Intraspecific competition is a common phenomenon in agricultural production,and maize is one of the most sensitive grass species to intraspecific competition due to its low tillering ability.This study evaluated and a...Intraspecific competition is a common phenomenon in agricultural production,and maize is one of the most sensitive grass species to intraspecific competition due to its low tillering ability.This study evaluated and analyzed intraspecific competition in maize,and screened competitive indices that could be used to evaluate intraspecific competition in a maize population.A 2-year field experiment was conducted using the maize hybrid Zhongdan 2 at 12 plant densities ranging from 1.5 to 18.0 plants（pl）m-2.The results showed that the response of single-plant grain yield and dry matter at harvest to increased plant density decreased exponentially and that the harvest index decreased linearly.The response of population-level grain yield to plant density was curvilinear,producing a maximum value at the optimum population density.However,the yielddensity equation agreed well with the Steinhart-Hart equation curves,but not with the quadratic equation curves reported by most previous studies.Competitive indices are used to evaluate competition in a plant population or plant species.The present results show that competitive intensity（CI）and absolute severity of competition（ASC）increased with increasing plant density;however,relative yield（RY）and relative reproductive efficiency（RReff）decreased.The different responses of these indices reflect different aspects of competition.According to the analysis of CI,ASC,RY,and RReff,higher CI and ASC values indicate higher intraspecific competition,whereas higher RY and RReff values indirectly reflect lower intraspecific competition.These competitive indices evaluate not only the intraspecific competitive intensity under different plant densities of the same cultivar but also those of different cultivars under the same plant density.However,some overlap exists in the calculations of ASC,CI,and RY,so one could simply select any one of these indices to evaluate intraspecific competition in a maize population.In conclusion,the present study provides a method to evaluate intraspecific competition in maize populations,which may be beneficial for breeding high-yield maize varieties in the future.展开更多
The inlfuences of tillage systems on soil carbon （C） stocks have been studied extensively, but the distribution of soil C within aggregate fractions is not well understood. The objective of this study was to determi...The inlfuences of tillage systems on soil carbon （C） stocks have been studied extensively, but the distribution of soil C within aggregate fractions is not well understood. The objective of this study was to determine the inlfuences of various tillage systems on soil aggregation and aggregate-associated C under wheat （Triticum aestivum L.） and corn （Zea mays L.） double cropping systems in the North China Plain. The experiment was established in 2001, including four treatments：moldboard plow （MP） with residue （MP＋R） and without residue （MP-R）, rotary tillage with residue （RT）, and no-till with residue （NT）. In 2007 soil samples were collected from the 0-5, 5-10, and 10-20 cm depths, and were separated into four aggregate-size classes （〉2 000, 250-2 000, 53-250, and〈53 μm） by wet-sieving method. Aggregate-associated C was determined, and the relationships between total soil C concentration and aggregation-size fractions were examined. The results showed that NT and RT treatments signiifcantly increased the proportion of macroaggregate fractions （〉2 000 and 250-2 000 μm） compared with the MP-R and MP＋R treatments. Averaged across all depths, mean weight diameters of aggregates （MWD） in NT and RT were 47 and 20% higher than that in MP＋R. The concentration of bulk soil organic C was positively correlated with MWD （r=0.98; P=0.024） and macroaggregate fraction （r=0.96; P=0.036） in the 0-5 cm depth. In the 0-20 cm depth, comparing with MP＋R, total C occluded in the〉2 000 μm fraction was increased by 9 and 6%under NT and RT, respectively. We conclude that adoption of conservation tillage system, especially no-till, can increase soil macro-aggregation and total C accumulation in macroaggregates, which may improve soil C sequestration in the intensive agricultural region of the North China Plain.展开更多
The shortage of groundwater resources is a considerable challenge for winter wheat production on the North China Plain.Water-saving technologies and procedures are thus urgently required.To determine the water-saving ...The shortage of groundwater resources is a considerable challenge for winter wheat production on the North China Plain.Water-saving technologies and procedures are thus urgently required.To determine the water-saving potential of using micro-sprinkling irrigation(MSI)for winter wheat production,field experiments were conducted from 2012 to 2015.Compared to traditional flooding irrigation(TFI),micro-sprinkling thrice with 90 mm water(MSI1)and micro-sprinkling four times with 120 mm water(MSI2)increased the water use efficiency by 22.5 and 16.2%,respectively,while reducing evapotranspiration by 17.6 and 10.8%.Regardless of the rainfall pattern,MSI(i.e.,MSI1 or MSI2)either stabilized or significantly increased the grain yield,while reducing irrigation water volumes by 20–40%,compared to TFI.Applying the same volumes of irrigation water,MSI(i.e.,MSI3,micro-sprinkling five times with 150 mm water)increased the grain yield and water use efficiency of winter wheat by 4.6 and 11.7%,respectively,compared to TFI.Because MSI could supply irrigation water more frequently in smaller amounts each time,it reduced soil layer compaction,and may have also resulted in a soil water deficit that promoted the spread of roots into the deep soil layer,which is beneficial to photosynthetic production in the critical period.In conclusion,MSI1 or MSI2 either stabilized or significantly increased grain yield while reducing irrigation water volumes by 20–40%compared to TFI,and should provide water-saving technological support in winter wheat production for smallholders on the North China Plain.展开更多
Receptor-like kinases(RLKs)are important for plant growth,development and defense responses.The S-receptor protein kinases(SRKs),which represent an RLK subfamily,control the selfincompatibility among Brassica species....Receptor-like kinases(RLKs)are important for plant growth,development and defense responses.The S-receptor protein kinases(SRKs),which represent an RLK subfamily,control the selfincompatibility among Brassica species.However,little information is available regarding SRK functions in rice.We identified a gene OsSRK1 encoding an atypical SRK.The transcript of OsSRK1 was induced by abscisic acid(ABA),salt and polyethylene glycol.OsSRK1 localized to the plasma membrane and cytoplasm.Leaf width was increased in OsSRK1-overexpression(OsSRK1-OX)transgenic rice plants,likely because of an increase in cell number per leaf.Furthermore,the expression levels of OsCYCA3-1 and OsCYCD2-1,which encode positive regulators of cell division,were up-regulated in leaf primordium of OsSRK1-OX rice plants relative to those in wild type.Meanwhile,the expression level of OsKRP1,which encodes cell cycle inhibitor,was down-regulated in the OsSRK1-OX plants.Therefore,it is deduced that OsSRK1 regulates leaf width by promoting cell division in the leaf primordium.Additionally,OsSRK1-OX plants exhibited enhanced ABA sensitivity and salt tolerance compared with wild type.These results suggest that OsSRK1 plays important roles in leaf development and salt responses in rice.展开更多
The internal transcribed spacer(ITS)region(ITS1,ITS2 and 5.8S rDNA)of the nuclear ribosomal DNA(nrDNA)was amplified via the PCR method in seventeen different isolates of Phytophthora sojae using the common primers of ...The internal transcribed spacer(ITS)region(ITS1,ITS2 and 5.8S rDNA)of the nuclear ribosomal DNA(nrDNA)was amplified via the PCR method in seventeen different isolates of Phytophthora sojae using the common primers of the ITS of fungi.Around 800 bp-1,000 bp fragments were obtained based on the DL2000 marker and the sequences of the PCR products were tested.Taking isolate USA as outgroup,the phylogenetic tree was constructed by means of maximum parsimony analysis,and the genetic evolution among isolates was analyzed.The results showed that there is a great difference between the base constitution of ITS 1 and ITS2 among various isolates.The seventeen isolates are classified into three groups,and the isolates from the same region belong to the same group,which shows the variation in geography.展开更多
Competition is a common phenomenon in agriculture production.Research on the relationship between competitive ability and crop yield is extensive,but the results have been inconsistent.Few studies have focused on the ...Competition is a common phenomenon in agriculture production.Research on the relationship between competitive ability and crop yield is extensive,but the results have been inconsistent.Few studies have focused on the relationship between population competitive intensity and yield of maize（Zea mays L.）cultivars.The main objective of this study was to determine if a consistent relationship exists between maize yield and competitive ability.A two-year field experiment was conducted,employing a de Wit replacement series design.When two maize cultivars were grown in a mixture,yield was reduced for the modern cultivar and increased for the older cultivar.In each replacement series,per plant level yield of each cultivar,and population level yield of the mixture,decreased with increasing proportion of the older cultivar.Competitive ratio（CR）reflected differences in competitive ability of the three maize cultivars.In each replacement series,population competition pressure（PCP）increased with increasing proportion of the older cultivar,indicating that the older cultivar was a strong competitor.Biomass yield,grain yield,harvest index,thousand-kernel weight,and kernel number per plant,were negatively correlated with PCP.Our results demonstrated that inter-cultivar competition affects maize productivity,and increasing PCP will decrease translocation of assimilates to grain and,ultimately,reduce yield.Therefore,there is a negative correlation between population competitive intensity and yield performance in maize,breeders should develop a communal ideotype that would not perform well in competition in future.展开更多
The study of sperm cellular components at molecular level is crucial for the diagnosis of male unexplained infertility. The aim of the study was to compare the molecular profile of steroid receptors and aromatase in s...The study of sperm cellular components at molecular level is crucial for the diagnosis of male unexplained infertility. The aim of the study was to compare the molecular profile of steroid receptors and aromatase in spermatozoa obtained from two normozoospermic groups of patients issued from couples treated for infertility. We investigated 46 male patients from unexplained infertility couples and from men, 38 where female partners presented with tubal infertility. Sperm ERs (estrogen receptors: alpha and beta), GPER (G protein-coupled estrogen receptor), AR (androgen receptor) and aromatase mRNA expression levels by TaqMan qPCR were analyzed. AR transcript level was significantly lower in sperm of men from unexplained infertility couples vs. men from couples with tubal factor infertility (P = 0.04). Although the AR mRNA expression level did not had any effect on embryo development and its implantation, a significant correlation between AR mRNA levels and clinical pregnancy in unexplained infertility patients was observed. Taken together, AR transcript presence in ejaculated spermatozoa could be a potential marker for unexplained infertility.展开更多
While agricultural green development(AGD)is highly recognized and has become a national strategy in China,it is imperative to bridge the knowledge gaps between AGD and the UN Sustainable Development Goals(SDGs),and to...While agricultural green development(AGD)is highly recognized and has become a national strategy in China,it is imperative to bridge the knowledge gaps between AGD and the UN Sustainable Development Goals(SDGs),and to evaluate the contribution of AGD to meeting the SDGs.The first aim of this study was to compare the AGD goals and indicators with those of the SDGs so as to identify their relationship.The next aim was to examine the historical evolution of AGD indicators and analyze the gaps between the current status of various indicators and their benchmarks.Limiting factors were identified in China's transition toward AGD.These findings reveal that the indicators of AGD align with those of the SDGs,but have greater specificity to the context in China and are more quantifiable.There has been a significant increase per capita calorie and protein intakes in China,as well as a notable rise in agricultural output per unit of arable land and rural incomes from 1980 to the 2010s.However,these achievements have been accompanied by a high resource use and environmental pollution,highlighting the need for a more sustainable,environmentally responsible agriculture in China.展开更多
Given climate change can potentially influence crop phenology and subsequent yield, an investigation of relevant adaptation measures could increase the understanding and mitigation of these responses in the future. In...Given climate change can potentially influence crop phenology and subsequent yield, an investigation of relevant adaptation measures could increase the understanding and mitigation of these responses in the future. In this study, field observations at 10 stations in the Huang- Huai-Hai Plain of China （HHHP） are used in combination with the Agricultural Production Systems Simulator （APSIM）-Wheat model to determine the effect of thermal time shift on the phenology and potential yield of wheat from 1981-2009. Warming climate speeds up winter wheat development and thereby decreases the duration of the wheat growth period. However, APSIM-Wheat model simulation suggests prolongation of the period from flowering to maturity （Gr） of winter wheat by 0.2-0.8 d·10yr^-1 as the number of days by which maturity advances, which is less than that by which flowering advances. Based on computed thermal time of the two critical growth phases of wheat, total thermal time from floral initiation to flowering （TT_floral_initiation） increasesd in seven out of the 10 investigated stations. Altematively, total thermal time from the start of grainfilling to maturity （TT_start grain_fill） increased in all investigated stations, except Laiyang. It is thus concluded that thermal time shift during the past three decades （1981- 2009） prolongs Gr by 0.2-3.0 d·10yr^-1 in the study area. This suggests that an increase in thermal time （TT） of the wheat growth period is critical for mitigating the effect of growth period reduction due to warming climatic condition. Furthermore, climate change reduces potential yield of winter wheat in 80% of the stations by 2.3-58.8 kg·yr^-1. However, thermal time shift （TTS） increases potential yield of winter wheat in most of the stations by 3.0-51.0 Received September 16, 2015; accepted January 24, 2016 kg·yr^-1. It is concluded that wheat cultivars with longer growth periods and higher thermal requirements could mitigate the negative effects of warming climate on crop production in the study area.展开更多
The expression of humanα-1,2-fucosyltransferase(HT)or complement regulatory proteins has been proved as an strategy to overcome hypercute rejection in discordant xenogeneic organ transplantation.In this study,we exam...The expression of humanα-1,2-fucosyltransferase(HT)or complement regulatory proteins has been proved as an strategy to overcome hypercute rejection in discordant xenogeneic organ transplantation.In this study,we examined whether peripheral blood mononuclear cells(PBMCs)from polytransgenic mice expressing the human HT,and complement regulatory proteins(DAF and CD59),can provide more effective protection against xenograft rejection.Transgenic mice were produced by co-injection of gene constructs for human HT,DAF and/or CD59.Flow Cytometry(FCM)was used to screen the positive transgenic mice.PBMCs from transgenic mice were incubated with 15%human serum to evaluate natural antibody binding,complement activation and expression of adhesion molecules.Three transgenes were strongly expressed in PBMCs of transgenic mice,and HT expression signifi-cantly reduced expression of the major xenoepitope galactose-α-1,3-galactose(α-Gal).Functional studies with PBMCs showed that co-expression of HT and DAF or CD59 markedly increased their re-sistance to human serum-mediated cytolysis when compared with single transgenic PBMCs.Moreover,the combined expression of triple transgenes in PBMCs led to the greatest protection against human serum-mediated cytolysis,avoided hyperacute rejection and reduced expression of adhesion mole-cules.Strong co-expression of triple transgenes was completely protected from xenograft hyperacute rejection and partially inhibited acute vascular rejection.The studies suggest that engineering mice to express triple molecules represents an critical step toward prolonging xenograft survival and might be more suitable for xenotransplantation.展开更多
A method of constructing restriction map by optical mapping and single molecule fluorescent microscopy is described. DNA molecules were aligned and adsorbed on a glass coverslip surface by a modified 'molecular co...A method of constructing restriction map by optical mapping and single molecule fluorescent microscopy is described. DNA molecules were aligned and adsorbed on a glass coverslip surface by a modified 'molecular combing' technique, and then the surface-immobilized DNAs were cleaved in situ with a restriction endonuclease. Individual DNA molecules digested by the endonuclease EcoR I were observable with fluorescent microscopy. Using optical mapping, a physical map of a rice bacterial artificial chro-mosome clone was constructed. This method will facilitate genomic mapping and tracing the dynamic process in real time at a single molecule level with fluorescence microscopy.展开更多
The classical view of signaling between cells of immune system includes two major routes of intercellular communication:Through the release of extracellular molecules or a direct interaction between membrane bound rec...The classical view of signaling between cells of immune system includes two major routes of intercellular communication:Through the release of extracellular molecules or a direct interaction between membrane bound receptor and its membrane bound ligand,which initiate a cascade of signaling in target cell.However,recent studies indicate that besides these canonical modes of signaling there are also noncanonical routs of intercellular communications through membrane stripping/membrane exchange/trogocytosis,extracellular traps,exosomes and ectososmes/microparticles.In this review we discuss what are the components of noncanonical pathways of signaling and what role they play in immune cells interactions.展开更多
THE Loess Plateau of Shaanxi Province has traditionally been a poverty-stricken area.Local farmers would grow grains like winter wheat and spring corn,and every July,August,and September plow the fields and collect ra...THE Loess Plateau of Shaanxi Province has traditionally been a poverty-stricken area.Local farmers would grow grains like winter wheat and spring corn,and every July,August,and September plow the fields and collect rain water.The plateau featured desolate scenery with dry,powdery,wind-blown soil,with barely a trace of green.展开更多
Auxin and jasmonic acid （JA） are two plant phytohormones that both participate in the regulation of many developmental processes. Jasmonic acid also plays important roles in plant stress response reactions. Although...Auxin and jasmonic acid （JA） are two plant phytohormones that both participate in the regulation of many developmental processes. Jasmonic acid also plays important roles in plant stress response reactions. Although extensive investigations have been undertaken to study the biological functions of auxin and JA, little attention has been paid to the cross-talk between their regulated pathways. In the few available reports examining the effects of auxin on the expression of JA or JA-responsive genes, both synergetic and antagonistic results have been found. To further investigate the relationship between auxin and JA, we adopted an integrative method that combines microarray expression data with pathway information to study the behavior of the JA biosynthesis pathway under auxin treatment. Our results showed an overall downregulation of genes involved in JA biosynthesis, providing the first report of a relationship between auxin and the JA synthesis pathway in Arabidopsis seedlings.展开更多
Myostatin(GDF8,MSTN)is a member of the transforming growth factor beta su-perfamily that is essential for proper regulation of skeletal muscle mass.In order to study its ex-pression and regulatory mechanism deeply,we ...Myostatin(GDF8,MSTN)is a member of the transforming growth factor beta su-perfamily that is essential for proper regulation of skeletal muscle mass.In order to study its ex-pression and regulatory mechanism deeply,we have presented a comparative analysis of about 170-kb pig BAC sequence containing the myostatin gene among pig,human and mouse.The genomic region is characterized by high interspersed repeats and low G+C content.As for the myostatin gene,a higher sequence similarity is found between human and pig than between these species and the mouse.One striking feature is that the structure of two TATA-boxes in the nearby downstream of CCAAT-box is identified in the promoter.Further analysis reveals that the TATA-box1 is responsible for the transcription in pig and human,but the TATA-box2 acts on the transcription in mouse.The other interesting feature is that two polyadenylation signal sequences(AATAAA)exist in 3′UTR of the pig myostatin gene.Moreover,a large number of potential tran-scription factor-binding sites are also identified in evolutionary conserved regions(ECRs),which may be associated with the regulation of myostatin.Many putative transcription factors play an important role in the muscle development,and the complex interaction between myostatin and these factors may be required for proper muscle development.展开更多
A better understanding of wheat functional genomics can improve targeted breeding for better agronomic traits and environmental adaptation.However,the lack of gene-indexed mutants and the low transformation efficiency...A better understanding of wheat functional genomics can improve targeted breeding for better agronomic traits and environmental adaptation.However,the lack of gene-indexed mutants and the low transformation efficiency of wheat limit in-depth gene functional studies and genetic manipulation for breeding.In this study,we created a library for KN9204,a popular wheat variety in northern China,with a reference genome,transcriptome,and epigenome of different tissues,using ethyl methyl sulfonate(EMS)mutagenesis.This library contains a vast developmental diversity of critical tissues and transition stages.Exome capture sequencing of 2090 mutant lines using KN9204 genome-designed probes revealed that 98.79%of coding genes had mutations,and each line had an average of 1383 EMS-type SNPs.We identified new allelic variations for crucial agronomic trait-related genes such as Rht-D1,Q,TaTB1,and WFZP.We tested 100 lines with severemutations in 80 NAC transcription factors(TFs)under drought and salinity stress and identified 13 lines with altered sensitivity.Further analysis of three lines using transcriptome and chromatin accessibility data revealed hundreds of direct NAC targets with altered transcription patterns under salt or drought stress,including SNAC1,DREB2B,CML16,and ZFP182,factors known to respond to abiotic stress.Thus,we have generated and indexed a KN9204 EMS mutant library that can facilitate functional genomics research and offer resources for genetic manipulation of wheat.展开更多
Using trans-lysozyme gene rice line D2-1-2 and its restorer Zhonghua No.9 as test materials,we studied their agronomic characters and grain qualities under two ecological conditions of Yunnan Province.The results show...Using trans-lysozyme gene rice line D2-1-2 and its restorer Zhonghua No.9 as test materials,we studied their agronomic characters and grain qualities under two ecological conditions of Yunnan Province.The results show that there were no significant differences in the agronomic characters between D2-1-2 and Zhonghua No.9,but the seed setting rate and plant height of D2-1-2 were significantly lower,while the protein,amino acid and mineral element(Ca,Fe and Zn in particular)contents in its crude grain were higher than those of Zhonghua No.9.It is suggested that there could be some potential genetic variances in the transgenic plant and the possibly induced environmental risk should be evaluated in multi-plots for several years.展开更多
The fabrication of surface enhanced Raman spectroscopy(SERS)substrates with controlled high density hot spots still remains challenging.Herein,we report highly effective SERS substrates containing the self-generating(...The fabrication of surface enhanced Raman spectroscopy(SERS)substrates with controlled high density hot spots still remains challenging.Herein,we report highly effective SERS substrates containing the self-generating(SG)nanogaps from polystyrene nanosphere monolayer through isotropic plasma etching.The emergence of multimode hot spots,i.e.,metal film over nanosphere(MFON)-like hot spots(closed gaps,0 nm),individual self-aligned hot spots(discrete gaps,>20 nm)and threedimensional(3D)hot spots(nanogaps,1-10 nm),makes the SG SERS substrates superior as compared to the traditional MFON or the well-ordered self-aligned SERS substrates in terms of enhancement,uniformity,and reproducibility.The SG SERS substrates can function as the excellent SERS platforms for trace molecule detection in the practical application fields.展开更多
基金the National Key Research and Development Program of China (2017YFD0300302)the earmarked fund for China Agriculture Research System (CARS-02-25)the Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences for their support
文摘Intraspecific competition is a common phenomenon in agricultural production,and maize is one of the most sensitive grass species to intraspecific competition due to its low tillering ability.This study evaluated and analyzed intraspecific competition in maize,and screened competitive indices that could be used to evaluate intraspecific competition in a maize population.A 2-year field experiment was conducted using the maize hybrid Zhongdan 2 at 12 plant densities ranging from 1.5 to 18.0 plants（pl）m-2.The results showed that the response of single-plant grain yield and dry matter at harvest to increased plant density decreased exponentially and that the harvest index decreased linearly.The response of population-level grain yield to plant density was curvilinear,producing a maximum value at the optimum population density.However,the yielddensity equation agreed well with the Steinhart-Hart equation curves,but not with the quadratic equation curves reported by most previous studies.Competitive indices are used to evaluate competition in a plant population or plant species.The present results show that competitive intensity（CI）and absolute severity of competition（ASC）increased with increasing plant density;however,relative yield（RY）and relative reproductive efficiency（RReff）decreased.The different responses of these indices reflect different aspects of competition.According to the analysis of CI,ASC,RY,and RReff,higher CI and ASC values indicate higher intraspecific competition,whereas higher RY and RReff values indirectly reflect lower intraspecific competition.These competitive indices evaluate not only the intraspecific competitive intensity under different plant densities of the same cultivar but also those of different cultivars under the same plant density.However,some overlap exists in the calculations of ASC,CI,and RY,so one could simply select any one of these indices to evaluate intraspecific competition in a maize population.In conclusion,the present study provides a method to evaluate intraspecific competition in maize populations,which may be beneficial for breeding high-yield maize varieties in the future.
基金funded by the National Natural Science Foundation of China(31000250)the National 973 Program of China(2009CB118607)
文摘The inlfuences of tillage systems on soil carbon （C） stocks have been studied extensively, but the distribution of soil C within aggregate fractions is not well understood. The objective of this study was to determine the inlfuences of various tillage systems on soil aggregation and aggregate-associated C under wheat （Triticum aestivum L.） and corn （Zea mays L.） double cropping systems in the North China Plain. The experiment was established in 2001, including four treatments：moldboard plow （MP） with residue （MP＋R） and without residue （MP-R）, rotary tillage with residue （RT）, and no-till with residue （NT）. In 2007 soil samples were collected from the 0-5, 5-10, and 10-20 cm depths, and were separated into four aggregate-size classes （〉2 000, 250-2 000, 53-250, and〈53 μm） by wet-sieving method. Aggregate-associated C was determined, and the relationships between total soil C concentration and aggregation-size fractions were examined. The results showed that NT and RT treatments signiifcantly increased the proportion of macroaggregate fractions （〉2 000 and 250-2 000 μm） compared with the MP-R and MP＋R treatments. Averaged across all depths, mean weight diameters of aggregates （MWD） in NT and RT were 47 and 20% higher than that in MP＋R. The concentration of bulk soil organic C was positively correlated with MWD （r=0.98; P=0.024） and macroaggregate fraction （r=0.96; P=0.036） in the 0-5 cm depth. In the 0-20 cm depth, comparing with MP＋R, total C occluded in the〉2 000 μm fraction was increased by 9 and 6%under NT and RT, respectively. We conclude that adoption of conservation tillage system, especially no-till, can increase soil macro-aggregation and total C accumulation in macroaggregates, which may improve soil C sequestration in the intensive agricultural region of the North China Plain.
基金the National Key Research and Development Program of China(2017YFD0300203 and 2016YFD0300105)。
文摘The shortage of groundwater resources is a considerable challenge for winter wheat production on the North China Plain.Water-saving technologies and procedures are thus urgently required.To determine the water-saving potential of using micro-sprinkling irrigation(MSI)for winter wheat production,field experiments were conducted from 2012 to 2015.Compared to traditional flooding irrigation(TFI),micro-sprinkling thrice with 90 mm water(MSI1)and micro-sprinkling four times with 120 mm water(MSI2)increased the water use efficiency by 22.5 and 16.2%,respectively,while reducing evapotranspiration by 17.6 and 10.8%.Regardless of the rainfall pattern,MSI(i.e.,MSI1 or MSI2)either stabilized or significantly increased the grain yield,while reducing irrigation water volumes by 20–40%,compared to TFI.Applying the same volumes of irrigation water,MSI(i.e.,MSI3,micro-sprinkling five times with 150 mm water)increased the grain yield and water use efficiency of winter wheat by 4.6 and 11.7%,respectively,compared to TFI.Because MSI could supply irrigation water more frequently in smaller amounts each time,it reduced soil layer compaction,and may have also resulted in a soil water deficit that promoted the spread of roots into the deep soil layer,which is beneficial to photosynthetic production in the critical period.In conclusion,MSI1 or MSI2 either stabilized or significantly increased grain yield while reducing irrigation water volumes by 20–40%compared to TFI,and should provide water-saving technological support in winter wheat production for smallholders on the North China Plain.
基金This work was supported by grants from Excellent Middle-Aged and Youth Scientist Award Foundation of Shandong Province(Grant No.BS2014SW029)the Shandong Natural Science Foundation(Grant Nos.ZR2016CB17 and ZR2018ZC08N2)Shandong Major Agricultural Applied Technological Innovation Projects(Grant No.2017.04-2020.04)in China.
文摘Receptor-like kinases(RLKs)are important for plant growth,development and defense responses.The S-receptor protein kinases(SRKs),which represent an RLK subfamily,control the selfincompatibility among Brassica species.However,little information is available regarding SRK functions in rice.We identified a gene OsSRK1 encoding an atypical SRK.The transcript of OsSRK1 was induced by abscisic acid(ABA),salt and polyethylene glycol.OsSRK1 localized to the plasma membrane and cytoplasm.Leaf width was increased in OsSRK1-overexpression(OsSRK1-OX)transgenic rice plants,likely because of an increase in cell number per leaf.Furthermore,the expression levels of OsCYCA3-1 and OsCYCD2-1,which encode positive regulators of cell division,were up-regulated in leaf primordium of OsSRK1-OX rice plants relative to those in wild type.Meanwhile,the expression level of OsKRP1,which encodes cell cycle inhibitor,was down-regulated in the OsSRK1-OX plants.Therefore,it is deduced that OsSRK1 regulates leaf width by promoting cell division in the leaf primordium.Additionally,OsSRK1-OX plants exhibited enhanced ABA sensitivity and salt tolerance compared with wild type.These results suggest that OsSRK1 plays important roles in leaf development and salt responses in rice.
基金supported by National Natural Science Fundation of China(No.30400285,30671317)Postdoctoral Grant from Ag-riculture Sciences Academy of Heilongjiang Province(No.LRB06-010)+4 种基金China Postdoctoral Grant,Item for Teachers from Heilongjiang University(No.140022)Young People’s Science Fund of Heilongjiang Province(No.QC06C012)973(No.2004CB117203-4)the Opening Fund of Key Opening Laboratory of Physiology and Ecology of Crop in Cold Terra of Agriculture Ministry"the Cloning and Mapping of cDNA Sequence from Related Gene Resistant to Phytophthora sojaeInternational Tech-nology Cooperation Item(No.2005DFA30340).
文摘The internal transcribed spacer(ITS)region(ITS1,ITS2 and 5.8S rDNA)of the nuclear ribosomal DNA(nrDNA)was amplified via the PCR method in seventeen different isolates of Phytophthora sojae using the common primers of the ITS of fungi.Around 800 bp-1,000 bp fragments were obtained based on the DL2000 marker and the sequences of the PCR products were tested.Taking isolate USA as outgroup,the phylogenetic tree was constructed by means of maximum parsimony analysis,and the genetic evolution among isolates was analyzed.The results showed that there is a great difference between the base constitution of ITS 1 and ITS2 among various isolates.The seventeen isolates are classified into three groups,and the isolates from the same region belong to the same group,which shows the variation in geography.
基金National Basic Research Program of China (973 Program, 2015CB150401)the National Maize Industry Technology Research and Development Center, Ministry of Agriculture,Chinathe Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences for their supports
文摘Competition is a common phenomenon in agriculture production.Research on the relationship between competitive ability and crop yield is extensive,but the results have been inconsistent.Few studies have focused on the relationship between population competitive intensity and yield of maize（Zea mays L.）cultivars.The main objective of this study was to determine if a consistent relationship exists between maize yield and competitive ability.A two-year field experiment was conducted,employing a de Wit replacement series design.When two maize cultivars were grown in a mixture,yield was reduced for the modern cultivar and increased for the older cultivar.In each replacement series,per plant level yield of each cultivar,and population level yield of the mixture,decreased with increasing proportion of the older cultivar.Competitive ratio（CR）reflected differences in competitive ability of the three maize cultivars.In each replacement series,population competition pressure（PCP）increased with increasing proportion of the older cultivar,indicating that the older cultivar was a strong competitor.Biomass yield,grain yield,harvest index,thousand-kernel weight,and kernel number per plant,were negatively correlated with PCP.Our results demonstrated that inter-cultivar competition affects maize productivity,and increasing PCP will decrease translocation of assimilates to grain and,ultimately,reduce yield.Therefore,there is a negative correlation between population competitive intensity and yield performance in maize,breeders should develop a communal ideotype that would not perform well in competition in future.
文摘The study of sperm cellular components at molecular level is crucial for the diagnosis of male unexplained infertility. The aim of the study was to compare the molecular profile of steroid receptors and aromatase in spermatozoa obtained from two normozoospermic groups of patients issued from couples treated for infertility. We investigated 46 male patients from unexplained infertility couples and from men, 38 where female partners presented with tubal infertility. Sperm ERs (estrogen receptors: alpha and beta), GPER (G protein-coupled estrogen receptor), AR (androgen receptor) and aromatase mRNA expression levels by TaqMan qPCR were analyzed. AR transcript level was significantly lower in sperm of men from unexplained infertility couples vs. men from couples with tubal factor infertility (P = 0.04). Although the AR mRNA expression level did not had any effect on embryo development and its implantation, a significant correlation between AR mRNA levels and clinical pregnancy in unexplained infertility patients was observed. Taken together, AR transcript presence in ejaculated spermatozoa could be a potential marker for unexplained infertility.
基金financially supported by the National Natural Science Foundation of China(31972517)Key R&D Program of Hebei,China(21327507D)。
文摘While agricultural green development(AGD)is highly recognized and has become a national strategy in China,it is imperative to bridge the knowledge gaps between AGD and the UN Sustainable Development Goals(SDGs),and to evaluate the contribution of AGD to meeting the SDGs.The first aim of this study was to compare the AGD goals and indicators with those of the SDGs so as to identify their relationship.The next aim was to examine the historical evolution of AGD indicators and analyze the gaps between the current status of various indicators and their benchmarks.Limiting factors were identified in China's transition toward AGD.These findings reveal that the indicators of AGD align with those of the SDGs,but have greater specificity to the context in China and are more quantifiable.There has been a significant increase per capita calorie and protein intakes in China,as well as a notable rise in agricultural output per unit of arable land and rural incomes from 1980 to the 2010s.However,these achievements have been accompanied by a high resource use and environmental pollution,highlighting the need for a more sustainable,environmentally responsible agriculture in China.
基金Acknowledgements This study is supported by the National Natural Science Foundation of China （Grant Nos. 41401104 and 41371002）, Natural Science Foundation of Hebei Province, China （D2015302017）, China Postdoctoral Science Foundation funded project （2015M570167）, and the Science and Technology Planning Project of Hebei Academy of Science （15101）. We are grateful to the editors and anonymous reviewers for their insightful inputs at the review phase of this work.
文摘Given climate change can potentially influence crop phenology and subsequent yield, an investigation of relevant adaptation measures could increase the understanding and mitigation of these responses in the future. In this study, field observations at 10 stations in the Huang- Huai-Hai Plain of China （HHHP） are used in combination with the Agricultural Production Systems Simulator （APSIM）-Wheat model to determine the effect of thermal time shift on the phenology and potential yield of wheat from 1981-2009. Warming climate speeds up winter wheat development and thereby decreases the duration of the wheat growth period. However, APSIM-Wheat model simulation suggests prolongation of the period from flowering to maturity （Gr） of winter wheat by 0.2-0.8 d·10yr^-1 as the number of days by which maturity advances, which is less than that by which flowering advances. Based on computed thermal time of the two critical growth phases of wheat, total thermal time from floral initiation to flowering （TT_floral_initiation） increasesd in seven out of the 10 investigated stations. Altematively, total thermal time from the start of grainfilling to maturity （TT_start grain_fill） increased in all investigated stations, except Laiyang. It is thus concluded that thermal time shift during the past three decades （1981- 2009） prolongs Gr by 0.2-3.0 d·10yr^-1 in the study area. This suggests that an increase in thermal time （TT） of the wheat growth period is critical for mitigating the effect of growth period reduction due to warming climatic condition. Furthermore, climate change reduces potential yield of winter wheat in 80% of the stations by 2.3-58.8 kg·yr^-1. However, thermal time shift （TTS） increases potential yield of winter wheat in most of the stations by 3.0-51.0 Received September 16, 2015; accepted January 24, 2016 kg·yr^-1. It is concluded that wheat cultivars with longer growth periods and higher thermal requirements could mitigate the negative effects of warming climate on crop production in the study area.
基金Supported by the Doctor Initiation Foundation of Zhengzhou University
文摘The expression of humanα-1,2-fucosyltransferase(HT)or complement regulatory proteins has been proved as an strategy to overcome hypercute rejection in discordant xenogeneic organ transplantation.In this study,we examined whether peripheral blood mononuclear cells(PBMCs)from polytransgenic mice expressing the human HT,and complement regulatory proteins(DAF and CD59),can provide more effective protection against xenograft rejection.Transgenic mice were produced by co-injection of gene constructs for human HT,DAF and/or CD59.Flow Cytometry(FCM)was used to screen the positive transgenic mice.PBMCs from transgenic mice were incubated with 15%human serum to evaluate natural antibody binding,complement activation and expression of adhesion molecules.Three transgenes were strongly expressed in PBMCs of transgenic mice,and HT expression signifi-cantly reduced expression of the major xenoepitope galactose-α-1,3-galactose(α-Gal).Functional studies with PBMCs showed that co-expression of HT and DAF or CD59 markedly increased their re-sistance to human serum-mediated cytolysis when compared with single transgenic PBMCs.Moreover,the combined expression of triple transgenes in PBMCs led to the greatest protection against human serum-mediated cytolysis,avoided hyperacute rejection and reduced expression of adhesion mole-cules.Strong co-expression of triple transgenes was completely protected from xenograft hyperacute rejection and partially inhibited acute vascular rejection.The studies suggest that engineering mice to express triple molecules represents an critical step toward prolonging xenograft survival and might be more suitable for xenotransplantation.
基金Thiswork was supported by the Fund of the Chinese Academy of Sciences (Grant No. Kj-951-603).
文摘A method of constructing restriction map by optical mapping and single molecule fluorescent microscopy is described. DNA molecules were aligned and adsorbed on a glass coverslip surface by a modified 'molecular combing' technique, and then the surface-immobilized DNAs were cleaved in situ with a restriction endonuclease. Individual DNA molecules digested by the endonuclease EcoR I were observable with fluorescent microscopy. Using optical mapping, a physical map of a rice bacterial artificial chro-mosome clone was constructed. This method will facilitate genomic mapping and tracing the dynamic process in real time at a single molecule level with fluorescence microscopy.
基金Supported by William Stamps Farish FundDonald D.Hammill Foundation
文摘The classical view of signaling between cells of immune system includes two major routes of intercellular communication:Through the release of extracellular molecules or a direct interaction between membrane bound receptor and its membrane bound ligand,which initiate a cascade of signaling in target cell.However,recent studies indicate that besides these canonical modes of signaling there are also noncanonical routs of intercellular communications through membrane stripping/membrane exchange/trogocytosis,extracellular traps,exosomes and ectososmes/microparticles.In this review we discuss what are the components of noncanonical pathways of signaling and what role they play in immune cells interactions.
文摘THE Loess Plateau of Shaanxi Province has traditionally been a poverty-stricken area.Local farmers would grow grains like winter wheat and spring corn,and every July,August,and September plow the fields and collect rain water.The plateau featured desolate scenery with dry,powdery,wind-blown soil,with barely a trace of green.
文摘Auxin and jasmonic acid （JA） are two plant phytohormones that both participate in the regulation of many developmental processes. Jasmonic acid also plays important roles in plant stress response reactions. Although extensive investigations have been undertaken to study the biological functions of auxin and JA, little attention has been paid to the cross-talk between their regulated pathways. In the few available reports examining the effects of auxin on the expression of JA or JA-responsive genes, both synergetic and antagonistic results have been found. To further investigate the relationship between auxin and JA, we adopted an integrative method that combines microarray expression data with pathway information to study the behavior of the JA biosynthesis pathway under auxin treatment. Our results showed an overall downregulation of genes involved in JA biosynthesis, providing the first report of a relationship between auxin and the JA synthesis pathway in Arabidopsis seedlings.
基金The sequence data described in this paper have been submitted to GenBank under accession No.AY208121.
文摘Myostatin(GDF8,MSTN)is a member of the transforming growth factor beta su-perfamily that is essential for proper regulation of skeletal muscle mass.In order to study its ex-pression and regulatory mechanism deeply,we have presented a comparative analysis of about 170-kb pig BAC sequence containing the myostatin gene among pig,human and mouse.The genomic region is characterized by high interspersed repeats and low G+C content.As for the myostatin gene,a higher sequence similarity is found between human and pig than between these species and the mouse.One striking feature is that the structure of two TATA-boxes in the nearby downstream of CCAAT-box is identified in the promoter.Further analysis reveals that the TATA-box1 is responsible for the transcription in pig and human,but the TATA-box2 acts on the transcription in mouse.The other interesting feature is that two polyadenylation signal sequences(AATAAA)exist in 3′UTR of the pig myostatin gene.Moreover,a large number of potential tran-scription factor-binding sites are also identified in evolutionary conserved regions(ECRs),which may be associated with the regulation of myostatin.Many putative transcription factors play an important role in the muscle development,and the complex interaction between myostatin and these factors may be required for proper muscle development.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA24010204)to J.X.,the Hebei Natural Science Foundation(C2021205013)"Full-time introduction of high-end talent research project"(2020HBQZYC004)to X.-g.L.+3 种基金the National Natural Science Foundation of China(U22A6009)to J.-m.L.the Research Program for Network Security and Information of the Chinese Academy of Sciences(CAS-WX2021SF-0109)to F.H.and J.X.the National Key Research and Developmental Program of China(2021YFD1201500)to J.X.a China Postdoctoral Science Foundation-funded project(2020M680742)to D.-z.W.
文摘A better understanding of wheat functional genomics can improve targeted breeding for better agronomic traits and environmental adaptation.However,the lack of gene-indexed mutants and the low transformation efficiency of wheat limit in-depth gene functional studies and genetic manipulation for breeding.In this study,we created a library for KN9204,a popular wheat variety in northern China,with a reference genome,transcriptome,and epigenome of different tissues,using ethyl methyl sulfonate(EMS)mutagenesis.This library contains a vast developmental diversity of critical tissues and transition stages.Exome capture sequencing of 2090 mutant lines using KN9204 genome-designed probes revealed that 98.79%of coding genes had mutations,and each line had an average of 1383 EMS-type SNPs.We identified new allelic variations for crucial agronomic trait-related genes such as Rht-D1,Q,TaTB1,and WFZP.We tested 100 lines with severemutations in 80 NAC transcription factors(TFs)under drought and salinity stress and identified 13 lines with altered sensitivity.Further analysis of three lines using transcriptome and chromatin accessibility data revealed hundreds of direct NAC targets with altered transcription patterns under salt or drought stress,including SNAC1,DREB2B,CML16,and ZFP182,factors known to respond to abiotic stress.Thus,we have generated and indexed a KN9204 EMS mutant library that can facilitate functional genomics research and offer resources for genetic manipulation of wheat.
文摘Using trans-lysozyme gene rice line D2-1-2 and its restorer Zhonghua No.9 as test materials,we studied their agronomic characters and grain qualities under two ecological conditions of Yunnan Province.The results show that there were no significant differences in the agronomic characters between D2-1-2 and Zhonghua No.9,but the seed setting rate and plant height of D2-1-2 were significantly lower,while the protein,amino acid and mineral element(Ca,Fe and Zn in particular)contents in its crude grain were higher than those of Zhonghua No.9.It is suggested that there could be some potential genetic variances in the transgenic plant and the possibly induced environmental risk should be evaluated in multi-plots for several years.
基金This work was supported by the National Natural Science Foundation of China(Nos.51821002 and 21790053)the China Postdoctoral Science Foundation(No.2016M591908).
文摘The fabrication of surface enhanced Raman spectroscopy(SERS)substrates with controlled high density hot spots still remains challenging.Herein,we report highly effective SERS substrates containing the self-generating(SG)nanogaps from polystyrene nanosphere monolayer through isotropic plasma etching.The emergence of multimode hot spots,i.e.,metal film over nanosphere(MFON)-like hot spots(closed gaps,0 nm),individual self-aligned hot spots(discrete gaps,>20 nm)and threedimensional(3D)hot spots(nanogaps,1-10 nm),makes the SG SERS substrates superior as compared to the traditional MFON or the well-ordered self-aligned SERS substrates in terms of enhancement,uniformity,and reproducibility.The SG SERS substrates can function as the excellent SERS platforms for trace molecule detection in the practical application fields.
