up-regulated in 4% FS treatment compared to control after ten weeks, contributing to tolerating the shade stress. Our findings indicated the capacity of P. indicus seedlings to tolerate and acclimate low light conditions causing shade stress by generating specific physiological and morphological responses, especially Rubisco enzyme activity as well as gene expression related to photosynthetic activity. The present study will improve our understanding of the tolerance mechanism of Narra plant under light-deficient conditions, thereby providing a better strategy for efficiently growing seedlings of this species in tropical rainforests.

Green algae have been receiving widespread attention for their use as biofertilizers for agricultural production, but more studies are required to increase the efficiency of their use. This study aimed to investigate the effects of different levels of Chlorella fusca CHK0059 application on strawberry plant growth and fruit quality. A total of 800 strawberry seedlings were planted in a greenhouse and were grown for seven months under different Chlorella application rates: 0 (control), 0.1, 0.2, and 0.4% of the optimal cell density (OCD; 1.0 × 107 cells mL−1). The Chlorella application was conducted weekly via an irrigation system, and the characteristics of fruit samples were monitored monthly over a period of five months. The growth (e.g., phenotype, dry weight, and nutrition) and physiological (e.g., Fv/Fm and chlorophylls) parameters of strawberry plants appeared to be enhanced by Chlorella application over time, an enhancement which became greater as the application rate increased. Likewise, the hardness and P content of strawberry fruits had a similar trend. Meanwhile, 0.2% OCD treatment induced the highest values of soluble solid content (9.3–12 °Brix) and sucrose content (2.06–2.97 g 100 g−1) in the fruits as well as fruit flavor quality indices (e.g., sugars:acids ratio and sweetness index) during the monitoring, whilst control treatment represented the lowest values. In addition, the highest anthocyanin content in fruits was observed in 0.4% OCD treatment, which induced the lowest incidence of grey mold disease (Botrytis cinerea) on postharvest fruits for 45 days. Moreover, a high correlation between plants’ nutrients and photosynthetic variables and fruits’ sucrose and anthocyanin contents was identified through the results of principal component analysis. Overall, C. fusca CHK0059 application was found to promote the overall growth and performance of strawberry plants, contributing to the improvement of strawberry quality and yield, especially in 0.2% OCD treatment.

Abstract Background Plants in nature interact with other species, among which are mutualistic microorganisms that affect plant health. The co-existence of microbial symbionts with the host contributes to host fitness in a natural context. In turn, the composition of the plant microbiota responds to the environment and the state of the host, raising the possibility that it can be engineered to benefit the plant. However, technology for engineering the structure of the plant microbiome is not yet available. Results The loss of diversity and reduction in population density of Streptomyces globisporus SP6C4, a core microbe, was observed coincident with the aging of strawberry plants. Here, we show that glutamic acid reshapes the plant microbial community and enriches populations of Streptomyces, a functional core microbe in the strawberry anthosphere. Similarly, in the tomato rhizosphere, treatment with glutamic acid increased the population sizes of Streptomyces as well as those of Bacillaceae and Burkholderiaceae. At the same time, diseases caused by species of Botrytis and Fusarium were significantly reduced in both habitats. We suggest that glutamic acid directly modulates the composition of the microbiome community. Conclusions Much is known about the structure of plant-associated microbial communities, but less is understood about how the community composition and complexity are controlled. Our results demonstrate that the intrinsic level of glutamic acid in planta is associated with the composition of the microbiota, which can be modulated by an external supply of a biostimulant. Video Abstract

Anthropogenic activities cause the leaching of heavy metals into groundwater and their accumulation in soil. Excess levels of heavy metals cause toxicity in plants, inducing the production of reactive oxygen species (ROS) and possible death caused by the resulting oxidative stress. Heavy metal stresses repress auxin biosynthesis and transport, inhibiting plant growth. Here, we investigated whether nickel (Ni) heavy metal toxicity is reduced by exogenous auxin application and whether Ni stress tolerance in Arabidopsis thaliana is mediated by the bifunctional enzyme YUCCA6 (YUC6), which functions as an auxin biosynthetic enzyme and a thiol-reductase (TR). We found that an application of up to 1 µM exogenous indole-3-acetic acid (IAA) reduces Ni stress toxicity. yuc6-1D, a dominant mutant of YUC6 with high auxin levels, was more tolerant of Ni stress than wild-type (WT) plants, despite absorbing significantly more Ni. Treatments of WT plants with YUCASIN, a specific inhibitor of YUC-mediated auxin biosynthesis, increased Ni toxicity; however yuc6-1D was not affected by YUCASIN and remained tolerant of Ni stress. This suggests that rather than the elevated IAA levels in yuc6-1D, the TR activity of YUC6 might be critical for Ni stress tolerance. The loss of TR activity in YUC6 caused by the point-mutation of Cys85 abolished the YUC6-mediated Ni stress tolerance. We also found that the Ni stress–induced ROS accumulation was inhibited in yuc6-1D plants, which consequently also showed reduced oxidative damage. An enzymatic assay and transcriptional analysis revealed that the peroxidase activity and transcription of PEROXIREDOXIN Q were enhanced by Ni stress to a greater level in yuc6-1D than in the WT. These findings imply that despite the need to maintain endogenous IAA levels for basal Ni stress tolerance, the TR activity of YUC6, not the elevated IAA levels, plays the predominant role inNi stress tolerance by lowering Ni-induced oxidative stress.

Plant immune responses can be triggered by chemicals, microbes, pathogens, insects, or abiotic stresses. In particular, induced systemic resistance (ISR) refers to the activation of the immune system due to a plant’s interaction with beneficial microorganisms. The phenolic compound, 2,4-diacetylphloroglucinol (DAPG), which is produced by beneficial Pseudomonas spp., acts as an ISR elicitor, yet DAPG’s mechanism in ISR remains unclear. In this study, transgenic Arabidopsis thaliana plants overexpressing the DAPG hydrolase gene (phlG) were generated to investigate the functioning of DAPG in ISR. DAPG was applied onto 3-week-old A. thaliana Col-0 and these primed plants showed resistance to the pathogens Botrytis cinerea and Pseudomonas syringae pv. tomato DC3000. However, in the phlG transgenic A. thaliana, the ISR was not triggered against these pathogens. The DAPG-mediated ISR phenotype was impaired in transgenic A. thaliana plants overexpressing phlG, thus showing similar disease severity when compared to untreated control plants. Furthermore, the DAPG-treated A. thaliana Col-0 showed an increase in their gene expression levels of PDF1.2 and WRKY70 but this failed to occur in the phlG transgenic lines. Collectively, these experimental results indicate that jasmonic acid/ethylene signal-based defense system is effectively disabled in phlG transgenic A. thaliana lines.

Hydroxyurea (HU) is the replication stress known to carry out cell cycle arrest by inhibiting ribonucleotide reductase (RNR) enzyme upon generating excess hydrogen peroxide (H2O2) in plants. Phytohormones undergo synergistic and antagonistic interactions with reactive oxygen species (ROS) and redox signaling to protect plants against biotic and abiotic stress. Therefore, in this study, we investigated the protective role of Indole-3-acetic acid (IAA) in mitigating HU-induced toxicity in rice seedlings. The results showed that IAA augmentation improved the growth of the seedlings and biomass production by maintaining photosynthesis metabolism under HU stress. This was associated with reduced H2O2 and malondialdehyde (MDA) contents and improved antioxidant enzyme [superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), and peroxidase (POD)] activity that was significantly affected under HU stress. Furthermore, we showed that the HU stress-induced DNA damage leads to the activation of uridine 5′-diphosphate-glucosyltransferase (UGT), which mediates auxin homeostasis by catalyzing IAA-glucose conjugation in rice. This IAA-glucose conjugation upregulates the RNR, transcription factor 2 (E2F2), cyclin-dependent kinase (CDK), and cyclin (CYC) genes that are vital for DNA replication and cell division. As a result, perturbed IAA homeostasis significantly enhanced the key phytohormones, such as abscisic acid (ABA), salicylic acid (SA), cytokinin (CTK), and gibberellic acid (GA), that alter plant architecture by improving growth and development. Collectively, our results contribute to a better understanding of the physiological and molecular mechanisms underpinning improved growth following the HU + IAA combination, activated by phytohormone and ROS crosstalk upon hormone conjugation via UGT.

Long-term application of soil organic amendments (SOA) can improve the formation of soil organic carbon (SOC) pool as well as soil fertility and health of paddy lands. However, the effects of SOA may vary with the input amount and its characteristics. In this work, a descriptive field research was conducted during one cropping season to investigate the responses of various SOC fractions to different long-term fertilization practices in rice fields and their relationships with soil biogeochemical properties and the emission of greenhouse gases (GHG). The field sites included two conventional paddies applied with chemical fertilizer (CF) or CF + rice straw (RS) and six organic agriculture paddies applied with oilseed cake manure (OCM) + wheat straw (WS), cow manure (CM) + WS, or CM + RS. The two paddy soils treated with CM + RS had significantly higher concentrations of recalcitrant to labile C forms, such as loss-on-ignition C (LOIC; 56–73 g kg−1), Walkley–Black C (WBC; 20–25 g kg−1), permanganate oxidizable C (POXC; 835–853 mg kg−1), and microbial biomass carbon (MBC; 133–141 mg kg−1), than soils treated with other SOA. Likewise, long-term application of CM + RS seemed to be the best for regulating soil fertility parameters, such as ammonium (11–141 mg kg−1); phosphate (61–106 mg kg−1); and soluble Ca, K, and Mg (7–10, 0.5–1.2, and 1.9–3.8 mg kg−1, respectively), although the results varied with the location and soil properties of rice fields. Additionally, the two paddy sites had the largest cumulative methane emission (754–762 kg ha−1), seemingly attributed to increased microbial biomass and labile C fractions. The significant correlations of most SOC fractions with soil microbial biomass, trophic factors, and methane emissions were confirmed with multivariate data analysis. It was also possible to infer that long-term SOA application, especially with CM + RS, enhanced interaction in belowground paddy fields, contributing to soil fertility and rice production sustainability. Based on our findings, we suggest the need for analysis of various types of SOC fractions to efficiently manage soil fertility and quality of paddy fields, C sequestration, and GHG emissions.

Saponarin content in barley sprouts may vary greatly with environmental conditions, such as climate, leading to difficulty in uniformly producing saponarin-rich barley sprouts in situ farmlands throughout the year. This research was an early attempt to identify the optimal conditions of various climatic factors, such as temperature, light, and humidity according to seasonal change, for maximizing the saponarin content of sprouted barley through the two-year field experiment. As a result, the growth index, as leaf length relative to growth period, of barley sprouts varied greatly with sowing time, and they tended to decrease with an increase in the ambient temperature, such as average daily temperature. In contrast, higher saponarin contents were observed in the sprouts collected in March, April, September, and October than those collected from May to August. We also found significantly positive correlations of saponarin content with daily temperature range and average light period, indicating that they could be decisive climatic factors for the production of barley sprouts with a higher saponarin content. Interestingly, the polynomial relationship between saponarin yield and leaf length showed the highest yield with 2.18 mg plant−1 at 15.9 cm in length, suggesting a best cutting time for the production of saponarin-rich barely sprouts based on the leaf length. Overall, the decisive climatic factors according to seasonal change for saponarin biosynthesis may be considered to be daily temperature differences and light hours.

Some intensive farmers tend to expect short-term beneficial effects by applying soil amendments, but inconsistent fertilization practices are often conducted, causing economic losses and environmental problems. This study aimed at investigating the short-term application effects of different soil amendments on soil organic carbon (SOC) fractions, biogeochemical properties, and crop performance for finding the best land management approach using one-year field trial growing Chinese cabbages. This filed experiment was conducted in 2020 and included eight fertilizer treatments: control (w/o fertilizers), chemical fertilizer (CF), manure compost (MC), double MC amount (2MC), CF + MC, CF + rice husk (RH), MC + RH, and CF + MC + RH. As a result, the concentrations of recalcitrant to labile C forms, including Loss-On-Ignition C (LOIC), Walkley-Black C, permanganate oxidizable C (POXC), and microbial biomass C, were the highest in a mixture of MC and RH and 2MC. Additionally, the treatment with the largest difference from the control in key soil parameters was 2MC: bulk density (10%), total N (30%), available P (186%), and CO2 (433%) and N2O (825%) emissions, followed by MC + RH. Moreover, more than 20% higher fresh weight (FW) of cabbage was found in 2MC and MC + RH than in the control. Therefore, these two organic amendments appeared to benefit SOC storage and overall soil biogeochemical processes, contributing to higher biomass crop production. Moreover, LOIC significantly correlated to bulk density, available P and K, and FW, while POXC significantly correlated to N concentration in plants, indicating the short-term fertilization effects on the status of SOC fractions and the qualities of soil and plant by applying soil amendments. Overall, our findings suggest that applying MC + RH would be an alternative to replace the conventional farming practices for promoting soil quality and crop performance, but further studies to sustain the application effects of this amendment should be monitored for longer durations.

Veterinary antibiotics, including erythromycin (Ery) and chlortetracycline (CTC), are often detected in agricultural land. Although these contaminants affect plant growth and development, their effects on crops remain elusive. In this study, the effects of Ery and CTC on plant growth were investigated and compared by analyzing transcript abundance in Brassica campestris seedlings. Treatment with Ery and/or CTC reduced chlorophyll content in leaves and photosynthetic efficiency. Examination of the chloroplast ultrastructure revealed the presence of abnormally shaped plastids in response to Ery and CTC treatments. The antibiotics produced similar phenotypes of lower accumulation of photosynthetic genes, including RBCL and LHCB1.1. Analysis of the transcript levels revealed that Ery and CTC differentially down-regulated genes involved in the tetrapyrrole biosynthetic pathway and primary root growth. In the presence of Ery and CTC, chloroplasts were undeveloped and photosynthesis efficiency was reduced. These results suggest that both Ery and CTC individually affect gene expression and influence plant physiological activity, independently of one another.

Abstract: Research on the occurrence of perfluorochemicals (PFCs) such as perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in the agricultural environment is lacking, in spite of their potential risk via food chain transfer from aquatic and soil-plant systems to animals and/or humans. In the present study, for the first time, soil and water samples collected from 243 different agricultural sites adjacent to waste water treatment plants (WWTPs) belonging to 81 cities and 5 provinces with different levels of industrialization in South Korea were monitored for concentrations of PFOS and PFOA by use of solid phase extraction and liquid chromatography-tandem mass spectroscopy (LC-MS/MS). Significant mean concentrations of PFOA (0.001–0.007 µg L−1 water and

Plants possess adaptive reprogramed modules to prolonged environmental stresses, including adjustment of metabolism and gene expression for physiological and morphological adaptation. CCoAOMT1 encodes a caffeoyl CoA O-methyltransferase and is known to play an important role in adaptation of Arabidopsis plants to prolonged saline stress. In this study, we showed that the CCoAOMT1 gene plays a role in drought stress response. Transcript of CCoAOMT1 was induced by salt, dehydration (drought), and methyl viologen (MV), and loss of function mutants of CCoAOMT1, ccoaomt1-1, and ccoaomt1-2 exhibit hypersensitive phenotypes to drought and MV stresses. The ccoaomt1 mutants accumulated higher level of H2O2 in the leaves and expressed lower levels of drought-responsive genes including RD29B, RD20, RD29A, and ERD1, as well as ABA3 3 and NCED3 encoding ABA biosynthesis enzymes during drought stress compared to wild-type plants. A seed germination assay of ccoaomt1 mutants in the presence of ABA also revealed that CCoAOMT1 functions in ABA response. Our data suggests that CCoAOMT1 plays a positive role in response to drought stress response by regulating H2O2 accumulation and ABA signaling.

Erythromycin (Ery) is a commonly used veterinary drug that prevents infections and promotes the growth of farm animals. Ery is often detected in agricultural fields due to the effects of manure application in the ecosystem. However, there is a lack of information on Ery toxicity in crops. In this study, we performed a comparative proteomic analysis to identify the molecular mechanisms of Ery toxicity during seedling growth based on our observation of a decrease in chlorophyll (Chl) contents using Brassica campestris. A total of 452 differentially abundant proteins (DAPs) were identified including a ribulose-1,5-bisphosphate carboxylase (RuBisCO). The proteomic analysis according to gene ontology (GO) classification revealed that many of these DAPs responding to Ery treatment functioned in a cellular process and a metabolic process. The molecular function analysis showed that DAPs classified within catalytic activity were predominantly changed by Ery, including metabolite interconversion enzyme and protein modifying enzyme. An analysis of functional pathways using MapMan revealed that many photosynthesis components were downregulated, whereas many protein biosynthesis components were upregulated. A good relationship was observed between protein and transcript abundance in a photosynthetic pathway, as determined by qPCR analysis. These combined results suggest that Ery affects plant physiological activity by downregulating protein abundance in the photosynthetic pathway.

Veterinary antibiotics such as sulfonamides are widely used to increase feed efficiency and to protect against disease in livestock production. The sulfonamide antimicrobial mechanism involves the blocking of folate biosynthesis by inhibiting bacterial dihydropteroate synthase (DHPS) activity competitively. Interestingly, most treatment antibiotics can be released into the environment via manure and result in significant diffuse pollution in the environment. However, the physiological effects of sulfonamide during plant growth and development remain elusive because the plant response is dependent on folate biosynthesis and the concentration of antibiotics. Here, we present a chemical interaction docking model between Napa cabbage (Brassica campestris) DHPS and sulfamethoxazole and sulfamethazine, which are the most abundant sulfonamides detected in the environment. Furthermore, seedling growth inhibition was observed in lentil bean (Lens culinaris), rice (Oryza sativa), and Napa cabbage plants upon sulfonamide exposure. The results revealed that sulfonamide antibiotics target plant DHPS in a module similar to bacterial DHPS and affect early growth and the development of crop seedlings. Taking these results together, we suggest that sulfonamides act as pollutants in crop fields.

The compositional components (lignan, protein, and oil) as well as antioxidant properties of white and black sesame seeds from different crop years were evaluated. Various solvent extracts of sesame seeds possessed two major peaks and their chemical structures were confirmed as sesamin (1) and sesamolin (2) using NMR spectroscopy and HPLC–DAD–ESI/MS technique. Moreover, their optimal extraction was achieved using 90% acetonitrile for 6 h at 25 °C. Lignans differed significantly with seed colours, cultivars, and crop years, whereas protein and oil contents exhibited slight variations. Interestingly, total average lignan of white cultivars (7.36 mg/g) was two times more than that of black sesasme (3.10 mg/g). Antioxidant effects of the 90% acetonitrile extracts of all cultivars also varied with black cultivars showing higher values than white seeds. Additionally, Kopoom (white) and Kangbaek (black) may be recommended as potential cultivars due to the highest lignan content (9.08 mg/g) and antioxidant capacity (DPPH: 81.5 and ABTS: 93.2% at 90 μg/ml: the concentration of the 90% acetonitrile extract on dried seed weight). Thus, antioxidant effects of sesame seeds may not well correlate with their contents of lignans.

This research was the first to investigate nutritional components, including soluble phenolics (isoflavones and anthocyanins), protein, oil, and fatty acid as well as antioxidant activities in different coloured seed coat soybeans (yellow, black, brown, and green) for two crop years. The soluble phenolics differed significantly with cultivars, crop years, and seed coat colours, while protein, oil, and fatty acid exhibited only slight variations. Especially, malonylgenistin and cyanidin-3-O-glucoside compositions had the most remarkable variations. Green soybeans had the highest average isoflavone content (3079.42 μg/g), followed by yellow (2393.41 μg/g), and black soybeans (2373.97 μg/g), with brown soybeans showing the lowest value (1821.82 μg/g). Anthocyanins showed only in black soybeans, with the average contents of the primary anthocyanins, cyanidin-3-O-glucoside, delphinidine-3-O-glucoside, and petunidin-3-O-glucoside, quantified at 11.046, 1.971, and 0.557 mg/g, respectively. Additionally, Nogchae of green soybean and Geomjeongkong 2 of black soybean may be recommended as potential cultivars owing to the highest average isoflavone (4411.10 μg/g) and anthocyanin (21.537 mg/g) contents. The scavenging activities of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radicals also differed remarkably, depending upon isoflavone and anthocyanin contents, with black soybeans exhibiting the highest antioxidant effects.

Korean historical constellations and their names are similar to Chinese ones. Although Korean historical astronomy is influenced by China, they have distinct differences in each shape and names of the constellations. We, therefore, compare Bocheonga (步天歌) of the early Joseon dynasty (朝鮮, 1392~1910) preserved in Gyujanggark (奎章閣) with that of the Sui dynasty ((隋代, 581~618 of China written by Wang Ximing(王希明) in terms of star charts and descriptions of the contents. We find out that the two books are partly different all over the books. First, there are definite differences in preface, three area of constellations (三垣) in the heaven, and the description of the Milky Way. Second, some of constellations show different in shape, the number of stars. Especially connecting pattern in some constellations shows different in each other. Third, Joseon Bocheonga describes their colors for some stars. These mean that Joseon has a unique tradition of star maps unlike Chinese one. We also summarize the differences and distinctive characteristics of Joseon star charts compared with Chinese ones.

We study on the astronomical calendars that was used in the Silla era. The calendars are deduced from the records in Samguksagi. They were influenced from calendaric system of Tang Dynasty, which are Lin duk calendar(?), Ta yen calendar(?) and Sun myung calendar(?). We analyse them in detail according to the time and duration of use. Water clock system of Unified Silla was used four water vessels for supplying water. We found the model from documents on ancient water clock that are appeared in the old Korean, Chinese and Japanese historical records. We have assumed the model of Unified Silla clepsydra is similar type with Chinese records during Tang dynasty and with Japanese reconstructed water clock in Temple Asoka. After fluid dynamic experiment, we decide the suitable diameter of supplying pipe and volume of the vessels used in the clepsydra. We introduce the experimental instruments and methods for accomplishing the clock. We designed and reconstructed the water clock of Unified Silla and float rods for measuring time, that is based on the Silla's calendaric system.

Chlorella species of microalgae are utilized in the crop and food industries. The aim of this research was to investigate the metabolite profiles of Chlorella fusca for the first time and evaluate its biological properties. The two ion modes of UPLC-Q-TOF-MS/MS were used to identify a total of 62 components in the methanol extract of C. fusca, with 26 in the negative and 36 in the positive ion mode, including 10 identical ingredients. Fatty acids (negative mode) and combinations of chlorophyll and fatty acids (positive mode) were the most prevalent chemical structures, constituting over 80 and 70% of the total metabolites, respectively, followed by chlorophyll, polar lipids, carotenoids, and fatty alcohols. Moreover, this extract exhibited potent antioxidant and anti-aging benefits in decreasing order of potency at a concentration of 200 |g mL-1: tyrosinase inhibition (100%), ABTS radical scavenging (90%), elastase inhibition (88%), and DPPH radical scavenging (34%). Notably, this extract protected the mobility of DNA fragments up to 5 μg mL-1 (26%), with potential effects (> 60% at 200 μg mL-1). These findings suggest that C. fusca may be a promising candidate for applications related to its biological functions, owing to the high accumulation of fatty acids and chlorophyll derivatives. [ABSTRACT FROM AUTHOR]