Sustained stoichiometric imbalance and its ecological consequences in a large oligotrophic lake.

Considerable attention is given to absolute nutrient levels in lakes, rivers, and oceans, but less is paid to their relative concentrations, their nitrogen:phosphorus (N:P) stoichiometry, and the consequences of imbalanced stoichiometry. Here, we report 38 y of nutrient dynamics in Flathead Lake, a large oligotrophic lake in Montana, and its inflows. While nutrient levels were low, the lake had sustained high total N: total P ratios (TN:TP: 60 to 90:1 molar) throughout the observation period. N and P loading to the lake as well as loading N:P ratios varied considerably among years but showed no systematic long-term trend. Surprisingly, TN:TP ratios in river inflows were consistently lower than in the lake, suggesting that forms of P in riverine loading are removed preferentially to N. In-lake processes, such as differential sedimentation of P relative to N or accumulation of fixed N in excess of denitrification, likely also operate to maintain the lake's high TN:TP ratios. Regardless of causes, the lake's stoichiometric imbalance is manifested in P limitation of phytoplankton growth during early and midsummer, resulting in high C:P and N:P ratios in suspended particulate matter that propagate P limitation to zooplankton. Finally, the lake's imbalanced N:P stoichiometry appears to raise the potential for aerobic methane production via metabolism of phosphonate compounds by P-limited microbes. These data highlight the importance of not only absolute N and P levels in aquatic ecosystems, but also their stoichiometric balance, and they call attention to potential management implications of high N:P ratios.

OsGADD45a1: a multifaceted regulator of rice architecture, grain yield, and blast resistance.

KEY MESSAGE: The homolog gene of the Growth Arrest and DNA Damage-inducible 45 (GADD45) in rice functions in the regulation of plant architecture, grain yield, and blast resistance. The Growth Arrest and DNA Damage-inducible 45 (GADD45) family proteins, well-established stress sensors and tumor suppressors in mammals, serve as pivotal regulators of genotoxic stress responses and tumorigenesis. In contrast, the homolog and role of GADD45 in plants have remained unclear. Herein, using forward genetics, we identified an activation tagging mutant AC13 exhibited dwarf characteristics resulting from the loss-of-function of the rice GADD45α homolog, denoted as OsGADD45a1. osgadd45a1 mutants displayed reduced plant height, shortened panicle length, and decreased grain yield compared to the wild-type Kitaake. Conversely, no obvious differences in plant height, panicle length, or grain yield were observed between wild-type and OsGADD45a1 overexpression plants. OsGADD45a1 displayed relatively high expression in germinated seeds and panicles, with localization in both the nucleus and cytoplasm. RNA-sequencing analysis suggested a potential role for OsGADD45a1 in the regulation of photosynthesis, and binding partner identification indicates OsGADD45a1 interacts with OsRML1 to regulate rice growth. Intriguingly, our study unveiled a novel role for OsGADD45a1 in rice blast resistance, as osgadd45a1 mutant showed enhanced resistance to Magnaporthe oryzae, and the expression of OsGADD45a1 was diminished upon blast fungus treatment. The involvement of OsGADD45a1 in rice blast fungus resistance presents a groundbreaking finding. In summary, our results shed light on the multifaceted role of OsGADD45a1 in rice, encompassing biotic stress response and the modulation of several agricultural traits, including plant height, panicle length, and grain yield.

Autophagy receptor OsNBR1 modulates salt stress tolerance in rice.

KEY MESSAGE: Autophagy receptor OsNBR1 modulates salt stress tolerance by affecting ROS accumulation in rice. The NBR1 (next to BRCA1 gene 1), as important selective receptors, whose functions have been reported in animals and plants. Although the function of NBR1 responses to abiotic stress has mostly been investigated in Arabidopsis thaliana, the role of NBR1 under salt stress conditions remains unclear in rice (Oryza sativa). In this study, by screening the previously generated activation-tagged line, we identified a mutant, activation tagging 10 (AC10), which exhibited salt stress-sensitive phenotypes. TAIL-PCR (thermal asymmetric interlaced PCR) showed that the AC10 line carried a loss-of-function mutation in the OsNBR1 gene. OsNBR1 was found to be a positive regulator of salt stress tolerance and was localized in aggregates. A loss-of-function mutation in OsNBR1 increased salt stress sensitivity, whereas overexpression of OsNBR1 enhanced salt stress resistance. The osnbr1 mutants showed higher ROS (reactive oxygen species) production, whereas the OsNBR1 overexpression (OsNBR1OE) lines showed lower ROS production, than Kitaake plants under normal and salt stress conditions. Furthermore, RNA-seq analysis revealed that expression of OsRBOH9 (respiratory burst oxidase homologue) was increased in osnbr1 mutants, resulting in increased ROS accumulation in osnbr1 mutants. Together our results established that OsNBR1 responds to salt stress by influencing accumulation of ROS rather than by regulating transport of Na+ and K+ in rice.

Plasma membrane-localized Hsp40/DNAJ chaperone protein facilitates OsSUVH7-OsBAG4-OsMYB106 transcriptional complex formation for OsHKT1;5 activation.

The salinization of irrigated land affects agricultural productivity. HIGH-AFFINITY POTASSIUM (K+ ) TRANSPORTER 1;5 (OsHKT1;5)-dependent sodium (Na+ ) transport is a key salt tolerance mechanism during rice growth and development. Using a previously generated high-throughput activation tagging-based T-DNA insertion mutant pool, we isolated a mutant exhibiting salt stress-sensitive phenotype, caused by a reduction in OsHKT1;5 transcripts. The salt stress-sensitive phenotype of this mutant results from the loss of function of OsDNAJ15, which encodes plasma membrane-localized heat shock protein 40 (Hsp40). osdnaj15 loss-of-function mutants show decreased plant height, increased leaf angle, and reduced grain number caused by shorter panicle length and fewer branches. On the other h'and, OsDNAJ15-overexpression plants showed salt stress-tolerant phenotypes. Intriguingly, salt stress facilitates the nuclear relocation of OsDNAJ15 so that it can interact with OsBAG4, and OsDNAJ15 and OsBAG4 synergistically facilitate the DNA-binding activity of OsMYB106 to positively regulate the expression of OsHKT1;5. Overall, our results reveal a novel function of plasma membrane-localized Hsp40 protein in modulating, alongside chaperon regulator OsBAG4, transcriptional regulation under salinity stress tolerance.

Key rules of life and the fading cryosphere: Impacts in alpine lakes and streams.

Alpine regions are changing rapidly due to loss of snow and ice in response to ongoing climate change. While studies have documented ecological responses in alpine lakes and streams to these changes, our ability to predict such outcomes is limited. We propose that the application of fundamental rules of life can help develop necessary predictive frameworks. We focus on four key rules of life and their interactions: the temperature dependence of biotic processes from enzymes to evolution; the wavelength dependence of the effects of solar radiation on biological and ecological processes; the ramifications of the non-arbitrary elemental stoichiometry of life; and maximization of limiting resource use efficiency across scales. As the cryosphere melts and thaws, alpine lakes and streams will experience major changes in temperature regimes, absolute and relative inputs of solar radiation in ultraviolet and photosynthetically active radiation, and relative supplies of resources (e.g., carbon, nitrogen, and phosphorus), leading to nonlinear and interactive effects on particular biota, as well as on community and ecosystem properties. We propose that applying these key rules of life to cryosphere-influenced ecosystems will reduce uncertainties about the impacts of global change and help develop an integrated global view of rapidly changing alpine environments. However, doing so will require intensive interdisciplinary collaboration and international cooperation. More broadly, the alpine cryosphere is an example of a system where improving our understanding of mechanistic underpinnings of living systems might transform our ability to predict and mitigate the impacts of ongoing global change across the daunting scope of diversity in Earth's biota and environments.

Turning up the heat: warming influences plankton biomass and spring phenology in subtropical waters characterized by extensive fish omnivory.

Understanding how biological communities respond to climate change is a major challenge in ecology. The response of ectotherms to changes in temperature depends not only on their species-specific thermal tolerances but also on temperature-mediated interactions across different trophic levels. Warming is predicted to reinforce trophic cascades in linear aquatic food chains, but little is known about how warming might affect the lower trophic levels of food webs involving extensive fish omnivory, a common scenario in subtropical and tropical waterbodies. In this study, a mesocosm warming experiment was conducted involving a pelagic food chain (fish-zooplankton-phytoplankton) topped by the omnivorous bighead carp [Aristichthys nobilis (Richardson)]. We found that temperature elevation significantly enhanced the growth of fish and suppressed zooplankton, including both metazooplankton and ciliates, while abundances of phytoplankton, despite disruption of temporal dynamics, did not increase correspondingly-likely due to fish predation. Our results suggest that trophic cascades are less unlikely to be reinforced by warming in food chains involving significant omnivory. Moreover, we found that warming advanced the spring abundance peak of phytoplankton abundance and that of the parthenogenetic rotifer Brachionus quadridentatus; whereas, it had no effect on the only sexually reproducing copepod, Mesocyclops leuckarti, presumably due to its prolonged life history. Our study also confirmed that warming may lead to a phenological mismatch between some predators and their prey because of the distinct life histories among taxa, with potentially severe consequences for resource flow in the food chain, at least in the short term.

A tryptophan metabolite of the skin microbiota attenuates inflammation in patients with atopic dermatitis through the aryl hydrocarbon receptor.

BACKGROUND: Previous studies have revealed significant alterations in the skin microbiota of patients with atopic dermatitis (AD) not only in diversity and composition but also in function, and the tryptophan (Trp) metabolic pathway is attenuated in the skin microbiota of patients with AD. OBJECTIVE: We sought to assess Trp metabolites on the skin surfaces of patients with AD and to explore the function of the microbial Trp metabolites in skin inflammation in patients with AD. METHODS: A gel-patch method was developed to collect metabolites on the skin surface, which were then assessed by using liquid chromatography-tandem mass spectrometry. A mouse model of calcipotriol (MC903)-induced AD-like dermatitis was used to evaluate the effects of microbial metabolites on AD, and aryl hydrocarbon receptor (AhR)-null mice and keratinocyte cultures were used to investigate the mechanism. RESULTS: Major microbial metabolites of Trp were detected on the skin surfaces of healthy subjects, and the level of indole-3-aldehyde (IAId), an indole derivative of Trp catabolism, was significantly lower in lesional and nonlesional skin of patients with AD than that of healthy subjects. IAId significantly attenuated skin inflammation in mice with MC903-induced AD-like dermatitis, and this effect was blocked by an AhR antagonist and abolished in AhR-null mice. Furthermore, IAId was found to inhibit the MC903-induced expression of thymic stromal lymphopoietin in keratinocytes in vivo and in vitro, which was mediated by binding of AhR to the thymic stromal lymphopoietin promoter. CONCLUSION: IAId, a skin microbiota-derived Trp metabolite, negatively regulated skin inflammation in patients with AD, revealing that skin microbiota play a significant functional role in the pathogenesis of AD.

Physicochemical characteristics of oil-based cuttings from pretreatment in shale gas well sites.

Understanding the physicochemical characteristics of oil-based cuttings (OBCs) is an important foundation for subsequent treatment and management. The macro- and microscopic properties of white oil-based cuttings (WOBCs) and diesel-based cuttings (DBCs) after the different pretreatment steps have been assessed using scanning electron microscopy. The organic and inorganic compositions of OBCs have been analyzed using X-ray diffraction, Fourier-transform infrared spectrometry, and gas chromatography-mass spectrometry. Inorganic matter (SiO2, BaSO4, and CaCO3), alkanes, aromatic compounds, and water were the main components of OBCs. The organic content (26.14%) and alkane content of the WOBCs were higher than that of the DBCs, whereas for the inorganic content (70.87%), the reverse was true. The macro- and micromorphologies of OBCs were quite different because their oil and water contents were different. The oil contents of OBCs decreased in the order A1 (14.64%) > A3 (12.67%) > A2 (11.06%) and B1 (9.19%) > B3 (8.94%) > B2 (4.66%); the water contents decreased in the order A1 (2.99%) > A3 (2.19%) > A2 (1.09%) and B1 (2.30%) > B3 (1.87%) > B2 (1.09%). Moreover, a skid-mounted treatment technology for OBCs was proposed. The results can be a scientific guidance for the treatment and management of OBCs.

OsATG8c-Mediated Increased Autophagy Regulates the Yield and Nitrogen Use Efficiency in Rice.

Autophagy, a conserved pathway in eukaryotes, degrades and recycles cellular components, thus playing an important role in nitrogen (N) remobilization. N plays an important role in the growth and development of plants, which also affects plant yield and quality. In this research, it was found that the transcriptional level of a core autophagy gene of rice (Oryza sativa), OsATG8c, was increased during N starvation conditions. It was found that the overexpression of OsATG8c significantly enhanced the activity of autophagy and that the number of autophagosomes, dwarfed the plant height and increased the effective tillers' number and yield. The nitrogen uptake efficiency (NUpE) and nitrogen use efficiency (NUE) significantly increased in the transgenic rice under both optimal and suboptimal N conditions. Based on our results, OsATG8c is considered to be a good candidate gene for increasing NUE, especially under suboptimal field conditions.

Enhanced Prophylactic and Therapeutic Effects of Polylysine-Modified Ara h 2 DNA Vaccine in a Mouse Model of Peanut Allergy.

BACKGROUND: The prevalence of food allergy has been increasing, but treatment is very limited. DNA vaccination has been recognized as a promising method for the treatment of allergic diseases; however, poor immunogenicity has hindered its application. METHODS: BALB/c mice were intradermally injected with plasmid DNA encoding the peanut protein Ara h 2 (pAra h 2) or pAra h 2 pretreated with poly-L- lysine (PLL) before or after sensitization with Ara h 2 protein. Ara h 2-specific antibodies were measured by ELISA. CD207+ dendritic cells (DCs) and Treg cells in draining lymph nodes were analyzed by flow cytometry after DNA immunization, and cytokine production in splenocytes was also analyzed. RESULTS: In the prophylactic study, pretreatment with pAra h 2 or PLL-pAra h 2 resulted in lower levels of Ara h 2-specific IgG1, IgG2a, and IgE after sensitization with Ara h 2 protein, and mice in the PLL-pAra h 2 group had a significantly lower level of antibodies than those in the pAra h 2 group. In the treatment study, intradermal injection with pAra h 2 or PLL-pAra h 2 after Ara h 2 protein sensitization significantly decreased the level of Ara h 2-specific antibodies, and PLL- pAra h 2 had stronger effects than pAra h 2. There were increased numbers of CD207+ DCs and Treg cells in the mice receiving intradermal injection with PLL-pAra h 2, and splenocytes from PLL-pAra h 2-treated mice secreted increased levels of IFN-γ and IL-10. CONCLUSIONS: Modification of pAra h 2 with PLL improved its prophylactic and therapeutic effects in peanut-allergic mice.

A Mitochondrial Localized Chaperone Regulator OsBAG6 Functions in Saline-Alkaline Stress Tolerance in Rice.

B-cell lymphoma 2 (Bcl-2)-associated athanogene (BAG) family genes play prominent roles in regulating plant growth, development, and stress response. Although the molecular mechanism underlying BAG's response to abiotic stress has been studied in Arabidopsis, the function of OsBAG underlying saline-alkaline stress tolerance in rice remains unclear. In this study, OsBAG6, a chaperone regulator localized to mitochondria, was identified as a novel negative regulator of saline-alkaline stress tolerance in rice. The expression level of OsBAG6 was induced by high concentration of salt, high pH, heat and abscisic acid treatments. Overexpression of OsBAG6 in rice resulted in significantly reduced plant heights, grain size, grain weight, as well as higher sensitivity to saline-alkaline stress. By contrast, the osbag6 loss-of-function mutants exhibited decreased sensitivity to saline-alkaline stress. The transcriptomic analysis uncovered differentially expressed genes related to the function of "response to oxidative stress", "defense response", and "secondary metabolite biosynthetic process" in the shoots and roots of OsBAG6-overexpressing transgenic lines. Furthermore, cytoplasmic levels of Ca2+ increase rapidly in plants exposed to saline-alkaline stress. OsBAG6 bound to calcium sensor OsCaM1-1 under normal conditions, which was identified by comparative interactomics, but not in the presence of elevated Ca2+. Released OsCaM1-1 saturated with Ca2+ is then able to regulate downstream stress-responsive genes as part of the response to saline-alkaline stress. OsBAG6 also interacted with energy biosynthesis and metabolic pathway proteins that are involved in plant growth and saline-alkaline stress response mechanisms. This study reveals a novel function for mitochondrial localized OsBAG6 proteins in the saline-alkaline stress response alongside OsCaM1-1.

Spherical cluster heterojunction engineering of NiFeP/g-C3N4 for efficient oxygen evolution reaction in alkaline solution.

The construction of heterojunctions can reduce the energy barrier for the oxygen evolution reaction (OER), which is crucial for the design of efficient electrocatalysts. A novel OER electrocatalyst, composed of g-C3N4-supported NiFeP spherical nanoclusters, was successfully synthesized using a simple hydrothermal method and a gas-phase precipitation method. Benefiting from its unique spherical nanocluster structure and strong electronic interactions among Ni, Fe, and P, the catalyst exhibited outstanding performance under alkaline conditions, with an overpotential of only 232 mV at a current density of 10 mA cm-2 and a Tafel slope of 103 mV dec-1. Additionally, the electrical resistance of NiFeP/g-C3N4 (Rct = 5.1 Ω) was much lower than that of NiFeP (Rct = 10.8 Ω) and layered g-C3N4 (Rct = 44.8 Ω). The formation of a Schottky barrier heterojunction efficiently reduced electron transfer impedance during the OER process, accelerating the electron transfer from g-C3N4 to NiFeP, enhancing the carrier concentration, and thereby improving the OER activity. Moreover, The robust g-C3N4 chain-mail protects NiFeP from adverse reaction environments, maintaining a balance between catalytic activity and stability. Furthermore, ab initio molecular dynamics (AIMD) and density functional theory (DFT) were conducted to explore the thermal stability and internal electron transfer behavior of the cluster heterojunction structure. This study offers a broader design strategy for the development of transition metal phosphide (TMPs) materials in the oxygen evolution reaction.

Geochemical records of human-induced environmental changes in two small remote lakes of Songnen Plain, Northeast China.

The abundance and composition of aliphatic hydrocarbon biomarkers were determined in dated sediment cores from Lakes Qijiapao (QJP) and Huoshaoheipao (HSH) in the Songnen Plain, Northeast China, to investigate historical environmental changes in these lakes and identify likely controlling factors. Based on these results, the recent environmental history of the two lakes can be divided into three periods. Before 1950, low Paq values (avg. 0.23 and 0.27, respectively) and middle-chain n-alkane abundances (normalized to total organic carbon, avg. 14.82 and 16.01 µg g-1 TOC, respectively) in both lakes suggested low aquatic productivity and the limited input of submerged macrophyte organic matter (OM). However, the significant increase in the abundance of short-chain n-alkanes in Lake HSH (from 8.34 to 16.68 µg g-1 TOC) indicated the emergence of early nutrient enrichment in the lake. From 1950 to 2000, marked increase in the abundance of middle-chain n-alkanes (avg. 21.72 and 22.62 µg g-1 TOC in Lakes QJP and HSH, respectively) and Paq values indicated that both lakes had undergone eutrophication because of the population explosion and agricultural intensification. From 2000 to 2013, the abundance of short- and middle-chain n-alkanes in Lake QJP markedly exceeded those in Lake HSH and indicated a larger eutrophication in Lake QJP, which could be caused by the development of ecotourism in Lake HSH and the concomitant increase in aquaculture in Lake QJP in recent years. The highest abundance of C30 αß-hopane (~ 10.24 µg g-1 TOC) and the lowest CPIH values in Lake QJP revealed a possible petroleum pollution since 2008. Taken together, lake eutrophication in the Songnen Plain accelerated after 1950 and was influenced primarily by agriculture and aquaculture. This is in contrast to lakes in other regions of China (such as the Yangtze River Basin and Yunnan Province), where urbanization and industrialization have exerted a dominant influence on the lake environment.

CD36-SREBP1 Axis Mediates TSLP Production in Obesity-Exacerbated Atopic Dermatitis.

Obesity is associated with an increased risk of atopic dermatitis (AD) and may accelerate its development. Keratinocyte dysfunction has been observed in obesity-related skin diseases, including psoriasis and acanthosis nigricans, but is not fully understood in AD. In this study, we found that high-fat diet-induced obesity exacerbated AD-like dermatitis in mice, with elevated inflammatory molecules and increased CD36-SREBP1-related fatty acid accumulation in the lesional skin. Blocking CD36 or SREBP1 with chemical inhibitors effectively alleviated AD-like inflammation, decreased fatty acid accumulation, and downregulated TSLP expression in obese calcipotriol (MC903)-treated mice. Moreover, palmitic acid treatment induced TSLP overexpression in keratinocytes through the activation of the CD36-SREBP1 signaling pathway. The chromatin immunoprecipitation assay further revealed increased binding of SREBP1 to the TSLP promoter region. Our findings provide compelling evidence that obesity triggers the activation of the CD36-SREBP1-TSLP axis in keratinocytes, leading to epidermal lipid disorders and the aggravation of AD-like inflammation. By targeting CD36 or SREBP1, future combination therapies or modified treatment strategies could be developed to help manage patients with both obesity and AD.

Bacterial functional redundancy and carbon metabolism potentials in soil, sediment, and water of thermokarst landscapes across the Qinghai-Tibet Plateau: Implications for the fate of permafrost carbon.

Permafrost thaw create widespread thermokarst landscapes. As a result, distinct habitats are provided to harbor different bacterial communities in degraded permafrost soil (PBCs), thermokarst lake sediment (SBCs), and lake water (WBCs), driving carbon metabolism differentially. In this study, we investigated functional diversity and redundancy, and carbon metabolism potentials of PBCs, SBCs, and WBCs in thermokarst landscapes across the Qinghai-Tibet Plateau. The results showed that PBCs and SBCs had higher taxonomic and functional alpha diversity than WBCs, while WBCs had lower functional redundancy. WBCs had the highest beta diversity followed by SBCs and PBCs, suggesting strong determination of taxonomic variations on functional differences. Community assembly processes also had significant influences on beta diversity, especially for SBCs. Metabolism pathways of carbohydrate metabolism, methane metabolism, and carbon fixation were enriched differentially in PBCs, SBCs, and WBCs, suggesting different C fate in distinct habitats. Carbohydrate metabolism data suggested that PBCs might have stronger potentials to mineralize a greater diversity of organic carbon substrate than SBCs and WBCs, promoting degradation of organic carbon stocks in degraded permafrost soils. Methane metabolism data showed that SBCs had a stronger methanogenesis potential followed by PBCs and WBCs, while PBCs had a stronger methane oxidation potential. High abundance of genes involving in formaldehyde assimilation might suggested that a large proportion of produced methane might be assimilated by methanotrophs in the thermokarst landscapes. Both aerobic and anaerobic carbon fixation pathways were enriched in PBCs. The results added our understanding of functional properties and biogeochemical carbon cycles in thermokarst landscapes, improving our abilities in accurate modeling of carbon dynamics and the ultimate fate of permafrost carbon in a warming world.

Piscivore stocking significantly suppresses small fish but does not facilitate a clear-water state in subtropical shallow mesocosms: A biomanipulation experiment.

Biomanipulation by piscivore stocking has been widely used to combat eutrophication in north temperate lakes, but its applicability in warm lakes has not yet been well elucidated. Here, we used experimental mesocosms to test the effects of a native benthi-piscivore (snakehead, Channa argus Cantor) on water clarity under subtropical conditions where small omni-benthivorous fish like crucian carp (Carassius carassius L.) prevail. Our results showed that, despite of a great reduction of crucian carp biomass, snakehead stocking did not create a strong trophic cascade as neither (herbivorous) zooplankton biomass nor their grazing pressure, indicated by biomass ratio of (herbivorous) zooplankton to phytoplankton, changed significantly. Moreover, snakehead stocking significantly increased water non-algal turbidity as well as nutrient and chlorophyll-a concentrations, suggesting that these benthi-piscivores also disturbed sediments like crucian carp did. Our study showed that biomanipulation by stocking of snakehead does not facilitate clear-water state in warm shallow lakes, even on the short-term.

Research on the influencing factors and mechanism of single-phase microemulsion cleaning of shale gas oil-based cuttings.

Oil-based cuttings (OBCs) produced by shale gas exploitation are classified as hazardous waste. Their appropriate utilization and disposal is a key issue that urgently needs to be resolved. A single-phase microemulsion (SPM) has ultra-low interfacial tension and strong solubilization ability. In view of this, based on an analysis of the characteristics of OBCs, SPMs have been selected for their cleaning. The effects of microemulsion components and other conditions on the cleaning efficacy have been explored, as well as the deoiling mechanism and the recycling efficiency of the SPM. Our results have shown that sodium dodecylbenzene sulfonate (SDBS), n-butanol, water, and white oil in appropriate proportions can form an effective SPM. The oil content (OC) of OBCs after cleaning was reduced from 11.89% (±0.32%) to 1.13% (±0.02%) when the proportions of the aforementioned components of the SPM were 14.3%, 14.3%, 66.6%, and 4.8%, respectively. The OC of the residue further decreased to 0.28% (±0.05%) after a second cleaning with an alkaline solution. The optimum SPM conditions for cleaning OBCs were identified as a stirring speed of 200 rpm, a temperature of 30 °C, a cleaning time of 30 min, and a solid to liquid mass to volume ratio of 1:4. The main mechanism whereby the SPM cleans the OBCs is that the former reduces the combined work and adhesion work required for the removal of oil droplets from the cuttings, so that the adhesive oil is easily gathered up. Furthermore, the gathered oil phase is solubilized by the SPM.

Eutrophication decrease compositional dissimilarity in freshwater plankton communities.

Human activities, such as land use change and eutrophication, threaten freshwater biodiversity and ecosystem function. In this study, we examined both the α- and ß-diversity of plankton communities, that is, bacteria/prokaryotic algae, eukaryotic algae, and zooplankton/metazoans, using both classical microscopy and high-throughput sequencing methods across 40 lakes of the Yangtze River Basin. The spatial variations in plankton communities were explained by environmental variables such as trophic status index (TSI) and environmental heterogeneity according to non-metric multidimensional scaling analyses, mantel tests, and structural equation model. Our results showed that the compositional dissimilarities of bacteria, cyanobacteria, eukaryotic algae, and metazoans all decreased with the increasing TSI values, and were significantly positively related to environmental dissimilarity. Both the species richness and compositional dissimilarity of zooplankton had positive effects on zooplankton/phytoplankton biomass ratio. Zooplankton diversity was not directly affected by TSI and environmental dissimilarity; however, it was indirectly affected by the biotic interactions with cyanobacteria or eukaryotic algae. In addition, there were significant positive relationships between bacteria/cyanobacteria and eukaryotic algae dissimilarities. Our results indicated that increased trophic status and decreased environmental dissimilarity as consequences of eutrophication may weaken the trophic cascading effects of planktonic food chain via reducing the top-down effects of zooplankton on phytoplankton.

Quinolinic Acid, a Tryptophan Metabolite of the Skin Microbiota, Negatively Regulates NLRP3 Inflammasome through AhR in Psoriasis.

Psoriasis is a chronic inflammatory skin disease whose pathogenesis involves skin microbiota dysbiosis. Multiple studies have revealed the changes in microbiota abundances between psoriatic lesions and healthy skin. However, the metabolic pathways of skin microbiota (especially tryptophan metabolism, which is closely related to immunosuppression) are far less understood. In this study, we first detected the major microbial metabolites of tryptophan on the skin surfaces, finding that the quinolinic acid was significantly lower in the lesional skin of patients with psoriasis than in that of healthy subjects and correlated negatively with the severity of psoriasis. In vitro and in vivo, applying quinolinic acid significantly alleviated skin inflammation in an AhR-dependent manner, resulting in inhibition of the NLRP3 inflammasome activation. Furthermore, in mice with imiquimod-induced psoriasis-like dermatitis, topical application of Ahr-targeted small interfering RNA substantially exacerbated the disease severity, with increased NLRP3 inflammasome activation. Collectively, our data suggest that quinolinic acid, a skin microbiota-derived metabolite, negatively regulates aryl hydrocarbon receptor-NLRP3 inflammasome signaling activation in patients with psoriasis, providing an insight into the correlation between microbiota metabolism and the host skin in individuals with psoriasis.

Autophagy mediates grain yield and nitrogen stress resistance by modulating nitrogen remobilization in rice.

Autophagy, a conserved cellular process in eukaryotes, has evolved to a sophisticated process to dispose of intracellular constituents and plays important roles in plant development, metabolism, and efficient nutrients remobilization under suboptimal nutrients conditions. Here, we show that OsATG8b, an AUTOPHAGY-RELATED8 (ATG8) gene in rice, was highly induced by nitrogen (N) starvation. Elevated expression of OsATG8b significantly increased ATG8 lipidation, autophagic flux, and grain yield in rice under both sufficient and deficient N conditions. Overexpressing of OsATG8b could greatly increase the activities of enzymes related to N metabolism. Intriguingly, the 15N-labeling assay further revealed that more N was remobilized to seeds in OsATG8b-overexpressing rice, which significantly increased the N remobilization efficiency (NRE), N harvest index, N utilization efficiency (NUE), and N uptake efficiency (NUpE). Conversely, the osatg8b knock-out mutants had the opposite results on these characters. The substantial transcriptional changes of the overexpressed transgenic lines indicated the presence of complex signaling to developmental, metabolic process, and hormone, etc. Excitingly, the transgenic rice under different backgrounds all similarly be boosted in yield and NUE with OsATG8b overexpression. This work provides an excellent candidate gene for improving N remobilization, utilization, and yield in crops simultaneously.