The temperature drop of plants from the optimal requirements can increase tolerance to severe chilling stress. Photosynthesis and osmoregulators were analyzed during chilling stress to explore the adaptation mechanism...The temperature drop of plants from the optimal requirements can increase tolerance to severe chilling stress. Photosynthesis and osmoregulators were analyzed during chilling stress to explore the adaptation mechanisms that underlie the induction of chilling tolerance in response to suboptimal temperature. The relationships of these processes to suboptimal temperature acclimation in watermelon were then determined.Suboptimal temperature-acclimated watermelon plants demonstrated tolerance during chilling stress, as indicated by the decreased electrolyte leakage and malondialdehyde accumulation compared with those non-acclimated watermelon plants. Chilling-induced photoinhibition and reduction in CO2 assimilation rate were alleviated after suboptimal temperature acclimation. The xanthophyll cycle level was enhanced by improving thermal dissipation ability and avoiding light damage. Consequently, the chilling tolerance of suboptimal temperature-acclimated watermelon plants was enhanced. The osmoregulation ability induced by suboptimal temperature acclimation protected watermelon plants against chilling injury because of the accumulation of small molecular substances, such as soluble sugar and proline. The protein levels of Rubisco activase(ClRCA) and the gene expression of the Benson–Calvin cycle simultaneously increased in suboptimal temperature-acclimated watermelon plants during chilling stress. Chilling tolerance in watermelon plants induced by suboptimal temperature acclimation is associated with enhanced photosynthetic adaptability and osmoregulation ability.展开更多
Turbot harbor a relatively remarkable ability to adapt to opposing osmotic challenges and are an excellent model species to study the physiological adaptations of flounder associated with osmoregulatory plasticity.The...Turbot harbor a relatively remarkable ability to adapt to opposing osmotic challenges and are an excellent model species to study the physiological adaptations of flounder associated with osmoregulatory plasticity.The kidney transcriptome of turbot treated 24 h in water of hypo-salinity(salinity 5)and seawater(salinity 30)was sequenced and characterized.In silico analysis indicated that all unigenes had significant hits in seven databases.The functional annotation analysis of the transcriptome showed that the immune system and biological processes associated with digestion,absorption,and metabolism played an important role in the osmoregulation of turbot in response to hypo-salinity.Analysis of biological processes associated with inorganic channels and transporters indicated that mineral absorption and bile secretion contributed to iono-osmoregulation resulting in cell volume regulation and cell phenotypic plasticity.Moreover,we analyzed and predicted the mechanisms of canonical signaling transduction.Biological processes involved in renin secretion,ECM-receptor interaction,adherens junction,and focal adhesion played an important role in the plasticity phenotype in hypo-stress,while the signal transduction network composed of the MAPK signaling pathway and PI3K-Akt signaling pathway with GABAergic synapse,worked in hypoosmoregulation signal transduction in the turbot.In addition,analysis of the tissue specificity of targeted gene expression using qPCR during salinity stress was carried out.The results showed that the kidney,gill,and spleen were vital regulating organs of osmotic pressure,and the osmoregulation pattern of euryhaline fish dif fered among species.展开更多
Diurnal variation in phloem sap composition has a strong infuence on aphid performance.The sugar-rich phloem sap serves as the sole diet for aphids and a suite of physiological mechanisms and behaviors allowv them to ...Diurnal variation in phloem sap composition has a strong infuence on aphid performance.The sugar-rich phloem sap serves as the sole diet for aphids and a suite of physiological mechanisms and behaviors allowv them to tolerate the high osmotic stress.Here,we tested the hypothesis that night-time feeding by aphids is a behavior that takes advantage of the low sugar diet in the night to compensate for osmotic stress incurred while feeding on high sugar diet during the day.Using the electrical penetration graph(EPG)technique.we examined the eiects of diurmal rhythm on feeding behaviors of bird cherry-oat aphid(Rhopalosiphurm padi L.)on wheat.A strong diurmal rhythm in aphids as indicated by the presence of a cyclical pattern of expression in a core clock gene did not impact aphid feeding and similar feeding behaviors were observed during day and night.The major difference observed between day and night feeding was that aphids spent significantly longer time in phloem salivation during the night compared to the day.In contrast,aphid hydration was reduced at the end of the day-time feeding compared to end of the night-time fepding.Gene expression analysis of R.padi osmoregulatory genes indicated that sugar break down and water transport into the aphid gut was reduced at night.These data suggest that while diumal variation occurs in phloem sap composition,aphids use night time feeding to overcome the high osmotic stress incurred while feeding on sugar-rich phloem sap during the day.展开更多
Distinct from the motile flagellated sperm of animals and early land plants,the non-motile sperm cells of flowering plants are carried in the pollen grain to the female pistil.After pollination,a pair of sperm cells a...Distinct from the motile flagellated sperm of animals and early land plants,the non-motile sperm cells of flowering plants are carried in the pollen grain to the female pistil.After pollination,a pair of sperm cells are delivered into the embryo sac by pollen tube growth and rupture.Unlike other walled plant cells with an equilibrium between internal turgor pressure and mechanical constraints of the cell walls,sperm cells wrapped inside the cytoplasm of a pollen vegetative cell have only thin and discontinuous cell walls.The sperm cells are uniquely ellipsoid in shape,although it is unclear how they maintain this shape within the pollen tubes and after release.In this study,we found that genetic disruption of three endomembrane-associated cation/H+exchangers specifically causes sperm cells to become spheroidal in hydrated pollens of Arabidopsis.Moreover,the released mutant sperm cells are vulnerable and rupture before double fertilization,leading to failed seed set,which can be partially rescued by depletion of the sperm-expressed vacuolar water channel.These results suggest a critical role of cell-autonomous osmoregulation in adjusting the sperm cell shape for successful double fertilization in flowering plants.展开更多
A two-factor(23)orthogonal testwas conducted to investigate the effects of dietary myo-inositol(MI)on the osmoregulation and carbohydrate metabolism of euryhaline fish tilapia(Oreochromis niloticus)under sustained hyp...A two-factor(23)orthogonal testwas conducted to investigate the effects of dietary myo-inositol(MI)on the osmoregulation and carbohydrate metabolism of euryhaline fish tilapia(Oreochromis niloticus)under sustained hypertonic stress(20 practical salinity units[psu]).6 diets containing either normal carbohydrate(NC,30%)or high carbohydrate(HC,45%)levels,with 3 levels(0,400 and 1,200 mg/kg diet)of MI,respectively,were fed to 540 fish under 20 psu for 8 weeks.Dietary MI supplementation significantly improved growth performance and crude protein content of whole fish,and decreased the content of crude lipid of whole fish(P<0.05).Curled,disordered gill lamella and cracked gill filament cartilage were observed in the gill of fish fed diets without MI supplementation.The ion transport capacity in gill was significantly improved in the 1,200 mg/kg MI supplementation groups compared with the 0 mg/kg MI groups(P<0.05).Moreover,the contents of Na^(+),K^(+),Cl^(-)in serum weremarkedly reduced with the dietary MI supplementation(P<0.05).The fish fed 1,200 mg/kg MI supplementation had the highest MI content in the gills and the lowest MI content in the serum(P<0.05).Additionally,the fish fed with 1,200 mg/kg MI supplementation had the highest MI synthesis capacity in gills and brain(P<0.05).Dietary MI markedly promoted the ability of carbohydrate metabolism in liver(P<0.05).Moreover,fish in the 1,200 mg/kg MI groups had the highest antioxidant capacity(P<0.05).This study indicated that high dietary carbohydrate would intensify stress,and impair the ability of osmoregulation in tilapia under a long-term hypersaline exposure.The supplementation of MI at 1,200 mg/kg in the high carbohydrate diet could promote carbohydrate utilization and improve the osmoregulation capacity of tilapia under long-term hypertonic stress.展开更多
To investigate the effects of arbuscular mycorrhizal(AM)fungi on the growth and saline–alkaline tolerance of Potentilla anserina L.,the seedlings were inoculated with Claroideoglomus etunicatum(W.N.Becker&Gerd.)C...To investigate the effects of arbuscular mycorrhizal(AM)fungi on the growth and saline–alkaline tolerance of Potentilla anserina L.,the seedlings were inoculated with Claroideoglomus etunicatum(W.N.Becker&Gerd.)C.Walker&A.Schüßler in pot cultivation.After 90 days of culture,saline–alkaline stress was induced with NaCl and NaHCO_(3)solution according to the main salt components in saline–alkaline soils.Based on the physiological response of P.anserina to the stress in the preliminary experiment,the solution concentrations of 0 mmol/L,75 mmol/L,150 mmol/L,225 mmol/L and 300 mmol/L were treated with stress for 10 days,respectively.The mycorrhizal colonization rate,mycorrhizal dependence,chlorophyll content,malondialdehyde content,antioxidant enzyme activities,osmoregulation substances content and water status were measured.The results showed that with the increase of NaCl and NaHCO_(3)stress concentration,mycorrhizal colonization rate,colonization intensity,arbuscular abundance and vesicle abundance decreased,and reached the lowest value at 300 mmol/L.Strong mycorrhizal dependence was observed after the symbiosis with AM fungus,and the dependence was higher under NaHCO_(3)treatment.Under NaCl and NaHCO_(3)stress,inoculation with AM fungus could increase chlorophyll content,decrease malondialdehyde content,increase activities of superoxide dismutase,peroxidase and catalase,increase contents of proline,soluble sugar and soluble protein,increase tissue relative water content and decrease water saturation deficit.It was concluded that salt–alkali stress inhibited the colonization of AM fungus,but the mycorrhiza still played a positive role in maintaining the normal growth of plants under salt–alkali stress.展开更多
The Pacific white shrimp(Litopenaeus vannamei)is a marine species commonly farmed worldwide.In northern China,it has been increasingly cultured in high-salinity waters(>40),but exhibits poor growth performance.In t...The Pacific white shrimp(Litopenaeus vannamei)is a marine species commonly farmed worldwide.In northern China,it has been increasingly cultured in high-salinity waters(>40),but exhibits poor growth performance.In this study,postlarval shrimps were acclimated to salinity 55,cultivated for 3 months at this salinity,and compared with a control group reared at general salinity 25.Subsequently,high-throughput RNA sequencing was applied to compare the transcriptomic responses in the gills and hepatopancreas of the shrimps in the control group and the treatment group,while the weights of the shrimps in these two groups were significantly different.The results revealed that 11834 and 2115 genes were significantly differentially expressed in the gills and hepatopancreas,respectively.Additionally,enrichment analysis of the differentially expressed genes indicated that osmoregula-tion-associated Gene Ontology terms and KEGG pathways were similar between the two subgroups of the shrimp maintained at high salinity,suggesting that the growth rate of shrimp at high salinity is independent of osmoregulation.Furthermore,examination of the shrimp with different growth rates(i.e.,weights)at high salinity revealed molt-associated processes,namely,increased expression of ecdysone response genes and downstream effector genes in the gills and hepatopancreas of slow-growing shrimp,suggesting a role of the molt-associated processes in the regulation of shrimp growth at high salinity.Thus,we not only report adaptive transcriptomic responses of L.vannamei to prolonged high-salinity stress,but also provide new insights into the shrimp growth regulation at high salinity.展开更多
Currently, obtaining sustainable fuels, such as biodiesel and bioethanol, from cheap and renewable materials is a challenge. In recent years, a new approach being developed consists of producing, sugars from algae by ...Currently, obtaining sustainable fuels, such as biodiesel and bioethanol, from cheap and renewable materials is a challenge. In recent years, a new approach being developed consists of producing, sugars from algae by photosynthesis. Sugar accumulation can be increased under osmotic stress (osmoregulation). The aim of this study is to show the pro-duction of sugars from algae, isolated from natural sources, and the effect of osmotic stress on fermentable sugars ac-cumulation. Strain isolation, production of sugars from each alga and the effect of osmotic stress on growth and sugar production are described. Twelve algal strains were isolated, showing growths between 0.6 and 1.8 g of biomass dry weight /L, all with production of intracellular and extracellular sugars. The strain identified as Chlorella sp. showed an increase in sugar production from 23.64 to 421 mg of sugars/g of biomass dry weight after 24 h of osmotic stress with 0.4 M NaCl. Sucrose and trehalose, both fermentable sugars, were the compatible osmolytes accumulated in response to the osmotic stress. The isolated strains are potential producers of fermentable sugars, using the photosynthetic pathway and osmotic stress.展开更多
The effects of Hg exposure on blood parameters and gill physiology of tilapia(Oreochromis niloticus)were analyzed.Fish maintained in freshwater were exposed for 7 days(d)to sublethal mercury concentrations(0.1 and 1 m...The effects of Hg exposure on blood parameters and gill physiology of tilapia(Oreochromis niloticus)were analyzed.Fish maintained in freshwater were exposed for 7 days(d)to sublethal mercury concentrations(0.1 and 1 mg/L).Blood serum osmolality(SO),sodium(Nat),potassium(K^+)and chloride(Cl^-)ionic concentrations,and hematological parameters were assessed after 1 up to 7 d of exposure.Serum osmolality and ionic concentrations of exposed fish appeared differently affected throughout the experimental period compared to the controls.Osmolality was reduced at the 2 tested concentrations but Nat and Cl^-contents were only altered at 1 mg/L of Hg after 1 d of exposure and values rapidly returned to the control values thereafter.K^+content was also modified and significantly increased at both concentrations after 1 d of exposure but returned to the control values after 3 d of exposure.Red blood cell(RBC),white blood cell(WBC)and hemoglobin(Hb)levels were significantly increased throughout the experiment but returned to control values after 7 d of exposure only for the 0.1 mg/L concentration.The hematocrit(Ht)levels remained unaffected due to Hg exposure.Therefore,tilapias exposed to sublethal concentrations of Hg present a marked osmotic imbalance with ionic and hematological disorders that are rapidly compensated.展开更多
Adaptations of animals to the xeric environment have been studied in various taxonomic groups and across several deserts.Despite the impressive data that have been accumulated,the focus in most of these studies is mai...Adaptations of animals to the xeric environment have been studied in various taxonomic groups and across several deserts.Despite the impressive data that have been accumulated,the focus in most of these studies is mainly on the significance of one variable at a time.Here,we attempt to integrate between responses of several physiological systems,challenged by increasing diet and water salinity and extreme temperatures,acquired in different studies of thermo and osmo-regulatory adaptations,of small rodents,to the xeric environment.Studies have shown differen-tial thermoregulatory responses to increased dietary salinity,which were attributed to habitat and habits of the relevant species.In the thermoregulatory studies,a potential adaptive significance of low metabolic rate was demonstrated.From an evolutionary point of view,the most important adaptation is in the timing of reproduction,as it enables the transfer of genetic properties to the next generation in an unpredictable ecosystem,where repro-duction might not occur every year.Results in this aspect show that increased dietary salinity,through an increase in vasopressin plasma levels,plays an important role as a regulator of the reproductive system.We assume that the amount of food existing in the habitat and the amount of reserves in the animal in the form of white adipose tissue are important for reproduction.Photoperiod affects all studied physiological responses,emphasizing the impor-tance of pre-acclimation to seasonal characteristics.We summarize the existing data and suggest neuro-endocrine pathways,which have a central role in these adaptations by affecting thermoregulation,osmoregulation and repro-duction to create the optimal response to xeric conditions.These hypotheses can be used as the basis for future studies.展开更多
Gill morphological changes and physiological responses in juvenile large yellow croaker(Larimichthys crocea)were examined upon exposure to low salinity after indoor culture of the fish at salinities of 2,4,6,8,and 24...Gill morphological changes and physiological responses in juvenile large yellow croaker(Larimichthys crocea)were examined upon exposure to low salinity after indoor culture of the fish at salinities of 2,4,6,8,and 24‰(control group).The thickness of the lamellae was significantly higher in the low-salinity groups than in the control group;in contrast,the interlamellar space was significantly lower in the low-salinity groups than in the control group.Additionally,a significant negative correlation was found between the thickness of lamellae and interlamellar spaces(P<0.01).Mitochondria-rich cells(MRCs)were mainly found in the filament at 24‰salinity and proliferated in the lamellae at lower salinities,suggesting that filament and lamellar MRCs are responsible for ion secretion and absorption,respectively.Meanwhile,the activity of Na+/K+-ATPase(NKA)was significantly elevated with the decrease in salinity from 24‰to 4‰(P<0.05),which was consistent with MRCs proliferation.Finally,the activity of NKA declined at 2‰salinity(P<0.05),indicating the limit of osmoregulation,which was consistent with the degeneration and necrosis of the lamellae.Additionally,different levels of gill histopathological lesions,including pavement cell(PVC)exfoliation,lamellar epithelial lifting,edema,fusion,aneurism,and necrosis,were observed from salinities of 24 to 4‰,likely reducing the respiratory efficiency and compromising the health of juvenile fish.In conclusion,large yellow croaker juveniles could improve the osmoregulatory capacity by increasing lamellar MRCs and NKA activity with the decrease in salinity from 24 to 4‰.However,the associated histopathological lesions are likely to negatively influence the fish by affecting respiration and osmoregulation,especially when the salinity is below 4‰.展开更多
基金funded by Hubei Provincial Natural Science Foundation of China (Grant No. 2015CFB385)the National Natural Science Foundation of China (Grant No. 31501783)the earmarked fund for Modern Agro-industry Technology Research System (Grant No. CARS-25)
文摘The temperature drop of plants from the optimal requirements can increase tolerance to severe chilling stress. Photosynthesis and osmoregulators were analyzed during chilling stress to explore the adaptation mechanisms that underlie the induction of chilling tolerance in response to suboptimal temperature. The relationships of these processes to suboptimal temperature acclimation in watermelon were then determined.Suboptimal temperature-acclimated watermelon plants demonstrated tolerance during chilling stress, as indicated by the decreased electrolyte leakage and malondialdehyde accumulation compared with those non-acclimated watermelon plants. Chilling-induced photoinhibition and reduction in CO2 assimilation rate were alleviated after suboptimal temperature acclimation. The xanthophyll cycle level was enhanced by improving thermal dissipation ability and avoiding light damage. Consequently, the chilling tolerance of suboptimal temperature-acclimated watermelon plants was enhanced. The osmoregulation ability induced by suboptimal temperature acclimation protected watermelon plants against chilling injury because of the accumulation of small molecular substances, such as soluble sugar and proline. The protein levels of Rubisco activase(ClRCA) and the gene expression of the Benson–Calvin cycle simultaneously increased in suboptimal temperature-acclimated watermelon plants during chilling stress. Chilling tolerance in watermelon plants induced by suboptimal temperature acclimation is associated with enhanced photosynthetic adaptability and osmoregulation ability.
基金Supported by the Earmarked Fund for Modern Agro-Industry Technology Research System(No.CARS-47-G01)the Ao Shan Talents Cultivation Program supported by Qingdao National Laboratory for Marine Science and Technology(No.2017ASTCP-OS04)+3 种基金the National Natural Science Foundation of China(No.41706168)the Agricultural Fine Breed Project of Shandong(No.2019LZGC013)the Basal Research Fund,Chinese Academy of Fishery Sciences(No.2016HY-JC0301)the Yantai Science and Technology Project(No.2018ZDCX021)
文摘Turbot harbor a relatively remarkable ability to adapt to opposing osmotic challenges and are an excellent model species to study the physiological adaptations of flounder associated with osmoregulatory plasticity.The kidney transcriptome of turbot treated 24 h in water of hypo-salinity(salinity 5)and seawater(salinity 30)was sequenced and characterized.In silico analysis indicated that all unigenes had significant hits in seven databases.The functional annotation analysis of the transcriptome showed that the immune system and biological processes associated with digestion,absorption,and metabolism played an important role in the osmoregulation of turbot in response to hypo-salinity.Analysis of biological processes associated with inorganic channels and transporters indicated that mineral absorption and bile secretion contributed to iono-osmoregulation resulting in cell volume regulation and cell phenotypic plasticity.Moreover,we analyzed and predicted the mechanisms of canonical signaling transduction.Biological processes involved in renin secretion,ECM-receptor interaction,adherens junction,and focal adhesion played an important role in the plasticity phenotype in hypo-stress,while the signal transduction network composed of the MAPK signaling pathway and PI3K-Akt signaling pathway with GABAergic synapse,worked in hypoosmoregulation signal transduction in the turbot.In addition,analysis of the tissue specificity of targeted gene expression using qPCR during salinity stress was carried out.The results showed that the kidney,gill,and spleen were vital regulating organs of osmotic pressure,and the osmoregulation pattern of euryhaline fish dif fered among species.
基金TI,SM,and TA were supported by startup funds provided to VN by Purdue Fort Wayne and Colorado State University.DF and JK were supported by USDA NIFA MO-HAPS0006 and the University of Missouri Research Board.JK was supported by AFRI EWD(2019-67011-29729)from the U.S.Department of Agriculture,National Institute of Food and Agriculture.The authors wish to thank Bruce Arnold for technical support with the electrical penetration graph machine.
文摘Diurnal variation in phloem sap composition has a strong infuence on aphid performance.The sugar-rich phloem sap serves as the sole diet for aphids and a suite of physiological mechanisms and behaviors allowv them to tolerate the high osmotic stress.Here,we tested the hypothesis that night-time feeding by aphids is a behavior that takes advantage of the low sugar diet in the night to compensate for osmotic stress incurred while feeding on high sugar diet during the day.Using the electrical penetration graph(EPG)technique.we examined the eiects of diurmal rhythm on feeding behaviors of bird cherry-oat aphid(Rhopalosiphurm padi L.)on wheat.A strong diurmal rhythm in aphids as indicated by the presence of a cyclical pattern of expression in a core clock gene did not impact aphid feeding and similar feeding behaviors were observed during day and night.The major difference observed between day and night feeding was that aphids spent significantly longer time in phloem salivation during the night compared to the day.In contrast,aphid hydration was reduced at the end of the day-time feeding compared to end of the night-time fepding.Gene expression analysis of R.padi osmoregulatory genes indicated that sugar break down and water transport into the aphid gut was reduced at night.These data suggest that while diumal variation occurs in phloem sap composition,aphids use night time feeding to overcome the high osmotic stress incurred while feeding on sugar-rich phloem sap during the day.
基金supported by the National Natural Science Foundation of China(31991203 to W.-C.Y.and 31870295 and 32170343to H.-J.L.).
文摘Distinct from the motile flagellated sperm of animals and early land plants,the non-motile sperm cells of flowering plants are carried in the pollen grain to the female pistil.After pollination,a pair of sperm cells are delivered into the embryo sac by pollen tube growth and rupture.Unlike other walled plant cells with an equilibrium between internal turgor pressure and mechanical constraints of the cell walls,sperm cells wrapped inside the cytoplasm of a pollen vegetative cell have only thin and discontinuous cell walls.The sperm cells are uniquely ellipsoid in shape,although it is unclear how they maintain this shape within the pollen tubes and after release.In this study,we found that genetic disruption of three endomembrane-associated cation/H+exchangers specifically causes sperm cells to become spheroidal in hydrated pollens of Arabidopsis.Moreover,the released mutant sperm cells are vulnerable and rupture before double fertilization,leading to failed seed set,which can be partially rescued by depletion of the sperm-expressed vacuolar water channel.These results suggest a critical role of cell-autonomous osmoregulation in adjusting the sperm cell shape for successful double fertilization in flowering plants.
基金grants from the National Natural Science Foundation of China(No.32172946)China Postdoctoral Science Foundation(2018 M630418)the Fundamental Research Funds for the Central Universities,ECNU and China Agriculture Research System-46(CARS-46).
文摘A two-factor(23)orthogonal testwas conducted to investigate the effects of dietary myo-inositol(MI)on the osmoregulation and carbohydrate metabolism of euryhaline fish tilapia(Oreochromis niloticus)under sustained hypertonic stress(20 practical salinity units[psu]).6 diets containing either normal carbohydrate(NC,30%)or high carbohydrate(HC,45%)levels,with 3 levels(0,400 and 1,200 mg/kg diet)of MI,respectively,were fed to 540 fish under 20 psu for 8 weeks.Dietary MI supplementation significantly improved growth performance and crude protein content of whole fish,and decreased the content of crude lipid of whole fish(P<0.05).Curled,disordered gill lamella and cracked gill filament cartilage were observed in the gill of fish fed diets without MI supplementation.The ion transport capacity in gill was significantly improved in the 1,200 mg/kg MI supplementation groups compared with the 0 mg/kg MI groups(P<0.05).Moreover,the contents of Na^(+),K^(+),Cl^(-)in serum weremarkedly reduced with the dietary MI supplementation(P<0.05).The fish fed 1,200 mg/kg MI supplementation had the highest MI content in the gills and the lowest MI content in the serum(P<0.05).Additionally,the fish fed with 1,200 mg/kg MI supplementation had the highest MI synthesis capacity in gills and brain(P<0.05).Dietary MI markedly promoted the ability of carbohydrate metabolism in liver(P<0.05).Moreover,fish in the 1,200 mg/kg MI groups had the highest antioxidant capacity(P<0.05).This study indicated that high dietary carbohydrate would intensify stress,and impair the ability of osmoregulation in tilapia under a long-term hypersaline exposure.The supplementation of MI at 1,200 mg/kg in the high carbohydrate diet could promote carbohydrate utilization and improve the osmoregulation capacity of tilapia under long-term hypertonic stress.
基金This work was supported by the National Natural Science Foundation of China(31601986)Heilongjiang Postdoctoral Scientific Research Developmental Fund(LBH–Q16005).
文摘To investigate the effects of arbuscular mycorrhizal(AM)fungi on the growth and saline–alkaline tolerance of Potentilla anserina L.,the seedlings were inoculated with Claroideoglomus etunicatum(W.N.Becker&Gerd.)C.Walker&A.Schüßler in pot cultivation.After 90 days of culture,saline–alkaline stress was induced with NaCl and NaHCO_(3)solution according to the main salt components in saline–alkaline soils.Based on the physiological response of P.anserina to the stress in the preliminary experiment,the solution concentrations of 0 mmol/L,75 mmol/L,150 mmol/L,225 mmol/L and 300 mmol/L were treated with stress for 10 days,respectively.The mycorrhizal colonization rate,mycorrhizal dependence,chlorophyll content,malondialdehyde content,antioxidant enzyme activities,osmoregulation substances content and water status were measured.The results showed that with the increase of NaCl and NaHCO_(3)stress concentration,mycorrhizal colonization rate,colonization intensity,arbuscular abundance and vesicle abundance decreased,and reached the lowest value at 300 mmol/L.Strong mycorrhizal dependence was observed after the symbiosis with AM fungus,and the dependence was higher under NaHCO_(3)treatment.Under NaCl and NaHCO_(3)stress,inoculation with AM fungus could increase chlorophyll content,decrease malondialdehyde content,increase activities of superoxide dismutase,peroxidase and catalase,increase contents of proline,soluble sugar and soluble protein,increase tissue relative water content and decrease water saturation deficit.It was concluded that salt–alkali stress inhibited the colonization of AM fungus,but the mycorrhiza still played a positive role in maintaining the normal growth of plants under salt–alkali stress.
基金supported by the National Natural Sci-ence Foundation of China(No.31802269)the Open Fund of Shandong Key Laboratory of Disease Control in Mari-culture(No.KF201901)+2 种基金the Shrimp&Crab Innovation Team of Shandong Agriculture Research System(No.SD AIT-15-011)the High-Level Talent Research Fund of Qing-dao Agricultural University(Nos.663/1119054 and 663/1120027)the First Class Fishery Discipline Program in Shandong Province.
文摘The Pacific white shrimp(Litopenaeus vannamei)is a marine species commonly farmed worldwide.In northern China,it has been increasingly cultured in high-salinity waters(>40),but exhibits poor growth performance.In this study,postlarval shrimps were acclimated to salinity 55,cultivated for 3 months at this salinity,and compared with a control group reared at general salinity 25.Subsequently,high-throughput RNA sequencing was applied to compare the transcriptomic responses in the gills and hepatopancreas of the shrimps in the control group and the treatment group,while the weights of the shrimps in these two groups were significantly different.The results revealed that 11834 and 2115 genes were significantly differentially expressed in the gills and hepatopancreas,respectively.Additionally,enrichment analysis of the differentially expressed genes indicated that osmoregula-tion-associated Gene Ontology terms and KEGG pathways were similar between the two subgroups of the shrimp maintained at high salinity,suggesting that the growth rate of shrimp at high salinity is independent of osmoregulation.Furthermore,examination of the shrimp with different growth rates(i.e.,weights)at high salinity revealed molt-associated processes,namely,increased expression of ecdysone response genes and downstream effector genes in the gills and hepatopancreas of slow-growing shrimp,suggesting a role of the molt-associated processes in the regulation of shrimp growth at high salinity.Thus,we not only report adaptive transcriptomic responses of L.vannamei to prolonged high-salinity stress,but also provide new insights into the shrimp growth regulation at high salinity.
基金Funding by Instituto Politecnico Nacional PIFI-20100242.
文摘Currently, obtaining sustainable fuels, such as biodiesel and bioethanol, from cheap and renewable materials is a challenge. In recent years, a new approach being developed consists of producing, sugars from algae by photosynthesis. Sugar accumulation can be increased under osmotic stress (osmoregulation). The aim of this study is to show the pro-duction of sugars from algae, isolated from natural sources, and the effect of osmotic stress on fermentable sugars ac-cumulation. Strain isolation, production of sugars from each alga and the effect of osmotic stress on growth and sugar production are described. Twelve algal strains were isolated, showing growths between 0.6 and 1.8 g of biomass dry weight /L, all with production of intracellular and extracellular sugars. The strain identified as Chlorella sp. showed an increase in sugar production from 23.64 to 421 mg of sugars/g of biomass dry weight after 24 h of osmotic stress with 0.4 M NaCl. Sucrose and trehalose, both fermentable sugars, were the compatible osmolytes accumulated in response to the osmotic stress. The isolated strains are potential producers of fermentable sugars, using the photosynthetic pathway and osmotic stress.
基金The authors are grateful to the Ministry of Research,Technology and Higher Education of Republic of Indonesia,Directorate General of Resources for Science Technology and Higher Education for supporting this work under the Sandwich-Like Program at the University of Montpellier(Grant no.1406.58/D3/PG/2018).
文摘The effects of Hg exposure on blood parameters and gill physiology of tilapia(Oreochromis niloticus)were analyzed.Fish maintained in freshwater were exposed for 7 days(d)to sublethal mercury concentrations(0.1 and 1 mg/L).Blood serum osmolality(SO),sodium(Nat),potassium(K^+)and chloride(Cl^-)ionic concentrations,and hematological parameters were assessed after 1 up to 7 d of exposure.Serum osmolality and ionic concentrations of exposed fish appeared differently affected throughout the experimental period compared to the controls.Osmolality was reduced at the 2 tested concentrations but Nat and Cl^-contents were only altered at 1 mg/L of Hg after 1 d of exposure and values rapidly returned to the control values thereafter.K^+content was also modified and significantly increased at both concentrations after 1 d of exposure but returned to the control values after 3 d of exposure.Red blood cell(RBC),white blood cell(WBC)and hemoglobin(Hb)levels were significantly increased throughout the experiment but returned to control values after 7 d of exposure only for the 0.1 mg/L concentration.The hematocrit(Ht)levels remained unaffected due to Hg exposure.Therefore,tilapias exposed to sublethal concentrations of Hg present a marked osmotic imbalance with ionic and hematological disorders that are rapidly compensated.
文摘Adaptations of animals to the xeric environment have been studied in various taxonomic groups and across several deserts.Despite the impressive data that have been accumulated,the focus in most of these studies is mainly on the significance of one variable at a time.Here,we attempt to integrate between responses of several physiological systems,challenged by increasing diet and water salinity and extreme temperatures,acquired in different studies of thermo and osmo-regulatory adaptations,of small rodents,to the xeric environment.Studies have shown differen-tial thermoregulatory responses to increased dietary salinity,which were attributed to habitat and habits of the relevant species.In the thermoregulatory studies,a potential adaptive significance of low metabolic rate was demonstrated.From an evolutionary point of view,the most important adaptation is in the timing of reproduction,as it enables the transfer of genetic properties to the next generation in an unpredictable ecosystem,where repro-duction might not occur every year.Results in this aspect show that increased dietary salinity,through an increase in vasopressin plasma levels,plays an important role as a regulator of the reproductive system.We assume that the amount of food existing in the habitat and the amount of reserves in the animal in the form of white adipose tissue are important for reproduction.Photoperiod affects all studied physiological responses,emphasizing the impor-tance of pre-acclimation to seasonal characteristics.We summarize the existing data and suggest neuro-endocrine pathways,which have a central role in these adaptations by affecting thermoregulation,osmoregulation and repro-duction to create the optimal response to xeric conditions.These hypotheses can be used as the basis for future studies.
基金This work was supported by the National Key R&D Program of China(2018YFD0900906)the AoShan Talents Cultivation Program Supported by the Qingdao National Laboratory for Marine Science and Technology(2017ASTCP-ES07)+3 种基金the Key Laboratory of Sustainable Development of Marine Fisheries,Ministry of Agriculture,P.R.China(2018HY-XKQ01)the STS project of Fujian Province(2017T3016)the Ningde Normal University Special Fund Program(2019ZX406)the Fujian Province Think Tank of Science and Technology(decision-making consulting)key projects(FJKX-A1618).
文摘Gill morphological changes and physiological responses in juvenile large yellow croaker(Larimichthys crocea)were examined upon exposure to low salinity after indoor culture of the fish at salinities of 2,4,6,8,and 24‰(control group).The thickness of the lamellae was significantly higher in the low-salinity groups than in the control group;in contrast,the interlamellar space was significantly lower in the low-salinity groups than in the control group.Additionally,a significant negative correlation was found between the thickness of lamellae and interlamellar spaces(P<0.01).Mitochondria-rich cells(MRCs)were mainly found in the filament at 24‰salinity and proliferated in the lamellae at lower salinities,suggesting that filament and lamellar MRCs are responsible for ion secretion and absorption,respectively.Meanwhile,the activity of Na+/K+-ATPase(NKA)was significantly elevated with the decrease in salinity from 24‰to 4‰(P<0.05),which was consistent with MRCs proliferation.Finally,the activity of NKA declined at 2‰salinity(P<0.05),indicating the limit of osmoregulation,which was consistent with the degeneration and necrosis of the lamellae.Additionally,different levels of gill histopathological lesions,including pavement cell(PVC)exfoliation,lamellar epithelial lifting,edema,fusion,aneurism,and necrosis,were observed from salinities of 24 to 4‰,likely reducing the respiratory efficiency and compromising the health of juvenile fish.In conclusion,large yellow croaker juveniles could improve the osmoregulatory capacity by increasing lamellar MRCs and NKA activity with the decrease in salinity from 24 to 4‰.However,the associated histopathological lesions are likely to negatively influence the fish by affecting respiration and osmoregulation,especially when the salinity is below 4‰.
