Background Cold stress has negative effects on the growth and health of mammals, and has become a factor restricting livestock development at high latitudes and on plateaus. The gut-liver axis is central to energy met...Background Cold stress has negative effects on the growth and health of mammals, and has become a factor restricting livestock development at high latitudes and on plateaus. The gut-liver axis is central to energy metabolism, and the mechanisms by which it regulates host energy metabolism at cold temperatures have rarely been illustrated. In this study, we evaluated the status of glycolipid metabolism and oxidative stress in pigs based on the gut-liver axis and propose that AMP-activated protein kinase(AMPK) is a key target for alleviating energy stress at cold temperatures by dietary fat supplementation.Results Dietary fat supplementation alleviated the negative effects of cold temperatures on growth performance and digestive enzymes, while hormonal homeostasis was also restored. Moreover, cold temperature exposure increased glucose transport in the jejunum. In contrast, we observed abnormalities in lipid metabolism, which was characterized by the accumulation of bile acids in the ileum and plasma. In addition, the results of the ileal metabolomic analysis were consistent with the energy metabolism measurements in the jejunum, and dietary fat supplementation increased the activity of the mitochondrial respiratory chain and lipid metabolism. As the central nexus of energy metabolism, the state of glycolipid metabolism and oxidative stress in the liver are inconsistent with that in the small intestine. Specifically, we found that cold temperature exposure increased glucose transport in the liver, which fully validates the idea that hormones can act on the liver to regulate glucose output. Additionally, dietary fat supplementation inhibited glucose transport and glycolysis, but increased gluconeogenesis, bile acid cycling, and lipid metabolism. Sustained activation of AMPK, which an energy receptor and regulator, leads to oxidative stress and apoptosis in the liver;dietary fat supplementation alleviates energy stress by reducing AMPK phosphorylation.Conclusions Cold stress reduced the growth performance and aggravated glycolipid metabolism disorders and oxidative stress damage in pigs. Dietary fat supplementation improved growth performance and alleviated cold temperature-induced energy stress through AMPK-mediated mitochondrial homeostasis. In this study, we high-light the importance of AMPK in dietary fat supplementation-mediated alleviation of host energy stress in response to environmental changes.展开更多
Loquat(Eriobotrya japonica Lindl.),a rare fruit native to China,has a long history of cultivation in China.Low temperature is the key factor restricting loquat growth and severely affects yield.Low temperature induces...Loquat(Eriobotrya japonica Lindl.),a rare fruit native to China,has a long history of cultivation in China.Low temperature is the key factor restricting loquat growth and severely affects yield.Low temperature induces the regeneration and metabolism of reduced glutathione(GSH)to alleviate stress damage via the participation of glu-tathione S-transferases(GSTs)in plants.In this study,16 GSTs were identified from the loquat genome according to their protein sequence similarity with Arabidopsis GSTs.On the basis of domain characteristics and phyloge-netic analysis of AtGSTs,these EjGSTs can be divided into 4 subclasses:Phi,Theta,Tau and Zeta.The basic prop-erties,subcellular localization,structures,motifs,chromosomal distribution and collinearity of the EjGST proteins or genes were further analyzed.Tandem and segmental gene duplications play pivotal roles in EjGST expansion.Cis-elements that respond to various hormones and stresses,especially those associated with low-temperature responsiveness,were predicted to be present in the promoters of EjGSTs.Moreover,analysis of gene expression profiles revealed that 9 of 16 EjGSTs may be involved in the low-temperature responsiveness of loquat leaves.In agriculture,5-aminolevulinic acid(ALA),a potential multifunctional plant growth regulator,can improve the stress response of plants.Among the 9 low-temperature-responsive EjGSTs,the expression of EjGSTU1 and EjGSTF1 significantly differed under cold stress in response to exogenous 5-aminolevulinic acid(ALA)pretreat-ment.The remarkable increase in GST activity and GSH/GSSG ratio reflected the increase in the cold response ability of loquat plants caused by exogenous ALA,thereby alleviating H2O2 accumulation and membrane lipid preoxidation.Overall,this study provides an initial exploration of the cold tolerance function of GSTs in loquat,offering a theoretical foundation for the development of cold-resistant loquat cultivars and new antifreeze agents.展开更多
Cold stress adversely affects rice growth,particularly at the early vegetative growth stage.In higher plants,nitrogen metabolism plays a central role in amino acid metabolism,plant defense mechanisms and productivity....Cold stress adversely affects rice growth,particularly at the early vegetative growth stage.In higher plants,nitrogen metabolism plays a central role in amino acid metabolism,plant defense mechanisms and productivity.This report investigated the effects of cold stress and supplementalγ-aminobutyric acid(GABA)under cold stress on nitrogen metabolism in rice seedlings.Cold stress resulted in a greater increase in the transformation to NH_(4)^(+)by nitrate reductase(NR)in roots,it further resulted in lower levels of NO_(3)^(-)content in roots,weakened glutamine glutamate(GOGAT/GS)pathway and elevated glutamate dehydrogenase(GDH)pathway of rice seedlings.Whereas,compared with cold stress,supplementation of GABA(2.5 mmol·L^(-1))could increase relative water content(79.43%)and biomass(34.15%)of rice seedlings.GABA could act as an amplifier of stress signal conduction/transduction to increase NR activity and promote NO_(3)^(-)assimilation in leaves.In addition,GABA elicited the Ca^(2+)signaling pathway which could promote the GDH pathway and GABA shunt,increase the activities of GS and GDH,and the expression of OsGAD2 and OsGDH family.The GABA might increase the ratio of the Glu family and avoid NH4+toxicity in order to raise the concentration of organic compounds and alleviate the harmful consequences of cold stress.Based on these observations,this study proposed that GABA mediated cold tolerance in rice seedlings by activating Ca^(2+)burst and subsequent crosstalk among Ca^(2+)signaling,GDH pathway and GABA shunt.展开更多
Three different stress states of the combination of tensile(t) stress and compressive(c) stress,t t,t c and t c c,exist in the deformed commercially pure titanium(CP-Ti) sheet during cold drawing-bulging.The tex...Three different stress states of the combination of tensile(t) stress and compressive(c) stress,t t,t c and t c c,exist in the deformed commercially pure titanium(CP-Ti) sheet during cold drawing-bulging.The textures and microstructures in the different stress state regions were investigated by means of XRD and TEM analysis.Similar development of texture and microstructure is achieved with less thickness strain under multiaxial stresses in drawing-bulging than in cold rolling.The results show that texture and microstructure are much sensitive to multiaxial stresses.Twinning is more easily activated under compressive stress than tensile stress.Prism a slip is heavily affected by tensile stress,resulting in a remarkable change of the intensity of(0°,35°,0°) texture,while pyramidal c+a slip,forming(20°,35°,30°) texture,weakens with the increase of thickness strain in spite of stress state.展开更多
In order to study the change laws of cold tolerance in wheat under drought stress, 11 wheat varieties planted in Huang-Huai wheat area and one variety representative in middle-lower Yangtze River wheat area were selec...In order to study the change laws of cold tolerance in wheat under drought stress, 11 wheat varieties planted in Huang-Huai wheat area and one variety representative in middle-lower Yangtze River wheat area were selected, and the their change laws of cold tolerance under normal moisture condition and drought stress condition. The results showed that under drought condition, the cold tolerance of wheat in various growth stages was remarkably lower than that under nondrought condition, and the decreasing amplitudes were the largest in overwintering stage with an average of 4.91 ℃, the smallest in regreening stage, and in the middle in the jointing stage. Under non-drought condition, the cold tolerance of semi- winter varieties in various growth stages was better than that of spring varieties, there were significant differences between different varieties, and the cold tolerance of all varieties in overwintering stage was improved compared with before winter, and rapidly decreased after overwintering. Semiwinter varieties showed cold tolerance remarkably enhanced in overwintering stage, and the cold tolerance of spring varieties was also improved to a certain degree.展开更多
The paper was to study the change trend of the physiological indexes in plants of Malvaceae under normal and low temperature condition.The result showed that the increase extent of electrical conductivity of plants wi...The paper was to study the change trend of the physiological indexes in plants of Malvaceae under normal and low temperature condition.The result showed that the increase extent of electrical conductivity of plants with cold tolerance in Malvaceae was significantly lower than the plant without cold tolerance under the cold stress condition,while their proline contents and soluble protein contents were all higher than the plants without cold tolerance.The above physiological indicators all can be used for the screening of varieties with cold tolerance in Malvaceae,which will also provide theoretical guidance for the cold tolerance screening of other garden plants.展开更多
[Objective] The research aimed to study the effects of reducing the concentrations of Mn2+, Cu2+ or Zn2+ in nutrient solution on the contents of Mn, Cu and Zn of grafted cucumber leaves as well as on the SOD and is...[Objective] The research aimed to study the effects of reducing the concentrations of Mn2+, Cu2+ or Zn2+ in nutrient solution on the contents of Mn, Cu and Zn of grafted cucumber leaves as well as on the SOD and isozymes activities and the rate of electrolytic leakage under cold stress. [Method] Nutrient solution containing low concentrations of Mn2+, Cu2+ or Zn2+ were used for cultivating the grafted cucumber seedlings for the cold treatment. [Result] The results indicated that reducing the concentrations of Mn2+, Cu2+ or Zn2+ in nutrient solution had declined the SOD activities in grafted cucumber leaves and increased the rates of electrolytic leakage. Mn2+ had shown the maximum influences, followed by Cu2+, and Zn2+ had shown the minimum influences. [Conclusion] Cold resistance of cucumber can be improved by changing the contents of Mn2+, Cu2+ or Zn2+ in nutrient solution.展开更多
Although Pinus sibirica and Pinus koraiensis are resistant to cold or low temperatures in the cold temperate regions of the northern hemisphere,the former has a stronger cold resistance.Research has been limited to th...Although Pinus sibirica and Pinus koraiensis are resistant to cold or low temperatures in the cold temperate regions of the northern hemisphere,the former has a stronger cold resistance.Research has been limited to the comparison of physiological responses of the two species to cold stress.In this study,5-year-old seedlings of P.sibirica and P.koraiensis were subjected to six temperature treatments,[20℃(control),0℃,-20℃,-40℃,-60℃,and-80℃],under different stress periods(6,12,24,and 48 h).The results showed that differences in each physiological index were significant between P.sibirica and P.koraiensis,except for the permeability of cell membranes,reactive oxygen species,proline and soluble proteins.An ANOVA test indicated that there were extreme differences among the temperatures for each index,stress time and temperature 9 time for most indices.All indices showed a similar trend for P.sibirica and P.koraiensis with decreasing temperature or the extension of stress time.Soluble sugars and proline increased at 0 to-20℃and then remained unchanged with temperature decline.Other indices showed an increase from 20 to-20℃,stable from-20 to-40℃and a decrease from-40 to-80℃.All the indices increased and then declined along with the prolonged cold stress time,except for the control.From 0 to-40℃,the permeability of cell membranes,relative conductivity,reactive oxygen species and malonaldehyde of P.koraiensis seedlings were higher than in P.sibirica,but superoxide dismutase,peroxidase,catalase activity and soluble sugars,proline,and soluble proteins content emerged as opposite.This study compared the physiological mechanism responses to cold stress between P.sibirica and P.koraiensis to provide the basis for the introduction,distribution,and genetic improvement of these coniferous species.展开更多
The objective of the study was to determine the physiological mechanisms of plants in response to brassinolide(BR) alleviating cold water stress on rice. In this study, physiological responses of rice to exogenous BR ...The objective of the study was to determine the physiological mechanisms of plants in response to brassinolide(BR) alleviating cold water stress on rice. In this study, physiological responses of rice to exogenous BR and cold water submergence were investigated using the chilling-tolerant cultivar Kongyu 131(KY131) and the chilling-sensitive cultivar Kenjiandao 6(KJD6). A total of 2 mg L^-1 BR increased activities of superoxide dismutase(SOD) and peroxidase(POD) and the contents of soluble sugar, soluble protein, and chlorophyll, but decreased the malondialdehyde(MDA) content in KY131 and KJD6 under cold water stress. The observed decreases in SOD and POD activities and MDA content recovered quickly after plants were returned to irrigation with water at temperatures of about 23.0°C in 2014. Additionally, the contents of nitrogen(N), phosphorous(P), and potassium(K) were increased by BR treatment under cold water stress. Exposure to BR also raised the percentage of high effective leaf area and leaf area index at the heading stage. Furthermore, it promoted soluble sugar synthesis, increased the rate of dry matter accumulation, and enhanced the export and translocation rates of the stem-sheath. The yield in KJD6 was significantly(P≤0.01 and P≤0.05) higher than that of the control in 2013 and 2014, respectively. The effect of BR treatment on rice leaf SOD and POD activities, MDA, chlorophyll, P, and stem-sheath K contents were more significant in KJD6 than in KY131. In conclusion, exogenous BR effectively reduced the physiological and metabolic damage in rice due to cold stress at the booting stage, promoted functional recovery in plants that received irrigation with water at a normal temperature following cold stress, and mitigated the effects of cold water stress on yield.The two varieties exhibited differential responses to BR;the weaker cold-resistant variety was more sensitive to BR and displayed stronger responses to exogenous BR.展开更多
Low temperature is one of the most important abiotic factors inhibiting growth, productivity, and distribution of rapeseed(Brassica napus L.). Therefore, it is important to identify and cultivate cold-tolerant germpla...Low temperature is one of the most important abiotic factors inhibiting growth, productivity, and distribution of rapeseed(Brassica napus L.). Therefore, it is important to identify and cultivate cold-tolerant germplasm. The objective of this study was to figure out the mechanism of chilling(4 and 2°C) and freezing(–2 and –4°C) stresses along with a control(22°C) in B. napus cultivars(1801 and C20) under controlled environment(growth chamber). The experiment was arranged in a complete randomized design with three replications. Our results exhibited that under chilling and freezing stresses, the increment of proline accumulation, soluble sugar and protein contents, and antioxidant enzyme activity were enhanced more in 1801 cultivar compared with C20 cultivar. At –2 and –4°C, the seedlings of C20 cultivar died completely compared with 1801 cultivar. Hydrogen peroxide(H2 O2) and malondialdehyde contents(MDA) increased in both cultivars, but when the temperature was decreased up to –2 and –4°C, the MDA and H2 O2 contents continuously dropped in 1801 cultivar. Moreover, we found that leaf abscisic acid(ABA) was enhanced in 1801 cultivar under chilling and freezing stresses. Additionally, the transcriptional regulations of cold-tolerant genes(COLD1, CBF4, COR6.6, COR15, and COR25) were also determined using real-time quantitative PCR(RT-q PCR). RT-q PCR showed that higher expression of these genes were found in 1801 as compared to C20 under cold stress(chilling and freezing stresses). Therefore, it is concluded from this experiment that 1801 cultivar has a higher ability to respond to cold stress(chilling and freezing stresses) by maintaining hormonal, antioxidative, and osmotic activity along with gene transcription process than C20. The result of this study will provide a solid foundation for understanding physiological and molecular mechanisms of cold stress signaling in rapeseed(B. napus).展开更多
This study was to investigate the effects of cold stress on the contents of total antioxidant capacity (T-AOC) malondialdehyde (MDA) and superoxide dismutase (SOD) in duodenum, jejunum and ileum of chickens. A t...This study was to investigate the effects of cold stress on the contents of total antioxidant capacity (T-AOC) malondialdehyde (MDA) and superoxide dismutase (SOD) in duodenum, jejunum and ileum of chickens. A total of 80 15-dayold male chickens were treated by cold stress with the duration of the acute cold stress being 1, 3, 6, 12, and 24 h, and the chronic cold stress was 5, 10, and 20 days, respectively. Cold stress temperature was (12±1)℃. The chemical colorimetric method was used to detect the changes of the T-AOC, SOD activities and MDA contents. The results showed that compared with the corresponding control group, effects of acute cold stress on the T-AOC in duodenum, jejunum and ileum of chickens significantly (P〈0.05) increased firstly and then decreased. Under chronic cold stress, the T-AOC significantly (P〈0.05) decreased. Under acute cold stress and chronic cold stress, the MDA contents significantly (P〈0.05) increased in duodenum, jejunum and ileum of chickens. The effects of acute cold stress on the SOD activities in duodenum, jejunum and ileum of chickens significantly (P〈0.05) increased firstly and then decreased Under chronic cold stress the SOD activities significantly (P〈0.05) decreased in jejunum and ileum, but significantly (P〈0.05) decreased firstly and then increased in duodenum.展开更多
The Yellow Sea is located between the China Mainland and the Korean Peninsula, representing a typical shallow epicontinental sea. The Yellow Sea Cold Water Mass(YSCWM) is one of the most important physical features ...The Yellow Sea is located between the China Mainland and the Korean Peninsula, representing a typical shallow epicontinental sea. The Yellow Sea Cold Water Mass(YSCWM) is one of the most important physical features in the Yellow Sea. The characteristics of vertical profiles and seasonal variations of biogenic elements in the YSCWM may lead the variations of nutrient availability(e.g., phosphorus) and phosphorus stress of phytoplankton. In this study, the authors surveyed the seasonal variations of phytoplankton phosphorus stress with emphasis on the effect of the YSCWM during the four cruises in April and October 2006, March and August 2007. Using both bulk and single-cell alkaline phosphatase activity(APA) assays, this study evaluated phosphorus status of phytoplankton community, succession of phytoplankton community and ecophysiological responses of phytoplankton to phosphorus in the typical region of the YSCWM. With the occurrence of the YSCWM, especially the variations of concentration of dissolved inorganic phosphorus(DIP), the results of bulk APA appeared corresponding seasonal variations. Along Transects A and B, the mean APA in August was the highest, and that in March was the lowest. According to the ELF-labeled assay's results, seasonal variations of the ELF-labeled percentages within dominant species indicated that diatoms were dominant in March, April and October, while dinoflagellates were dominant in August. During the four cruises, the ELF-labeled percentages of diatoms except Paralia sulcata showed that diatoms were not phosphorus deficient in April 2006 at all, but suffered from severe phosphorus stress in August 2007. In comparison, the ELF-labeled percentages of dinoflagellates were all above 50% during the four time series, which meant dinoflagellates such as Alexandrium and Scrippsiella, sustained perennial phosphorus stress.展开更多
Recent studies have shown that the R2R3-MYB transcription factor MdMYB73 is involved in salt stress response in apple. However, no research was done whether MdMYB73 mediated cold tolerance in apple or not. In this stu...Recent studies have shown that the R2R3-MYB transcription factor MdMYB73 is involved in salt stress response in apple. However, no research was done whether MdMYB73 mediated cold tolerance in apple or not. In this study, we found that the expression of MdMYB73 was obviously induced by cold stress. Functional analysis showed that MdMYB73 significantly increased cold tolerance in transgenic apple calli and Arabidopsis. Quantitative real-time PCR (qRT-PCR) assay indicated that the expression levels of cold-responsive genes including MdCBF2, MdCBF3, MdCBF4, and MdCBF5 were obviously enhanced in MdMYB73 transgenic calli, suggesting that MdMYB73 increased cold tolerance via C-repeat binding factor (CBF) cold response pathway. Finally, we found that soluble sugar, which provides an osmoticum for cells, was increased in MdMYB73 transgenic calli compared to that in the wild type control. These findings provide a new insights into how MdMYB73 is involved in cold stress response.展开更多
AIM: To study the protective effect of acupuncturing Tsusanli (ST36) on cold stress ulcer, and the expression of nitric oxide synthase (NOS) in hypothalarnus and adrenal gland. METHODS: Ulcer index in rats and R...AIM: To study the protective effect of acupuncturing Tsusanli (ST36) on cold stress ulcer, and the expression of nitric oxide synthase (NOS) in hypothalarnus and adrenal gland. METHODS: Ulcer index in rats and RT-PCR were used to study the protective effect of acupuncture on cold stress ulcer, and the expression of NOS in hypothalamus and adrenal gland. Images were analyzed with semi-quantitative method. RESULTS: The ulcer index significantly decreased in rats with stress ulcer. Plasma cortisol concentration was up regulated during cold stress, which could be depressed by pre-acupuncture. The expression of NOS1 in hypothallamus increased after acupuncture. The increased expression of NOS2 was related with stress ulcer, which could be decreased by acupuncture. The expression of NOS3 in hypothalamus was similar to NOS2, but the effect of acupuncture was limited. The expression of NOS2 and NOS3 in adrenal gland increased after cold stress, only the expression of NOS1 could be repressed with acupuncture. There was no NOS2 expression in adrenal gland in rats with stress ulcer. CONCLUSION: The protective effect of acupuncturing Tsusanli (ST36) on the expression of NOS in hypothalamus and adrenal gland can be achieved.展开更多
Cold stress responses help insects to survive under low temperatures that would be lethal otherwise.This phenomenon might contribute to the invasion of some Bemisia tabaci cryptic species from subtropical areas to tem...Cold stress responses help insects to survive under low temperatures that would be lethal otherwise.This phenomenon might contribute to the invasion of some Bemisia tabaci cryptic species from subtropical areas to temperate regions.However,the molecular mechanisms regulating cold stress responses in whitefly are yet unclear.Mitogen-activated protein kinases(MAPKs)which including p38,ERK,and JNK,are well known for their roles in regulating metabolic responses to cold stress in many insects.In this study,we explored the possible roles of the MAPKs in response to low temperature stresses in the Mediterranean cryptic species(the Q-biotype)of the B.tabaci species complex.First,we cloned the p38 and ERK genes from the whitefly cDNA library.Next,we analyzed the activation of MAPKs during cold stress in the Mediterranean cryptic species by immuno-blotting.After cold stress,the level of phospho-p38 increased but no significant change was observed in the phosphorylation of ERK and JNK,thus suggesting that the p38 might be responsible for the defense response to low temperature stress.Furthermore,we demonstrated that:i)3 min chilling at 0°C was sufficient for the activation of p38 MAPK pathway in this whitefly;and ii)the amount of phosphorylated p38 increased significantly in the first 20 min of chilling,reversed by 60 min,and then returned to the original level by 120 min.Taken together,our results suggest that the p38 pathway is important during response to low temperature stress in the Mediterranean cryptic species of the B.tabaci species complex.展开更多
Cemented paste backfill(CPB) is largely used in underground mines worldwide.A key issue associated with application of CPB is to estimate the stresses in backfilled stopes and on barricades.Recent numerical and experi...Cemented paste backfill(CPB) is largely used in underground mines worldwide.A key issue associated with application of CPB is to estimate the stresses in backfilled stopes and on barricades.Recent numerical and experimental results show that arching effect is absent shortly after the placement of CPB in stopes.However,stress decreases in barricade drift with increasing distance between the measurement points and drawpoint have also been observed,demonstrating arching effect shortly after the pouring of CPB.To explain these paradoxes,CPB is considered as Bingham fluid having a yield shear stress.Three dimensional analytical solutions are proposed to evaluate the short-term total stresses in backfilled stopes and on barricades,accounting for the CPB's yield shear stress-induced arching effect.Stress diminution due to such arching effect in the backfilled stopes and on barricades is indeed obtained.But the reduction becomes insignificant using typical yield shear stress and stope geometry.More analyses indicate that the typical yield shear stress values do not fully correspond to field conditions where the yield shear stress would increase exponentially due to apparent consolidation(loss of water by drainage,a phenomenon similar to the desiccation of overly saturated fine-grained materials).展开更多
The effect of different cold plasma treatments on the germination and seedling growth of alfalfa(Medicago sativa L.) seeds under simulated drought stress conditions was investigated.Polyethyleneglycol-6000(PEG 6000...The effect of different cold plasma treatments on the germination and seedling growth of alfalfa(Medicago sativa L.) seeds under simulated drought stress conditions was investigated.Polyethyleneglycol-6000(PEG 6000)with the mass fraction of 0%(purified water), 5%, 10%,and 15% were applied to simulate the drought environment. The alfalfa seeds were treated with15 different power levels ranged between 0–280 W for 15 s. The germination potential,germination rate, germination index, seedling root length, seedling height, and vigor index were investigated. Results indicated significant differences between treated with proper power and untreated alfalfa seeds. With the increase of treatment power, these indexes mentioned above almost presented bimodal curves. Under the different mass fractions of PEG 6000, results showed that the lower power led to increased germination, and the seedlings presented good adaptability to different drought conditions. Meanwhile, higher power levels resulted in a decreased germination rate. Seeds treated with 40 W resulted in higher germination potential,germination rate, seedling height, root length, and vigor index. Vigor indexes of the treated seeds under different PEG 6000 stresses increased by 38.68%, 43.91%, 74.34%, and 39.20%respectively compared to CK_(0-0), CK_(5-0), CK_(10-0), and CK_(15-0)(the control sample under 0%, 5%,10%, and 15% PEG 6000). Therefore, 40 W was regarded as the best treatment in this research.Although the trend indexes of alfalfa seeds treated with the same power were statistically the same under different PEG 6000 stresses, the cold plasma treatment had a significant effect on the adaptability of alfalfa seeds in different drought environments. Thus, this kind of treatment is worth implementing to promote seed growth under drought situations.展开更多
An F9 recombinant inbred lines (RIL) population, derived from a cross between IR28 (Oryza sativa L. spp. indica) and Daguandao (O. sativa L. spp. japonica), was used to construct a molecular linkage map and to i...An F9 recombinant inbred lines (RIL) population, derived from a cross between IR28 (Oryza sativa L. spp. indica) and Daguandao (O. sativa L. spp. japonica), was used to construct a molecular linkage map and to identify germination ability including the traits of imbibition rate, germination rate, germination index, root length, shoot length and seed vigor at 14℃ for 23 d. A composite interval mapping approach was applied to conduct genetic analysis for germination ability. The frequency distributions of the germination ability traits under the cold stress in the RIL population showed continuous segregation, suggesting they were quantitative traits controlled by several genes. A total of seven QTLs were identified on chromosomes 4 6 and 9, including two for imbibition rate (qIR-6, qIR-9), one for germination rate (qGR-4), two for germination index (qGI-4-1, qGI-4-2) and two for root length (qRL-4-1, qRL-4-2). There were no detected QTLs controlling shoot length and seed vigor. The phenotypic variance explained by a single QTL ranged from 9.1% to 37.0%, and two major QTLs, qlR-6 and qGI-4-2, accounted for over 30% of the phenotypic variance. The expressions of QTLs were developmentally regulated and growth stage-specific. Most of the QTLs observed here were located in the regions similar to the QTLs for rice cold tolerance reported previously, indicating that these QTLs were reliable. However, qRL-4-2 is not reported before.展开更多
Freezing injury in winter is an important abiotic stress that seriously affects plant growth and development.Deciduous fruit trees resist freezing injury by inducing dormancy.However,different cultivars of the same sp...Freezing injury in winter is an important abiotic stress that seriously affects plant growth and development.Deciduous fruit trees resist freezing injury by inducing dormancy.However,different cultivars of the same species have different cold resistance strategies.Little is known about the molecular mechanism of apple trees in response to freezing injury during winter dormancy.Therefore,in this study,1-year-old branches of the cold-resistant cultivar‘Hanfu’(HF)and the cold-sensitive cultivar‘Changfuji No.2’(CF)were used to explore their cold resistance through physiological,biochemical,transcriptomics,and metabolomics analyses.Combining physiological and biochemical data,we found that HF had a stronger osmotic regulation ability and antioxidant enzyme activity than CF,as well as stronger cold resistance.The functional enrichment analysis showed that both cultivars were significantly enriched in pathways related to signal transduction,hormone regulation,and sugar metabolism under freezing stress.In addition,the differentially expressed genes(DEGs)encoding galactinol synthase,raffinose synthase,and stachyose synthetase in raffinose family oligosaccharides(RFOs)metabolic pathways were upregulated in HF,and raffinose and stachyose were accumulated,while their contents in CF were lower.HF accumulated 4-aminobutyric acid,spermidine,and ascorbic acid to scavenge reactive oxygen species(ROS).While the contents of oxidized glutathione,vitamin C,glutathione,and spermidine in CF decreased under freezing stress,consequently,the ability to scavenge ROS was low.Furthermore,the transcription factors apetala 2/ethylene responsive factor(AP2/ERF)and WRKY were strongly induced under freezing stress.In summary,the difference in key metabolic components of HF and CF under freezing stress is the major factor affecting their difference in cold resistance.The obtained results deepen our understanding of the cold resistance mechanism in apple trees in response to freezing injury during dormancy.展开更多
Eugenol is a natural phenolic compound known for its health-promoting properties and its ability to add a floral scent to tea plants.Plant eugenol glycosides have been identified and shown to make important contributi...Eugenol is a natural phenolic compound known for its health-promoting properties and its ability to add a floral scent to tea plants.Plant eugenol glycosides have been identified and shown to make important contributions to fruit floral quality.However,the details of their biosynthesis and metabolism in tea plants are still unknown.Here,eugenol glucoside was unambiguously identified as a native metabolite in the tea plant,and its biosynthesis was shown to be induced by low temperature treatment.Through the analysis of UGTs induced by low temperature,the glycosyltransferase CsUGT78A15 was identified in tea,and its encoded protein was shown to catalyze the glucosylation of eugenol.Vmax/Km ratios showed that eugenol was the most suitable substrate for CsUGT78A15.Sugar donor preference analysis showed that CsUGT78A15 had a higher selectivity for glucose,followed by galactose and glucuronic acid.The expression of CsUGT78A15was correlatedwith the accumulation of eugenol glucoside in different tissues and genotypes of tea.Down-regulation of CsUGT78A15 led to a decreased eugenol glucoside content under cold stress,indicating that CsUGT78A15 plays an important role in the biosynthesis of eugenol glucoside under cold stress.The identification of eugenol glucoside in the tea plant and the discovery of a cold stress-induced eugenol glucosyltransferase in tea provide the foundation for the improvement of tea flavor under cold stress and the biotechnological production of eugenol glucoside.展开更多
基金funded by the National Key Research and Development Program of China (2021YFD1300403)。
文摘Background Cold stress has negative effects on the growth and health of mammals, and has become a factor restricting livestock development at high latitudes and on plateaus. The gut-liver axis is central to energy metabolism, and the mechanisms by which it regulates host energy metabolism at cold temperatures have rarely been illustrated. In this study, we evaluated the status of glycolipid metabolism and oxidative stress in pigs based on the gut-liver axis and propose that AMP-activated protein kinase(AMPK) is a key target for alleviating energy stress at cold temperatures by dietary fat supplementation.Results Dietary fat supplementation alleviated the negative effects of cold temperatures on growth performance and digestive enzymes, while hormonal homeostasis was also restored. Moreover, cold temperature exposure increased glucose transport in the jejunum. In contrast, we observed abnormalities in lipid metabolism, which was characterized by the accumulation of bile acids in the ileum and plasma. In addition, the results of the ileal metabolomic analysis were consistent with the energy metabolism measurements in the jejunum, and dietary fat supplementation increased the activity of the mitochondrial respiratory chain and lipid metabolism. As the central nexus of energy metabolism, the state of glycolipid metabolism and oxidative stress in the liver are inconsistent with that in the small intestine. Specifically, we found that cold temperature exposure increased glucose transport in the liver, which fully validates the idea that hormones can act on the liver to regulate glucose output. Additionally, dietary fat supplementation inhibited glucose transport and glycolysis, but increased gluconeogenesis, bile acid cycling, and lipid metabolism. Sustained activation of AMPK, which an energy receptor and regulator, leads to oxidative stress and apoptosis in the liver;dietary fat supplementation alleviates energy stress by reducing AMPK phosphorylation.Conclusions Cold stress reduced the growth performance and aggravated glycolipid metabolism disorders and oxidative stress damage in pigs. Dietary fat supplementation improved growth performance and alleviated cold temperature-induced energy stress through AMPK-mediated mitochondrial homeostasis. In this study, we high-light the importance of AMPK in dietary fat supplementation-mediated alleviation of host energy stress in response to environmental changes.
基金This research was funded by grants from the Fujian Provincial Science and Technology Project(2021N5014,2022N5006)the Science and Technology Plan Project of Putian(2023GJGZ001).
文摘Loquat(Eriobotrya japonica Lindl.),a rare fruit native to China,has a long history of cultivation in China.Low temperature is the key factor restricting loquat growth and severely affects yield.Low temperature induces the regeneration and metabolism of reduced glutathione(GSH)to alleviate stress damage via the participation of glu-tathione S-transferases(GSTs)in plants.In this study,16 GSTs were identified from the loquat genome according to their protein sequence similarity with Arabidopsis GSTs.On the basis of domain characteristics and phyloge-netic analysis of AtGSTs,these EjGSTs can be divided into 4 subclasses:Phi,Theta,Tau and Zeta.The basic prop-erties,subcellular localization,structures,motifs,chromosomal distribution and collinearity of the EjGST proteins or genes were further analyzed.Tandem and segmental gene duplications play pivotal roles in EjGST expansion.Cis-elements that respond to various hormones and stresses,especially those associated with low-temperature responsiveness,were predicted to be present in the promoters of EjGSTs.Moreover,analysis of gene expression profiles revealed that 9 of 16 EjGSTs may be involved in the low-temperature responsiveness of loquat leaves.In agriculture,5-aminolevulinic acid(ALA),a potential multifunctional plant growth regulator,can improve the stress response of plants.Among the 9 low-temperature-responsive EjGSTs,the expression of EjGSTU1 and EjGSTF1 significantly differed under cold stress in response to exogenous 5-aminolevulinic acid(ALA)pretreat-ment.The remarkable increase in GST activity and GSH/GSSG ratio reflected the increase in the cold response ability of loquat plants caused by exogenous ALA,thereby alleviating H2O2 accumulation and membrane lipid preoxidation.Overall,this study provides an initial exploration of the cold tolerance function of GSTs in loquat,offering a theoretical foundation for the development of cold-resistant loquat cultivars and new antifreeze agents.
基金Supported by the National Natural Science Foundation of China(32301935)the Heilongjiang Province Natural Science Foundation Project(LH2020C005)+1 种基金the Postdoctoral Fund to Research Start-up of Heilongjiang Province(LBH-Q21077)Heilongjiang Province Applied Technology Research and Development Plan Project(GA20B101)。
文摘Cold stress adversely affects rice growth,particularly at the early vegetative growth stage.In higher plants,nitrogen metabolism plays a central role in amino acid metabolism,plant defense mechanisms and productivity.This report investigated the effects of cold stress and supplementalγ-aminobutyric acid(GABA)under cold stress on nitrogen metabolism in rice seedlings.Cold stress resulted in a greater increase in the transformation to NH_(4)^(+)by nitrate reductase(NR)in roots,it further resulted in lower levels of NO_(3)^(-)content in roots,weakened glutamine glutamate(GOGAT/GS)pathway and elevated glutamate dehydrogenase(GDH)pathway of rice seedlings.Whereas,compared with cold stress,supplementation of GABA(2.5 mmol·L^(-1))could increase relative water content(79.43%)and biomass(34.15%)of rice seedlings.GABA could act as an amplifier of stress signal conduction/transduction to increase NR activity and promote NO_(3)^(-)assimilation in leaves.In addition,GABA elicited the Ca^(2+)signaling pathway which could promote the GDH pathway and GABA shunt,increase the activities of GS and GDH,and the expression of OsGAD2 and OsGDH family.The GABA might increase the ratio of the Glu family and avoid NH4+toxicity in order to raise the concentration of organic compounds and alleviate the harmful consequences of cold stress.Based on these observations,this study proposed that GABA mediated cold tolerance in rice seedlings by activating Ca^(2+)burst and subsequent crosstalk among Ca^(2+)signaling,GDH pathway and GABA shunt.
基金Project(2010CB731701) supported by the National Basic Research Program of ChinaProjects(50805121,51175428) supported by the National Natural Science Foundation of China+3 种基金Project(50935007) supported by the National Natural Science Foundation of China for Key ProgramProject(NPU-FFR-JC20100229) supported by the Foundation for Fundamental Research of Northwestern Polytechnical University in ChinaProject(2011-P06) supported by the Foundation of the State Key Laboratory of Materials Processing and Die & Mould Technology,Huazhong University of Science and TechnologyProject(B08040) supported by Program of Introducing Talents of Discipline to Universities("111"),China
文摘Three different stress states of the combination of tensile(t) stress and compressive(c) stress,t t,t c and t c c,exist in the deformed commercially pure titanium(CP-Ti) sheet during cold drawing-bulging.The textures and microstructures in the different stress state regions were investigated by means of XRD and TEM analysis.Similar development of texture and microstructure is achieved with less thickness strain under multiaxial stresses in drawing-bulging than in cold rolling.The results show that texture and microstructure are much sensitive to multiaxial stresses.Twinning is more easily activated under compressive stress than tensile stress.Prism a slip is heavily affected by tensile stress,resulting in a remarkable change of the intensity of(0°,35°,0°) texture,while pyramidal c+a slip,forming(20°,35°,30°) texture,weakens with the increase of thickness strain in spite of stress state.
文摘In order to study the change laws of cold tolerance in wheat under drought stress, 11 wheat varieties planted in Huang-Huai wheat area and one variety representative in middle-lower Yangtze River wheat area were selected, and the their change laws of cold tolerance under normal moisture condition and drought stress condition. The results showed that under drought condition, the cold tolerance of wheat in various growth stages was remarkably lower than that under nondrought condition, and the decreasing amplitudes were the largest in overwintering stage with an average of 4.91 ℃, the smallest in regreening stage, and in the middle in the jointing stage. Under non-drought condition, the cold tolerance of semi- winter varieties in various growth stages was better than that of spring varieties, there were significant differences between different varieties, and the cold tolerance of all varieties in overwintering stage was improved compared with before winter, and rapidly decreased after overwintering. Semiwinter varieties showed cold tolerance remarkably enhanced in overwintering stage, and the cold tolerance of spring varieties was also improved to a certain degree.
基金Supported by Research Project in Shanghai Green(Forest)Authority(G060317)~~
文摘The paper was to study the change trend of the physiological indexes in plants of Malvaceae under normal and low temperature condition.The result showed that the increase extent of electrical conductivity of plants with cold tolerance in Malvaceae was significantly lower than the plant without cold tolerance under the cold stress condition,while their proline contents and soluble protein contents were all higher than the plants without cold tolerance.The above physiological indicators all can be used for the screening of varieties with cold tolerance in Malvaceae,which will also provide theoretical guidance for the cold tolerance screening of other garden plants.
基金Supported by Shandong Provincial Outstanding Young Scientist Research Award Fund(BS2009NY016)National Natural Science Foundation(30571271)~~
文摘[Objective] The research aimed to study the effects of reducing the concentrations of Mn2+, Cu2+ or Zn2+ in nutrient solution on the contents of Mn, Cu and Zn of grafted cucumber leaves as well as on the SOD and isozymes activities and the rate of electrolytic leakage under cold stress. [Method] Nutrient solution containing low concentrations of Mn2+, Cu2+ or Zn2+ were used for cultivating the grafted cucumber seedlings for the cold treatment. [Result] The results indicated that reducing the concentrations of Mn2+, Cu2+ or Zn2+ in nutrient solution had declined the SOD activities in grafted cucumber leaves and increased the rates of electrolytic leakage. Mn2+ had shown the maximum influences, followed by Cu2+, and Zn2+ had shown the minimum influences. [Conclusion] Cold resistance of cucumber can be improved by changing the contents of Mn2+, Cu2+ or Zn2+ in nutrient solution.
基金financially supported by National Key Research and Development Program of China(2017YFD0600601)
文摘Although Pinus sibirica and Pinus koraiensis are resistant to cold or low temperatures in the cold temperate regions of the northern hemisphere,the former has a stronger cold resistance.Research has been limited to the comparison of physiological responses of the two species to cold stress.In this study,5-year-old seedlings of P.sibirica and P.koraiensis were subjected to six temperature treatments,[20℃(control),0℃,-20℃,-40℃,-60℃,and-80℃],under different stress periods(6,12,24,and 48 h).The results showed that differences in each physiological index were significant between P.sibirica and P.koraiensis,except for the permeability of cell membranes,reactive oxygen species,proline and soluble proteins.An ANOVA test indicated that there were extreme differences among the temperatures for each index,stress time and temperature 9 time for most indices.All indices showed a similar trend for P.sibirica and P.koraiensis with decreasing temperature or the extension of stress time.Soluble sugars and proline increased at 0 to-20℃and then remained unchanged with temperature decline.Other indices showed an increase from 20 to-20℃,stable from-20 to-40℃and a decrease from-40 to-80℃.All the indices increased and then declined along with the prolonged cold stress time,except for the control.From 0 to-40℃,the permeability of cell membranes,relative conductivity,reactive oxygen species and malonaldehyde of P.koraiensis seedlings were higher than in P.sibirica,but superoxide dismutase,peroxidase,catalase activity and soluble sugars,proline,and soluble proteins content emerged as opposite.This study compared the physiological mechanism responses to cold stress between P.sibirica and P.koraiensis to provide the basis for the introduction,distribution,and genetic improvement of these coniferous species.
基金supported by the earmarked fund for Agriculture Research System of China(CARS-01)the Agroresearch Projects in Public Interest of China(201403002 and 201303102)the National Key R&D Program of China(2016YFD0300504-2)。
文摘The objective of the study was to determine the physiological mechanisms of plants in response to brassinolide(BR) alleviating cold water stress on rice. In this study, physiological responses of rice to exogenous BR and cold water submergence were investigated using the chilling-tolerant cultivar Kongyu 131(KY131) and the chilling-sensitive cultivar Kenjiandao 6(KJD6). A total of 2 mg L^-1 BR increased activities of superoxide dismutase(SOD) and peroxidase(POD) and the contents of soluble sugar, soluble protein, and chlorophyll, but decreased the malondialdehyde(MDA) content in KY131 and KJD6 under cold water stress. The observed decreases in SOD and POD activities and MDA content recovered quickly after plants were returned to irrigation with water at temperatures of about 23.0°C in 2014. Additionally, the contents of nitrogen(N), phosphorous(P), and potassium(K) were increased by BR treatment under cold water stress. Exposure to BR also raised the percentage of high effective leaf area and leaf area index at the heading stage. Furthermore, it promoted soluble sugar synthesis, increased the rate of dry matter accumulation, and enhanced the export and translocation rates of the stem-sheath. The yield in KJD6 was significantly(P≤0.01 and P≤0.05) higher than that of the control in 2013 and 2014, respectively. The effect of BR treatment on rice leaf SOD and POD activities, MDA, chlorophyll, P, and stem-sheath K contents were more significant in KJD6 than in KY131. In conclusion, exogenous BR effectively reduced the physiological and metabolic damage in rice due to cold stress at the booting stage, promoted functional recovery in plants that received irrigation with water at a normal temperature following cold stress, and mitigated the effects of cold water stress on yield.The two varieties exhibited differential responses to BR;the weaker cold-resistant variety was more sensitive to BR and displayed stronger responses to exogenous BR.
基金supported by the National Key Research and Development Program of China (2017YFD0101700)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciencesthe Hubei Agricultural Science and Technology Innovation Center, China
文摘Low temperature is one of the most important abiotic factors inhibiting growth, productivity, and distribution of rapeseed(Brassica napus L.). Therefore, it is important to identify and cultivate cold-tolerant germplasm. The objective of this study was to figure out the mechanism of chilling(4 and 2°C) and freezing(–2 and –4°C) stresses along with a control(22°C) in B. napus cultivars(1801 and C20) under controlled environment(growth chamber). The experiment was arranged in a complete randomized design with three replications. Our results exhibited that under chilling and freezing stresses, the increment of proline accumulation, soluble sugar and protein contents, and antioxidant enzyme activity were enhanced more in 1801 cultivar compared with C20 cultivar. At –2 and –4°C, the seedlings of C20 cultivar died completely compared with 1801 cultivar. Hydrogen peroxide(H2 O2) and malondialdehyde contents(MDA) increased in both cultivars, but when the temperature was decreased up to –2 and –4°C, the MDA and H2 O2 contents continuously dropped in 1801 cultivar. Moreover, we found that leaf abscisic acid(ABA) was enhanced in 1801 cultivar under chilling and freezing stresses. Additionally, the transcriptional regulations of cold-tolerant genes(COLD1, CBF4, COR6.6, COR15, and COR25) were also determined using real-time quantitative PCR(RT-q PCR). RT-q PCR showed that higher expression of these genes were found in 1801 as compared to C20 under cold stress(chilling and freezing stresses). Therefore, it is concluded from this experiment that 1801 cultivar has a higher ability to respond to cold stress(chilling and freezing stresses) by maintaining hormonal, antioxidative, and osmotic activity along with gene transcription process than C20. The result of this study will provide a solid foundation for understanding physiological and molecular mechanisms of cold stress signaling in rapeseed(B. napus).
基金Supported by the Special Foundation of Technological Innovation Project of Harbin (DEDE-2010RFXXN041)
文摘This study was to investigate the effects of cold stress on the contents of total antioxidant capacity (T-AOC) malondialdehyde (MDA) and superoxide dismutase (SOD) in duodenum, jejunum and ileum of chickens. A total of 80 15-dayold male chickens were treated by cold stress with the duration of the acute cold stress being 1, 3, 6, 12, and 24 h, and the chronic cold stress was 5, 10, and 20 days, respectively. Cold stress temperature was (12±1)℃. The chemical colorimetric method was used to detect the changes of the T-AOC, SOD activities and MDA contents. The results showed that compared with the corresponding control group, effects of acute cold stress on the T-AOC in duodenum, jejunum and ileum of chickens significantly (P〈0.05) increased firstly and then decreased. Under chronic cold stress, the T-AOC significantly (P〈0.05) decreased. Under acute cold stress and chronic cold stress, the MDA contents significantly (P〈0.05) increased in duodenum, jejunum and ileum of chickens. The effects of acute cold stress on the SOD activities in duodenum, jejunum and ileum of chickens significantly (P〈0.05) increased firstly and then decreased Under chronic cold stress the SOD activities significantly (P〈0.05) decreased in jejunum and ileum, but significantly (P〈0.05) decreased firstly and then increased in duodenum.
基金The National Natural Science Foundation of China under contract Nos 41206106 and 41222038the National Basic Research Program of China under contract No.2006CB400604+1 种基金the National High Technology Research and Development Program under contract No.2007AA092003-01Cooperation on the Development of Basic Technologies for the Yellow Sea and East China Sea Operational Oceanographic System(YOOS)
文摘The Yellow Sea is located between the China Mainland and the Korean Peninsula, representing a typical shallow epicontinental sea. The Yellow Sea Cold Water Mass(YSCWM) is one of the most important physical features in the Yellow Sea. The characteristics of vertical profiles and seasonal variations of biogenic elements in the YSCWM may lead the variations of nutrient availability(e.g., phosphorus) and phosphorus stress of phytoplankton. In this study, the authors surveyed the seasonal variations of phytoplankton phosphorus stress with emphasis on the effect of the YSCWM during the four cruises in April and October 2006, March and August 2007. Using both bulk and single-cell alkaline phosphatase activity(APA) assays, this study evaluated phosphorus status of phytoplankton community, succession of phytoplankton community and ecophysiological responses of phytoplankton to phosphorus in the typical region of the YSCWM. With the occurrence of the YSCWM, especially the variations of concentration of dissolved inorganic phosphorus(DIP), the results of bulk APA appeared corresponding seasonal variations. Along Transects A and B, the mean APA in August was the highest, and that in March was the lowest. According to the ELF-labeled assay's results, seasonal variations of the ELF-labeled percentages within dominant species indicated that diatoms were dominant in March, April and October, while dinoflagellates were dominant in August. During the four cruises, the ELF-labeled percentages of diatoms except Paralia sulcata showed that diatoms were not phosphorus deficient in April 2006 at all, but suffered from severe phosphorus stress in August 2007. In comparison, the ELF-labeled percentages of dinoflagellates were all above 50% during the four time series, which meant dinoflagellates such as Alexandrium and Scrippsiella, sustained perennial phosphorus stress.
基金supported by the National Natural Science Foundation of China (31601728,31272142,31325024)the Natural Science Foundation of Shandong Province,China (ZR2016CQ13)the Youth Science and Technology Innovation Fund of Shandong Agricultural University,China (24024)
文摘Recent studies have shown that the R2R3-MYB transcription factor MdMYB73 is involved in salt stress response in apple. However, no research was done whether MdMYB73 mediated cold tolerance in apple or not. In this study, we found that the expression of MdMYB73 was obviously induced by cold stress. Functional analysis showed that MdMYB73 significantly increased cold tolerance in transgenic apple calli and Arabidopsis. Quantitative real-time PCR (qRT-PCR) assay indicated that the expression levels of cold-responsive genes including MdCBF2, MdCBF3, MdCBF4, and MdCBF5 were obviously enhanced in MdMYB73 transgenic calli, suggesting that MdMYB73 increased cold tolerance via C-repeat binding factor (CBF) cold response pathway. Finally, we found that soluble sugar, which provides an osmoticum for cells, was increased in MdMYB73 transgenic calli compared to that in the wild type control. These findings provide a new insights into how MdMYB73 is involved in cold stress response.
基金Supported by the National Natural Science Foundation of China,No. 30171135
文摘AIM: To study the protective effect of acupuncturing Tsusanli (ST36) on cold stress ulcer, and the expression of nitric oxide synthase (NOS) in hypothalarnus and adrenal gland. METHODS: Ulcer index in rats and RT-PCR were used to study the protective effect of acupuncture on cold stress ulcer, and the expression of NOS in hypothalamus and adrenal gland. Images were analyzed with semi-quantitative method. RESULTS: The ulcer index significantly decreased in rats with stress ulcer. Plasma cortisol concentration was up regulated during cold stress, which could be depressed by pre-acupuncture. The expression of NOS1 in hypothallamus increased after acupuncture. The increased expression of NOS2 was related with stress ulcer, which could be decreased by acupuncture. The expression of NOS3 in hypothalamus was similar to NOS2, but the effect of acupuncture was limited. The expression of NOS2 and NOS3 in adrenal gland increased after cold stress, only the expression of NOS1 could be repressed with acupuncture. There was no NOS2 expression in adrenal gland in rats with stress ulcer. CONCLUSION: The protective effect of acupuncturing Tsusanli (ST36) on the expression of NOS in hypothalamus and adrenal gland can be achieved.
基金supported by the National Natural Science Foundation of China(30730061)the National Basic Research Program of China(2009CB119203)
文摘Cold stress responses help insects to survive under low temperatures that would be lethal otherwise.This phenomenon might contribute to the invasion of some Bemisia tabaci cryptic species from subtropical areas to temperate regions.However,the molecular mechanisms regulating cold stress responses in whitefly are yet unclear.Mitogen-activated protein kinases(MAPKs)which including p38,ERK,and JNK,are well known for their roles in regulating metabolic responses to cold stress in many insects.In this study,we explored the possible roles of the MAPKs in response to low temperature stresses in the Mediterranean cryptic species(the Q-biotype)of the B.tabaci species complex.First,we cloned the p38 and ERK genes from the whitefly cDNA library.Next,we analyzed the activation of MAPKs during cold stress in the Mediterranean cryptic species by immuno-blotting.After cold stress,the level of phospho-p38 increased but no significant change was observed in the phosphorylation of ERK and JNK,thus suggesting that the p38 might be responsible for the defense response to low temperature stress.Furthermore,we demonstrated that:i)3 min chilling at 0°C was sufficient for the activation of p38 MAPK pathway in this whitefly;and ii)the amount of phosphorylated p38 increased significantly in the first 20 min of chilling,reversed by 60 min,and then returned to the original level by 120 min.Taken together,our results suggest that the p38 pathway is important during response to low temperature stress in the Mediterranean cryptic species of the B.tabaci species complex.
基金the Natural Sciences and Engineering Research Council of Canada(NSERC)Institut de recherche Robert-Sauve en sante et en securite du travail(IRSST)industrial partners of the Research Institute on Mines and the Environment(RIME UQAT-Polytechnique)
文摘Cemented paste backfill(CPB) is largely used in underground mines worldwide.A key issue associated with application of CPB is to estimate the stresses in backfilled stopes and on barricades.Recent numerical and experimental results show that arching effect is absent shortly after the placement of CPB in stopes.However,stress decreases in barricade drift with increasing distance between the measurement points and drawpoint have also been observed,demonstrating arching effect shortly after the pouring of CPB.To explain these paradoxes,CPB is considered as Bingham fluid having a yield shear stress.Three dimensional analytical solutions are proposed to evaluate the short-term total stresses in backfilled stopes and on barricades,accounting for the CPB's yield shear stress-induced arching effect.Stress diminution due to such arching effect in the backfilled stopes and on barricades is indeed obtained.But the reduction becomes insignificant using typical yield shear stress and stope geometry.More analyses indicate that the typical yield shear stress values do not fully correspond to field conditions where the yield shear stress would increase exponentially due to apparent consolidation(loss of water by drainage,a phenomenon similar to the desiccation of overly saturated fine-grained materials).
基金supported by China Agriculture Research System(CARS-34)
文摘The effect of different cold plasma treatments on the germination and seedling growth of alfalfa(Medicago sativa L.) seeds under simulated drought stress conditions was investigated.Polyethyleneglycol-6000(PEG 6000)with the mass fraction of 0%(purified water), 5%, 10%,and 15% were applied to simulate the drought environment. The alfalfa seeds were treated with15 different power levels ranged between 0–280 W for 15 s. The germination potential,germination rate, germination index, seedling root length, seedling height, and vigor index were investigated. Results indicated significant differences between treated with proper power and untreated alfalfa seeds. With the increase of treatment power, these indexes mentioned above almost presented bimodal curves. Under the different mass fractions of PEG 6000, results showed that the lower power led to increased germination, and the seedlings presented good adaptability to different drought conditions. Meanwhile, higher power levels resulted in a decreased germination rate. Seeds treated with 40 W resulted in higher germination potential,germination rate, seedling height, root length, and vigor index. Vigor indexes of the treated seeds under different PEG 6000 stresses increased by 38.68%, 43.91%, 74.34%, and 39.20%respectively compared to CK_(0-0), CK_(5-0), CK_(10-0), and CK_(15-0)(the control sample under 0%, 5%,10%, and 15% PEG 6000). Therefore, 40 W was regarded as the best treatment in this research.Although the trend indexes of alfalfa seeds treated with the same power were statistically the same under different PEG 6000 stresses, the cold plasma treatment had a significant effect on the adaptability of alfalfa seeds in different drought environments. Thus, this kind of treatment is worth implementing to promote seed growth under drought situations.
基金supported by the Jiangsu Agricultural Three-Area-Focused Program,China (Grant No.Q200670)the Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT),China
文摘An F9 recombinant inbred lines (RIL) population, derived from a cross between IR28 (Oryza sativa L. spp. indica) and Daguandao (O. sativa L. spp. japonica), was used to construct a molecular linkage map and to identify germination ability including the traits of imbibition rate, germination rate, germination index, root length, shoot length and seed vigor at 14℃ for 23 d. A composite interval mapping approach was applied to conduct genetic analysis for germination ability. The frequency distributions of the germination ability traits under the cold stress in the RIL population showed continuous segregation, suggesting they were quantitative traits controlled by several genes. A total of seven QTLs were identified on chromosomes 4 6 and 9, including two for imbibition rate (qIR-6, qIR-9), one for germination rate (qGR-4), two for germination index (qGI-4-1, qGI-4-2) and two for root length (qRL-4-1, qRL-4-2). There were no detected QTLs controlling shoot length and seed vigor. The phenotypic variance explained by a single QTL ranged from 9.1% to 37.0%, and two major QTLs, qlR-6 and qGI-4-2, accounted for over 30% of the phenotypic variance. The expressions of QTLs were developmentally regulated and growth stage-specific. Most of the QTLs observed here were located in the regions similar to the QTLs for rice cold tolerance reported previously, indicating that these QTLs were reliable. However, qRL-4-2 is not reported before.
基金funded by the National Key Research and Development Program of China(Grant No.2020YFD1000201)China Agriculture Research System of MOF and MARA(Grant No.CARS-27)+1 种基金the National Natural Science Foundation of China(Grant No.31972359)the Agricultural Research and Industrialization Project of Liaoning Province(Grant No.2020JH2/10200028).
文摘Freezing injury in winter is an important abiotic stress that seriously affects plant growth and development.Deciduous fruit trees resist freezing injury by inducing dormancy.However,different cultivars of the same species have different cold resistance strategies.Little is known about the molecular mechanism of apple trees in response to freezing injury during winter dormancy.Therefore,in this study,1-year-old branches of the cold-resistant cultivar‘Hanfu’(HF)and the cold-sensitive cultivar‘Changfuji No.2’(CF)were used to explore their cold resistance through physiological,biochemical,transcriptomics,and metabolomics analyses.Combining physiological and biochemical data,we found that HF had a stronger osmotic regulation ability and antioxidant enzyme activity than CF,as well as stronger cold resistance.The functional enrichment analysis showed that both cultivars were significantly enriched in pathways related to signal transduction,hormone regulation,and sugar metabolism under freezing stress.In addition,the differentially expressed genes(DEGs)encoding galactinol synthase,raffinose synthase,and stachyose synthetase in raffinose family oligosaccharides(RFOs)metabolic pathways were upregulated in HF,and raffinose and stachyose were accumulated,while their contents in CF were lower.HF accumulated 4-aminobutyric acid,spermidine,and ascorbic acid to scavenge reactive oxygen species(ROS).While the contents of oxidized glutathione,vitamin C,glutathione,and spermidine in CF decreased under freezing stress,consequently,the ability to scavenge ROS was low.Furthermore,the transcription factors apetala 2/ethylene responsive factor(AP2/ERF)and WRKY were strongly induced under freezing stress.In summary,the difference in key metabolic components of HF and CF under freezing stress is the major factor affecting their difference in cold resistance.The obtained results deepen our understanding of the cold resistance mechanism in apple trees in response to freezing injury during dormancy.
基金the Science Fund for the National Natural Science Foundation of China(Grant Nos.31961133030,31870678)the National Key Research and Development Program of China(Grant No.2018YFD1000601)+1 种基金Distinguished Young Scientists of Anhui Province(Grant No.1908085J12)the Graduate Innovation Fund(Grant No.2020ysj-32).
文摘Eugenol is a natural phenolic compound known for its health-promoting properties and its ability to add a floral scent to tea plants.Plant eugenol glycosides have been identified and shown to make important contributions to fruit floral quality.However,the details of their biosynthesis and metabolism in tea plants are still unknown.Here,eugenol glucoside was unambiguously identified as a native metabolite in the tea plant,and its biosynthesis was shown to be induced by low temperature treatment.Through the analysis of UGTs induced by low temperature,the glycosyltransferase CsUGT78A15 was identified in tea,and its encoded protein was shown to catalyze the glucosylation of eugenol.Vmax/Km ratios showed that eugenol was the most suitable substrate for CsUGT78A15.Sugar donor preference analysis showed that CsUGT78A15 had a higher selectivity for glucose,followed by galactose and glucuronic acid.The expression of CsUGT78A15was correlatedwith the accumulation of eugenol glucoside in different tissues and genotypes of tea.Down-regulation of CsUGT78A15 led to a decreased eugenol glucoside content under cold stress,indicating that CsUGT78A15 plays an important role in the biosynthesis of eugenol glucoside under cold stress.The identification of eugenol glucoside in the tea plant and the discovery of a cold stress-induced eugenol glucosyltransferase in tea provide the foundation for the improvement of tea flavor under cold stress and the biotechnological production of eugenol glucoside.