With the development of information technology,more and more devices are connected to the Internet through wireless communication to complete data interconnection.Due to the broadcast characteristics ofwireless channe...With the development of information technology,more and more devices are connected to the Internet through wireless communication to complete data interconnection.Due to the broadcast characteristics ofwireless channels,wireless networks have suffered more and more malicious attacks.Physical layer security has received extensive attention from industry and academia.MIMO is considered to be one of the most important technologies related to physical layer security.Through beamforming technology,messages can be transmitted to legitimate users in an offset direction that is as orthogonal as possible to the interference channel to ensure the reception SINR by legitimate users.Combining the symbiotic radio(SR)technology,this paper considers a symbiotic radio antijamming MIMO system equipped with a multi-antenna system at the main base station.In order to avoid the interference signal and improve the SINR of the signal received by the user.The base station is equipped with a uniform rectangular antenna array,and using Null Space Projection(NSP)Beamforming,Intelligent Reflecting Surface(IRS)can assist in changing the beam’s angle.The simulation results show that NSP Beamforming could make a better use of the null space of interference,which can effectively improve the received SINR of users under directional interference,and improve the utilization efficiency of signal energy.展开更多
Rhizobia induces nitrogen-fixing nodules in legumes used in agricultural production,providing a direct source of combined nitrogen to leguminous crops.Small peptides,such as CLAVATA3/EMBRYO SURROUNDING REGION peptides(...Rhizobia induces nitrogen-fixing nodules in legumes used in agricultural production,providing a direct source of combined nitrogen to leguminous crops.Small peptides,such as CLAVATA3/EMBRYO SURROUNDING REGION peptides(CLE),are known to regulate the formation and development of nitrogen-fixing nodules in legumes.Root meristem growth factor(RGF)peptides from Medicago truncatula not only regulate root develop-ment but also modulate nodulation symbiosis with Sinorhizobium meliloti.However,the impact of RGF peptides from one leguminous species on the others remains unclear.In this study,we investigate the effects of the RGF family peptide MtRGF6p from M.truncatula on nodulation symbiosis and root development in Lotus japonicus.The MtRGF6 gene is predominantly expressed in the root nodules of M.truncatula and shows low identity with RGF homologous genes from L.japonicus.The gene promoter is active in the primordia of root nodules and lat-eral roots,as well as in young nodules and roots,and the meristem,infection,and nitrogen-fixing regions of the mature nodule.Chemically synthesized MtRGF6p promoted primary root growth in M.truncatula but sup-pressed the growth of L.japonicus primary roots.The peptide negatively affected the initiation of nodule primor-dia,the formation of infection threads,and nodulation in both legumes,with a low dosage showing effects on L.japonicus compared to M.truncatula.These results suggest that the MtRGF6 peptide from M.truncatula may serve as an inter-species signal affecting the root organ development of L.japonicus.展开更多
It was focused on the effect of different sludge concentrations on the performances of an algal-activated sludge symbiotic system in terms of wastewater treatment, algal-activated sludge characteristics and community ...It was focused on the effect of different sludge concentrations on the performances of an algal-activated sludge symbiotic system in terms of wastewater treatment, algal-activated sludge characteristics and community structure. The results showed that the highest nutrient removal efficiencies were obtained in the reactor R^2 with soluble chemical oxygen demand(sC OD), ammonia nitrogen(NH_4^+-N) and phosphate(PO_4^(3-)-P) removal efficiencies of(90.6 ± 2.3)%,(97.69 ± 2.6)% and(83.81 ± 2.3)%, respectively. Further investigation exhibited that sludge concentration has a great effect on the dissolved oxygen(DO) concentration, the pH, the growth of algae and the extracellular polymeric substance(EPS) production, which resulted in influencing the settleability and the performance of symbiotic system. The denaturing gradient gel electrophoresis(DGGE) analysis demonstrated that the sludge concentration had a selective power for particular members of algae. Meantime, the stimulated algal population would selectively excite the members of bacteria benefited for the formation of algal-bacterial consortia.The variation of microbial compositions, which was influenced by the different sludge concentrations, might be ultimately responsible for the different treatment performances.展开更多
Background Apolygus lucorum is a worldwide omnivorous pest damaging a range of crops and causing great economic losses.Symbiotic bacteria living in insects play a key role in the nutrition,physiology,and behavior of h...Background Apolygus lucorum is a worldwide omnivorous pest damaging a range of crops and causing great economic losses.Symbiotic bacteria living in insects play a key role in the nutrition,physiology,and behavior of hosts.Here,we present an experiment using Illumina HiSeq sequencing targeting the V3–V4 regions of bacteria’s 16S rRNA throughout the entire life cycle of A.lucorum.Results The first and second instar nymphs have the largest alpha diversity compared with other life stages of the insect.Bacterial phyla Proteobacteria(72.29%),Firmicutes(15.24%),Actinobacteria(7.76%)exhibit the largest relative abundance in all developmental stages.Erwinia(23.97%)and Lactococcus(10.62%)are the two genera with the high-est relative abundance.The relative abundance of Erwinia in the nymph stage is significantly greater than the adult stage,and the relative abundance of Lactococcus in 6-day-old and 9-day-old adult females is higher compared with adult males.Conclusions These results reveal that microbial community composition and relative abundance shift dynamically at different life stages,implying that different bacterial phyla and genera may have specific roles in specific life stages such as metabolism,nutrition absorption,detoxification,and reproduction.This study reveals for the first time the community composition and ecological dynamics of symbiotic bacteria throughout the life stages of A.lucorum,and thus may provide insight to new strategies for pest control.展开更多
The symbiotic FM radio data system(SRDS)is a radio data system that a specially designed OFDM signal co-lives with FM signal,which enables a significantly higher data rate than existing radio data systems.The cyclic p...The symbiotic FM radio data system(SRDS)is a radio data system that a specially designed OFDM signal co-lives with FM signal,which enables a significantly higher data rate than existing radio data systems.The cyclic prefix of the OFDM symbol has the same length as the OFDM body,which enables the analytic separation of the co-channel OFDM and FM signal at receiver side,utilizing the fact that the OFDM body and prefix is equal.In this work,we show that the OFDM body and prefix cannot be viewed as equal when there is sufficient carrier frequency offset(CFO).Thus,we propose a two-step CFO estimation algorithm for FM and SRDS hybrid signal.The first step estimates the coarse CFO by exploring the characteristics of the FM signal.Once the coarse CFO is removed,the residual CFO is small enough for FM and OFDM separation.The second step fine estimates CFO from the OFDM-only signal using its repeated PN structure after the separation.Detailed mathematical equations are formulated and simulation results are given.The results show that the proposed algorithm works fine with the simulation setup and has a final residual CFO less than 3.9Hz.展开更多
This paper presents a reconfiguration of electric power distribution network based on the symbiotic organism search algorithm (SOS). The goal here is to come out with an optimal reconfiguration of a power distribution...This paper presents a reconfiguration of electric power distribution network based on the symbiotic organism search algorithm (SOS). The goal here is to come out with an optimal reconfiguration of a power distribution network that minimises the active power losses for a good power flow. This method is applied to IEEE 33 bus and the results show a significant reduction of active power losses. The execution time for this algorithm is found to be smaller compared to other metaheuristic algorithms.展开更多
Symbiotic radio(SR)is an emerging green technology for the Internet of Things(IoT).One key challenge of the SR systems is to design efficient and low-complexity detectors,which is the focus of this paper.We first driv...Symbiotic radio(SR)is an emerging green technology for the Internet of Things(IoT).One key challenge of the SR systems is to design efficient and low-complexity detectors,which is the focus of this paper.We first drive the mathematical expression of the optimal maximum-likelihood(ML)detector,and then propose a suboptimal iterative detector with low complexity.Finally,we show through numerical results that our proposed detector can obtain near-optimal bit error rate(BER)performance at a low computational cost.展开更多
Reconfigurable intelligent surface(RIS)-assisted symbiotic radio is a spectrum-and energy-efficient communication paradigm,in which an RIS performs passive beamforming to enhance active transmission,while using the el...Reconfigurable intelligent surface(RIS)-assisted symbiotic radio is a spectrum-and energy-efficient communication paradigm,in which an RIS performs passive beamforming to enhance active transmission,while using the electromagnetic waves from the active transmission for additional information transfer(i.e.,passive transmission).In this paper,a hybrid RIS-based modulation,termed hybrid phase and code modulation(HPCM),is proposed to improve the reliability of RIS-assisted symbiotic radio.In RIS-HPCM,the RIS simultaneously performs direct sequence spread spectrum and passive beamforming on incident signals.Moreover,both the spreading code and phase offset are exploited to carry the RIS’s own information.A low-complexity detector is designed,in which the receiver first detects the spreading codes and then demodulates the constellation symbols.We analyze the bit error rate(BER)performance of RIS-HPCM over Rician fading channels.BER upper bounds and approximate BER expressions are derived in closed-form for maximum-likelihood and low-complexity detectors,respectively.Simulation results in terms of BER verify the analysis and show the superiority of RIS-HPCM over the existing RIS-based modulation.展开更多
Symbiotic stars are interacting binary systems, making them valuable for studying various astronomical phenomena, such as stellar evolution, mass transfer, and accretion processes. Despite recent progress in the disco...Symbiotic stars are interacting binary systems, making them valuable for studying various astronomical phenomena, such as stellar evolution, mass transfer, and accretion processes. Despite recent progress in the discovery of symbiotic stars, a significant discrepancy between the observed population of symbiotic stars and the number predicted by theoretical models. To bridge this gap, this study utilized machine learning techniques to efficiently identify new symbiotic star candidates. Three algorithms(XGBoost, LightGBM, and Decision Tree)were applied to a data set of 198 confirmed symbiotic stars and the resulting model was then used to analyze data from the LAMOST survey, leading to the identification of 11,709 potential symbiotic star candidates. Out of these potential symbiotic star candidates listed in the catalog, 15 have spectra available in the Sloan Digital Sky Survey(SDSS) survey. Among these 15 candidates, two candidates, namely V^(*)V603 Ori and V^(*)GN Tau, have been confirmed as symbiotic stars. The remaining 11 candidates have been classified as accreting-only symbiotic star candidates. The other two candidates, one of which has been identified as a galaxy by both SDSS and LAMOST surveys, and the other identified as a quasar by SDSS survey and as a galaxy by LAMOST survey.展开更多
This study explored the concurrent scheduling of machines, tools, and tool transporter(TT) with alternative machines in a multi-machine flexible manufacturing system(FMS), taking into mind the tool transfer durations ...This study explored the concurrent scheduling of machines, tools, and tool transporter(TT) with alternative machines in a multi-machine flexible manufacturing system(FMS), taking into mind the tool transfer durations for minimization of the makespan(MSN). When tools are expensive, just a single copy of every tool kind is made available for use in the FMS system. Because the tools are housed in a central tool magazine(CTM), which then distributes and delivers them to many machines, because there is no longer a need to duplicate the tools in each machine, the associated costs are avoided. Choosing alternative machines for job operations(jb-ons), assigning tools to jb-ons, sequencing jb-ons on machines, and arranging allied trip activities, together with the TT’s loaded trip times and deadheading periods, are all challenges that must be overcome to achieve the goal of minimizing MSN. In addition to a mixed nonlinear integer programming(MNLIP) formulation for this simultaneous scheduling problem, this paper suggests a symbiotic organisms search algorithm(SOSA) for the problem’s solution. This algorithm relies on organisms’ symbiotic interaction strategies to keep living in an ecosystem. The findings demonstrate that SOSA is superior to the Jaya algorithm in providing solutions and that using alternative machines for operations helps bring down MSN.展开更多
Under the goal of "double carbon " strategy,the government and enterprises collaborate to form an efficient environmental governance symbiosis network to reduce pollution and carbon.Based on the panel data o...Under the goal of "double carbon " strategy,the government and enterprises collaborate to form an efficient environmental governance symbiosis network to reduce pollution and carbon.Based on the panel data of 30 provinces,the static and dynamic eco-efficiency of the symbiotic network of environmental governance PPP projects are measured by using the SBM model and Malmquist index considering the super-efficiency of non-expected output.The results show that:(1) 8 provinces,including Hebei,have efficiency values greater than 1;11 provinces,including Liaoning,have organizational technology and management levels conducive to efficiency improvement,and 12 provinces,including Zhejiang,are closest to optimal scale efficiency.(2) Redundancy of energy conservation and environmental protection expenditures,urban environmental infrastructure construction investment and new product development projects,insufficient waste gas treatment capacity,environmental emergencies and carbon emission redundancy are all significant factors affecting eco-efficiency.(3) The dynamic efficiency of 8 provinces,including Fujian,shows a decreasing trend,and the Malmquist index and its decomposition indicate that the utilization rate of environmental governance technology should be improved and environmental resources should be allocated rationally.展开更多
Maize(Zea mays L.)-soybean(Glycine max L.Merr.)relay intercropping provides a way to enhance land productivity.However,the late-planted soybean suffers from shading by the maize.After maize harvest,how the recovery gr...Maize(Zea mays L.)-soybean(Glycine max L.Merr.)relay intercropping provides a way to enhance land productivity.However,the late-planted soybean suffers from shading by the maize.After maize harvest,how the recovery growth influences the leaf and nodule traits remains unclear.A three-year field experiment was conducted to evaluate the effects of genotypes,i.e.,supernodulating(nts1007),Nandou 12(ND12),and Guixia 3(GX3),and crop configurations,i.e.,the interspecific row spacing of 45(I45),60(I60),75 cm(I75),and sole soybean(SS),on soybean recovery growth and N fixation.The results showed that intercropping reduced the soybean total leaf area(LA)by reducing both the leaf number(LN)and unit leaflet area(LUA),and it reduced the nodule dry weight(NW)by reducing both the nodule number(NN)and nodule diameter(ND)compared with the SS.The correlation and principal component analysis(PCA)indicated a co-variability of the leaf and nodule traits in response to the genotype and crop configuration interactions.During the recovery growth stages,the compensatory growth promoted soybean growth to reduce the gaps of leaf and nodule traits between intercropping and SS.The relative growth rates of ureide(RGR_U)and nitrogen(RGR_N)accumulation were higher in intercropping than in SS.Intercropping achieved more significant sucrose and starch contents compared with SS.ND12 and GX3 showed more robust compensatory growth than nts1007 in intercropping.Although the recovery growth of relay intercropping soybean improved biomass and nitrogen accumulation,ND12 gained a more significant partial land equivalent ratio(pLER)than GX3.The I60 treatment achieved more robust compensation effects on biomass and N accumulation than the other configurations.Meanwhile,I60 showed a higher nodule sucrose content and greater shoot ureide and N accumulation than SS.Finally,intercropping ND12 with maize using an interspecific row spacing of 60 cm was optimal for both yield advantage and N accumulation.展开更多
Arbuscular mycorrhizae(AM)fungi form symbiotic associations with plant roots,providing nutritional benefits and promoting plant growth and defenses against various stresses.Metabolic changes in the roots during AM fun...Arbuscular mycorrhizae(AM)fungi form symbiotic associations with plant roots,providing nutritional benefits and promoting plant growth and defenses against various stresses.Metabolic changes in the roots during AM fungal colonization are key to understanding the development and maintenance of these symbioses.Here,we investigated metabolic changes in the roots of peanut(Arachis hypogaea L.)plants during the colonization and development of AM symbiosis,and compared them to uncolonized roots.The primary changes during the initial stage of AM colonization were in the contents and compositions of phenylpropanoid and flavonoid compounds.These compounds function in signaling pathways that regulate recognition,interactions,and pre-colonization between roots and AM fungi.Flavonoid compounds decreased by 25%when the symbiosis was fully established compared to the initial colonization stage.After AM symbiosis was established,general metabolism strongly shifted toward the formation of lipids,amino acids,carboxylic acids,and carbohydrates.Lipid compounds increased by 8.5%from the pre-symbiotic stage to well-established symbiosis.Lyso-phosphatidylcholines,which are signaling compounds,were only present in AM roots,and decreased in content after the symbiosis was established.In the initial stage of AM establishment,the content of salicylic acid increased two-fold,whereas jasmonic acid and abscisic acid decreased compared to uncolonized roots.The jasmonic acid content decreased in roots after the symbiosis was well established.AM symbiosis was associated with high levels of calcium,magnesium,and D-(+)-mannose,which stimulated seedling growth.Overall,specific metabolites that favor the establishment of AM symbiosis were common in the roots,primarily during early colonization,whereas general metabolism was strongly altered when AM symbiosis was well-established.In conclusion,specialized metabolites function as signaling compounds to establish AM symbiosis.These compounds are no longer produced after the symbiosis between the roots and AM becomes fully established.展开更多
Suppression of roots and/or their symbiotic microorganisms,such as mycorrhizal fungi and rhizobia,is an effective way for alien plants to outcompete native plants.However,little is known about how invasive and native ...Suppression of roots and/or their symbiotic microorganisms,such as mycorrhizal fungi and rhizobia,is an effective way for alien plants to outcompete native plants.However,little is known about how invasive and native plants interact with the quantity and activity of nutrient-acquisition agents.Here a pot experiment was conducted with monoculture and mixed plantings of an invasive plant,Xanthium strumarium,and a common native legume,Glycine max.We measured traits related to root and nodule quantity and activity and mycorrhizal colonization.Compared to the monoculture,fine root quantity(biomass,surface area)and activity(root nitrogen(N)concentration,acid phosphatase activity)of G.max decreased in mixed plantings;nodule quantity(biomass)decreased by 45%,while nodule activity in Nfixing via rhizobium increased by 106%;mycorrhizal colonization was unaffected.Contribution of N fixation to leaf N content in G.max increased in the mixed plantings,and this increase was attributed to a decrease in the rhizosphere soil N of G.max in the mixed plantings.Increased root quantity and activity,along with a higher mycorrhizal association was observed in X.strumarium in the mixed compared to monoculture.Together,the invasive plant did not directly scavenge N from nodule-fixed N,but rather depleted the rhizosphere soil N of the legume,thereby stimulating the activity of N-fixation and increasing the dependence of the native legume on this N source.The quantity-activity framework holds promise for future studies on how native legumes respond to alien plant invasions.展开更多
Coal and oil shale are two common sedimentary energy sources which are often symbiotically developed in M esozoic- Cenozoic continental fault basins. However, the mechanisms and characteristics of the symbiotic develo...Coal and oil shale are two common sedimentary energy sources which are often symbiotically developed in M esozoic- Cenozoic continental fault basins. However, the mechanisms and characteristics of the symbiotic development are not yet clearly known. In this research study, the typical continental fault basins of eastern China were chosen as examples for the purpose of conducting an examination of the coal and oil shale symbiotic assemblage types, genetic environmental differences, and transformation mechanisms, as well as the development and occurrence characteristics o f different assemblage types. Through a large number of investigations, systematic experimental testing, and sequence stratigraphy studies, the following conclusions were obtained:(1) There were five types of coal and oil shale symbiotic assemblages observed in the continental fault basins,(2) The development of coal and oil shale deposits requires a warm and humid climate, stable structure, abundant organic matter supply, a certain water depth, and a lower terrestrial source debris supply. The observed differences were that the water depth conditions were diversified in the study area, as well as the sources, types, and content of the organic matter.(3) The rapid transformations of the coal and oil shale genetic environments were mainly controlled by the tectonic settings and climatic conditions, which were determined to control the changes in the water depths, salinity,redox conditions, and lake productivity of the genetic environments. Also, in the symbiotic assemblages, genetic environment changes had induced the development of oil shale deposits, which gradually evolved into coal genetic environments.(4) In the isochronous sequence stratigraphic framework of the coal and oil shale symbiotic assemblages, the lake expansion system tracts (EST) were determined to be the most beneficial to the growth o f all the types of assemblages and were characterized by more assemblage development phases and smaller bed thicknesses. From the early to the late stages of the EST, and from the lakesides to lake centers, the thicknesses of the coal seams in the symbiotic assemblages showed trends of thinning, while the thicknesses of the oil shale deposits exhibited increasing trends. The early stages of high stand system tracts were found to be beneficial to the development of the symbiotic assemblages of coal seams overlying the oil shale. This tract type generally presented large bed thicknesses and distribution ranges. The low stand system tract and the late high stand system tract were determined to be unconducive to the development of the symbiotic assemblages.展开更多
Paralytic shellfish poisoning (PSP) toxins are potent neurotoxins mainly produced by dinoflagellates and being concentrated in bivalves through food web transfer. Increasing number of findings of toxin-producing bacte...Paralytic shellfish poisoning (PSP) toxins are potent neurotoxins mainly produced by dinoflagellates and being concentrated in bivalves through food web transfer. Increasing number of findings of toxin-producing bacteria in the cells of dinoflagellate such as Alexandriumtamarense supports the hypothesis of the bacterial origin of PSP toxins. Evidence that there are specific symbiosis bacterial taxa associated with the phytoplankton indicates the presence of specific selective mechanisms between them, and implies that the symbiosis bacteria have some vital function to the benefit of the dinoflagellates. Studies on the role of toxin-producing symbiosis bacteria in the marine ecosystem are considered to be becoming more important. Although toxigenic bacteria could be isolated from toxic dinoflagellates, it was not clearly proven whether the isolated bacterial strains based on culture-dependent manner and the corresponding intracellular bacteria were the same because of microbial unculturability. This paper aims to demonstrate the biodiversity of the symbiotic bacteria associated with toxic dinoflagellate A. tamarense using the culture-indepen- dent high-throughput pyrosequencing method, as well as the phylogenetic analysis based on 16S rDNA sequences of the symbiotic cultivable bacteria strains isolated from toxic Alexander tamarense.展开更多
The symbiotic matching for nodulation of Bradyrhizobium japonicum strains is a synergy of multi-proteins and plays a key role in symbiotic nitrogen fixation in nature. Studies on mechanism of symbiotic matching are si...The symbiotic matching for nodulation of Bradyrhizobium japonicum strains is a synergy of multi-proteins and plays a key role in symbiotic nitrogen fixation in nature. Studies on mechanism of symbiotic matching are significant in both theory and practice. In this paper, B. japonicum USDA110-A with high symbiotic matching with high-oil content soybean cultivar Suinong 20 and B. japonicum 2178 with low symbiotic matching were selected for proteomic to reveal mechanism of different symbiotic nodulation. The results showed that the amount and categories of proteins identified in this test were different when the two strains were treated by symbiotic nodulation. There were 10 up-regulated proteins and 5 down-regulated proteins with significant difference for B. japonicum USDA110-A. Proteins associated with nodulation and metabolism of energy and material, which were propitious to symbiotic nodulation, were all up-regulated, such as PHDPS synthase, metal-dependent phosphohydrolase, glycosyl transferase family. In contrast, only 5 up-regulated and 7 down-regulated differential proteins were detected in B. japonicum 2178. Molecular chaperones and defensive proteins, which influence the folding of nascent polypeptide chains and the active of azotase were down-regulated. To a certain extent, the different responses of B. japonicum to daidzein were one of the most important reasons that cause varieties in symbiotic matching ability.展开更多
Symbiotic algae (Symbiodinium sp.) in scleractinian corals are important in understanding how coral reefs will respond to global climate change. The present paper reports on the diversity of Symbiodinium sp. in 48 s...Symbiotic algae (Symbiodinium sp.) in scleractinian corals are important in understanding how coral reefs will respond to global climate change. The present paper reports on the diversity of Symbiodinium sp. in 48 scleractinian coral species from 25 genera and 10 families sampled from the Xisha Islands in the South China Sea, which were identified with the use of restriction fragment length polymorphism (RFLP) of the nuclear ribosomal DNA large subunit gene (rDNA). The results showed that: (i) Symbiodinium Clade C was the dominant zooxanthellae in scleractinian corals in the Xisha Islands; (ii) Symbiodinium Clade D was found in the corals Montipora aequituberculata, Galaxea fascicularis, and Plerogyra sinuosa; and (iii) both Symbiodinium Clades C and D were found simultaneously in Montipora digitata, Psammocora contigua, and Galaxeafascicularis. A poor capacity for symbiosis polymorphism, as uncovered by RFLP, in the Xisha Islands indicates that the scleractinian corals have low adaptability to environmental changes. Further studies are needed to investigate zooxanthellae diversity using other molecular markers.展开更多
We conducted a greenhouse experiment to investigate the role of seed source in growth and symbiotic nitrogen fixation of black locust (Robinia pseudoacacia L). Seeds from different sources were planted in the same e...We conducted a greenhouse experiment to investigate the role of seed source in growth and symbiotic nitrogen fixation of black locust (Robinia pseudoacacia L). Seeds from different sources were planted in the same environmental conditions and inoculated with a suspension of mixed Rhizobium. We used the modified ^15N isotope dilution method to estimate biological nitrogen fixation of Robinia trees. Different Robinia seed sources differed significantly in terms of tissue dry weight (50.6-80.1 g), total N (1.31-2.16 g) and proportion of nitrogen derived from the atmosphere ( 0-51%). A higher nitrogen fixation rate of Robinia trees was associated with higher dry weight. Moreover, the leaves of Robinia proved to adequately represent the nitrogen fixation capacity of entire plants. Our results confirmed that assessment of seed sources is a useful way to improve the nitrogen fixation capacity and therefore the growth rate of Robinia.展开更多
‘Tianlong 1’ is widely popularized and applied with good comprehensive characters and is also good receptor for genetic transformation. However, little is known about symbiotic nitrogen fixation of ‘Tianlong 1’. I...‘Tianlong 1’ is widely popularized and applied with good comprehensive characters and is also good receptor for genetic transformation. However, little is known about symbiotic nitrogen fixation of ‘Tianlong 1’. In this report, 10 soybean rhizobia from different areas were selected to perform symbiotic matching test with ‘Tianlong 1’ in chamber. Two aboveground indicators (fresh weight aboveground and plant height) and 4 underground indicators (length of root, number of nodules, dry weight of root nodules per plant and morphology of nodules) were measured and data were statistically analyzed. Results showed that ‘Tianlong 1’ was a broad-hosted soybean which has different symbiotic matching abilities with these 10 rhizobia. Bradyrhizobium japonicum has more advantages than Sinorhizobium fredii in promoting plant growth and nodulation. 113-2 and 5036 were high effective strains. 113-2 was regarded as the most effective rhizobium matching to ‘Tianlong 1’ due to geographical advantages and adaptability. This research will promote symbiotic fixation of ‘Tianlong 1’ in agricultural industry for the first time.展开更多
基金This work was supported by the National Natural Science Foundation of China(62271192)Henan Provincial Scientists Studio(GZS2022015),Central Plains Talents Plan(ZYYCYU202012173)+8 种基金National Key R&D Program of China(2020YFB2008400)the Program of CEMEE(2022Z00202B)LAGEO of Chinese Academy of Sciences(LAGEO-2019-2)Program for Science&Technology Innovation Talents in the University of Henan Province(20HASTIT022)Natural Science Foundation of Henan under Grant 202300410126Program for Innovative Research Team in University of Henan Province(21IRTSTHN015)Equipment Pre-Research Joint Research Program of Ministry of Education(8091B032129)Training Program for Young Scholar of Henan Province forColleges andUniversities(2020GGJS172)Programfor Science&Technology Innovation Talents in Universities of Henan Province under Grand(22HASTIT020)and Henan Province Science Fund for Distinguished Young Scholars(222300420006).
文摘With the development of information technology,more and more devices are connected to the Internet through wireless communication to complete data interconnection.Due to the broadcast characteristics ofwireless channels,wireless networks have suffered more and more malicious attacks.Physical layer security has received extensive attention from industry and academia.MIMO is considered to be one of the most important technologies related to physical layer security.Through beamforming technology,messages can be transmitted to legitimate users in an offset direction that is as orthogonal as possible to the interference channel to ensure the reception SINR by legitimate users.Combining the symbiotic radio(SR)technology,this paper considers a symbiotic radio antijamming MIMO system equipped with a multi-antenna system at the main base station.In order to avoid the interference signal and improve the SINR of the signal received by the user.The base station is equipped with a uniform rectangular antenna array,and using Null Space Projection(NSP)Beamforming,Intelligent Reflecting Surface(IRS)can assist in changing the beam’s angle.The simulation results show that NSP Beamforming could make a better use of the null space of interference,which can effectively improve the received SINR of users under directional interference,and improve the utilization efficiency of signal energy.
基金supported by the grant from the Natural Science Foundation of China(No.31900214 to JY)the Open Fund of State Key Laboratory of Tea Plant Biology and Utilization(SKLTOF20210113 to LL).
文摘Rhizobia induces nitrogen-fixing nodules in legumes used in agricultural production,providing a direct source of combined nitrogen to leguminous crops.Small peptides,such as CLAVATA3/EMBRYO SURROUNDING REGION peptides(CLE),are known to regulate the formation and development of nitrogen-fixing nodules in legumes.Root meristem growth factor(RGF)peptides from Medicago truncatula not only regulate root develop-ment but also modulate nodulation symbiosis with Sinorhizobium meliloti.However,the impact of RGF peptides from one leguminous species on the others remains unclear.In this study,we investigate the effects of the RGF family peptide MtRGF6p from M.truncatula on nodulation symbiosis and root development in Lotus japonicus.The MtRGF6 gene is predominantly expressed in the root nodules of M.truncatula and shows low identity with RGF homologous genes from L.japonicus.The gene promoter is active in the primordia of root nodules and lat-eral roots,as well as in young nodules and roots,and the meristem,infection,and nitrogen-fixing regions of the mature nodule.Chemically synthesized MtRGF6p promoted primary root growth in M.truncatula but sup-pressed the growth of L.japonicus primary roots.The peptide negatively affected the initiation of nodule primor-dia,the formation of infection threads,and nodulation in both legumes,with a low dosage showing effects on L.japonicus compared to M.truncatula.These results suggest that the MtRGF6 peptide from M.truncatula may serve as an inter-species signal affecting the root organ development of L.japonicus.
基金supported by the HIT Environment and Ecology Innovation Special Funds (No.HSCJ201609)the Applied Technology Research and Development Program of Harbin (No.2017AB4AS035)+1 种基金the National Natural Science Foundation of China (No.51708157)Harbin Youth Talent Support Program (No.2017RAQXJ230)
文摘It was focused on the effect of different sludge concentrations on the performances of an algal-activated sludge symbiotic system in terms of wastewater treatment, algal-activated sludge characteristics and community structure. The results showed that the highest nutrient removal efficiencies were obtained in the reactor R^2 with soluble chemical oxygen demand(sC OD), ammonia nitrogen(NH_4^+-N) and phosphate(PO_4^(3-)-P) removal efficiencies of(90.6 ± 2.3)%,(97.69 ± 2.6)% and(83.81 ± 2.3)%, respectively. Further investigation exhibited that sludge concentration has a great effect on the dissolved oxygen(DO) concentration, the pH, the growth of algae and the extracellular polymeric substance(EPS) production, which resulted in influencing the settleability and the performance of symbiotic system. The denaturing gradient gel electrophoresis(DGGE) analysis demonstrated that the sludge concentration had a selective power for particular members of algae. Meantime, the stimulated algal population would selectively excite the members of bacteria benefited for the formation of algal-bacterial consortia.The variation of microbial compositions, which was influenced by the different sludge concentrations, might be ultimately responsible for the different treatment performances.
基金This research was supported by Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences.
文摘Background Apolygus lucorum is a worldwide omnivorous pest damaging a range of crops and causing great economic losses.Symbiotic bacteria living in insects play a key role in the nutrition,physiology,and behavior of hosts.Here,we present an experiment using Illumina HiSeq sequencing targeting the V3–V4 regions of bacteria’s 16S rRNA throughout the entire life cycle of A.lucorum.Results The first and second instar nymphs have the largest alpha diversity compared with other life stages of the insect.Bacterial phyla Proteobacteria(72.29%),Firmicutes(15.24%),Actinobacteria(7.76%)exhibit the largest relative abundance in all developmental stages.Erwinia(23.97%)and Lactococcus(10.62%)are the two genera with the high-est relative abundance.The relative abundance of Erwinia in the nymph stage is significantly greater than the adult stage,and the relative abundance of Lactococcus in 6-day-old and 9-day-old adult females is higher compared with adult males.Conclusions These results reveal that microbial community composition and relative abundance shift dynamically at different life stages,implying that different bacterial phyla and genera may have specific roles in specific life stages such as metabolism,nutrition absorption,detoxification,and reproduction.This study reveals for the first time the community composition and ecological dynamics of symbiotic bacteria throughout the life stages of A.lucorum,and thus may provide insight to new strategies for pest control.
基金supported by the National Natural Science Foundation of China (Grant No.61671264)Basic scientific research project of Beijing University of Posts and Telecommunications (Grant No. 2019RC02)National Key R&D Program of China(Grant No.2018YFE0101000)
文摘The symbiotic FM radio data system(SRDS)is a radio data system that a specially designed OFDM signal co-lives with FM signal,which enables a significantly higher data rate than existing radio data systems.The cyclic prefix of the OFDM symbol has the same length as the OFDM body,which enables the analytic separation of the co-channel OFDM and FM signal at receiver side,utilizing the fact that the OFDM body and prefix is equal.In this work,we show that the OFDM body and prefix cannot be viewed as equal when there is sufficient carrier frequency offset(CFO).Thus,we propose a two-step CFO estimation algorithm for FM and SRDS hybrid signal.The first step estimates the coarse CFO by exploring the characteristics of the FM signal.Once the coarse CFO is removed,the residual CFO is small enough for FM and OFDM separation.The second step fine estimates CFO from the OFDM-only signal using its repeated PN structure after the separation.Detailed mathematical equations are formulated and simulation results are given.The results show that the proposed algorithm works fine with the simulation setup and has a final residual CFO less than 3.9Hz.
文摘This paper presents a reconfiguration of electric power distribution network based on the symbiotic organism search algorithm (SOS). The goal here is to come out with an optimal reconfiguration of a power distribution network that minimises the active power losses for a good power flow. This method is applied to IEEE 33 bus and the results show a significant reduction of active power losses. The execution time for this algorithm is found to be smaller compared to other metaheuristic algorithms.
文摘Symbiotic radio(SR)is an emerging green technology for the Internet of Things(IoT).One key challenge of the SR systems is to design efficient and low-complexity detectors,which is the focus of this paper.We first drive the mathematical expression of the optimal maximum-likelihood(ML)detector,and then propose a suboptimal iterative detector with low complexity.Finally,we show through numerical results that our proposed detector can obtain near-optimal bit error rate(BER)performance at a low computational cost.
基金supported in part by the National Natural Science Foundation of China under Grant 62201228 and Grant 62001190in part by the Science and Technology Major Project of Tibetan Autonomous Region of China under Grant No.XZ202201ZD0006G02.
文摘Reconfigurable intelligent surface(RIS)-assisted symbiotic radio is a spectrum-and energy-efficient communication paradigm,in which an RIS performs passive beamforming to enhance active transmission,while using the electromagnetic waves from the active transmission for additional information transfer(i.e.,passive transmission).In this paper,a hybrid RIS-based modulation,termed hybrid phase and code modulation(HPCM),is proposed to improve the reliability of RIS-assisted symbiotic radio.In RIS-HPCM,the RIS simultaneously performs direct sequence spread spectrum and passive beamforming on incident signals.Moreover,both the spreading code and phase offset are exploited to carry the RIS’s own information.A low-complexity detector is designed,in which the receiver first detects the spreading codes and then demodulates the constellation symbols.We analyze the bit error rate(BER)performance of RIS-HPCM over Rician fading channels.BER upper bounds and approximate BER expressions are derived in closed-form for maximum-likelihood and low-complexity detectors,respectively.Simulation results in terms of BER verify the analysis and show the superiority of RIS-HPCM over the existing RIS-based modulation.
基金the generous support of the Natural Science Foundation of Xinjiang No. 2021D01C075the National Natural Science Foundation of China, project Nos. 12163005, 12003025, U2031204, 11863005, and 12288102+12 种基金the science research grants from the China Manned Space Project with No. CMS-CSST-2021-A10the Scientific Research Program of the Higher Education Institution of Xinjiang (No. XJEDU2022P003)supported by China National Astronomical Data Center (NADC) and Chinese Virtual Observatory (China-VO)supported by Astronomical Big Data Joint Research Center, co-founded by National Astronomical Observatories, Chinese Academy of Sciences and Alibaba CloudThis publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/ California Institute of TechnologyNEOWISE, which is a project of the Jet Propulsion Laboratory/California Institute of TechnologyWISE and NEOWISE are funded by the National Aeronautics and Space AdministrationThis publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technologyfunded by the National Aeronautics and Space Administration and the National Science FoundationGuo Shou Jing Telescope (the Large Sky Area MultiObject Fiber Spectroscopic Telescope LAMOST) is a National Major Scientific Project built by the Chinese Academy of SciencesFunding for the project has been provided by the National Development and Reform CommissionFunding for the Sloan Digital Sky Survey IV has been provided by the Alfred P. Sloan Foundation, the U.S. Department of Energy Office of Science, and the Participating Institutionssupport and resources from the Center for High Performance Computing at the University of Utah。
文摘Symbiotic stars are interacting binary systems, making them valuable for studying various astronomical phenomena, such as stellar evolution, mass transfer, and accretion processes. Despite recent progress in the discovery of symbiotic stars, a significant discrepancy between the observed population of symbiotic stars and the number predicted by theoretical models. To bridge this gap, this study utilized machine learning techniques to efficiently identify new symbiotic star candidates. Three algorithms(XGBoost, LightGBM, and Decision Tree)were applied to a data set of 198 confirmed symbiotic stars and the resulting model was then used to analyze data from the LAMOST survey, leading to the identification of 11,709 potential symbiotic star candidates. Out of these potential symbiotic star candidates listed in the catalog, 15 have spectra available in the Sloan Digital Sky Survey(SDSS) survey. Among these 15 candidates, two candidates, namely V^(*)V603 Ori and V^(*)GN Tau, have been confirmed as symbiotic stars. The remaining 11 candidates have been classified as accreting-only symbiotic star candidates. The other two candidates, one of which has been identified as a galaxy by both SDSS and LAMOST surveys, and the other identified as a quasar by SDSS survey and as a galaxy by LAMOST survey.
文摘This study explored the concurrent scheduling of machines, tools, and tool transporter(TT) with alternative machines in a multi-machine flexible manufacturing system(FMS), taking into mind the tool transfer durations for minimization of the makespan(MSN). When tools are expensive, just a single copy of every tool kind is made available for use in the FMS system. Because the tools are housed in a central tool magazine(CTM), which then distributes and delivers them to many machines, because there is no longer a need to duplicate the tools in each machine, the associated costs are avoided. Choosing alternative machines for job operations(jb-ons), assigning tools to jb-ons, sequencing jb-ons on machines, and arranging allied trip activities, together with the TT’s loaded trip times and deadheading periods, are all challenges that must be overcome to achieve the goal of minimizing MSN. In addition to a mixed nonlinear integer programming(MNLIP) formulation for this simultaneous scheduling problem, this paper suggests a symbiotic organisms search algorithm(SOSA) for the problem’s solution. This algorithm relies on organisms’ symbiotic interaction strategies to keep living in an ecosystem. The findings demonstrate that SOSA is superior to the Jaya algorithm in providing solutions and that using alternative machines for operations helps bring down MSN.
基金supported by Major Social Science Project of Tianjin Education Commission(Grant No. 2019JWZD36)。
文摘Under the goal of "double carbon " strategy,the government and enterprises collaborate to form an efficient environmental governance symbiosis network to reduce pollution and carbon.Based on the panel data of 30 provinces,the static and dynamic eco-efficiency of the symbiotic network of environmental governance PPP projects are measured by using the SBM model and Malmquist index considering the super-efficiency of non-expected output.The results show that:(1) 8 provinces,including Hebei,have efficiency values greater than 1;11 provinces,including Liaoning,have organizational technology and management levels conducive to efficiency improvement,and 12 provinces,including Zhejiang,are closest to optimal scale efficiency.(2) Redundancy of energy conservation and environmental protection expenditures,urban environmental infrastructure construction investment and new product development projects,insufficient waste gas treatment capacity,environmental emergencies and carbon emission redundancy are all significant factors affecting eco-efficiency.(3) The dynamic efficiency of 8 provinces,including Fujian,shows a decreasing trend,and the Malmquist index and its decomposition indicate that the utilization rate of environmental governance technology should be improved and environmental resources should be allocated rationally.
基金supported by the China Agriculture Research System of MOF and MARA(Soybean,CARS04-PS20)the National Natural Science Foundation of China(3187101212 and 31671625).
文摘Maize(Zea mays L.)-soybean(Glycine max L.Merr.)relay intercropping provides a way to enhance land productivity.However,the late-planted soybean suffers from shading by the maize.After maize harvest,how the recovery growth influences the leaf and nodule traits remains unclear.A three-year field experiment was conducted to evaluate the effects of genotypes,i.e.,supernodulating(nts1007),Nandou 12(ND12),and Guixia 3(GX3),and crop configurations,i.e.,the interspecific row spacing of 45(I45),60(I60),75 cm(I75),and sole soybean(SS),on soybean recovery growth and N fixation.The results showed that intercropping reduced the soybean total leaf area(LA)by reducing both the leaf number(LN)and unit leaflet area(LUA),and it reduced the nodule dry weight(NW)by reducing both the nodule number(NN)and nodule diameter(ND)compared with the SS.The correlation and principal component analysis(PCA)indicated a co-variability of the leaf and nodule traits in response to the genotype and crop configuration interactions.During the recovery growth stages,the compensatory growth promoted soybean growth to reduce the gaps of leaf and nodule traits between intercropping and SS.The relative growth rates of ureide(RGR_U)and nitrogen(RGR_N)accumulation were higher in intercropping than in SS.Intercropping achieved more significant sucrose and starch contents compared with SS.ND12 and GX3 showed more robust compensatory growth than nts1007 in intercropping.Although the recovery growth of relay intercropping soybean improved biomass and nitrogen accumulation,ND12 gained a more significant partial land equivalent ratio(pLER)than GX3.The I60 treatment achieved more robust compensation effects on biomass and N accumulation than the other configurations.Meanwhile,I60 showed a higher nodule sucrose content and greater shoot ureide and N accumulation than SS.Finally,intercropping ND12 with maize using an interspecific row spacing of 60 cm was optimal for both yield advantage and N accumulation.
基金supported by the National Key R&D Program of China(2022YFD1000105)the Key R&D Program of Shandong Province,China(2021CXGC010804)+5 种基金the Taishan Scholars Project,China(202211275)the Youth Found of Shandong Natural Science Foundation,China(ZR2021QC163)the Natural Science Foundation of Shandong Province,China(ZR2020MC094)the Strategic Academic Leadership Program“Priority 2030”of the Kazan Federal University,Russiathe RUDN University Strategic Academic Leadership Program,Chinathe 2022 High-level Talent Innovation and Entrepreneurship(Platform)Project of Linyi,China。
文摘Arbuscular mycorrhizae(AM)fungi form symbiotic associations with plant roots,providing nutritional benefits and promoting plant growth and defenses against various stresses.Metabolic changes in the roots during AM fungal colonization are key to understanding the development and maintenance of these symbioses.Here,we investigated metabolic changes in the roots of peanut(Arachis hypogaea L.)plants during the colonization and development of AM symbiosis,and compared them to uncolonized roots.The primary changes during the initial stage of AM colonization were in the contents and compositions of phenylpropanoid and flavonoid compounds.These compounds function in signaling pathways that regulate recognition,interactions,and pre-colonization between roots and AM fungi.Flavonoid compounds decreased by 25%when the symbiosis was fully established compared to the initial colonization stage.After AM symbiosis was established,general metabolism strongly shifted toward the formation of lipids,amino acids,carboxylic acids,and carbohydrates.Lipid compounds increased by 8.5%from the pre-symbiotic stage to well-established symbiosis.Lyso-phosphatidylcholines,which are signaling compounds,were only present in AM roots,and decreased in content after the symbiosis was established.In the initial stage of AM establishment,the content of salicylic acid increased two-fold,whereas jasmonic acid and abscisic acid decreased compared to uncolonized roots.The jasmonic acid content decreased in roots after the symbiosis was well established.AM symbiosis was associated with high levels of calcium,magnesium,and D-(+)-mannose,which stimulated seedling growth.Overall,specific metabolites that favor the establishment of AM symbiosis were common in the roots,primarily during early colonization,whereas general metabolism was strongly altered when AM symbiosis was well-established.In conclusion,specialized metabolites function as signaling compounds to establish AM symbiosis.These compounds are no longer produced after the symbiosis between the roots and AM becomes fully established.
基金funded by the National Natural Science Foundation of China (32171746,31870522,42077450,32371786)the leading talents of basic research in Henan Province+3 种基金Funding for Characteristic and Backbone Forestry Discipline Group of Henan Provincethe Scientific Research Foundation of Henan Agricultural University (30500854)Research Funds for overseas returnee in Henan Province,Chinasupported by National Key Research and Development Program of China (2019YFE0117000)。
文摘Suppression of roots and/or their symbiotic microorganisms,such as mycorrhizal fungi and rhizobia,is an effective way for alien plants to outcompete native plants.However,little is known about how invasive and native plants interact with the quantity and activity of nutrient-acquisition agents.Here a pot experiment was conducted with monoculture and mixed plantings of an invasive plant,Xanthium strumarium,and a common native legume,Glycine max.We measured traits related to root and nodule quantity and activity and mycorrhizal colonization.Compared to the monoculture,fine root quantity(biomass,surface area)and activity(root nitrogen(N)concentration,acid phosphatase activity)of G.max decreased in mixed plantings;nodule quantity(biomass)decreased by 45%,while nodule activity in Nfixing via rhizobium increased by 106%;mycorrhizal colonization was unaffected.Contribution of N fixation to leaf N content in G.max increased in the mixed plantings,and this increase was attributed to a decrease in the rhizosphere soil N of G.max in the mixed plantings.Increased root quantity and activity,along with a higher mycorrhizal association was observed in X.strumarium in the mixed compared to monoculture.Together,the invasive plant did not directly scavenge N from nodule-fixed N,but rather depleted the rhizosphere soil N of the legume,thereby stimulating the activity of N-fixation and increasing the dependence of the native legume on this N source.The quantity-activity framework holds promise for future studies on how native legumes respond to alien plant invasions.
基金supported by the National Key Research and Development Plan (2017YFC0601400)SDUST Research Fund (2018TDJH101)the National Natural Science Foundation of China (41402086, 272172)
文摘Coal and oil shale are two common sedimentary energy sources which are often symbiotically developed in M esozoic- Cenozoic continental fault basins. However, the mechanisms and characteristics of the symbiotic development are not yet clearly known. In this research study, the typical continental fault basins of eastern China were chosen as examples for the purpose of conducting an examination of the coal and oil shale symbiotic assemblage types, genetic environmental differences, and transformation mechanisms, as well as the development and occurrence characteristics o f different assemblage types. Through a large number of investigations, systematic experimental testing, and sequence stratigraphy studies, the following conclusions were obtained:(1) There were five types of coal and oil shale symbiotic assemblages observed in the continental fault basins,(2) The development of coal and oil shale deposits requires a warm and humid climate, stable structure, abundant organic matter supply, a certain water depth, and a lower terrestrial source debris supply. The observed differences were that the water depth conditions were diversified in the study area, as well as the sources, types, and content of the organic matter.(3) The rapid transformations of the coal and oil shale genetic environments were mainly controlled by the tectonic settings and climatic conditions, which were determined to control the changes in the water depths, salinity,redox conditions, and lake productivity of the genetic environments. Also, in the symbiotic assemblages, genetic environment changes had induced the development of oil shale deposits, which gradually evolved into coal genetic environments.(4) In the isochronous sequence stratigraphic framework of the coal and oil shale symbiotic assemblages, the lake expansion system tracts (EST) were determined to be the most beneficial to the growth o f all the types of assemblages and were characterized by more assemblage development phases and smaller bed thicknesses. From the early to the late stages of the EST, and from the lakesides to lake centers, the thicknesses of the coal seams in the symbiotic assemblages showed trends of thinning, while the thicknesses of the oil shale deposits exhibited increasing trends. The early stages of high stand system tracts were found to be beneficial to the development of the symbiotic assemblages of coal seams overlying the oil shale. This tract type generally presented large bed thicknesses and distribution ranges. The low stand system tract and the late high stand system tract were determined to be unconducive to the development of the symbiotic assemblages.
文摘Paralytic shellfish poisoning (PSP) toxins are potent neurotoxins mainly produced by dinoflagellates and being concentrated in bivalves through food web transfer. Increasing number of findings of toxin-producing bacteria in the cells of dinoflagellate such as Alexandriumtamarense supports the hypothesis of the bacterial origin of PSP toxins. Evidence that there are specific symbiosis bacterial taxa associated with the phytoplankton indicates the presence of specific selective mechanisms between them, and implies that the symbiosis bacteria have some vital function to the benefit of the dinoflagellates. Studies on the role of toxin-producing symbiosis bacteria in the marine ecosystem are considered to be becoming more important. Although toxigenic bacteria could be isolated from toxic dinoflagellates, it was not clearly proven whether the isolated bacterial strains based on culture-dependent manner and the corresponding intracellular bacteria were the same because of microbial unculturability. This paper aims to demonstrate the biodiversity of the symbiotic bacteria associated with toxic dinoflagellate A. tamarense using the culture-indepen- dent high-throughput pyrosequencing method, as well as the phylogenetic analysis based on 16S rDNA sequences of the symbiotic cultivable bacteria strains isolated from toxic Alexander tamarense.
基金supported by the National 863 Program of China (2010AA10A203)the Basic Scientific and Business Fund and Central Public Research Project, China (202-10)the Special Fund for Establishment of Modern Agri-cultural R&D System, Ministry of Agriculture, China(nycytx-004)
文摘The symbiotic matching for nodulation of Bradyrhizobium japonicum strains is a synergy of multi-proteins and plays a key role in symbiotic nitrogen fixation in nature. Studies on mechanism of symbiotic matching are significant in both theory and practice. In this paper, B. japonicum USDA110-A with high symbiotic matching with high-oil content soybean cultivar Suinong 20 and B. japonicum 2178 with low symbiotic matching were selected for proteomic to reveal mechanism of different symbiotic nodulation. The results showed that the amount and categories of proteins identified in this test were different when the two strains were treated by symbiotic nodulation. There were 10 up-regulated proteins and 5 down-regulated proteins with significant difference for B. japonicum USDA110-A. Proteins associated with nodulation and metabolism of energy and material, which were propitious to symbiotic nodulation, were all up-regulated, such as PHDPS synthase, metal-dependent phosphohydrolase, glycosyl transferase family. In contrast, only 5 up-regulated and 7 down-regulated differential proteins were detected in B. japonicum 2178. Molecular chaperones and defensive proteins, which influence the folding of nascent polypeptide chains and the active of azotase were down-regulated. To a certain extent, the different responses of B. japonicum to daidzein were one of the most important reasons that cause varieties in symbiotic matching ability.
基金supported by grantsfrom the National Natural Science Fundation of China(40776085 and 40576052)State Oceanic Administration of China(908-ST-01-08-Coral Reefs Survey)Bureau of Science and Technology for Resources and Environment(YTZJJ0502)
文摘Symbiotic algae (Symbiodinium sp.) in scleractinian corals are important in understanding how coral reefs will respond to global climate change. The present paper reports on the diversity of Symbiodinium sp. in 48 scleractinian coral species from 25 genera and 10 families sampled from the Xisha Islands in the South China Sea, which were identified with the use of restriction fragment length polymorphism (RFLP) of the nuclear ribosomal DNA large subunit gene (rDNA). The results showed that: (i) Symbiodinium Clade C was the dominant zooxanthellae in scleractinian corals in the Xisha Islands; (ii) Symbiodinium Clade D was found in the corals Montipora aequituberculata, Galaxea fascicularis, and Plerogyra sinuosa; and (iii) both Symbiodinium Clades C and D were found simultaneously in Montipora digitata, Psammocora contigua, and Galaxeafascicularis. A poor capacity for symbiosis polymorphism, as uncovered by RFLP, in the Xisha Islands indicates that the scleractinian corals have low adaptability to environmental changes. Further studies are needed to investigate zooxanthellae diversity using other molecular markers.
文摘We conducted a greenhouse experiment to investigate the role of seed source in growth and symbiotic nitrogen fixation of black locust (Robinia pseudoacacia L). Seeds from different sources were planted in the same environmental conditions and inoculated with a suspension of mixed Rhizobium. We used the modified ^15N isotope dilution method to estimate biological nitrogen fixation of Robinia trees. Different Robinia seed sources differed significantly in terms of tissue dry weight (50.6-80.1 g), total N (1.31-2.16 g) and proportion of nitrogen derived from the atmosphere ( 0-51%). A higher nitrogen fixation rate of Robinia trees was associated with higher dry weight. Moreover, the leaves of Robinia proved to adequately represent the nitrogen fixation capacity of entire plants. Our results confirmed that assessment of seed sources is a useful way to improve the nitrogen fixation capacity and therefore the growth rate of Robinia.
文摘‘Tianlong 1’ is widely popularized and applied with good comprehensive characters and is also good receptor for genetic transformation. However, little is known about symbiotic nitrogen fixation of ‘Tianlong 1’. In this report, 10 soybean rhizobia from different areas were selected to perform symbiotic matching test with ‘Tianlong 1’ in chamber. Two aboveground indicators (fresh weight aboveground and plant height) and 4 underground indicators (length of root, number of nodules, dry weight of root nodules per plant and morphology of nodules) were measured and data were statistically analyzed. Results showed that ‘Tianlong 1’ was a broad-hosted soybean which has different symbiotic matching abilities with these 10 rhizobia. Bradyrhizobium japonicum has more advantages than Sinorhizobium fredii in promoting plant growth and nodulation. 113-2 and 5036 were high effective strains. 113-2 was regarded as the most effective rhizobium matching to ‘Tianlong 1’ due to geographical advantages and adaptability. This research will promote symbiotic fixation of ‘Tianlong 1’ in agricultural industry for the first time.