The yield and nitrogen use efficiency(NUE)of hybrid rice combinations are closely related to restorer line.Therefore,it is essential to evaluate the agronomic characteristics of restorer lines with high yield and high...The yield and nitrogen use efficiency(NUE)of hybrid rice combinations are closely related to restorer line.Therefore,it is essential to evaluate the agronomic characteristics of restorer lines with high yield and high NUE(HYHN).However,it is unclear which restorer lines are HYHN,and neither have the common agronomic traits of the HYHN restorer lines been identified.Aiming to address this issue,we conducted two filed experiments using three nitrogen applications,which screened five HYHN restorer lines from 15 indica restorer lines.Yield,NUE and nutrient transportation of restorer lines with different yields and NUE types were examined.Yield and total nitrogen absorption in aboveground biomass(TNA)increased,whereas NUE for grain production decreased with increasing nitrogen application levels.The HYHN restorer lines had large spikelets and high weight per panicle that were significantly positively correlated with yield and NUE.Therefore,large sink potential may be beneficial for both yield and NUE.We further studied the differences in nutrient transportation to panicles between the HYHN and low yield and low NUE(LYLN)restorer lines and found that the former had a higher nitrogen absorption level and dry matter weight ratios of panicle in maturity.Moreover,the HYHN lines also had a higher root and neck-panicle node bleeding intensity per stem after heading and more developed vascular bundles of neck-panicle nodes and leaves than the LYLN lines,which could contribute to the transportation of nutrients from root to ground and from stem and leaf to spike.Therefore,the advantages of large sink potential of the HYHN restorer lines include large nutrient accumulation in and distribution to the panicles and smooth flow of nutrients along the transportation channels.展开更多
Background This study examined the efficacy of L-citrulline supplementation on the arginine/nitric oxide metabolism,and intestinal functions of broilers during arginine deficiency.A total of 288 day-old Arbor Acre bro...Background This study examined the efficacy of L-citrulline supplementation on the arginine/nitric oxide metabolism,and intestinal functions of broilers during arginine deficiency.A total of 288 day-old Arbor Acre broilers were randomly assigned to either an arginine deficient basal diet(NC diet),NC diet+0.50%L-arginine(PC diet),or NC diet+0.50%L-citrulline(NCL diet).Production performance was recorded,and at 21 days old,chickens were euthanized for tissue collection.Results The dietary treatments did not affect the growth performance of broilers(P>0.05),although NC diet increased the plasma alanine aminotransferase,urate,and several amino acids,except arginine(P<0.05).In contrast,NCL diet elevated the arginine and ornithine concentration higher than NC diet,and it increased the plasma citrulline greater than the PC diet(P<0.05).The nitric oxide concentration in the kidney and liver tissues,along with the plasma and liver e NOS activities were promoted by NCL diet higher than PC diet(P<0.05).In the liver,the activities of arginase 1,ASS,and ASL,as well as,the gene expression of i NOS and OTC were induced by PC diet greater than NC diet(P<0.05).In the kidney,the arginase 1,ASS and ASL enzymes were also increased by PC diet significantly higher than the NC and NCL diets.Comparatively,the kidney had higher abundance of n NOS,ASS,ARG2,and OTC genes than the liver tissue(P<0.05).In addition,NCL diet upregulated(P<0.05)the m RNA expression of intestinal nutrient transporters(EAAT3 and PEPT1),tight junction proteins(Claudin 1 and Occludin),and intestinal mucosal defense(MUC2 and p Ig R).The intestinal morphology revealed that both PC and NCL diets improved(P<0.05)the ileal VH/CD ratio and the jejunal VH and VH/CD ratio compared to the NC fed broilers.Conclusion This study revealed that NCL diet supported arginine metabolism,nitric oxide synthesis,and promoted the intestinal function of broilers.Thus,L-citrulline may serve as a partial arginine replacement in broiler’s diet without detrimental impacts on the performance,arginine metabolism and gut health of chickens.展开更多
High ambient temperatures are a critical challenge in the poultry industry which is a key producer of the animal-based food.To evaluate heat stress levels,various parameters have been used,including growth rates,blood...High ambient temperatures are a critical challenge in the poultry industry which is a key producer of the animal-based food.To evaluate heat stress levels,various parameters have been used,including growth rates,blood metabolites,and hormones.The most recent advances have explored expression profiling of genes that may play vital roles under stress.A high ambient temperature adversely affects nutrient uptake and is known to modulate the expression of genes encoding for sodium-dependent glucose transporters,glucose transporters,excitatory amino acid transporters,and fatty acidbinding proteins which are responsible for the absorption of macronutrients in the intestine.Various defensive activities are stimulated to protect the cell of different tissues from the heat-generated stress,including expression of early stress response genes coding for heat shock protein(HSP),c-FOS like protein,brain-derived neurotrophic factor(BDNF),and neuronal nitric oxide synthase(nNOS);antioxidant enzyme genes such as superoxide dismutase(SOD),catalase(CAT),and nicotinamide adenine dinucleotide phosphate oxidase(NOX4);and immune-related genes such as cytokines and toll-like receptors(TLRs).The potential role of HSPs in protecting the cell from stress and their presence in several tissues make them suitable markers to be evaluated under heat stress.BDNF and c-FOS genes expressed in the hypothalamus help cells to adapt to an adverse environment.Heat causes damage to the cell by generating reactive oxygen species(ROS).The NOX4 gene is the inducer of ROS under heat stress,which is in turns controlled by antioxidant enzymes such as SOD and CAT.TLRs are responsible for protecting against pathogenic attacks arising from enhanced membrane permeability,and cytokines help in controlling the pathogen and maintaining homeostasis.Thus,the evaluation of nutrient transporters and defense mechanisms using the latest molecular biology tools has made it possible to shed light on the complex cellular mechanism of heat-stressed chickens.As the impacts of heat stress on the above-mentioned aspects are beyond the extent to which the reduced growth performance could be explained,heat stress has more specific effects on the regulation of these genes than previously thought.展开更多
In many countries cacao (</span><i><span style="font-family:Verdana;">Theobroma cacao</span></i><span style="font-family:Verdana;"> L.) is invariably grown as an...In many countries cacao (</span><i><span style="font-family:Verdana;">Theobroma cacao</span></i><span style="font-family:Verdana;"> L.) is invariably grown as an understory crop in agroforestry types of cropping systems and subjected to low levels photosynthetic photon flux density (PPFD) due to presence of large number of upper story shade trees with poorly managed canopy structure. In recent years carbon dioxide concentration in the atmosphere is steadily increasing and it is unclear what impact this will have on performance of cacao grown under shade of upper story shade trees. A climatically controlled greenhouse experiment was undertaken to evaluate the effects of ambient and elevated carbon dioxide (400 and 700 μmol·mol</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) and three levels of PPFD (100, 200, and 400 μmol·m</span><sup><span style="font-family:Verdana;">-2</span></sup><span style="font-family:Verdana;">·s</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) on growth, and macro- and micronutrient use efficiency of three genetically contrasting cacao genotypes (CCN 51, VB 1117 and NO 81). Intraspecific variations were observed in cacao genotypes for growth parameters at ambient to elevated carbon dioxide and low to adequate levels of PPFD. With the exceptions of total root length and leaf area, irrespective of carbon dioxide and PPFD levels, all three genotypes showed significant differences in all the growth parameters. For all the cacao genotypes, increasing PPFD from 100 to 400 μmol·m</span><sup><span style="font-family:Verdana;">-2</span></sup><span style="font-family:Verdana;">·s</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> and carbon dioxide from 400 to 700 μmol·mol</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> increased overall growth parameters such as leaf, shoot and root biomass accumulation, stem height, leaf area, relative growth rate and net assimilation rate. Irrespective of carbon dioxide and PPFD, invariably genotypes differed significantly in macro-micronutrient uptake parameters such as concentration, uptake, influx, transport and use efficiency. With few exceptions, raising PPFD from 100 to 400 μmol·m</span><sup><span style="font-family:Verdana;">-2</span></sup><span style="font-family:Verdana;">·s</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> and carbon dioxide from 400 to 700 μmol·mol</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> increased nutrient use efficiency for all the cacao genotypes. Elevated carbon dioxide and adequate PPFD are benefi</span><span style="font-family:Verdana;">cial in improving cacao growth and mineral nutrient uptake and use efficiency.展开更多
Nutrient levels in the artificial channel constructed for the Middle Route Project are significant indicators of water quality safety and aquatic ecological integrity for this large,interbasin scheme.However,the distr...Nutrient levels in the artificial channel constructed for the Middle Route Project are significant indicators of water quality safety and aquatic ecological integrity for this large,interbasin scheme.However,the distribution and transport of nutrients along the channel were poorly understood.Based on a time-series dataset as well as mass balance and material flow analysis methods,the water and nutrient transport fluxes in the Middle Route of the South-to-North Water Diversion Project were identified in this study.The results indicate that the nutrient concentrations varied considerably with time,but there was no significant difference among the 30 stations of the main channel.Seasonal temperature difference was the major factor in the large fluctuations of water quality indicators over time.The nutrient loadings varied with the water volume outputs from the main channel to the waterreceiving cities.Atmospheric deposition was an important source of nutrients in the main channel,accounting for 9.13%,20.6%,and 0.635%of the nitrogen,phosphorus,and sulfur input from the Danjiangkou Reservoir,respectively.In 2021,a net accumulation of 988 tons of N,29 tons of P,and 2,540 tons of S,respectively,were present in the main channel.The increase of these external and internal nutrient loadings would cause water quality fluctuation and deterioration in some local sections of the main channel.Our study quantified the spatial and temporal patterns of nutrient transport in the Middle Route and revealed the ecological effects on the aquatic environment,assisting authorities on the project to develop effective water conservation strategies.展开更多
Vegetation canopies intercept and redistribute rainfall into throughfall and stemflow,which transfer substantial amounts of elements into the soil,influencing soil microbial community,plant survival,and plant communit...Vegetation canopies intercept and redistribute rainfall into throughfall and stemflow,which transfer substantial amounts of elements into the soil,influencing soil microbial community,plant survival,and plant community succession.Despite advancements in ecohydrological research,the implication of nutrient enrichment resulting from this redistribution of rainfall by canopies remains largely unexplored.To address this gap,we conducted a systematic review of 1020 papers published between 2000 and 2022,gathering data on nutrient concentration and enrichment for critical ions(including K^(+),Na^(+),Ca^(2+),Mg^(2+),NH_(4)^(+),Cl^(-),NO_(3)^(-)and SO_(4)^(2-))from the Web of Science and Chinese Knowledge Infrastructure databases.We aimed to synthesize the mechanisms,quantify the enrichments,and identify global patterns of nutrient enrichment in stemflow and throughfall across climate zones,and vegetation types and ecosystems.The results of this study indicate that stemflow exhibits,on average,2.1times greater ion concentration(6.13 mg L^(-1))compared to throughfall.In particular,among the investigated ions,SO_(4)^(2-)(12.45and 6.32 mg L^(-1))for stemflow and throughfall,respectively,and Cl^(-)(9.21 and 4.81 mg L^(-1))exhibit the highest concentrations in both rainfall redistribution components,while K^(+)(13.7 and 5.8)and Mg^(2+)(5.6 and 2.8)have the highest enrichment factors.Across climate zones,throughfall and stemflow show the lowest ion concentrations but the highest enrichment factors in extremely humid regions.Along the temperature gradient,ion concentrations are the highest in cold climates with no clear patterns observed for enrichment factors with increasing temperature.In addition,shrubs,conifers,mixed forests,and artificial ecosystems demonstrate enrichment factors 1.1 to 3.0 times greater than those of trees,broad-leaved plants,pure forests,and natural ecosystems.These findings emphasize the need for increased attentions to artificial ecosystems,such as urban and agricultural ecosystems,which often received limited research focus,especially regarding shrubs and conifers exhibiting stronger nutrients enrichment capabilities.Future investigations should integrate soil moisture analysis to better understand the impact of rainfall redistribution on the nutrient enrichment processes,patterns,and nutrient balance in global terrestrial ecosystems.展开更多
Nutrients supply especially like nutrients and oxygen play vital role in tissue engineering process.It is found that tissue could not grow very well in the middle of the scaffold because few nutrients could transport ...Nutrients supply especially like nutrients and oxygen play vital role in tissue engineering process.It is found that tissue could not grow very well in the middle of the scaffold because few nutrients could transport to the middle.Nutrient limitations would reduce cell proliferation and differentiation.In that case,there is urgent need to understand the nutrient distribution for both in vitro and in vivo study,as no technology is able for researchers to observe the nutrients transport during those process.In this paper,a numerical model coupling with VOF(volume of fluid)model and species transport model together for predicting the distribution of oxygen and glucose in the scaffold after implantation in to the site is developed.Comparing with our previous in vivo tests,the regenerated tissue distribution has a similar trend as oxygen distribution rather than glucose.The reported scaffold manufactured by additive manufacturing provided a good interconnected structure which facilitated the nutrient transportation in the scaffold.Considering nutrient transportation,this numerical model could be used in better understanding the nutrients transportation in the scaffold,and leading to a better understanding of tissue formation in the scaffold.展开更多
Male and female broiler chickens differ in their growth performance,carcass part weights and nutrient requirements.The potential reasons for these differences have been explored by looking at differences in nutrient d...Male and female broiler chickens differ in their growth performance,carcass part weights and nutrient requirements.The potential reasons for these differences have been explored by looking at differences in nutrient digestibility,nutrient transporter gene expression as well as gut microbiota populations between male and female birds.Studies have shown that male broilers have higher crude protein requirements compared to female broilers.The expression of monosaccharide and amino acid transporters show conflicting results as expression depends on the interactions between sex and bird age and breed as well as which tissue is sampled.Differences in microbiota populations between the genders were reported which may contribute towards performance differences,however research in this area is limited.The differences observed between the sexes contribute to increased variation in nutrition trials,and the potential to rear birds as equally mixed-sex becomes an option to reduce the variation introduced by the sex effect.Difference in rearing options obviously would only be feasible provided a quick,practical and cost-effective method of sexing birds is available,a topic that is also discussed in this review.展开更多
A trophic state increase relates to surface water bodies nutrient enrichment,due to the chemical products used such as fertilizers in agriculture and residues from cattle raising activities.This research consists of n...A trophic state increase relates to surface water bodies nutrient enrichment,due to the chemical products used such as fertilizers in agriculture and residues from cattle raising activities.This research consists of nutrient transport numerical modeling to analyze the Betancíreservoir trophic state in Colombia;Water samples were collected to analyze total nitrogen,total phosphorus,ammonia,nitrates,nitrites,phosphates,chlorophyll-a,dissolved oxygen,BOD,COD,suspended solids,and water trans-parency.The water quality model MOHID Studio was implemented and after its calibration,scenarios of increase and decrease of nutrients and inflows to the reservoir through its main tributaries were simulated to reproduce the agricultural activity changes in the basin and the effects that would have on the reservoir's trophic state dynamics;Therefore,the Carlson Trophic Status Index was calculated for each case.The results show that variations in total nitrogen concentration and increased inflows present short-term consequences on the reservoir's trophic state.Increasing the incoming total nitrogen con-centrations by 100%causes the reservoir to change from a light eutrophic to a hypereutrophic state.The results of this research provide a starting tool to water resources integrated management in reservoirs.展开更多
The objective of this study was to investigate whether supplementation with N-carbamoylglutamate(NCG)to cows during late gestation alters uteroplacental tissue nutrient transporters,calf metabolism and newborn weight....The objective of this study was to investigate whether supplementation with N-carbamoylglutamate(NCG)to cows during late gestation alters uteroplacental tissue nutrient transporters,calf metabolism and newborn weight.Thirty multiparous Chinese Holstein cows were used in a randomized complete block design experiment.During the last 28 d of pregnancy,cows were fed a diet without(CON)or with NCG(20 g/d per cow).The body weight of calves was weighed immediately after birth.Placentome samples were collected at parturition and used to assess mRNA expression of genes involved in transport of arginine,glucose,fatty acid and angiogenesis factors,as well as the mammalian target of rapamycin(mTOR)pathway.Blood samples of calves before colostrum consumption were also collected for the detection of plasma parameters,amino acids(AA)and metabolomics analysis.The newborn weight(P=0.02)and plasma Arg concentration of NCG-calves was significantly higher(P=0.05)than that of CON-calves,and the plasma concentrations of urea nitrogen tended to be lower(P=0.10)in the NCG group.The mRNA abundance of genes involved in glucose transport(solute carrier family 2 member 3[SLC2 A3],P<0.01),angiogenesis(nitric oxide synthase 3[NOS3],P=0.02),and mTOR pathway(serine/threonine-protein kinase 1[ACT1],P=0.10;euka ryotic translation initiation factor 4 B pseudogene 1[EIF4 BP1],P=0.08;EIF4 EBP2,P=0.04;and E74-like factor 2[ELF2],P=0.03)was upregulated in the placentome of NCG-supplemented cows.In addition,17 metabolites were significantly different in the placentome of NCG-supplemented cows compared to non-supplemented cows,and these metabolites are mainly involved in arginine and proline metabolism,alanine,aspartate and glutamate metabolism,and citrate cycle.In summary,the increased body weight of newborn calves from the NCG supplemented dairy cows maybe attributed to the increased angiogenesis and uteroplacental nutrient transport and to the activated mTOR signal pathway,which may result in the increased nutrient supply to the fetus,and improved AA metabolism and urea cycle of the fetus.展开更多
Aims The volume of soil beyond a plant’s roots from which that plant is able to acquire a particular nutrient depends upon the mobility of that nutrient in the soil.For this reason it has been hypothesized that the s...Aims The volume of soil beyond a plant’s roots from which that plant is able to acquire a particular nutrient depends upon the mobility of that nutrient in the soil.For this reason it has been hypothesized that the strength of competitive interactions between plants vary with soil nutrient mobility.We aimed to provide an experimental test of this hypothesis.Methods We devised two experimental systems to investigate specifically the effect of nutrient transport rates upon intraspecific competition.In the first,the exchange of rhizosphere water and dissolved nutrients between two connected pots,each containing one plant,was manipulated by alternately raising and lowering the pots.In the second experiment,the roots systems of two competing plants were separated by partitions of differing porosity,thereby varying the plants’access to water and nutrients in the other plant's rhizosphere.In this second experiment,we also applied varying amounts of nutrients to test whether higher nutrient input would reduce competition when competition for light is avoided,and applied different water levels to affect nutrient concentrations without changing nutrient supply.Important findings In both experiments,lower mobility reduced competitive effects on plant biomass and on relative growth rate(RGR),as hypothesized.In the second experiment,however,competition was more intense under high nutrient input,suggesting that low nutrient supply rates reduced the strength of the superior competitor.Competitive effects on RGR were only evident under the low water level,suggesting that under lower nutrient concentrations,competitive effects might be less pronounced.Taken together,our results provide the first direct experimental evidence that a reduction in nutrient mobility can reduce the intensity of competition between plants.展开更多
基金the National Natural Science Foundation of China(31871564)the National Key R&D Program of China(2016YFD0300506 and 2017YFD0301700)the Sichuan Breeding Key Research Project,China(2016NYZ0051)。
文摘The yield and nitrogen use efficiency(NUE)of hybrid rice combinations are closely related to restorer line.Therefore,it is essential to evaluate the agronomic characteristics of restorer lines with high yield and high NUE(HYHN).However,it is unclear which restorer lines are HYHN,and neither have the common agronomic traits of the HYHN restorer lines been identified.Aiming to address this issue,we conducted two filed experiments using three nitrogen applications,which screened five HYHN restorer lines from 15 indica restorer lines.Yield,NUE and nutrient transportation of restorer lines with different yields and NUE types were examined.Yield and total nitrogen absorption in aboveground biomass(TNA)increased,whereas NUE for grain production decreased with increasing nitrogen application levels.The HYHN restorer lines had large spikelets and high weight per panicle that were significantly positively correlated with yield and NUE.Therefore,large sink potential may be beneficial for both yield and NUE.We further studied the differences in nutrient transportation to panicles between the HYHN and low yield and low NUE(LYLN)restorer lines and found that the former had a higher nitrogen absorption level and dry matter weight ratios of panicle in maturity.Moreover,the HYHN lines also had a higher root and neck-panicle node bleeding intensity per stem after heading and more developed vascular bundles of neck-panicle nodes and leaves than the LYLN lines,which could contribute to the transportation of nutrients from root to ground and from stem and leaf to spike.Therefore,the advantages of large sink potential of the HYHN restorer lines include large nutrient accumulation in and distribution to the panicles and smooth flow of nutrients along the transportation channels.
基金funded by the Key Technologies Research and Development Program of China (2021YFD1300405)Key Technology Research and Development Program of Shandong province (2019JZZY020602)+1 种基金the Earmarked Fund for China Agriculture Research System (CARS-40-K09)National Natural Science Foundation of China (31772619)。
文摘Background This study examined the efficacy of L-citrulline supplementation on the arginine/nitric oxide metabolism,and intestinal functions of broilers during arginine deficiency.A total of 288 day-old Arbor Acre broilers were randomly assigned to either an arginine deficient basal diet(NC diet),NC diet+0.50%L-arginine(PC diet),or NC diet+0.50%L-citrulline(NCL diet).Production performance was recorded,and at 21 days old,chickens were euthanized for tissue collection.Results The dietary treatments did not affect the growth performance of broilers(P>0.05),although NC diet increased the plasma alanine aminotransferase,urate,and several amino acids,except arginine(P<0.05).In contrast,NCL diet elevated the arginine and ornithine concentration higher than NC diet,and it increased the plasma citrulline greater than the PC diet(P<0.05).The nitric oxide concentration in the kidney and liver tissues,along with the plasma and liver e NOS activities were promoted by NCL diet higher than PC diet(P<0.05).In the liver,the activities of arginase 1,ASS,and ASL,as well as,the gene expression of i NOS and OTC were induced by PC diet greater than NC diet(P<0.05).In the kidney,the arginase 1,ASS and ASL enzymes were also increased by PC diet significantly higher than the NC and NCL diets.Comparatively,the kidney had higher abundance of n NOS,ASS,ARG2,and OTC genes than the liver tissue(P<0.05).In addition,NCL diet upregulated(P<0.05)the m RNA expression of intestinal nutrient transporters(EAAT3 and PEPT1),tight junction proteins(Claudin 1 and Occludin),and intestinal mucosal defense(MUC2 and p Ig R).The intestinal morphology revealed that both PC and NCL diets improved(P<0.05)the ileal VH/CD ratio and the jejunal VH and VH/CD ratio compared to the NC fed broilers.Conclusion This study revealed that NCL diet supported arginine metabolism,nitric oxide synthesis,and promoted the intestinal function of broilers.Thus,L-citrulline may serve as a partial arginine replacement in broiler’s diet without detrimental impacts on the performance,arginine metabolism and gut health of chickens.
基金supported in part by the Korea Research Fellowship Program(2019H1D3A1A01071142)through the National Research Foundation of Korea(NRF)and by the Forest Science Technology R&D Program(2020193C10-2022-BA01)provided by Korea Forest Service(Korea Forestry Promotion Institute).
文摘High ambient temperatures are a critical challenge in the poultry industry which is a key producer of the animal-based food.To evaluate heat stress levels,various parameters have been used,including growth rates,blood metabolites,and hormones.The most recent advances have explored expression profiling of genes that may play vital roles under stress.A high ambient temperature adversely affects nutrient uptake and is known to modulate the expression of genes encoding for sodium-dependent glucose transporters,glucose transporters,excitatory amino acid transporters,and fatty acidbinding proteins which are responsible for the absorption of macronutrients in the intestine.Various defensive activities are stimulated to protect the cell of different tissues from the heat-generated stress,including expression of early stress response genes coding for heat shock protein(HSP),c-FOS like protein,brain-derived neurotrophic factor(BDNF),and neuronal nitric oxide synthase(nNOS);antioxidant enzyme genes such as superoxide dismutase(SOD),catalase(CAT),and nicotinamide adenine dinucleotide phosphate oxidase(NOX4);and immune-related genes such as cytokines and toll-like receptors(TLRs).The potential role of HSPs in protecting the cell from stress and their presence in several tissues make them suitable markers to be evaluated under heat stress.BDNF and c-FOS genes expressed in the hypothalamus help cells to adapt to an adverse environment.Heat causes damage to the cell by generating reactive oxygen species(ROS).The NOX4 gene is the inducer of ROS under heat stress,which is in turns controlled by antioxidant enzymes such as SOD and CAT.TLRs are responsible for protecting against pathogenic attacks arising from enhanced membrane permeability,and cytokines help in controlling the pathogen and maintaining homeostasis.Thus,the evaluation of nutrient transporters and defense mechanisms using the latest molecular biology tools has made it possible to shed light on the complex cellular mechanism of heat-stressed chickens.As the impacts of heat stress on the above-mentioned aspects are beyond the extent to which the reduced growth performance could be explained,heat stress has more specific effects on the regulation of these genes than previously thought.
文摘In many countries cacao (</span><i><span style="font-family:Verdana;">Theobroma cacao</span></i><span style="font-family:Verdana;"> L.) is invariably grown as an understory crop in agroforestry types of cropping systems and subjected to low levels photosynthetic photon flux density (PPFD) due to presence of large number of upper story shade trees with poorly managed canopy structure. In recent years carbon dioxide concentration in the atmosphere is steadily increasing and it is unclear what impact this will have on performance of cacao grown under shade of upper story shade trees. A climatically controlled greenhouse experiment was undertaken to evaluate the effects of ambient and elevated carbon dioxide (400 and 700 μmol·mol</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) and three levels of PPFD (100, 200, and 400 μmol·m</span><sup><span style="font-family:Verdana;">-2</span></sup><span style="font-family:Verdana;">·s</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) on growth, and macro- and micronutrient use efficiency of three genetically contrasting cacao genotypes (CCN 51, VB 1117 and NO 81). Intraspecific variations were observed in cacao genotypes for growth parameters at ambient to elevated carbon dioxide and low to adequate levels of PPFD. With the exceptions of total root length and leaf area, irrespective of carbon dioxide and PPFD levels, all three genotypes showed significant differences in all the growth parameters. For all the cacao genotypes, increasing PPFD from 100 to 400 μmol·m</span><sup><span style="font-family:Verdana;">-2</span></sup><span style="font-family:Verdana;">·s</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> and carbon dioxide from 400 to 700 μmol·mol</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> increased overall growth parameters such as leaf, shoot and root biomass accumulation, stem height, leaf area, relative growth rate and net assimilation rate. Irrespective of carbon dioxide and PPFD, invariably genotypes differed significantly in macro-micronutrient uptake parameters such as concentration, uptake, influx, transport and use efficiency. With few exceptions, raising PPFD from 100 to 400 μmol·m</span><sup><span style="font-family:Verdana;">-2</span></sup><span style="font-family:Verdana;">·s</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> and carbon dioxide from 400 to 700 μmol·mol</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> increased nutrient use efficiency for all the cacao genotypes. Elevated carbon dioxide and adequate PPFD are benefi</span><span style="font-family:Verdana;">cial in improving cacao growth and mineral nutrient uptake and use efficiency.
基金supported by the National Natural Science Foundation of China (Nos.52270202,and 41877471)the special fund was from the State Key Joint Laboratory of Environment Simulation and Pollution Control (Research Center for Eco-environmental Sciences,Chinese Academy of Sciences) (No.21Z02ESPCR)。
文摘Nutrient levels in the artificial channel constructed for the Middle Route Project are significant indicators of water quality safety and aquatic ecological integrity for this large,interbasin scheme.However,the distribution and transport of nutrients along the channel were poorly understood.Based on a time-series dataset as well as mass balance and material flow analysis methods,the water and nutrient transport fluxes in the Middle Route of the South-to-North Water Diversion Project were identified in this study.The results indicate that the nutrient concentrations varied considerably with time,but there was no significant difference among the 30 stations of the main channel.Seasonal temperature difference was the major factor in the large fluctuations of water quality indicators over time.The nutrient loadings varied with the water volume outputs from the main channel to the waterreceiving cities.Atmospheric deposition was an important source of nutrients in the main channel,accounting for 9.13%,20.6%,and 0.635%of the nitrogen,phosphorus,and sulfur input from the Danjiangkou Reservoir,respectively.In 2021,a net accumulation of 988 tons of N,29 tons of P,and 2,540 tons of S,respectively,were present in the main channel.The increase of these external and internal nutrient loadings would cause water quality fluctuation and deterioration in some local sections of the main channel.Our study quantified the spatial and temporal patterns of nutrient transport in the Middle Route and revealed the ecological effects on the aquatic environment,assisting authorities on the project to develop effective water conservation strategies.
基金supported by the National Natural Science Foundation of China(Grant No.41901038)the Start-up Research Fund of Southwest University(Grant No.SWU-KR24003)+2 种基金the Open Foundation of the State Key Laboratory of Urban and Regional Ecology of China(Grant No.SKLURE2022-2-4)the Science Fund for Distinguished Young Scholars of Chongqing(Grant No.cstc2021jcyjjqX0026)the Special Fund for Youth Team of Southwest University(Grant No.SWUXDJH202306)。
文摘Vegetation canopies intercept and redistribute rainfall into throughfall and stemflow,which transfer substantial amounts of elements into the soil,influencing soil microbial community,plant survival,and plant community succession.Despite advancements in ecohydrological research,the implication of nutrient enrichment resulting from this redistribution of rainfall by canopies remains largely unexplored.To address this gap,we conducted a systematic review of 1020 papers published between 2000 and 2022,gathering data on nutrient concentration and enrichment for critical ions(including K^(+),Na^(+),Ca^(2+),Mg^(2+),NH_(4)^(+),Cl^(-),NO_(3)^(-)and SO_(4)^(2-))from the Web of Science and Chinese Knowledge Infrastructure databases.We aimed to synthesize the mechanisms,quantify the enrichments,and identify global patterns of nutrient enrichment in stemflow and throughfall across climate zones,and vegetation types and ecosystems.The results of this study indicate that stemflow exhibits,on average,2.1times greater ion concentration(6.13 mg L^(-1))compared to throughfall.In particular,among the investigated ions,SO_(4)^(2-)(12.45and 6.32 mg L^(-1))for stemflow and throughfall,respectively,and Cl^(-)(9.21 and 4.81 mg L^(-1))exhibit the highest concentrations in both rainfall redistribution components,while K^(+)(13.7 and 5.8)and Mg^(2+)(5.6 and 2.8)have the highest enrichment factors.Across climate zones,throughfall and stemflow show the lowest ion concentrations but the highest enrichment factors in extremely humid regions.Along the temperature gradient,ion concentrations are the highest in cold climates with no clear patterns observed for enrichment factors with increasing temperature.In addition,shrubs,conifers,mixed forests,and artificial ecosystems demonstrate enrichment factors 1.1 to 3.0 times greater than those of trees,broad-leaved plants,pure forests,and natural ecosystems.These findings emphasize the need for increased attentions to artificial ecosystems,such as urban and agricultural ecosystems,which often received limited research focus,especially regarding shrubs and conifers exhibiting stronger nutrients enrichment capabilities.Future investigations should integrate soil moisture analysis to better understand the impact of rainfall redistribution on the nutrient enrichment processes,patterns,and nutrient balance in global terrestrial ecosystems.
基金supported by Versus Arthritis UK(Grant no:21977)European Commission via a H2020-MSCA-RISE programme(BAMOS,Grant no:734156)+1 种基金Innovative UK via Newton Fund(Grant no:102872)Engineering and Physical Science Research Council(EPSRC)via DTP CASE programme(Grant no:EP/T517793/1).
文摘Nutrients supply especially like nutrients and oxygen play vital role in tissue engineering process.It is found that tissue could not grow very well in the middle of the scaffold because few nutrients could transport to the middle.Nutrient limitations would reduce cell proliferation and differentiation.In that case,there is urgent need to understand the nutrient distribution for both in vitro and in vivo study,as no technology is able for researchers to observe the nutrients transport during those process.In this paper,a numerical model coupling with VOF(volume of fluid)model and species transport model together for predicting the distribution of oxygen and glucose in the scaffold after implantation in to the site is developed.Comparing with our previous in vivo tests,the regenerated tissue distribution has a similar trend as oxygen distribution rather than glucose.The reported scaffold manufactured by additive manufacturing provided a good interconnected structure which facilitated the nutrient transportation in the scaffold.Considering nutrient transportation,this numerical model could be used in better understanding the nutrients transportation in the scaffold,and leading to a better understanding of tissue formation in the scaffold.
基金Sustainable Commercial Egg Production Scholarship of The University of New England (UNE) for funding Ashley England.
文摘Male and female broiler chickens differ in their growth performance,carcass part weights and nutrient requirements.The potential reasons for these differences have been explored by looking at differences in nutrient digestibility,nutrient transporter gene expression as well as gut microbiota populations between male and female birds.Studies have shown that male broilers have higher crude protein requirements compared to female broilers.The expression of monosaccharide and amino acid transporters show conflicting results as expression depends on the interactions between sex and bird age and breed as well as which tissue is sampled.Differences in microbiota populations between the genders were reported which may contribute towards performance differences,however research in this area is limited.The differences observed between the sexes contribute to increased variation in nutrition trials,and the potential to rear birds as equally mixed-sex becomes an option to reduce the variation introduced by the sex effect.Difference in rearing options obviously would only be feasible provided a quick,practical and cost-effective method of sexing birds is available,a topic that is also discussed in this review.
文摘A trophic state increase relates to surface water bodies nutrient enrichment,due to the chemical products used such as fertilizers in agriculture and residues from cattle raising activities.This research consists of nutrient transport numerical modeling to analyze the Betancíreservoir trophic state in Colombia;Water samples were collected to analyze total nitrogen,total phosphorus,ammonia,nitrates,nitrites,phosphates,chlorophyll-a,dissolved oxygen,BOD,COD,suspended solids,and water trans-parency.The water quality model MOHID Studio was implemented and after its calibration,scenarios of increase and decrease of nutrients and inflows to the reservoir through its main tributaries were simulated to reproduce the agricultural activity changes in the basin and the effects that would have on the reservoir's trophic state dynamics;Therefore,the Carlson Trophic Status Index was calculated for each case.The results show that variations in total nitrogen concentration and increased inflows present short-term consequences on the reservoir's trophic state.Increasing the incoming total nitrogen con-centrations by 100%causes the reservoir to change from a light eutrophic to a hypereutrophic state.The results of this research provide a starting tool to water resources integrated management in reservoirs.
基金financially supported by grants from the ChinaUSA Intergovernmental Collaborative Project in S&T Innovation under the National Key R&D Program(Grant No.2018YFE0111700)the China Agricultural Research System(Grant No.CARS-36)。
文摘The objective of this study was to investigate whether supplementation with N-carbamoylglutamate(NCG)to cows during late gestation alters uteroplacental tissue nutrient transporters,calf metabolism and newborn weight.Thirty multiparous Chinese Holstein cows were used in a randomized complete block design experiment.During the last 28 d of pregnancy,cows were fed a diet without(CON)or with NCG(20 g/d per cow).The body weight of calves was weighed immediately after birth.Placentome samples were collected at parturition and used to assess mRNA expression of genes involved in transport of arginine,glucose,fatty acid and angiogenesis factors,as well as the mammalian target of rapamycin(mTOR)pathway.Blood samples of calves before colostrum consumption were also collected for the detection of plasma parameters,amino acids(AA)and metabolomics analysis.The newborn weight(P=0.02)and plasma Arg concentration of NCG-calves was significantly higher(P=0.05)than that of CON-calves,and the plasma concentrations of urea nitrogen tended to be lower(P=0.10)in the NCG group.The mRNA abundance of genes involved in glucose transport(solute carrier family 2 member 3[SLC2 A3],P<0.01),angiogenesis(nitric oxide synthase 3[NOS3],P=0.02),and mTOR pathway(serine/threonine-protein kinase 1[ACT1],P=0.10;euka ryotic translation initiation factor 4 B pseudogene 1[EIF4 BP1],P=0.08;EIF4 EBP2,P=0.04;and E74-like factor 2[ELF2],P=0.03)was upregulated in the placentome of NCG-supplemented cows.In addition,17 metabolites were significantly different in the placentome of NCG-supplemented cows compared to non-supplemented cows,and these metabolites are mainly involved in arginine and proline metabolism,alanine,aspartate and glutamate metabolism,and citrate cycle.In summary,the increased body weight of newborn calves from the NCG supplemented dairy cows maybe attributed to the increased angiogenesis and uteroplacental nutrient transport and to the activated mTOR signal pathway,which may result in the increased nutrient supply to the fetus,and improved AA metabolism and urea cycle of the fetus.
基金Swiss National Science Foundation(31003A-112452).
文摘Aims The volume of soil beyond a plant’s roots from which that plant is able to acquire a particular nutrient depends upon the mobility of that nutrient in the soil.For this reason it has been hypothesized that the strength of competitive interactions between plants vary with soil nutrient mobility.We aimed to provide an experimental test of this hypothesis.Methods We devised two experimental systems to investigate specifically the effect of nutrient transport rates upon intraspecific competition.In the first,the exchange of rhizosphere water and dissolved nutrients between two connected pots,each containing one plant,was manipulated by alternately raising and lowering the pots.In the second experiment,the roots systems of two competing plants were separated by partitions of differing porosity,thereby varying the plants’access to water and nutrients in the other plant's rhizosphere.In this second experiment,we also applied varying amounts of nutrients to test whether higher nutrient input would reduce competition when competition for light is avoided,and applied different water levels to affect nutrient concentrations without changing nutrient supply.Important findings In both experiments,lower mobility reduced competitive effects on plant biomass and on relative growth rate(RGR),as hypothesized.In the second experiment,however,competition was more intense under high nutrient input,suggesting that low nutrient supply rates reduced the strength of the superior competitor.Competitive effects on RGR were only evident under the low water level,suggesting that under lower nutrient concentrations,competitive effects might be less pronounced.Taken together,our results provide the first direct experimental evidence that a reduction in nutrient mobility can reduce the intensity of competition between plants.
