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Wheat (Triticum aestivum L.) often faces salt stress and delayed sowing practices. These two events usually occur simultaneously in real field conditions that cause severe consequences on mineral balance, osmotic adjustment, reactive oxygen species (ROS) rampaging and antioxidant machinery. To address these issues, a two-year field-based study was directed at Jalalpur Pirwala Research Farm (JPRF), Multan-Pakistan. The experiment consisted of the following factors, a) timely sown under normal conditions (NS) and late sowing under normal conditions (LS) b) timely sown on saline conditions and late sown under saline conditions (LS+SS) c) foliar application of plant growth promoters hydrogen peroxide (H 2 O 2), salicylic acid (SA), thiourea (TU) and control (no spray) firstly to assess the influence of plant growth promoters (PGPRs) on the nutrient acquisition, osmoprotectants metabolism, ROS homeostasis and antioxidant clustering under SS, LS and their combined treatments. Results revealed that PGPRs foliar applications such as TU, followed by SA and H 2 O 2 played plausible roles in maintaining nutrient balance, osmoregulation, and circumventing the ROS. Exogenous application of TU increases the proline (18.24–20.01 %), total free amino acids (29.09 %-33.99 %), glycine betaine (3.43 %-15.34 %), total -soluble proteins (10.98 % -15.96 %) and total soluble sugars (15.21 %-20.36 %) for both years, under control conditions. Moreover, LS+SS followed by SS and LS declined the grain nutrient quality, shoot mineral content, and demolished the equilibrium between ROS and antioxidants, however, plants up-regulate the defensive mechanisms by enhancing the substantial content of antioxidants and osmoprotectants. So, wheat is moderately tolerant to combined LS+SS stress that evidently deteriorates its nutritional quality, but its performance can be enhanced by using PGPRs in delayed-sown wheat that often grows in marginally saline areas. [Display omitted] • Late-sown wheat faces severe nutrient imbalance under saline conditions. • Nutrient acquisition and, antioxidant metabolism play key role in wheat tolerance. • Plant growth promoters (PGPRs) improved the defence mechanisms and combat the effect of combined stress. • PGPRs maintain the nutrient balance and osmoregulation in late-sown wheat under salt stress. [ABSTRACT FROM AUTHOR]

Extreme temperatures and droughts are considered as the two main factors that limit wheat growth and production. Although responses of wheat plants to heat and drought stress have been extensively investigated, little is known about the extent to which wheat plants can recover after stress relief. In this study, a winter wheat pot experiment was conducted to evaluate the growth, physiological activities, and yield formation responses of wheat to stress and recovery periods under heat stress (36 °C, daily maximum temperature), drought (45–55% of soil water holding capacity), and combined stress conditions. Heat and drought stress significantly reduced photosynthesis, leaf relative water content (LRWC), leaf water potential (LWP noon), and nitrogen metabolism enzyme activities and increased electrolyte leakage. These parameters showed significant interactions between heat and drought stress. Beneficial osmoregulation of membrane stability was observed in stressed plants because of the accumulation of proline and soluble sugars. Within a range of stresses, the abovementioned physiological processes of individual heat- and drought-stressed plants recovered to levels comparable to those of the control. The recovery capacities of the physiological traits decreased gradually with increasing stress duration, particularly under combined stress. The recovery of LWP noon and LRWC contributed to the improved photosynthetic performance after stress relief. The combined stress caused greater yield losses than individual heat and drought stress, which was mainly attributed to low levels of thousand grain weight (TGW), the number of grains per ear, and the grain filling rate. After stress relief, the recovery of proline content, glutamine synthetase activity, photosynthetic rate, and LRWC were closely associated with grain yield and thousand grain weight. Collectively, these findings contribute to a better understanding of the coordinated responses of winter wheat during the combined heat and drought stress and recovery periods. • Combined heat and drought stress is more detrimental to wheat than individual stress. • Most physiological processes of plants were reversible within a range of stress. • Recovery of physiological traits was closely related to wheat yield. [ABSTRACT FROM AUTHOR]

A high-salt diet significantly impacts various diseases, ilncluding cancer and immune diseases. Recent studies suggest that the high-salt/hyperosmotic environment in the body may alter the chronic properties of cancer and immune cells in the disease context. However, little is known about the acute metabolic changes in hyperosmotic stress. Here, we found that hyperosmotic stress for a few minutes induces Warburg-like metabolic remodeling in HeLa and Raw264.7 cells and suppresses fatty acid oxidation. Regarding Warburg-like remodeling, we determined that the pyruvate dehydrogenase phosphorylation status was altered bidirectionally (high in hyperosmolarity and low in hypoosmolarity) to osmotic stress in isolated mitochondria, suggesting that mitochondria themselves have an acute osmosensing mechanism. Additionally, we demonstrate that Warburg-like remodeling is required for HeLa cells to maintain ATP levels and survive under hyperosmotic conditions. Collectively, our findings suggest that cells exhibit acute metabolic remodeling under osmotic stress via the regulation of pyruvate dehydrogenase phosphorylation by direct osmosensing within mitochondria. [ABSTRACT FROM AUTHOR]

• Soil salinity negatively affected primary physiological processes in L. alba. • Treatment with 120 mM nacl increased essential oil production in L. alba plants. • Mycorrhization modified the EO chemical profile of saline-treated L. alba plants. • Mycorrhization in saline-treated plants increased enzymatic antioxidant efficiency. The objective of this study was to evaluate the influence of salinity and mycorrhizal association on the physiological responses in Lippia alba and on the production and composition of the essential oil of the plant. Rooted cuttings were planted in a substrate containing a mix of spores of the arbuscular mycorrhizal fungi (AMF) Fuscutata heterogama and Claroideoglomus etunicatum. After 90 days of planting, the plants treated and not treated with AMF were irrigated with water (control) or 40, 80, or 120 mM NaCl solution for 30 days. Growth, gas exchange, primary metabolites, pigments, nutrients (nitrogen, phosphorus, potassium, and sodium), antioxidant system components, and essential oil (EO) yield and composition were analyzed. Salinity directly affected physiological processes such as gas exchange, total soluble carbohydrate (TSC) content in leaves, as well as sucrose and biomass production, and plants irrigated with 120 mM NaCl were the most affected. Conversely, leaf temperature and EO yield increased in these plants. Na+ accumulation was higher in the roots of plants treated with the lowest NaCl concentrations (40 mM); lower potassium (K +) content and higher Na+/ K + ratios were also observed after saline treatment. Mycorrhization resulted in lower Na+ and higher P and proline concentrations in plants treated with 120 mM NaCl. Under salinity conditions, plants without AMF accumulated TSCs in their roots. Mycorrhizal plants from all saline treatments showed higher antioxidative enzyme activity and an altered EO chemical profile with reduced monoterpene levels and increased levels of sesquiterpenes and phenylpropanoids. We concluded that salinity negatively affected the primary physiological responses but increased EO production in L. alba plants. Mycorrhization in saline-treated plants increased the enzymatic antioxidant efficiency and promoted changes in the EO chemical profile. Under salinity conditions, L. alba plants can be an alternative for the cultivation in moderately saline environments and mycorrhization may be a strategy to induce tolerance responses and secondary metabolites production. [ABSTRACT FROM AUTHOR]

Nanofluid consideration has been magnified due to their exceptional heat transfer characteristics and prospective applications in engineering and medical sciences after the pioneering work of Choi. Since, majority fluids are non-Newtonian in nature. Therefore, considering Jeffrey fluid as a base fluid in current study enhance its role in applications. Moreover, geometric configuration of the channel is taken as asymmetric with tapering effects. Since, majority of human physiological systems and industrial machinery have complex geometry and. Therefore, tapering channel consideration cannot be ignored. High molecular weight of non-Newtonian liquids make no-slip condition inapplicable. Thus, slip effects are incorporated in the current analysis. The consider analysis is performed for peristaltic flow of Jeffrey Nano fluid through a tapered asymmetric channel in the presence of magnetic field. Main motivation for performing this study is to analyze the heat transfer properties of nanofluid for the treatment of multiple diseases like cancer. The resulting nonlinear equations are coupled and simplified through lubrication approach. Poisson-Boltzmann equations are linearized through Debye-Huckle linearization. Built-in command of NDSolve in MATHEMATICS is applied to compute the results. The results for velocity, pressure gradient, streamlines, temperature and concentration are discussed for involved parameters. The results indicate that velocity shows parabolic behavior near the center while mixed behavior is observed near the boundaries. It can also be noticed that tapering parameter (m) influence the velocity greatly. As increasing the tapering effect causes the geometry to expand resulting in decreased velocity near the center of the channel. During digestion of food, multiple chemical reactions are performed by enzymes, therefore, studying the impact of (γ) on temperature and concentration cannot be ignored. The outcome of the study shows decrease in temperature and concentration as energy is utilized in performing the digestion. The size of trapped bolus is found to be increasing as the values of Hartman number (M) and fluid parameter (λ 1) are increased. Therefore, we can say that this study can provide basics to study physiological system with electroosmotic phenomenon. It also finds promising applications in drug delivery and food diagnostic etc. [ABSTRACT FROM AUTHOR]

Ongoing climate changes are expected to intensify drought periods in tropical regions, directly impacting epiphytic bromeliads that depend on intermittent water availability. This study aimed to elucidate if Acanthostachys pitcairnioides , an epiphytic bromeliad of Atlantic Forest, tolerates extended drought periods and the potential strategies involved in its tolerance and recovery capacity. We suppressed irrigation for 42 days, rehydrated plants for four days, and evaluated leaf water status, and photochemical, metabolic, and anatomical changes. During the initial 28 days of drought, translocation of water from hydrenchyma to chlorenchyma, higher chlorophyll content, and accumulation of abscisic and salicylic acid and antioxidants contributed to maintaining the cell turgor and functionality of photosynthetic apparatus. At 42 days, a significant reduction in leaf water content to 45.5% was accompanied by a 2.5-fold increase in non-photochemical quenching and enhanced levels of carotenoids, anthocyanins, osmoregulators (proline, myo-inositol, and trehalose), and phytohormones (abscisic acid and jasmonates). After rewatering, water storage in the hydrenchyma and almost all pigments, hormones, and metabolites were restored to pre-stress conditions. Leaf succulence, carbohydrate and organic acid accumulation, and carbon isotope data (δ13C−14.5‰) provide evidence of induction of CAM metabolism by water limitation in A. pitcairnioides. Our findings indicate the prevalence of water accumulation strategy during the first half of the drought stress. At the end of the drought period, the complete depletion of water from the hydrenchyma favored the osmotic adjustment. Considering this set of tolerance strategies and the rapid recovery after rehydration, A. pitcairnioides can successfully withstand environments with restricted water availability. [Display omitted] • The epiphytic bromeliad Acanthostachys pitcairnioides withstand 42 days of drought. • The translocation of water to chlorenchyma preserved the photosynthetic apparatus. • Increased content of carotenoids and anthocyanins avoided strong photoinhibition. • As drought intensifies, water preservation strategy shifts to osmotic adjustment. • Malate accumulation and δ13C close to −15‰ corroborate CAM metabolism. [ABSTRACT FROM AUTHOR]

This study provides a comprehensive analysis of the eco-physiological responses of the blue crab (Callinectes sapidus) to variations in salinity, shedding light on its adaptability and invasive success in aquatic environments. Gender-specific differences in osmoregulation and Electron Transport System (ETS) activity highlight the importance of considering sex-specific aspects when understanding the physiological responses of invasive species. Females exhibited increased ETS activity at lower salinities, potentially indicative of metabolic stress, while males displayed constant ETS activity across a range of salinities. Osmoregulatory capacity which depended on gender and salinity, was efficient within meso-polyhaline waters but decreased at higher salinities, particularly in males. These findings provide valuable understandings into how C. sapidus specimens in an invaded area responds to salinity changes, important for considerate its distribution through saline pathways during tidal cycle fluctuations. This study shows the importance of interdisciplinary research for effective management of invasive species and conservation of affected aquatic ecosystems. [Display omitted] • Efficient osmoregulation observed in meso-polyhaline waters. • Blue crab's gender-specific osmoregulation and ETS activity responses analysed. • Females showed increased ETS activity at lower salinities. [ABSTRACT FROM AUTHOR]

The freshwater shortage has become a global issue due to the population explosion. As an effective response to the water crisis, forward osmosis (FO) desalination technology is applied because of its comparatively low membrane fouling and low energy consumption. Hydrogels, as draw solutions in FO, have received increasing attention due to their properties of no reverse solute flux, and strong water recovery capability. However, the concentration in the feed solution is below 8000 ppm restricted by the lack of a clear mechanism for osmotic pressure regulation. In this work, a sodium alginate-graphene oxide (SA-GO) hydrogel was proposed with excellent performance in drawing water. The hydrogel has a homogeneous porous structure that enables easy water recovery through compression. When the SA-GO-1 hydrogel was used for the treatment of the simulated seawater (35,000 ppm NaCl solutions), the initial water flux achieved 0.4429 L m−2 h−1 (LMH), and the average water flux remained at 0.1783LMH. In contrast to conventional tactics, the osmotic pressure of hydrogel was regulated based on Flory-Rehner theory (FR). Moreover, the interaction energy was computed to reveal the mechanism of osmotic pressure regulation. This strategy provides a potential solution for the design of high-performance draw solutions for FO systems. • The FR theory was employed to mentor the osmotic pressure regulation of hydrogel. • An osmotic pressure regulation hydrogel was proposed as a draw solution in FO. • The hydrogel can obtain freshwater under 35,000 ppm NaCl solution. • The hydrogel possessed a stable performance during continuous FO operation. [ABSTRACT FROM AUTHOR]

Decapod Crustacea exhibit a marine origin, but many taxa have occupied environments ranging from brackish to fresh water and terrestrial habitats, overcoming their inherent osmotic challenges. Osmotic and ionic regulation is achieved by the gill epithelia, driven by two active ATP-hydrolyzing ion transporters, the basal (Na+, K+)-ATPase and the apical V(H+)-ATPase. The kinetic characteristic of gill (Na+, K+)-ATPase and the mRNA expression of its α subunit have been widely studied in various decapod species under different salinity challenges. However, the evolution of the primary structure has not been explored, especially considering the functional modifications associated with decapod phylogeny. Here, we proposed a model for the topology of the decapod α subunit, identifying the sites and motifs involved in its function and regulation, as well as the patterns of its evolution assuming a decapod phylogeny. We also examined both the amino acid substitutions and their functional implications within the context of biochemical and physiological adaptation. The α-subunit of decapod crustaceans shows greater conservation (∼94% identity) compared to the β-subunit (∼40%). While the binding sites for ATP and modulators are conserved in the decapod enzyme, the residues involved in the α-β interaction are only partially conserved. In the phylogenetic context of the complete sequence of (Na+, K+)-ATPase α-subunit, most substitutions appear to be characteristic of the entire group, with specific changes for different subgroups, especially among brachyuran crabs. Interestingly, there was no consistent separation of α-subunit partial sequences related to habitat, suggesting that the convergent evolution for freshwater or terrestrial modes of life is not correlated with similar changes in the enzyme's primary amino acid sequence. Topology of gill (Na+, K+)-ATPase highlighting the amino acid residue substitutions shown in a decapod phylogeny. [Display omitted] • The decapod (Na+, K+)-ATPase α-subunit shows greater conservation than β-subunit. • The binding sites for ATP and modulators are conserved in the decapod enzyme. • Most substitutions of α-subunit emerged at the onset of the Decapoda lineage. • Convergent evolution for freshwater life is not linked to similar sequence changes. • Substitution at TM1–2 may cause lower sensitivity to ouabain in decapods. [ABSTRACT FROM AUTHOR]

Drought is a principal environmental factor that affects the growth and development of plants. Accordingly, plants have evolved adaptive mechanisms to cope with adverse environmental conditions. One of the mechanisms is gene regulation mediated by microRNAs (miRNAs). miRNAs are regarded as primary modulators of gene expression at the post-transcriptional level and have been shown to participate in drought stress response, including ABA response, auxin signaling, antioxidant defense, and osmotic regulation through downregulating the corresponding targets. miRNA-based genetic reconstructions have the potential to improve the tolerance of plants to drought. However, there are few precise classification and discussion of miRNAs in specific response behaviors to drought stress and their applications. This review summarized and discussed the specific response behaviors of miRNAs under drought stress and the role of miRNAs as regulators in the response of plants to drought and highlighted that the modification of miRNAs might effectively improve the tolerance of plants to drought. [ABSTRACT FROM AUTHOR]

[Display omitted] • MCFA synthesis was inhibited at high total ammonia nitrogen (TAN) concentrations. • Hydrolysis, acidification and chain elongation processes were inhibited. • TAN stress did not result in a decrease in the abundance of CE bacteria. • The lower MCFA yield was due to the lower activities of key enzymes. • FAB pathway was the primary contributor for MCFA synthesis under TAN stress. This study used 16S rRNA gene sequencing and metatranscriptomic analysis to comprehensively illustrate how ammonia stress influenced medium-chain fatty acids (MCFA) biosynthesis. MCFA synthesis was inhibited at total ammonia nitrogen (TAN) concentrations above 1000 mg N/L. TAN stress hindered organic hydrolysis, acidification, and volatile fatty acids elongation. Chain-elongating bacteria (e.g., Clostridium_sensu_stricto_12 , Clostridium_sensu_stricto_1 , Caproiciproducens) abundance remained unchanged, but their activity decreased, partially due to the increased reactive oxygen species. Metatranscriptomic analysis revealed reduced activity of enzymes critical for MCFA production under TAN stress. Fatty acid biosynthesis pathway rather than reverse β-oxidation pathway primarily contributed to MCFA production, and was inhibited under TAN stress. Functional populations likely survived TAN stress through osmoprotectant generation and potassium uptake regulation to maintain osmotic pressure, with NADH-ubiquinone oxidoreductase potentially compensating for ATP loss. This study enhances understanding of MCFA biosynthesis under TAN stress, aiding MCFA production system stability and efficiency improvement. [ABSTRACT FROM AUTHOR]

Pot experiments were conducted using Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) and Phoebe bournei (Hemsl.) Yang) to investigate whether soil microplastics adversely affect the nurturing and renewal of plantations. Microplastics composed of polyethylene and polypropylene with a size of 48 μm were used. The treatments included a control group (without microplastics) and groups treated with microplastic concentrations of 1% and 2% (w/w). The effects of microplastics on the growth, photosynthetic pigments in leaves, antioxidant systems, and osmotic regulation substances of the seedlings were analysed by measuring the seedling height, ground-line diameter growth, chlorophyll (chlorophyll a , chlorophyll b , and total chlorophyll) contents, antioxidant enzyme (superoxide dismutase, peroxidase, catalase) activities, and malondialdehyde, soluble sugar, and soluble protein levels. The results indicated that treatment with 1% polyethylene microplastics increased the chlorophyll a , total chlorophyll, and soluble protein contents in the leaves of both types of seedlings while inhibiting superoxide dismutase and peroxidase activities in P. bournei seedlings. Treatment with 2% polyethylene or polypropylene microplastics suppressed the chlorophyll a , chlorophyll b , and total chlorophyll contents; superoxide dismutase, peroxidase, and catalase activities; and soluble sugar and soluble protein levels in the leaves of both types of seedlings, resulting in reduced growth in terms of height and ground-line diameter. The physiological effects of polyethylene microplastics were more evident than those of polypropylene at the same concentration. The results demonstrated that microplastics can affect photosynthesis, the antioxidant system, and osmotic regulation in Chinese fir and P. bournei seedlings, thereby inhibiting their normal growth and development. Exposure to 1% (w/w) microplastics triggered stress responses in seedlings, whereas 2% (w/w) microplastics impeded seedling growth. [Display omitted] • Microplastics of 1% (w/w) triggered stress responses in Chinese fir and P. bournei seedlings. • Microplastics of 2% (w/w) reduced the growth of Chinese fir and P. bournei seedlings. • Polyethylene is more toxic to seedlings than polypropylene at the same concentration. [ABSTRACT FROM AUTHOR]

Rare earth elements (REE) have an essential role and growing importance in the world's economy. They are attracting interest from society, policymakers, and scientists. The rapidly growing global demand for REE in several strategic industrial and agricultural sectors led many countries to consider the (re)-opening of mining activities for REE extraction. Hence, their increasing use led to the disruption of their biogeochemical cycles with anthropic abnormalities already observed in aquatic ecosystems. Nonetheless, REE remain less studied, and their mechanisms of toxicity actions are not fully understood. As amphipods, Gammarus fossarum represent an important part of the aquatic macroinvertebrate assemblage and are generally used in ecotoxicological studies for their high ecological relevance. However, their use for the study of REE effects has been rather limited so far. The current study aims to assess the potential effects of two naturally REE-enriched sediments (N2 and B4) on G. fossarum. Effects on life history traits, behavioural and physiological responses have been evaluated. Exposing G. fossarum males for 72h to sediments N2 and B4 led to a decrease in haemolymph osmolality and locomotion while an increase in ventilatory activity was observed. Exposing G. fossarum pre-copula pairs with females at the same reproductive stage to the naturally REE-enriched sediments, for one moult cycle duration (∼30 days) showed that sediment B4 led to i) a significant uptake of REE, ii) a significant decrease in the proportion of females with oocytes and iii) a significant reduction in the total number of juveniles. The physicochemical analyses of sediments showed that B4 contains the highest amount of REE with a higher proportion of light REE. The present study gives the first insights into the potential toxicity of REE on G. fossarum as they may have deleterious effects on G. fossarum population's dynamics, which may alter the functioning of aquatic ecosystems. [Display omitted] • REE-enriched sediments cause significant uptake of REE by females G. fossarum • REE-enriched sediments induce physiological and behavioural changes in G. fossarum • REE-enriched sediments impact G. fossarum reproduction revealing ecological risks [ABSTRACT FROM AUTHOR]

Sulfate is an important chemical component in seawater, which has a profound influence on the survival, growth, physiology and biochemistry of aquaculture species. The aim of this experiment was to study the effects of sulfate concentration on survival, osmotic regulation, oxidative stress and immune inflammation of mud crab(Scylla paramamosain). The results showed that the 72-h semi-lethal concentration of the crab was 3.373 g/L (1.353–8.589 g/L). After 28 days of cultivation, the contents of Na+-K+-2Cl− cotransporter (NKCC) and Na+-K+ ATPase (NKA) in the gill tissue of the S1 group (0 g/L Na 2 SO 4) were significantly higher than those in the other three groups, and the sulfate content increased and the SOD activity decreased.Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were affected by sulfate content, and the content levels in the S3 group (1 g/L Na 2 SO 4) were significantly lower than those in the other three groups. The activities of ACP and AKP first increased and then decreased with the increase of sulfate content in prepare solution, and the activities of ACP and AKP in the S3 group (1 g/L Na 2 SO 4) were significantly higher than those in the other three groups. The absence of sulfate or high concentration of sulfate will affect the survival rate of mud crabs, and have a stressful effect on the osmotic regulation of mud crabs, inhibit oxidative stress ability, and promote inflammatory response. The purpose of this study was to explore the feasibility of sulfate-type saline-alkali water aquaculture of mud crab by studying the effect of sulfate on the mud crab under low salt conditions, and to provide theoretical basis and technical guidance for the promotion of saline-alkali water aquaculture. • Use Chemical reagents to prepare aquaculture water bodies that could satisfy the survival of euryhaline seafood. • Short-term semi-lethal concentration and safe concentration range of sulfate for mud crabs during culture. • Development and utilization of inland sulfate saline-alkali waters • Sulfate affects the change of water index • Effects of sulfate on survival, antioxidant capacity and immune inflammation of mud crabs [ABSTRACT FROM AUTHOR]

The study evaluated the interactions between temperature (25 and 28 °C) and salinity (0, 15, and 32 ppt) on the growth performance, plasmatic ions, ATPases activities, and oxidative and antioxidant parameters in different tissues of common snook (Centropomus undecimalis) reared for 90 days by a 2 × 3 factorial design. The growth performance and feed conversion ratio were influenced by temperature and interaction between factors, with the best results observed in the combination between 28 °C and 15 ppt. There were effects of temperature and salinity (isolated or in interaction) for plasmatic ions, v-type H+-ATPase (VHA) and Na+/K+-ATPase (NKA) activities, and oxidative stress responses. Gill VHA (at 32 ppt) and NKA (at 0 and 15 ppt) activities were higher at 25 than at 28 °C. In the kidney, at 28 °C, the VHA (at 15 ppt) and NKA (at 32 ppt) activities were higher than at 25 °C. The VHA and NKA activities in the stomach at 28 °C and 32 ppt were higher than at the other treatments. In the intestine, the lowest activity of VHA at 25 and 28 °C occurred at 0 and 32 ppt, respectively, and the activity of NKA was highest in the interaction of 0 ppt and 25 °C. At 0 ppt, the plasmatic Na+ and Cl− values at both temperatures were decreased, and the plasmatic K+ values at 25 °C were increased. Liver thiobarbituric acid reactive substances and protein carbonyl content values were higher at the combinations of 15 ppt and 25 °C and 32 ppt and 28 °C than at the other interactions. Liver antioxidant responses (glutathione-S-transferase, glutathione peroxidase, non-protein thiols, and superoxide dismutase) were higher at 15 ppt than other salinities at both temperatures. In conclusion, the improved growth, osmoregulation, and antioxidant responses were found to be higher at 28 °C and 15 ppt. • Highest growth of common snook was verified at 15 ppt and 28 °C. • Plasma Na+ and Cl− values were decreased in fish subjected to 0 ppt. • Antioxidant responses were highest at 15 ppt at both temperatures. • Fish had the best osmoregulatory adjustments in a combination of 28 °C and 15 ppt. [ABSTRACT FROM AUTHOR]

Freshwater salinization is an escalating global environmental issue that threatens freshwater biodiversity, including fish populations. This study aims to uncover the molecular basis of salinity physiological responses in a non-native minnow species (Phoxinus septimaniae x P. dragarum) exposed to saline effluents from potash mines in the Llobregat River, Barcelona, Spain. Employing high-throughput mRNA sequencing and differential gene expression analyses, brain, gills, and liver tissues collected from fish at two stations (upstream and downstream of saline effluent discharge) were examined. Salinization markedly influenced global gene expression profiles, with the brain exhibiting the most differentially expressed genes, emphasizing its unique sensitivity to salinity fluctuations. Pathway analyses revealed the expected enrichment of ion transport and osmoregulation pathways across all tissues. Furthermore, tissue-specific pathways associated with stress, reproduction, growth, immune responses, methylation, and neurological development were identified in the context of salinization. Rigorous validation of RNA-seq data through quantitative PCR (qPCR) underscored the robustness and consistency of our findings across platforms. This investigation unveils intricate molecular mechanisms steering salinity physiological response in non-native minnows confronting diverse environmental stressors. This comprehensive analysis sheds light on the underlying genetic and physiological mechanisms governing fish physiological response in salinity-stressed environments, offering essential knowledge for the conservation and management of freshwater ecosystems facing salinization. [Display omitted] • Minnows adapt to salt stress, unveiling crucial molecular responses for survival. • Transcriptomics reveal salinity stress in gills, liver, and brain pathways. • The brain plays a pivotal role in stressor adaptation. • Transcriptomic analysis suggests potential strategies in conservation. [ABSTRACT FROM AUTHOR]

Pesticides are widely used to control weeds and pests in agricultural settings but harm non-target aquatic organisms. In this study, our objective was to evaluate the effect of short-term exposure (one week) to environmentally relevant concentrations of pesticides mixture (low concentration: 0.4 μg/l atrazine, 0.5 μg/l Roundup®, and 0.5 μg/l 2,4-D; high concentration: 0.8 μg/l atrazine, 1 μg/l Roundup®, and 1 μg/l 2,4-D) on tissue architecture, body fluid conditions, and 3-nitrotyrosine protein (NTP) and Na+/K+-ATPase, expressions in tissues of American oyster (Crassostrea virginica) under controlled laboratory conditions. Histological analysis demonstrated the atrophy in the gills and digestive glands of oysters exposed to pesticides mixture. Periodic acid-Schiff (PAS) staining showed the number of hemocytes in connective tissue increased in low- and high-concentration pesticides exposure groups. However, pesticides treatment significantly (P < 0.05) decreased the amount of mucous secretion in the gills and digestive glands of oysters. The extrapallial fluid (i.e., body fluid) protein concentrations and glucose levels were dropped significantly (P < 0.05) in oysters exposed to high-concentration pesticides exposure groups. Moreover, immunohistochemical analysis showed significant upregulations of NTP and Na+/K+-ATPase expressions in the gills and digestive glands in pesticides exposure groups. Our results suggest that exposure to environmentally relevant pesticides mixture causes morphological changes in tissues and alters body fluid conditions and NTP and Na+/K+-ATPase expressions in tissues, which may lead to impaired physiological functions in oysters. [Display omitted] • Pesticides are widely used to control weeds and pests in agricultural settings. • Aquatic environments are becoming increasingly inundated by pesticides. • Pesticides harm non-target aquatic organisms. • Pesticides altered the morphology of gills and digestive glands of oysters. • Pesticides induced nitrative stress and Na+/K+-ATPase expression in oysters. [ABSTRACT FROM AUTHOR]

With abnormal global climate change and the frequent occurrence of extreme weather, low-temperature stress poses an increasingly serious threat to the diversity of plants. Low temperatures accompanied by limitations in nitrogen cause a series of morphological, physiological, and molecular changes in plants. Nitrogen dioxide (NO 2) is a gas that is considered to be a toxic air pollutant. However, NO 2 in the atmosphere can be absorbed by plants and participate in nitrogen metabolism. In this study, tobacco (Nicotiana tabacum L.) seedlings were fumigated with a concentration of 4 µL·L−1 NO 2 at 4 ℃ for 10 days. NO 2 promoted the glutamine synthetase-glutamate synthase (GS/GOGAT) pathway in the leaves at low temperatures, which transforms more organic nitrogen that can be directly utilized by the plants, and improves the skeleton for carbon metabolism. Moreover, gamma-aminobutyric acid (GABA) was generated through the ornithine and glutamate pathways, and the biosynthesis of proline was also enhanced after treatment with NO 2. Together, these compounds regulate the osmotic balance of tobacco leaf cells under low-temperature stress. NO 2 activated the ascorbate-glutathione (AsA-GSH) cycle in the leaves under low-temperature stress, and this antioxidant enzyme system synergistically removed the intracellular free radicals that result from reactive oxygen species. Additionally, NO 2 significantly increased the content of nitric oxide (NO) in the leaves under low-temperature stress and enhanced the opening of stomata, thus, improving photosynthesis in the leaves. The biosynthesis of chlorophyll in the leaves was inhibited by low-temperature stress, but NO 2 promotes the biosynthesis of chlorophyll directly or through the nitric acid signaling pathway and improves the ability of plants to capture light energy. NO 2 also alleviates the photoinhibition induced by cold stress by regulating photosynthetic electron transfer and absorbing more energy for the assimilation of photosynthetic carbon. This improves the photochemical efficiency of tobacco leaves. In conclusion, NO 2 enhanced the tolerance of tobacco seedlings to low temperature by regulating nitrogen metabolism, the osmotic balance, antioxidant system, and photosynthesis. [Display omitted] • NO 2 promotes stomatal opening and chlorophyll synthesis to enhance the photosynthetic function. • NO 2 promotes the GS/GOGAT cycle in leaves at low temperatures and enhances N metabolism ability. • NO 2 regulates the osmotic balance of tobacco leaf cells under low temperature stress. • NO 2 activates the non-enzymatic antioxidant system in tobacco leaves under low temperature stress [ABSTRACT FROM AUTHOR]

In the context of climate change, the magnitude and frequency of temperature extremes (low and high temperatures) are increasing worldwide. Changes to the lower extremes of temperature, known as cold stress (CS), are one of the recurrent stressors in many parts of the world, severely limiting agricultural production. A series of plant reactions to CS could be generalized into morphological, physiological, and biochemical responses based on commonalities among crop plants. However, the differing originality of crops revealed varying degrees of sensitivity to cold and, therefore, exhibited large differences in these responses among the crops. This review discusses the vegetative and reproductive growth effects of CS and highlights the species-specific aspect of each growth stage whereby the reproductive growth CS appears more detrimental in rice and wheat, with marginal yield losses. To mitigate CS negative effects, crop plants have evolved cold-acclimation mechanisms (with differing capability), characterized by specific protein accumulation, membrane modification, regulation of signaling pathways, osmotic regulation, and induction of endogenous hormones. In addition, we reviewed a comprehensive account of management strategies for regulating tolerance mechanisms of crop plants under CS. • Effects of cold stress primarily depend on crop origin, species, growth stage and intensity, and duration of stress. • Cold-caused yield loss is mainly attributed to impaired grain development because of assimilates shortage due to source-sink imbalance. • Advances in genome editing approaches such as CRISPR-Cas9 provides a promising strategy to the development of cold-tolerant crop species. [ABSTRACT FROM AUTHOR]

The Echinoderes coulli -group is characterized by the presence of an enlarged nephridiopore composed of two regions apparently related to increase the osmoregulation efficiency. Representatives of this group are often intertidal species living in habitats with daily salinity changes, including mangroves. In the present study, two new species potentially belonging to this group are described from a lowly polluted mangrove in French Guiana (western Atlantic Ocean). Echinoderes angelae sp. nov. possesses spines in middorsal position on segment 4 and sublateral position on segments 6–7, plus tubes in lateroventral position on segments 5 and 8 and in laterodorsal position on segment 10. Besides, this species has modified type 2 glandular cell outlets throughout different positions on segments 2, 4–8 and 10 and large sensory spots on segment 1 with a transversal row of conspicuously elongated hairs at the posterior part of the papillae area. Echinoderes guianensis sp. nov. has spines in middorsal position on segment 4, lateroventral position on segment 6 and sublateral position on segment 7, plus tubes in lateroventral position on segment 5 and laterodorsal position on segment 10. Also, it lacks modified type 2 glandular cell outlets and large sensory spots with a posterior, transversal row of elongated hairs. These diagnostic features allow the distinction of the new species from the remaining congeners of the E. coulli -group. In addition, the presence of epibionts in some of the examined specimens is discussed. [ABSTRACT FROM AUTHOR]

Salinity stress is one of the major abiotic constraints that limit plant growth and yield, which thereby is a serious concern to world food security. It adversely affects crop production by inducing hyperosmotic stress and ionic toxicity as well as secondary stresses such as oxidative stress, all of which disturb optimum physiology and metabolism. Nonetheless, various strategies have been employed to improve salt tolerance in crop plants, among which the application of Melatonin (Mel) could also be used as it has demonstrated promising results. The ongoing experimental evidence revealed that Mel is a pleiotropic signaling molecule, which besides being involved in various growth and developmental processes also mediates environmental stress responses. The current review systematically discusses and summarizes how Mel mediates the response of plants under salt stress and could optimize the balance between plant growth performances and stress responses. Specifically, it covers the latest advances of Mel in fine-tuning the signaling in plants. Furthermore, it highlights plant-built tolerance of salt stress by manifesting the biosynthesis of Mel, its cross talks with nitric oxide (NO), and Mel as a multifaceted antioxidant molecule. • Salt stress is one of the major emerging environmental constraints around the globe. • Mel promoted salt tolerance by regulating physio-metabolic processes in plants. • Mel acts as a potent signaling molecule under salt stress. • Mel counteracted salt-induced toxicity by regulating redox homeostasis. • The application of Mel is a novel approach for conferring salt tolerance in plants. [ABSTRACT FROM AUTHOR]

Halomonas smyrnensis AAD6T is a moderately halophilic bacterium proven to be a powerful biotechnological tool with its ability to accumulate valuable biopolymers such as levan and poly(3-hydroxybutyrate) (PHB). Levan is a fructose homopolymer with β-2,6 fructofuranosidic linkages on the polymer backbone, and its distinctive applications in various industries such as food, pharmaceutical, medical, and chemical have been well-defined. On the other hand, PHB is a promising raw material to produce biodegradable plastics. Although it was shown in our previous studies that H. smyrnensis AAD6T exhibits one of the highest conversion yields of sucrose to levan reported to date, novel strategies are required to overcome high costs of levan production. In this study, we aimed at increasing levan productivity of H. smyrnensis AAD6T cultures using random mutagenesis techniques combined (i.e., ethyl methanesulfate treatment and/or ultraviolet irradiation). After several consecutive treatments, mutant strains BAE2, BAE5 and BAE6 were selected as efficient levan producers, as BAE2 standing out as the most efficient one not only in sucrose utilization and levan production rates, but also in final PHB concentrations. The mutants' whole genome sequences were analysed to determine the mutations occurred. Several mutations in genes related to central carbon metabolism and osmoregulation were found. Our results suggest that random mutagenesis can be a facile and efficient strategy to enhance the performance of extremophiles in adverse conditions. • Random mutagenesis can be a facile and efficient strategy to enhance the performance of extremophiles in adverse conditions. • An improved levan producer Halomonas strain is obtained, characterized and described. • Sucrose utilization and levan production rates, as well as final PHB yields were enhanced. [ABSTRACT FROM AUTHOR]

Drought stress commonly happens more than once during the life cycle of perennial trees. Stress memory endows better capacity to cope with repeated stresses for plants, while the underlying mechanisms are not fully elucidated. In this study, 2-month-old saplings of two mulberry cultivars (Husang32 and 7307 of Morus multicaulis) with or without an early soil water deficit were subjected to subsequent drought for 9 days. The shoot height growth, biomass production, stable carbon isotope discrimination, phytohormones, reactive oxygen species (ROS), osmotic substances and antioxidant enzymes were analyzed after the first and the second drought, respectively. Drought priming saplings sustained comparable or slightly higher biomass accumulation under the second drought than those non-priming. They also exhibited decreased levels of soluble sugars, free proline and soluble proteins, lower accumulation of malonaldehyde (MDA) and superoxide anion (O 2 •−), reduced activities of superoxide dismutase (SOD) and peroxidase (POD) compared to non-priming plants. Moreover, cultivar Husang32 exhibited elevated abscisic acid (ABA) and jasmonic acid (JA) where 7307 displayed opposite changes. PCA suggests that MDA, H 2 O 2 , free proline, SOD and POD in roots, and ROS, soluble sugars and glutamate reductase in leaves are dominant factors influenced by stress memory. ABA and JA in leaves also play important roles in exerting drought imprints. Collectively, stress memory can confer mulberry resistance to recurrent drought via combined regulations of antioxidative protection, osmotic adjustment and phytohormonal responses. • Cultivar Husang32 was more sensitive to drought than cultivar 7307. • Priming attenuated mulberry growth reduction under recurrent drought. • Antioxidative and osmotic regulations are key contributors for stress memory. • Stress memory could be intraspecific regarding phytohormonal response. [ABSTRACT FROM AUTHOR]

• Alkaline stress induced decline in growth and nutrient acquisition. • Taurine functioned as an endogenous antioxidant. • Taurine mediated ROS metabolism and ions homeostasis. • Taurine reduced the peroxidation of lipids. Alkaline stress is among major environmental constraints that impair plant growth and yield production worldwide. Taurine protects cells from oxidative injury in animals. There exists no report in the literature on taurine functions in plants under environmental constraints. Therefore, the current study was aimed to assess the role of taurine in lessening the harmful effects of alkaline stress on growth of Trifolium alexandrinum L. (Berseem clover). Alkaline conditions (0, 25, 50 and 75 mM Na 2 CO 3) resulted in a notable reduction in growth, chlorophyll contents, relative water content, and essential nutrient uptake. The uptake of toxic Na+ was significantly greater in plants under stress, creating specific ion toxicity. Further, oxidative damage due to alkaline stress was noticeable in plants mirrored as higher hydrogen peroxide (H 2 O 2), superoxide radical (O 2 •‒), methylglyoxal (MG), malondialdehyde (MDA), and oxidized glutathione GSSG generation. Taurine supplementation (0, 100, and 200 mg L‒1) protected plants from osmotic stress, ions excess toxicity, and oxidative injury under alkaline conditions. Taurine notably reduced the uptake and accumulation of Na+ in plants. In contrast, the K+, Ca2+, and P contents were several folds higher in plants treated with taurine under alkaline conditions. The schematic representation depicts taurine-mediated increased tolerance to alkaline stress. [Display omitted]. [ABSTRACT FROM AUTHOR]

Spermatozoa motility in freshwater and marine fish is mainly controlled by the difference in osmotic pressure. Specifically, zebrafish (Danio rerio) spermatozoa undergo hypoosmotic shock due to the decrease in extracellular potassium, which leads to membrane hyperpolarization and activation of flagellar motility. Previous studies have concluded that motility activation has a negative effect on the spermatozoa structure. However, no evidence exists about ultrastructural changes in zebrafish spermatozoa after motility activation. In this study, spermatozoa samples were obtained from ten adult zebrafish individuals before and 60 s after motility activation and analyzed using Scanning and Transmission Electron Microscopy. Results showed dramatic morphological and ultrastructural alterations of the zebrafish spermatozoa after activation. In particular, the spermatozoa head underwent severe morphological distortion, including swelling of the nucleus, the bursting of the plasma membrane, and the alteration of the genetic material. Midpieces were also affected after activation since rupture of the cell membrane and lysis of mitochondria occurred. Furthermore, after the hypoosmotic shock, most spermatozoa showed a coiled flagellum and a disaggregated plasma membrane. Overall, our findings show that the activation of motility leads to substantial zebrafish spermatozoa morphological and ultrastructural changes, which could modify their physiology and decrease the fertilizing potential. [Display omitted] • Zebrafish spermatozoa activation leads to substantial ultrastructural changes. • TEM micrographs show a marked DNA decondensation after activation. • After activation, many sperm have a coiled flagellum and a disaggregated membrane. [ABSTRACT FROM AUTHOR]

Potassium (K) scarcity of arable land is one of the important factors that hamper the growth of the plants and reduce yield worldwide. In the current study, we examine the physiological, biochemical, and metabolome response of Arachis hypogaea (GG7 genotype: fast-growing, tall, early maturing, and high yielding) under low K either solitary or in combination with Si to elucidate the ameliorative role of Si. The reduced fresh and dry biomass of peanut and photosynthetic pigments content was significantly alleviated by Si. Si application did not affect the leaf and stem K+, although it enhanced root K+ in K-limitation, which is probably due to up-regulated expression of genes responsible for K uptake. Si improves the potassium use efficiency in K-limitation as compared to control. K-deficiency increased MDA, O 2 •−, and H 2 O 2 levels in leaf and root of peanut. Si improved/maintained the activity of antioxidative enzymes, which significantly lowered the ROS accumulation in K-limitation. The AsA/DHA and GSH/GSSG ratio was approximately unaffected in both leaf and root, suggesting the maintained cellular redox potential in K-starved peanut. Si promotes accumulation of sugars and sugar alcohols, phytohormones indicating their probable involvement in signal transduction, osmotic regulation, and improvement of stress tolerance. Down-regulation of aspartic acid and glutamic acid while up-regulation of lysine, histidine, and arginine could maintain charge balance in K-deprived peanut. The significant accumulation of polyphenols under K limitation supplemented with Si suggests the role of polyphenols for ROS scavenging. Our results demonstrated that Si as a beneficial element can mitigate K-nutrient toxicity and improve KUE of peanut under K-limitation conditions. Moreover, our results demonstrate that Si application can improve crop yield, quality, and nutrient use efficiency under nutrient limitation conditions. [Display omitted] • Arachis hypogaea were imposed to K-deficiency stress with Si-supplementation. • Si-application reduced lipid peroxidation and ROS accumulation. • Si promotes absorption of mineral nutrients in response to K-limitation. • Si provides osmoprotection by higher accumulation of metabolites in A. hypogaea. • Si improved phytohormones levels in peanut as compared to non-Si treated plants. [ABSTRACT FROM AUTHOR]

Vegetation water content is a critical aspect of ecosystem water balance and plant physiology, including how plants cope with drought. Deciduous trees store significant water for use in transpiration throughout the growing season in the boreal forest of Alaska. Water content of shrub stems, and their role in the water balance, remains unquantified for many woody species in boreal and arctic tundra ecosystems. We adapted time-domain reflectometry (TDR) to continuously measure shrub water content. We created calibration equations relating apparent dielectric constant to volumetric water content of shrub stems of felt-leaf willow (Salix alaxensis), diamond-leaf willow (S. pulchra) and dwarf birch (Betula nana). Our results show seasonal patterns of volumetric stem water content ranging from 40 to 70%. Stem water content prior to leaf-out was minimal (scaled by biomass, <2mm) compared to total snowmelt water, implying little water uptake of snowmelt water. Stem water content was small compared to other components of the hydrologic water budget (precipitation, runoff, evaporation, evapotranspiration, infiltration), indicating the importance of shrub transpiration and dependence of shrubs on available soil moisture for uptake. The technique and findings here are needed to quantify the role of deciduous shrub vegetation in the hydrologic cycle of ecosystems, particularly those where shrubs predominate. [ABSTRACT FROM AUTHOR]

The world is rich in saline-alkali water resources, and the effective utilization of saline-alkali water resources is of great significance to the promotion of human economic development. This study investigated the effects of carbonate saline water on the immune, antioxidant, osmotic regulatory, and metabolic capacities of S. paramamosain. Bicarbonate stress resulted in damage to the hepatopancreas, as well as significantly upregulating the activities of superoxide dismutase and catalase, indicating that the antioxidant capacity increased under short-term bicarbonate stress, but then decreased. Long-term bicarbonate stress caused further oxidative damage. The activities of alkaline phosphatase and acid phosphatase also significantly increased, indicating an initially enhanced immune response of S. paramamosain to carbonate salinity stress that then declined, suggesting that the ability to mount an immune response decreased following long-term exposure. High bicarbonate levels also significantly inhibited the osmotic regulation ability of S. paramamosain , and negatively impacted metabolic indexes (e.g., glucose, total cholesterol, triglycerides, urea nitrogen, and uric acid). Three groups of metabolites were differentially upregulated and 95 were differentially downregulated, including 'organooxygen compounds', 'carboxylic acids and derivatives', 'fatty acyls', 'glycerophospholipids' and 'keto acids and derivatives'. Thus, long-term bicarbonate stress also decreased energy metabolism in S. paramamosain. Under long-term bicarbonate stress, related products of energy metabolism were significantly downregulated, and bicarbonate stress significantly inhibited energy uptake in S. paramamosain. This study analyzed the stress mechanism of bicarbonate on S. paramamosain , further enriched the culture theory of S. paramamosain , in order to provide a theoretical basis for the improvement of saline-alkaline water culture technology of S. paramamosain. [Display omitted] • Bicarbonate exposure damaged the hepatopancreas of Scylla paramamosain. • Stress of bicarbonate induced oxidative damage, decreased the immune response. • Bicarbonate stress inhibited the osmotic regulation ability of S. paramamosain. • Long-term bicarbonate stress reduced the metabolic level in S. paramamosain. [ABSTRACT FROM AUTHOR]

It is known that the marine euryhaline crab, mud crab (Scylla paramamosain) , is capable of adapting to low salinity conditions through an innate osmoregulatory system. However, the influence of nutritional conditions during low salinity adaptation has not been fully elucidated. In this study, transcriptome analysis was employed to examine whether low salinity affects the AMP-activated protein kinase (Ampk) signaling pathway, and thereby carbohydrate and lipid metabolism. Further analysis revealed that low salinity activated the expression of P-Ampk and promoted glycolysis and lipolysis, which enhances glycogen and lipid utilization. Nutritional deprivation confirmed that nutrients influenced the survival and osmotic pressure regulation of mud crab under to low salinity via the Ampk signaling pathway. During adaptation to low salinity, carbohydrates were the primary energy source in the initial 7 days, followed by lipids. Further investigation showed that pharmacological stimulation of mechanistic targets in the Ampk signaling pathway using metformin could promote the osmotic pressure regulation of mud crab, confirmed the pivotal role of this pathway in low salinity adaptation. Overall, the present study demonstrated that nutrition, metabolism and osmotic pressure regulation interactively contribute to salinity adaptation in mud crab. Specifically, low salinity induced remodeling of nutritional metabolism homeostasis and promoted glycolipid catabolism, thereby providing energy for osmotic pressure regulation in mud crabs. [Display omitted] • Nutrition metabolism is closely involved in low salinity adaptation in mud crabs. • Nutritional deprivation decreased the osmotic pressure regulation ability. • Enhanced utilization of carbohydrate and lipid was key for low salinity adaptation. • The Ampk is involved in the regulation of low salinity adaptation as a fuel sensor. [ABSTRACT FROM AUTHOR]

Proline serves as an important osmolyte in maintaining osmotic pressure and stabilizing cellular structure in aquatic organisms, and is essential for adaptation to salinity stress. This study focuses on the razor clam (Sinonovacula constricta), and investigated the metabolism and synthesis of proline in response to changing salinity. The proline content in gill tissues of razor clams significantly increased over time and with different levels of salinity exposure. The key genes involved in proline metabolism, including (Aminotransferase (ScOAT), Δ1-pyrroline-5-carboxylic acid synthase (ScP5CS), and proline dehydrogenase (ScProDH) were investigated, as well as enzyme activities associated with these genes in razor clams. The expression and activity of P5CS increased significantly under hypersalinity conditions, whereas that of OAT enzyme activity decreased. This suggested that the glutamate pathway had an important role in the proline synthesis during hypersalinity. ProDH activity was negatively correlated with salinity and regulated by the proline content, indicating a significant role of ProDH in proline accumulation under hypersalinity conditions. ScP5CS was heterologously expressed in yeast Saccharomyces cerevisiae , followed by exogenous proline supplementation studies. Recombinant S. cerevisiae incubated with ScP5CS exhibited elevated levels of proline, with the growth performance of recombinant strain surpassing that of the control group after salinity stress. In addition, razor clams exposed to exogenous proline under high salinity conditions showed expedite osmotic regulation, whereby the hemolymph pressure reached equilibrium more quickly. Together, these results indicated that the proline content increased under high salinity, which could improve the tolerance of razor clams to hypersalinity, offering novel perspectives into molecular mechanism of salinity adaptation in shellfish. • Hypersalinity stress induced accumulation of proline in razor clam. • Proline synthesis primarily relied on the glutamate synthesis pathway under hypersalinity. • The accumulation of proline can improve the salinity tolerance of razor clam. [ABSTRACT FROM AUTHOR]

Triclocarban (TCC), an emerging contaminant in water environments, its effects on freshwater biofilms remain insufficiently understood. This study investigates the effects of TCC exposure (at concentrations of 10 μg L−1 and 10 mg L−1) on mature freshwater biofilms. TCC was found to inhibit biofilm activity as evidenced by changes in surface morphology and the ratio of live/dead cells. Moreover, both concentrations of TCC were observed to modify the structure of the biofilm community. Metabolomics analysis revealed an overlap in the toxicity mechanisms and detoxification strategies triggered by various concentrations of TCC in biofilms. However, the higher toxicity induced by 10 mg L−1 TCC resulted from the downregulation of proline betaine, disrupting the homeostasis of cellular osmotic pressure regulation in biofilms. Notably, lipid and lipid-like molecules showed high sensitivity to different concentrations of TCC, indicating their potential as biomarkers for TCC exposure. Annotation of the differential metabolites by KEGG revealed that alterations in amino acid and carbon metabolism constituted the primary response mechanisms of biofilms to TCC. Moreover, the biofilm demonstrated enhanced nucleic acid metabolism, which bolstered resistance against TCC stress and heightened tolerance. Furthermore, elevated TCC concentrations prompted more robust detoxification processes for self-defense. Overall, short-term exposure to TCC induced acute toxicity in biofilms, yet they managed to regulate their community structure and metabolic levels to uphold oxidative homeostasis and activity. This research contributes to a deeper comprehension of TCC risk assessment and policy control in aquatic environments. [Display omitted] • The structure of C-cycling bacteria communities was damaged by triclocarban (TCC). • Rhizobiales were key bacterial communities in biofilm resistance to TCC stress. • Biofilm primarily responded to TCC via changes in amino acid and carbon metabolism. • The unique toxicity of 10 mg L−1 TCC downregulates proline betaine. • Biofilms enhanced nucleic acid metabolism to resist TCC stress. [ABSTRACT FROM AUTHOR]

Since the Industrial Revolution, increasing atmospheric CO 2 concentrations have had a substantial negative impact influence on coastal ecosystems because of direct effects including ocean acidification and indirect effects such as extreme rainfall events. Using a two-factor crossover indoor simulation experiment, this study examined the combined effects of acidification and hyposaline stress on Thalassia hemprichii. Seawater acidification increased the photosynthetic pigment content of T. hemprichii leaves and promoted seagrass growth rate. Hyposaline stress slowed down seagrass growth and had an impact on the osmotic potential and osmoregulatory substance content of seagrass leaves. Acidification and salinity reduction had significant interaction effects on the photosynthesis rate, photosynthetic pigment content, chlorophyll fluorescence parameters, and osmotic potential of T. hemprichii , but not on the growth rate. Overall, these findings have shown that the hyposaline stress inhibitory effect on the T. hemprichii physiological performance and growth may be reduced by acidification. • Thalassia hemprichii highly adapts to acidification and hyposalinity environments. • Acidification and hyposalinity had interaction effects on physiology of the seagrass. • Acidification and hyposalinity had no interaction effects on growth of the seagrass. • Acidification mitigates the inhibitory effects of hyposaline stress for the seagrass. [ABSTRACT FROM AUTHOR]

Plants have a protective mechanism called non-photochemical quenching to prevent damage caused by excessive sunlight. A critical component of this mechanism is energy-dependent quenching (qE). In Chlamydomonas reinhardtii , the protein expression called light-harvesting complex stress-related protein 3 (LHCSR3) is crucial for the qE mechanism. LHCSR3 expression is observed in various conditions that result in photooxidation, such as exposure to high light or nutrient deprivation, where the amount of captured light surpasses the maximum photosynthetic capacity. Although the role of LHCSR3 has been extensively studied under high light (HL) conditions, its function during nutrient starvation remains unclear. In this study, we demonstrate that LHCSR3 expression can occur under light intensities below saturation without triggering qE, particularly when nutrients are limited. To investigate this, we cultivated C. reinhardtii cells under osmotic stress, which replicates conditions of nutrient scarcity. Furthermore, we examined the photosynthetic membrane complexes of wild-type (WT) and npq4 mutant strains grown under osmotic stress. Our analysis revealed that LHCSR3 expression might modify the interaction between the photosystem II core and its peripheral light-harvesting complex II antennae. This alteration could potentially impede the transfer of excitation energy from the antenna to the reaction center. • The LHCSR3 expression is induced in osmotic stress, and its photoprotective function does not involve qE. • Photosystem II core D1 is protected by LHCSR3 expression. • The LHCSR3 expression affects the interaction between the PSII core with its peripheral LHCII antenna. • Thylakoid lumen acidification is essential for the expression and function of LHCSR3. • However, the expression of LHCSR3 induced changes in photosynthetic efficiency. [ABSTRACT FROM AUTHOR]

Nanoplastics pollution has emerged as a global issue due to its widespread potential toxicity. This study delved in to toxic effects of nanoplastics on juvenile P. clarkii and molecular mechanisms from perspectives of growth, biochemical, histopathological analysis and transcriptome level for the first time. The findings of this study indicated that nanoplastics of different concentrations have varying influence mechanisms on juvenile P. clarkii. Nanoplastics have inhibitory effects on growth of juvenile P. clarkii , can induce oxidative stress. The biochemical analysis and transcriptome results indicated that 10 mg/L nanoplastics can activate the antioxidant defense system and non-specific immune system in juvenile P. clarkii , and affect energy metabolism and oxidative phosphorylation. While 20 mg/L and 40 mg/L have a destructive influence on the immune function in juvenile P. clarkii , leading to lipid peroxidation and oxidative damage, and induce apoptosis, can affect ion transport and osmotic pressure regulation. The findings of this study can offer foundational data for delving further into impacts of nanoplastics on crustaceans and toxicity mechanism. [Display omitted] • Toxicity mechanism of nanoplastics on P. clarkii was studied from multiple levels. • Nanoplastics inhibit the growth of P. clarkii and induce oxidative stress and apoptosis. • 10 mg/L nanoplastics mainly affect the energy metabolism and oxidative phosphorylation. • 20 mg/L nanoplastics mainly affect the ion transport and osmotic pressure regulation. • 40 mg/L nanoplastics have damaging effects on the immune system of P. clarkii. [ABSTRACT FROM AUTHOR]

Citrus fruit rich in beneficial health-promoting nutrients used for functional foods or dietary supplements production. However, its quality and yield were damaged by citrus target spot. Citrus target spot is a low-temperature fungal disease caused by Pseudofabraea citricarpa , resulting in citrus production reductions and economic losses. In this study, transcriptome and gene knockout mutant analyses were performed on the growth and pathogenicity of P. citricarpa under different temperature conditions to quantify the functions of temperature-sensitive proteins (PscTSP). The optimum growth temperature for P. citricarpa strain WZ1 was 20 °C, while it inhibited or stopped growth above 30 °C and stopped growth below 4 °C or above 30 °C. Certain PscTSP-key genes of P. citricarpa were identified under high temperature stress. qRT-PCR analysis confirmed the expression levels of PscTSPs under high temperature stress. PscTSPs were limited by temperature and deletion of the PscTSP - X gene leads to changes in the integrity of citrus cell walls, osmotic regulation, oxidative stress response, calcium regulation, chitin synthesis, and the pathogenicity of P. citricarpa. These results provide insight into the underlying mechanisms of temperature sensitivity and pathogenicity in P. citricarpa , providing a foundation for developing resistance strategies against citrus target spot disease. [ABSTRACT FROM AUTHOR]

This study explored the role of myo -inositol in alleviating the low salinity stress of White Shrimp (Litopenaeus vannamei). Juvenile shrimp (0.4 ± 0.02 g) in low salinity (salinity 3) water were fed diets with myo -inositol levels of 0, 272, 518, 1020 and 1950 mg/kg (crude protein is 36.82 %, crude lipid is 7.58 %), fed shrimp in seawater at a salinity of 25 were fed a 0 mg/kg myo -inositol diet as a control (Ctrl). The experiment was carried out in tanks (50 L) with satiety feeding, and the experiment lasted for 6 weeks. After sampling, the serum was used to measure immune function, the hepatopancreas homogenate was used to measure the antioxidant capacity and hepatopancreas damage state, the hepatopancreas was used for transcriptomics analysis, and the gills were used for qPCR to measure osmotic pressure regulation. The results showed that the final weight and survival of the shrimp in the 1020 mg/kg group increased significantly compared with those in the other low salinity groups, but the final weight and biomass increase were significantly lower than those in the Ctrl group. Dietary myo -inositol improved the antioxidant capacity of shrimp under low salinity. B-cell hyperplasia and hepatic duct damage were observed in the hepatopancreas in the 0 mg/kg group. The results of transcriptome analysis showed that myo -inositol could participate in the osmotic pressure regulation of shrimp by regulating carbohydrate metabolism, amino acid metabolism, lipid metabolism and other related genes. Myo -inositol significantly affected the expression of related genes in ion transporter and G protein-coupled receptor-mediated pathways. This study demonstrated that myo -inositol can not only act as an osmotic pressure effector and participate in the osmolar regulation of shrimp through the phosphatidylinositol signaling pathway mediated by G protein-coupled receptors but also relieve low salinity stress by mediating physiological pathways such as immunity, antioxidation, and metabolism in shrimp. The binomial regression analysis of biomass increases and survival showed that the appropriate amount of myo -inositol in the L. vannamei diet was 862.50–1275.00 mg/kg under low salinity. [Display omitted] • Myo -inositol alleviated low salinity stress in Litopenaeus vannamei but could not completely offset the adverse effects. • The optimal amount of myo -inositol in the diet of L. vannamei under low salinity is 862.50-1275.00 mg/kg. • Myo -inositol enhances antioxidant capacity and reduces lipid synthesis. • Reduce oxidative damage under low salinity stress. [ABSTRACT FROM AUTHOR]

Osmoregulation is the homeostatic mechanism essential for the survival of organisms in hypoosmotic and hyperosmotic conditions. In freshwater or soil dwelling protists this is frequently achieved through the action of an osmoregulatory organelle, the contractile vacuole. This endomembrane organelle responds to the osmotic challenges and compensates by collecting and expelling the excess water to maintain the cellular osmolarity. As compared with other endomembrane organelles, this organelle is underappreciated and under-studied. Here we review the reported presence or absence of contractile vacuoles across eukaryotic diversity, as well as the observed variability in the structure, function, and molecular machinery of this organelle. Our findings highlight the challenges and opportunities for constructing cellular and evolutionary models for this intriguing organelle. [ABSTRACT FROM AUTHOR]

In this work, we have developed a novel asymptotic analysis using perturbation techniques for an electroosmotic flow in a rectangular microchannel, considering that the absolute viscosity η is a function of temperature; a situation that affects also the slip condition at the walls of the microchannel, u = − s η ∂ u ∂ n . The physical importance of this temperature dependence is based on the presence of the applied external electric field on the electrolyte solution, which originates the Joule heating effect that disturbances the isothermal hydrodynamic behavior. The above leads to a significant increase of the volumetric flow rate for this non-isothermal condition in comparison to the purely isothermal electroosmotic flow. This result is simultaneously controlled by the heat losses to the ambient and the slip effect: the lower the presence of the heat dissipation mechanism on the outer walls of the microchannel and the higher the sliding condition, the higher the values of the volumetric flow rate. The above trend differs substantially from the isothermal case and finds its justification in the recognition of the presence of the Joule heating effect that induces significant longitudinal and transverse temperature gradients along the microchannel. Considering the proper limitations of the asymptotic analysis, we compare the present asymptotic results with a full numerical solution of the governing equations, which are composed of the continuity, momentum, and energy equations for the electrolyte flow, together with the Poisson–Boltzmann. [Display omitted] • Asymptotic methods for obtaining the solution of a non-isothermal electroosmotic flow. • FreeFem++ is used to validate the analytical results. • The effect of viscosity and slip as a function of temperature promotes a significant increase in the flow rate through the microchannel. [ABSTRACT FROM AUTHOR]

• Copeptin is the C-terminal segment of arginine vasopressin (AVP) precursor peptide. • Copeptin level is associated with the osmotic pressure and stress reaction as AVP. • Copeptin may serve as a diagnostic and prognostic marker better than AVP in AVP-dependent fluid disorders and stress-associated diseases. Copeptin, a glycosylated peptide of 39 amino acids, is the C-terminal segment of arginine vasopressin (AVP) precursor peptide, which is consisted of two other fragments, vasopressin and neurophysin Ⅱ. The main physiological functions of AVP are fluid and osmotic balance, cardiovascular homeostasis and regulation of the endocrine stress response. Numerous studies have demonstrated that the endogenous AVP in plasma is a meaningful biomarker to guide diagnosis and therapy of diseases associated with fluids disorders and stress. However, due to its instability, short half-time life in circulation and lack of readily available AVP assays, clinical measurement of AVP is restricted. In contrast to AVP, copeptin which is released in an equimolar mode with AVP from the pituitary, has emerged as a stable and simple-to-measure surrogate marker of AVP and displays excellent potential in diagnosis, differentiation and prognosis of various diseases. This review will discuss the studies on the clinical value of copeptin in different diseases, especially in AVP-dependent fluids disorders, as well as issues and prospects of the application of this potential biomarker. [ABSTRACT FROM AUTHOR]

Cyclic-di-adenosine monophosphate (c-di-AMP) is an important nucleotide signaling molecule that plays a key role in osmotic regulation in bacteria. c-di-AMP is produced from two molecules of ATP by proteins containing a diadenylate cyclase (DAC) domain. In Bacillus subtilis, the main c-di-AMP cyclase, CdaA, is a membrane-linked cyclase with an N-terminal transmembrane domain followed by the cytoplasmic DAC domain. As both high and low levels of c-di-AMP have a negative impact on bacterial growth, the cellular levels of this signaling nucleotide are tightly regulated. Here we investigated how the activity of the B. subtilis CdaA is regulated by the phosphoglucomutase GlmM, which has been shown to interact with the c-di-AMP cyclase. Using the soluble B. subtilis CdaACD catalytic domain and purified full-length GlmM or the GlmMF369 variant lacking the C-terminal flexible domain 4, we show that the cyclase and phosphoglucomutase form a stable complex in vitro and that GlmM is a potent cyclase inhibitor. We determined the crystal structure of the individual B. subtilis CdaACD and GlmM homodimers and of the CdaACD:GlmMF369 complex. In the complex structure, a CdaACD dimer is bound to a GlmMF369 dimer in such a manner that GlmM blocks the oligomerization of CdaACD and formation of active head-to-head cyclase oligomers, thus suggesting a mechanism by which GlmM acts as a cyclase inhibitor. As the amino acids at the CdaACD:GlmM interphase are conserved, we propose that the observed mechanism of inhibition of CdaA by GlmM may also be conserved among Firmicutes. [ABSTRACT FROM AUTHOR]

Salinity is a major issue affecting photosynthesis and crop production worldwide. High salinity induces both osmotic and ionic stress in plant tissues as a result of complex interactions among morphological, physiological, and biochemical processes. Salinity, in turn, can provoke inactivation of some enzymes in the Calvin-Benson cycle and therefore affect the fine adjustment of electron transport in photosystem I and carbon related reactions. Here, we used three contrasting Jatropha curcas genotypes namely CNPAE183 (considered tolerant to salinity), CNPAE218 (sensible), and JCAL171 (intermediate) to understand salinity responses. By performing a long-term (12 months) experiment in land conditions, we investigated distinct mechanisms used by J. curcas to cope with threatening salinity effects by analyzing gas exchange, mineral nutrition and metabolic responses. First, our results highlighted the plasticity of stomatal development and density in J. curcas under salt stress. It also demonstrated that the CNPAE183 presented higher salt-tolerance whereas CNPAE218 displayed a more sensitive salt-tolerance response. Our results also revealed that both tolerance and sensitivity to salinity were connected with an extensive metabolite reprogramming in the Calvin-Benson cycle and Tricarboxylic Acid cycle intermediates with significant changes in amino acids and organic acids. Collectively, these results indicate that the CNPAE183 and CNPAE218 genotypes demonstrated certain characteristics of salt-tolerant-like and salt-sensitive-like genotypes, respectively. Overall, our results highlight the significance of metabolites associated with salt responses and further provide a useful selection criterion in during screening for salt tolerance in J. curcas in breeding programmes. Schematic summary model showing metabolic and physiologic responses to salt (NaCl) and plant mitochondria and chloroplast in J. curcas. Ions Na+ and Cl− were translocated by leaves through xylem. In the leaves, these ions provokes NaCl stress symptoms triggering oxidative ionic and osmotic stress on cells. Once inside the chloroplast the Na+ ions provokes downregulation of many Calvin-Benson cycle enzymes (e.g. Rubisco, Fructose 1,6-bisphosphatase, Sedoheptulose 1,7-bisphosphatase, transketolase, Ribulose 5-phosphate isomerase)1. This leads to the inhibition of the conversion of ribose 5-phosphate to Ribulose 5-phosphate by Ribulose 5-Phosphate Isomerase and ultimately to the downregulation of photosynthesis only in J. curcas salt-sensitive like plants (here referred as CNPAE183). Notably, in J. curcas salt-tolerant like plants (here referred as CNPAE218) a maintenance of photosynthesis occurs and it resulted in healthy foliage and fruiting. Once in mitochondria, Na+ ions appears to stimulate a complex metabolic reprograming that involved enhanced glycolysis, increase on the tricarboxylic cycle acid intermediates coupled with the synthesis of amino acids and organic acids. Abbreviations: TCA, tricarboxylic acid cycle; 1 = downregulation of Calvin-Benson cycle enzymes proposed by Lin et al. (2018) and Sivakumar et al. (2000). [Display omitted] • Jatropha curcas used combined protection mechanism to stabilize photosystems; • Differential changes promoted by tolerant-like plants may help to select elite genotypes; • Stomata regulate the transpiration force affecting physiological responses; • CNPAE218 is a promising candidate in the plant breeding based on its responses; [ABSTRACT FROM AUTHOR]

Soil salinization is a critical factor limiting growth and causing physiological dysfunction in plants. The damage from alkaline salt in most plants is significantly greater than that from neutral salt. However, there is still a lack of research on the action mechanism by which saline alkali stress on plants under the same salt concentration across different pH values. The present study examined the effects of different pH values (7.0, 8.0, 9.0, and 10.0) under the same salt concentration (200 mmolL−1) on photosynthetic function, photoprotective mechanism, nitrogen metabolism, and osmotic regulation in alfalfa (Medicago sativa) leaves, including a transcriptomic analysis of changes in gene expression related to the above metabolic processes. The results showed that low pH saline alkali stress (pH 7.0 and 8.0) promoted chlorophyll synthesis in alfalfa leaves, and non-photochemical quenching (NPQ) and cyclic electron transfer (CEF) were promoted. There was no significant effect on plant growth or photochemical activity. The soluble sugar, proline, and soluble protein contents did not change significantly, and there was no obvious oxidative damage in alfalfa leaves. However, when pH increased to 9.0 and 10.0, KEGG enrichment analysis showed that photosynthesis (map00195) and nitrogen metabolism (map00910) were significantly enriched (P < 0.05), and PSII antenna protein coding genes were down-regulated under pH 9.0 and 10.0 treatments. The activities of PSII and PSI were decreased under high pH saline alkali stress, and the expression levels of the photosynthetic electron transporter-related genes PetA , PetB , petE , and petF were also significantly down-regulated. PSII was more sensitive to high pH saline alkali stress than PSI, and the PSII receptor side was more sensitive to high pH saline alkali stress than the PSII donor side. The activities of the oxygen-evolving complex (OEC) and PSI were significantly damaged only at pH 10.0. The activities of nitrate reductase (NR) and nitrite reductase (NiR), the expression levels of their genes, and the content of soluble protein were also decreased under pH 9.0 and 10.0 treatments. The inhibition of plant growth and oxidative damage to alfalfa leaves caused by high pH saline alkali stress were mainly related to the inhibition of photosynthesis (light energy absorption, electron transfer) and nitrogen metabolism (NO 3 − reduction). Under high pH saline alkali stress (pH 10.0), the photoprotection mechanisms such as CEF and NPQ were inhibited, which was also one of the important reasons for photoinhibition in alfalfa leaves. The accumulation of osmotic adjustment substances, such as soluble sugar and proline, was an important mechanism by which alfalfa physiologically adapted to high pH alkaline salt stress. • Low pH saline alkali stress promoted chlorophyll synthesis in alfalfa leaves, photoprotective mechanisms were activated. • As the pH value increased 9.0 and 10.0, photosynthetic electron transfer was blocked and oxidative damage occurred in leaves. • CEF and NPQ were inhibited, photosynthetic inhibition especially the OEC damaged under pH10.0 alkaline salt stress. • Accumulation of osmotic adjustment substances was an important mechanism by which alfalfa to saline alkali stress. [ABSTRACT FROM AUTHOR]

As the dominant fungus during the fermentation of Fuzhuan brick tea, Aspergillus cristatus is easily induced to undergo a sexual cycle under low-salt stress. However, the underlying regulatory mechanism of sexual reproduction is unclear. Here, we report a P53-like transcription factor AcndtA , which encodes an NDT80 DNA binding protein and regulates fungal reproduction, pigmentation and the stress response. Both insertion and deletion mutants of AcndtA exhibited a complete blockade of cleistothecium formation, and overexpressing AcndtA strains (OE: AcndtA) exhibited significantly reduced cleistothecium production, indicating that AcndtA plays a vital role in sexual development. Osmotic stress tests showed that overexpression of AcndtA had a negative impact on growth and conidia production. Additionally, AcndtA insertion, deletion and overexpression mutants exhibited reduced pigment formation. All the above developmental defects were reversed by the re-introduction of the AcndtA gene in Δ AcndtA. Moreover, the growth of AcndtA mutants in carbon-limited medium was better than that of the WT and OE: AcndtA strains, indicating that AcndtA is involved in carbon metabolism. Transcriptional profiling data showed that AcndtA regulated the expression of several genes related to development, osmotic stress and carbon metabolism. • AcndtA plays a vital role in the sexual development of Aspergillus cristatus. • Overexpression of AcndtA reduced growth and conidia production in response to osmotic stress. • Deletion and overexpression of the AcndtA gene leads to reduced pigmentation. • The expression of several genes related to development, osmotic stress and carbon metabolism is affected by AcndtA. [ABSTRACT FROM AUTHOR]

Water transport in the brain is tightly controlled by blood-brain-barrier (BBB) composed of capillary endothelial cells expressing AQP1/AQP11 and glial foot processes expressing AQP4. Here we examined each AQP mRNA expression in acute hyponatremic and hypernatremic mouse models of wild type (WT) and AQP11 KO mice (KO). The expressions of AQP1, AQP4 and AQP11 mRNAs were quantified by real-time qRT-PCR analysis of whole brain RNA. Acute hyponatremia enhanced AQP4 expression without changing AQP1 expression in KO, whereas it did not change the expression of all AQPs in WT. On the other hand, acute hypernatremia increased AQP4 but decreased AQP1 expression by half in KO, whereas it decreased AQP1 and AQP11 by half without changing AQP4 expression in WT. Enhanced AQP4 expression by osmotic challenges with sodium in KO seems to be a compensation for the loss of AQP11. A stronger hypertonic stimulation with mannitol decreased all AQPs by 30–80% in WT. Since AQP4 plays an important role in the regulation of brain edema at BBB, the results suggest that AQP11 may also be involved in the osmotic regulation of the brain. [Display omitted] • The effects of osmotic challenges on the expression of brain aquaporins, AQP1, 4, 11 were examined in AQP11 KO mice. • Mannitol and hypertonic saline suppressed brain AQP expressions. • The loss of AQP11 seemed to be compensated by the increase of AQP4 expression. [ABSTRACT FROM AUTHOR]

Irritable bowel syndrome (IBS) is one of the most common gastro-intestinal disorders worldwide and is often treated by adjusting the diet of IBS patients. An increased intake of dietary fibre (DF) and a limitation of the intake of fermentable oligo-, di-,monosaccharides and polyols (FODMAP) are the two dietary adjustments which are frequently recommended for people suffering from IBS. However, one challenge of a diet low in FODMAPs is the limited number of suitable dietary fibres. The aim of this overview is to identify characteristics and DFs beneficial for IBS patients by comparing the physico-chemical properties of FODMAPs and DFs. Therefore, relevant literature about DFs and FODMAPs was collected and summarised. These characteristics and the associated technological properties were used for a selection of DFs which can be used to develop food products with an increased fibre content and a lower FODMAP content while assuring the product quality expected by the consumer. A low fermentation rate, low osmotic activity, insolubility and a high viscosity of soluble DFs have been identified as characteristics which are beneficial independent from the type of IBS. Soluble and non-viscous DFs can be beneficial depending on the occurrence of diarrhoea and their state of hydration. This finding highlights the importance of targeting a specific type of IBS. The above mentioned characteristics and the list of suitable DFs provide a good base for the development of functional foods and for future research regarding DF supporting the needs of IBS patients. • Comparison of the characteristics of both dietary fibre and FODMAPs. • Identification of characteristics of dietary fibres beneficial for IBS patients. • Use of either soluble or insoluble dietary fibre depending on IBS type. • Low fermentability only beneficial property independent from IBS type. • Technological properties limit use of dietary fibres in developing food products. [ABSTRACT FROM AUTHOR]

As a conditionally essential amino acid (CEAA), taurine plays an important role in the growth, development, and physiological metabolism of aquatic animals; however, its demand level in the mud crab Scylla paramamosain is still poorly understood. A 60-day growth trial was conducted to investigate the effects of different taurine levels (0% (T0.0), 0.2% (T0.2), 0.4% (T0.4), 0.8% (T0.8), and 1.6% (T1.6)) added to diet on the survival, growth, body composition, immunity, antioxidant and osmoregulatory capacity of early juvenile S. paramamosain (initial body weight 8.69 ± 0.19 mg). The results showed that dietary taurine levels >0.4% (inclusive) significantly increased the survival of early juvenile mud crabs. The growth performance (final body weight (FBW), weight gain (WG), specific growth rate (SGR)) of early juvenile mud crabs increased significantly with increasing dietary taurine levels, reaching a maximum in the T0.8 group, and the target of rapamycin (tor) gene transcription levels also peaked in the T0.8 group. The body composition of mud crabs was not affected by dietary treatments. Further, dietary taurine significantly increased digestive enzyme (trypsin, lipase, and amylase) activities and transcript levels of appetite-related genes (neuropeptide F1 (npf1) and neuropeptide F2 (npf2)) in early juvenile mud crabs. In addition, dietary taurine increased the expression levels of immune-related genes (prophenoloxidase (proPO), prophenoloxidase activating factor 1 (ppaf1), prophenoloxidase activating factor 2 (ppaf2), crustin antimicrobial peptide (crustin), lysozyme (lzm)) and antioxidant capacity (total antioxidant capacity (T-AOC), superoxide dismutase (SOD) and catalase (CAT) activities) in early juvenile mud crabs. Finally, the results of the acute salinity challenge showed that the early juvenile mud crabs' survival in the T0.8 group was significantly higher than that of the other groups, while significantly higher Na+/K+-ATPase (NKA) activity and Na+/K+-ATPase α-subunit (nka-α) and Na+/K+/2Cl−-cotransporter (nkcc) gene expression levels were also detected in the T0.8 group. Together with growth performance, immunity, antioxidant capacity and osmoregulatory capacity, the present study concluded that the appropriate dietary taurine level for early juvenile mud crabs was 1.08%–1.33%. [Display omitted] • The appropriate dietary taurine level for juvenile mud crabs was 1.08%–1.33%. • Dietary taurine above 0.4% significantly improved the survival of juvenile mud crabs. • Antioxidant capacity of mud crabs was significantly improved by 0.8% dietary taurine. • 0.8% dietary taurine significantly improved osmoregulation in juvenile mud crabs. [ABSTRACT FROM AUTHOR]

Euryhaline organisms can accumulate organic osmolytes to maintain osmotic balance between their internal and external environments. Proline is a pivotal organic small molecule and plays an important role in osmoregulation that enables marine shellfish to tolerate high-salinity conditions. During high-salinity challenge, NAD kinase (NADK) is involved in de novo synthesis of NADP(H) in living organisms, which serves as a reducing agent for the biosynthetic reactions. However, the role of shellfish NADK in proline biosynthesis remains elusive. In this study, we show the modulation of NADK on proline synthesis in the razor clam (Sinonovacula constricta) in response to osmotic stress. Under acute hypersaline conditions, gill tissues exhibited a significant increase in the expression of ScNADK. To elucidate the role of ScNADK in proline biosynthesis, we performed dsRNA interference in the expression of ScNADK in gill tissues to assess proline content and the expression levels of key enzyme genes involved in proline biosynthesis. The results indicate that the knock-down of ScNADK led to a significant decrease in proline content (P <0.01), as well as the expression levels of two proline synthetase genes P5CS and P5CR involved in the glutamate pathway. Razor clams preferred to use ornithine as substrate for proline synthesis when the glutamate pathway is blocked. Exogenous administration of proline greatly improved cell viability and mitigated cell apoptosis in gills. In conclusion, our results demonstrate the important role of ScNADK in augmenting proline production under high-salinity stress, by which the razor clam is able to accommodate salinity variations in the ecological niche. [Display omitted] • High-salinity stress activates high expression of the ScNADK. • ScNADK affects the proline synthesis and acts mainly through the glutamate pathway. • The ornithine pathway serves as a complementary pathway for proline synthesis when the glutamate cycle is blocked by the downgrade of ScNADK. • Exogenous proline can improve the biological condition and repair the ScNADK deficiency under salinity stress. [ABSTRACT FROM AUTHOR]

Eriocheir sinensis megalopa has a special life history of migrating from seawater to freshwater. In order to investigate how the megalopa adapt themselves to the freshwater environment, we designed an experiment to reduce the salinity of water from 30 ppt to 0 at rates of 30 ppt, 15 ppt, 10 ppt, and 5 ppt per 24 h to evaluate the effects of different degrees of hyposaline stress on the osmotic regulation ability and antioxidant system of the megalopa. Experimental results related to osmotic pressure regulation show that the gill tissue of megalopa in the treatment group of 30 ppt/24 h rapid reduction of salinity was damaged, while in the treatment group of 5 ppt/24 h it was intact. At the same time, the experiment also found that in each treatment group with different salinity reduction rates, compared with the control salinity, the NKA activity of megalopa increased significantly after the salinity was reduced to 20 ppt (p < 0.05). In addition, two genes involved in chloride ion transmembrane absorption have different expression patterns in the treatment groups with different salinity reduction rates. Among them, Clcn2 was significantly highly expressed only in the rapid salinity reduction intervals of 30 ppt/24 h and 15 ppt/24 h (p < 0.05). Slc26a6 was significantly highly expressed only in the slow salinity reduction intervals of 10 ppt/24 h and 5 ppt/24 h (p < 0.05). On the other hand, the results of antioxidant and apoptosis related experiments showed that in all treatment groups with different rates of salinity reduction, the activities of T-AOC, GSH-PX, and CAT basically increased significantly after salinity reduction compared to the control salinity. Moreover, the activities of T-AOC and CAT were significantly higher in the 10 ppt/24 h and 5 ppt/24 h treatment groups than in the 30 ppt/24 h and 15 ppt/24 h treatment groups. Finally, the experimental results related to apoptosis showed that the expression trends of Capase3 and Bax-2 were basically the same in the treatment groups with different salinity reduction rates, and their expressions were significantly higher in the 10 ppt/24 h and 5 ppt/24 h treatment groups than in the 30 ppt/24 h and 15 ppt/24 h treatment groups. In summary, the present study found that megalopa had strong hyposaline tolerance and were able to regulate osmolality at different rates of salinity reduction, but the antioxidant capacity differed significantly between treatment groups, with rapid salinity reduction leading to oxidative damage in the anterior gills and reduced antioxidant enzyme activity and apoptosis levels. [Display omitted] • When the environmental salinity decreases rapidly, tissue damage occurs in the anterior gills of E. sinensis megalopa • When the salinity is lower than 20 ppt, E. sinensis megalopa begin to actively absorb inorganic ions • When the environmental salinity slowly decreases, the antioxidant capacity and apoptosis levels of E. sinensis megalopa are higher. [ABSTRACT FROM AUTHOR]