Wheat is an important cereal crop used to produce diverse and popular food worldwide because of its high grain yield(GY)and grain protein content(GPC).However,GY and GPC are usually negatively correlated.We previously...Wheat is an important cereal crop used to produce diverse and popular food worldwide because of its high grain yield(GY)and grain protein content(GPC).However,GY and GPC are usually negatively correlated.We previously reported that favorable alleles of the wheat domestication gene Q can synchronously increase GY and GPC,but the underlying mechanisms remain largely unknown.In this study,we investigate the regulatory network involving Q associated with GY and GPC in young grains through DNA affinity purification sequencing and transcriptome sequencing analyses,electrophoretic mobility shift and dualluciferase assays,and transgenic approaches.Three Q-binding motifs,namely TTAAGG,AAACA[A/T]A,and GTAC[T/G]A,are identified.Notably,genes related to photosynthesis or carbon and nitrogen metabolism are enriched and regulated by Q.Moreover,Q is revealed to bind directly to its own gene and the glutamine synthetase gene GSr-4D to increase expression,thereby influencing nitrogen assimilation during the grain filling stage and increasing GPC.Considered together,our findings provide molecular evidence of the positive regulatory effects of Q on wheat GY and GPC.展开更多
Starch biosynthesis is a complex process that relies on the coordinated action of multiple enzymes.Resistant starch is not digested in the small intestine,thus preventing a rapid rise in the glycemic index.Starch synt...Starch biosynthesis is a complex process that relies on the coordinated action of multiple enzymes.Resistant starch is not digested in the small intestine,thus preventing a rapid rise in the glycemic index.Starch synthase 2a(SS2a)is a key enzyme in amylopectin biosynthesis that has significant effects on starch structure and properties.In this study,we identified an ss2a null mutant(M3-1413)with a single base mutation from an ethyl methane sulfonate(EMS)-mutagenized population of barley.The mutation was located at the 3'end of the first intron of the RNA splicing receptor(AG)site,and resulted in abnormal RNA splicing and two abnormal transcripts of ss2a,which caused the inactivation of the SS2a gene.The starch structure and properties were significantly altered in the mutant,with M3-1413 containing lower total starch and higher amylose and resistant starch levels.This study sheds light on the effect of barley ss2a null mutations on starch properties and will help to guide new applications of barley starch in the development of nutritious food products.展开更多
Productive tiller number(PTN)is a pivotal trait that significantly influences wheat grain yield.To date,there have been limited reports on the cloning of genes that regulate PTN in wheat.The quantitative trait locus(Q...Productive tiller number(PTN)is a pivotal trait that significantly influences wheat grain yield.To date,there have been limited reports on the cloning of genes that regulate PTN in wheat.The quantitative trait locus(QTL)QPtn.sau-4B,associated with PTN,was previously mapped between the markers KASP-1 and KASP-3 on the chromosome 4B.Here,utilizing 12 newly developed markers and phenotypic data of PTN from recombinants identified within this interval,QPtn.sau-4B was further fine-mapped to a 2.58 Mb interval on wheat chromosome arm 4BS.Within this interval,we identified 14 genes with high-confidence and 32 genes with low-confidence.A 0.17 Mb deletion fragment contained TraesCS4B03G0092600 and TraesCS4B03G0093100,which were assigned as candidate genes for QPtn.sau-4B.Additionally,QPtn.sau-4B had potential to enhance both PTN and grain yield in wheat.Cloning this locus would support the development of wheat cultivars with increased grain yield.展开更多
Stripe rust, caused by Puccinia striiformis f. sp. tritici(Pst), threatens wheat production worldwide, and resistant varieties tend to become susceptible after a period of cultivation owing to the variation of pathoge...Stripe rust, caused by Puccinia striiformis f. sp. tritici(Pst), threatens wheat production worldwide, and resistant varieties tend to become susceptible after a period of cultivation owing to the variation of pathogen races. In this study, a new resistance gene against Pst race CYR34 was identified and predicted using the descendants of a cross between AS1676, a highly resistant Chinese landrace, and Avocet S, a susceptible cultivar. From a heterozygous plant from a F7recombinant inbred line(RIL) population lacking the Yr18 gene, a near-isogenic line(NIL) population was developed to map the resistance gene. An allstage resistance gene, YrAS1676, was identified on chromosome arm 1AL via bulked-segregant exomecapture sequencing. By analyzing a large NIL population consisting of 6537 plants, the gene was further mapped to the marker interval between KA1A_485.36 and KA1A_490.13, spanning 485.36–490.13 Mb on1AL. A total of 66 annotated genes have been reported in this region. To characterize and predict the candidate gene(s), an RNA-seq was performed using NIL-R and NIL-S seedlings 3 days after CYR34 inoculation. Compared to NIL-S plants, NIL-R plants showed stronger immune reaction and higher expression levels of genes encoding pathogenesis-associated proteins. These differences may help to explain why NIL-R plants were more resistant to Pst race CYR34 than NIL-S plants. By combining fine-mapping and transcriptome sequencing, a calcium-dependent protein kinase gene was finally predicted as the potential candidate gene of YrAS1676. This gene contained a single-nucleotide polymorphism. The candidate gene was more highly expressed in NIL-R than in NIL-S plants. In field experiments with Pst challenge,the YrAS1676 genotype showed mitigation of disease damage and yield loss without adverse effects on tested agronomic traits. These results suggest that YrAS1676 has potential use in wheat stripe rust resistance breeding.展开更多
Tiller angle(TA)strongly influences plant architecture and grain yield in cereals.However,the genetic basis of TA in wheat is largely unknown.We identified three TA-related quantitative trait loci(QTL).One of them was...Tiller angle(TA)strongly influences plant architecture and grain yield in cereals.However,the genetic basis of TA in wheat is largely unknown.We identified three TA-related quantitative trait loci(QTL).One of them was QTa.sau-2 B-769,a major QTL localized on chromosome arm 2 BL.QTa.sau-2 B-769 was detected in seven environments,explaining 18.1%–51.1%of phenotypic variance.We developed a linked Kompetitive Allele-Specific Polymerase chain reaction(KASP)marker,KASP-AX-108792274,to further validate this locus in three additional populations in multiple environments.QTa.sau-2 B-769 increased TA by up to 24.9%in these populations.There were significant and positive correlations between TA and flag leaf angle(FLANG).However,TA was not correlated with plant height or anthesis date,suggesting that expression of QTa.sau-2 B-769 is independent of vernalization.Traes CS2 B01 G583800,a gene known to be involved in leaf angle regulation,was identified as the most likely candidate gene for QTa.sau-2 B-769.These results enrich our understanding of the mechanisms regulating wheat TA at maturity and may support precise mapping and cloning of gene(s)underlying QTa.sau-2 B-769.展开更多
Stripe rust,caused by Puccinia striiformis f.sp.tritici(Pst),is one of the most important diseases threatening the yield and stability of wheat production in China and many other countries.Identification and utilizati...Stripe rust,caused by Puccinia striiformis f.sp.tritici(Pst),is one of the most important diseases threatening the yield and stability of wheat production in China and many other countries.Identification and utilization of new genes for durable stripe rust resistance are important for ongoing control of this disease.The objectives of this study were to identify quantitative trait loci(QTL)associated with adult-plant stripe rust resistance in the Chinese wheat landrace Yibinzhuermai(YBZR)and to provide wheat breeders with new sources of potentially durable resistance.A total of 117 recombinant inbred lines(RILs)(F5:8)derived from a cross between YBZR and highly susceptible cultivar Taichung 29(TC29)were assessed for stripe rust severity in field experiments at Wenjiang in 2016 and 2017 and Chongzhou in 2016,2017,2018,and 2019 in Sichuan following inoculation with a mixture of current Pst races.The RILs were genotyped using the Wheat55K single nucleotide polymorphism(SNP)array.Three QTL were identified on chromosome arms 6AL,5BL and 7DS.QYr.YBZR-6AL and QYr.YBZR-7DS conferred major effects in all field environments,explaining 10.6%to 14.7%and 11.5%to 21.2%of phenotypic variation,respectively.The QTL on 5BL and 7DS likely correspond to previously known QTL,whereas QYr.YBZR-6AL is probably novel.Haplotype analysis revealed that the resistance allele at QYr.YBZR-6AL was present in 2.8%of 324 Chinese wheat landraces.SNP markers closely linked with QYr.YBZR-6AL were converted to kompetitive allele-specific PCR markers and validated in the RIL population and a subset of 92 wheat cultivars.QYr.YBZR-6AL and its markers should be useful in breeding programs to improve the level and durability of stripe rust resistance.展开更多
Stripe rust,caused by Puccinia striiformis f.sp.tritici(Pst),is a devastating disease in wheat worldwide.Discovering and characterizing new resistance genes/QTL is crucial for wheat breeding programs.In this study,we ...Stripe rust,caused by Puccinia striiformis f.sp.tritici(Pst),is a devastating disease in wheat worldwide.Discovering and characterizing new resistance genes/QTL is crucial for wheat breeding programs.In this study,we fine-mapped and characterized a stripe rust resistance gene,YRAYH,on chromosome arm 5BL in the Chinese wheat landrace Anyuehong(AYH).Evaluations of stripe rust response to prevalent Chinese Pst races in near-isogenic lines derived from a cross of Anyuehong and Taichung 29 showed that YrAYH conferred a high level of resistance at all growth stages.Fine mapping using a large segregating population of 9748 plants,narrowed the YRAYH locus to a 3.7 Mb interval on chromosome arm 5BL that included 61 annotated genes.Transcriptome analysis of two NIL pairs identified 64 upregulated differentially expressed genes(DEGs)in the resistant NILs(NILs-R).Annotations indicated that many of these genes have roles in plant disease resistance pathways.Through a combined approach of fine-mapping and transcriptome sequencing,we identified a serine/threonine-protein kinase SRPK as a candidate gene underlying YrAYH.A unique 25 bp insertion was identified in the NILs-R compared to the NILs-S and previously published wheat genomes.An InDel marker was developed and co-segregated with YrAYH.Agronomic trait evaluation of the NILs suggested that YrAYH not only reduces the impact of stripe rust but was also associated with a gene that increases plant height and spike length.展开更多
A new beech and self-tapping screw composite dowel is proposed and studied,its performance being compared with that of beech dowels and self-tapping screws alone.The single shear performance of components connected by...A new beech and self-tapping screw composite dowel is proposed and studied,its performance being compared with that of beech dowels and self-tapping screws alone.The single shear performance of components connected by composite dowels was tested.Results show that the dowels are a good choice for components requiring high stiffness.Screws remain a good choice for components requiring excellent seismic performance.Combination group presents similar maximum load stiffness to those of composite dowels,but other ductility parameters are superior for composite dowels.The best connection mode was provided by two composite dowels.Based on connecting two points,structural elements with two composite dowels showed much better load bearing ability than when joined by two beech dowels or by two self-tapping screws separately.The structural element with two composite dowels not only presented better initial stiffness,but also exhibited a better ductility coeffi-cient and less energy consumption.So,the composite dowels can be used for beam column connection,dowel laminated timber,and restoration or enhancement of ancient buildings.展开更多
The conserved DNA damage repair complex,MMS21-SMC5/6(Methyl methane sulfonate 21-Structural maintenance of chromosomes 5/6),has been extensively studied in yeast,animals,and plants.However,its role in phytopathogenic ...The conserved DNA damage repair complex,MMS21-SMC5/6(Methyl methane sulfonate 21-Structural maintenance of chromosomes 5/6),has been extensively studied in yeast,animals,and plants.However,its role in phytopathogenic fungi,particularly in the highly destructive rice blast fungus Magnaporthe oryzae,remains unknown.In this study,we functionally characterized the homologues of this complex,MoMMS21 and MoSMC5,in M.oryzae.We first demonstrated the importance of DNA damage repair in M.oryzae by showing that the DNA damage inducer phleomycin inhibited vegetative growth,infection-related development and pathogenicity in this fungus.Additionally,we discovered that MoMMS21 and MoSMC5 interacted in the nuclei,suggesting that they also function as a complex in M.oryzae.Gene deletion experiments revealed that both MoMMS21 and MoSMC5 are required for infection-related development and pathogenicity in M.oryzae,while only MoMMS21 deletion affected growth and sensitivity to phleomycin,indicating its specific involvement in DNA damage repair.Overall,our results provide insights into the roles of MoMMS21 and MoSMC5 in M.oryzae,highlighting their functions beyond DNA damage repair.展开更多
Electrical impedance tomography (EIT) aims to reconstruct the conductivity distribution using the boundary measured voltage potential. Traditional regularization based method would suffer from error propagation due to...Electrical impedance tomography (EIT) aims to reconstruct the conductivity distribution using the boundary measured voltage potential. Traditional regularization based method would suffer from error propagation due to the iteration process. The statistical inverse problem method uses statistical inference to estimate unknown parameters. In this article, we develop a nonlinear weighted anisotropic total variation (NWATV) prior density function based on the recently proposed NWATV regularization method. We calculate the corresponding posterior density function, i.e., the solution of the EIT inverse problem in the statistical sense, via a modified Markov chain Monte Carlo (MCMC) sampling. We do numerical experiment to validate the proposed approach.展开更多
Femtosecond laser filamentation has attracted significant attention due to its applications in remote sensing of atmospheric pollutants and artificial weather intervention.Nitrogen is the most abundant gas in the atmo...Femtosecond laser filamentation has attracted significant attention due to its applications in remote sensing of atmospheric pollutants and artificial weather intervention.Nitrogen is the most abundant gas in the atmosphere,and its stimulated ultraviolet emission is remarkably clean,distinctly different from the fluorescence obtained through electron impact or laser breakdown.展开更多
Photon upconversion through high harmonic generation,multiphoton absorption,Auger recombination and phonon scattering performs a vital role in energy conversion and renormalization.Considering the reduced dielectric s...Photon upconversion through high harmonic generation,multiphoton absorption,Auger recombination and phonon scattering performs a vital role in energy conversion and renormalization.Considering the reduced dielectric screening and enhanced Coulomb interactions,semiconductor monolayers provide a promising platform to explore photon upconversion at room temperature.Additionally,two-photon upconversion was recently demonstrated as an emerging technique to probe the excitonic dark states due to the extraordinary selection rule compared with conventional excitation.However,highly efficient two-photon upconversion still remains challenging due to the limited multiphoton absorption efficiency and long radiative lifetimes.Here,a 2440-fold enhancement of two-photon luminescence(TPL)is achieved in doubly resonant plasmonic nanocavities due to the amplified light collection,enhanced excitation rate,and increased quantum efficiency.To gain more insight into the attractive doubly resonant enhancement in such a plasmon−exciton coupling system,the intriguing thermally tuned excitonic upconversion and optimized amplification factor>3000 are realized at 350 K.Meanwhile,the single resonance enhanced photoluminescence(PL)(~890-fold)and second-harmonic generation(SHG)(~134-fold)are elaborately demonstrated.These results establish a foundation for developing cost-effective,high-performance nonlinear photonic devices and probing fine excitonic states via configuring plasmonic nanocavities.展开更多
Tooth breakage is a common issue in geared systems. The high-contact-ratio spur gear system (HCRSG) maintains continuoustransmission despite tooth breakage, but experiences increased impact vibration. In aviation, eve...Tooth breakage is a common issue in geared systems. The high-contact-ratio spur gear system (HCRSG) maintains continuoustransmission despite tooth breakage, but experiences increased impact vibration. In aviation, even if the gear teeth break, the gear'stransmission cannot be stopped immediately. Therefore, studying gear system dynamics with tooth breakage is crucial for assessing thereliability of mechanical equipment. This study treats the tooth-back contact induced by backlash as the tooth-back collision andpresents the multi-state meshing-collision pattern of HCRSG with one tooth breakage (OTB), including triple-tooth, double-tooth,single-tooth meshes, disengagement, and tooth-back collision. Time-varying meshing stiffness and load distribution coefficients ofHCRSG with OTB are calculated. Then a multi-state meshing-collision nonlinear dynamic model of HCRSG with OTB is established.The meshing forces of HCRSG with OTB and without OTB are calculated and compared to examine the effect of tooth breakage. Themulti-state meshing-collision nonlinear dynamics of HCRSG with OTB are studied via bifurcation diagram, phase portraits, andPoincaré maps by changing the transmission error amplitude. The results show that 3-2-3-2-3 meshing pattern of HCRSG is shifted to2-1-2-1-2 meshing pattern due to tooth breakage. The effect of tooth breakage on the meshing force and dynamic behavior significantlydepends on teeth disengagement or tooth-back collision. Tooth breakage greatly affects the bifurcation and chaos characteristics ofmultistate meshing-collision behavior of HCRSG. This study creates a framework to predict and assess the dynamics of gear transmissionsystems with tooth breakage in extreme aviation and aerospace environments.展开更多
Devices operating with excitons exhibit promising prospects for overcoming the dilemma of response time and integration in electron or/and photon based system.Strain engineering has emerged as an effective approach to...Devices operating with excitons exhibit promising prospects for overcoming the dilemma of response time and integration in electron or/and photon based system.Strain engineering has emerged as an effective approach to modulate exciton transport and dynamics,with bubbles induced biaxial strain attracting particular attention for nanoscopic manipulation of exciton flux.However,the unintentionally produced bubbles are completely stochastic in dimensions and morphology,thereby the active and controllable bubbles formation still remain challenge,which is imperative for modulating excitonic and opt-electric performance on demand.Here,we propose the annealing-driven reassembly of micro-bubbles to create the controllable artificial potential landscapes in atomically thin semiconductor,facilitating the active manipulation of exciton flux at room temperature.Correlating micro PL mappings with strain maps calculated from AFM topography and strain modeling,demonstrates the efficient localized exciton emission and exciton funneling in spectral.The imaging of exciton transport and emission provide more intuitive evidence in spatial that excitons flow towards bubble center from excitation location driven by the conventional diffusion and strain gradient induced drift effect,supported by drift-diffusion model.These findings demonstrate the great potential to control exciton dynamics on-demand through annealing driven reassembled micro-bubbles,and lay the foundation for promising applications in high-performance sensing,energy harvesting,and quantum information processing.展开更多
Terahertz(THz)radiation generation by two-color femtosecond laser filamentation is a promising path for high-intensity THz source development.The intrinsic characteristics of the filament,especially its length,play a ...Terahertz(THz)radiation generation by two-color femtosecond laser filamentation is a promising path for high-intensity THz source development.The intrinsic characteristics of the filament,especially its length,play a crucial role in determining the THz radiation strength.However,a detailed analysis of the underlying physical mechanism and the quantitative correlation between the laser filament length and the THz radiation intensity under a high-peak-power driving laser is still lacking.In this paper,the effect of filament length on the THz radiation is investigated by modulating the basic characteristics of the two-color laser field and changing the focal length.Experimental results show that the long filament length is advantageous for improving THz radiation intensity.The theoretical simulation indicates that enhancement of THz radiation arises from coherent accumulation of THz wave produced at each cross-section along the filament.These insights suggest that extending the filament length is an effective scheme to enhance the intensity of THz radiation generated by the two-color femtosecond laser filament.展开更多
Phonon-assisted photon upconversion(UPC)is an anti-Stokes process in which incident photons achieve higher energy emission by absorbing phonons.This letter studies phonon-assisted UPC in twisted 2D semiconductors,in w...Phonon-assisted photon upconversion(UPC)is an anti-Stokes process in which incident photons achieve higher energy emission by absorbing phonons.This letter studies phonon-assisted UPC in twisted 2D semiconductors,in which an inverted contrast between UPC and conventional photoluminescence(PL)of WSe2 twisted bilayer is emergent.A 4-fold UPC enhancement is achieved in 5.5°twisted bilayer while PL weakens by half.Reduced interlayer exciton conversion efficiency driven by lattice relaxation,along with enhanced pump efficiency resulting from spectral redshift,lead to the rotation-angle-dependent UPC enhancement.The counterintuitive phenomenon provides a novel insight into a unique way that twisted angle affects UPC and light-matter interactions in 2D semiconductors.Furthermore,the UPC enhancement platform with various superimposable means offers an effective method for lighting bilayers and expanding the application prospect of 2D stacked van der Waals devices.展开更多
Phonon-assisted upconverted emission is the heart of energy harvesting,bioimaging,optical cryptography,and optical refrigeration.It has been demonstrated that emerging two-dimensional(2D)semiconductors can provide an ...Phonon-assisted upconverted emission is the heart of energy harvesting,bioimaging,optical cryptography,and optical refrigeration.It has been demonstrated that emerging two-dimensional(2D)semiconductors can provide an excellent platform for efficient phonon-assisted upconversion due to the enhanced optical transition strength and phonon-exciton interaction of 2D excitons.However,there is little research on the further enhancement of excitonic upconverted emission in 2D semiconductors.Here,we report the enhanced multiphoton upconverted emission of 2D excitons in doubly resonant plasmonic nanocavities.Owing to the enhanced light collection,enhanced excitation rate,and quantum efficiency enhancement arising from the Purcell effect,an upconverted emission amplification of>1000-fold and a decrease of 2~3 orders of magnitude in the saturated excitation power are achieved.These findings pave the way for the development of excitonic upconversion lasing,nanoscopic thermometry,and sensing,revealing the possibility of optical refrigeration in future 2D electronic or excitonic devices.展开更多
Due to the promising applications of femtosecond laser filamentation in remote sensing,great demands exist for diagnosing the spatiotemporal dynamics of filamentation.However,until now,the rapid and accurate diagnosis...Due to the promising applications of femtosecond laser filamentation in remote sensing,great demands exist for diagnosing the spatiotemporal dynamics of filamentation.However,until now,the rapid and accurate diagnosis of a femtosecond laser filament remains a severe challenge.Here,a novel filament diagnosing method is proposed,which can measure the longitudinal spatial distribution of the filament by a single laser shot-induced acoustic pulse.The dependences of the point-like plasma acoustic emission on the detection distance and angle are obtained experimentally.The results indicate that the temporal profile of the acoustic wave is independent of the detection distance and detection angle.Using the measured relation among the acoustic emission and the detection distance and angle,a single measurement of the acoustic emission generated by a single laser pulse can diagnose the spatial distribution of the laser filament through the Wiener filter deconvolution(WFD)algorithm.The results obtained by this method are in good agreement with those of traditional point-by-point acoustic diagnosis methods.These findings provide a new solution and idea for the rapid diagnosis of filament,thereby laying a firm foundation for femtosecond laser filament-based promising applications.展开更多
The effects of turbulence intensity and turbulence region on the distribution of femtosecond laser filaments are experimentally elaborated.Through the ultrasonic signals emitted by the filaments,it is observed that in...The effects of turbulence intensity and turbulence region on the distribution of femtosecond laser filaments are experimentally elaborated.Through the ultrasonic signals emitted by the filaments,it is observed that increasing turbulence intensity and an expanding turbulence active region cause an increase in the start position of the filament and a decrease in filament length,which can be well explained by theoretical calculation.It is also observed that the random perturbation of the air refractive index caused by atmospheric turbulence expands the spot size of the filament.Additionally,when the turbulence refractive index structure constant reaches 8.37×10^(-12)m^(-2/3),multiple filaments are formed.Furthermore,the standard deviation of the transverse displacement of filament is found to be proportional to the square root of the turbulent structure constant under the experimental turbulence parameters in this paper.These results contribute to the study of femtosecond laser propagation mechanisms in complex atmospheric turbulence conditions.展开更多
基金supported by the National Key Research and Development Program of China(2023YFD1200404)the Science and Technology Department of Sichuan Province(2024ZYD0160)the National Natural Science Foundation of China(32072054).
文摘Wheat is an important cereal crop used to produce diverse and popular food worldwide because of its high grain yield(GY)and grain protein content(GPC).However,GY and GPC are usually negatively correlated.We previously reported that favorable alleles of the wheat domestication gene Q can synchronously increase GY and GPC,but the underlying mechanisms remain largely unknown.In this study,we investigate the regulatory network involving Q associated with GY and GPC in young grains through DNA affinity purification sequencing and transcriptome sequencing analyses,electrophoretic mobility shift and dualluciferase assays,and transgenic approaches.Three Q-binding motifs,namely TTAAGG,AAACA[A/T]A,and GTAC[T/G]A,are identified.Notably,genes related to photosynthesis or carbon and nitrogen metabolism are enriched and regulated by Q.Moreover,Q is revealed to bind directly to its own gene and the glutamine synthetase gene GSr-4D to increase expression,thereby influencing nitrogen assimilation during the grain filling stage and increasing GPC.Considered together,our findings provide molecular evidence of the positive regulatory effects of Q on wheat GY and GPC.
基金supported by the Major Program of National Agricultural Science and Technology of China(NK20220607)the Sichuan Science and Technology Program,China(2023YFH0041)。
文摘Starch biosynthesis is a complex process that relies on the coordinated action of multiple enzymes.Resistant starch is not digested in the small intestine,thus preventing a rapid rise in the glycemic index.Starch synthase 2a(SS2a)is a key enzyme in amylopectin biosynthesis that has significant effects on starch structure and properties.In this study,we identified an ss2a null mutant(M3-1413)with a single base mutation from an ethyl methane sulfonate(EMS)-mutagenized population of barley.The mutation was located at the 3'end of the first intron of the RNA splicing receptor(AG)site,and resulted in abnormal RNA splicing and two abnormal transcripts of ss2a,which caused the inactivation of the SS2a gene.The starch structure and properties were significantly altered in the mutant,with M3-1413 containing lower total starch and higher amylose and resistant starch levels.This study sheds light on the effect of barley ss2a null mutations on starch properties and will help to guide new applications of barley starch in the development of nutritious food products.
基金supported by National Key Research and Development Program of China(2023YFD1201900)National Nat-ural Science Foundation of China(32472078,31971937)+2 种基金Natural Science Foundation of Sichuan Province(2024NSFSC0312)Crop Characteristic Resources Creation and Utilization Key Laboratory of Sichuan Province(myzdsys24-01)the Key Laboratory of Exploitation and Study of Distinctive Plants in Education Department of Sichuan Province(TSZW2023ZB-10).
文摘Productive tiller number(PTN)is a pivotal trait that significantly influences wheat grain yield.To date,there have been limited reports on the cloning of genes that regulate PTN in wheat.The quantitative trait locus(QTL)QPtn.sau-4B,associated with PTN,was previously mapped between the markers KASP-1 and KASP-3 on the chromosome 4B.Here,utilizing 12 newly developed markers and phenotypic data of PTN from recombinants identified within this interval,QPtn.sau-4B was further fine-mapped to a 2.58 Mb interval on wheat chromosome arm 4BS.Within this interval,we identified 14 genes with high-confidence and 32 genes with low-confidence.A 0.17 Mb deletion fragment contained TraesCS4B03G0092600 and TraesCS4B03G0093100,which were assigned as candidate genes for QPtn.sau-4B.Additionally,QPtn.sau-4B had potential to enhance both PTN and grain yield in wheat.Cloning this locus would support the development of wheat cultivars with increased grain yield.
基金supported by the Major Program of National Agricultural Science and Technology of China (NK20220607)the National Natural Science Foundation of China (32272059 and31971883)the Science and Technology Department of Sichuan Province (2022ZDZX0014, 2021YFYZ0002, 2021YJ0297, and23NSFTD0045)。
文摘Stripe rust, caused by Puccinia striiformis f. sp. tritici(Pst), threatens wheat production worldwide, and resistant varieties tend to become susceptible after a period of cultivation owing to the variation of pathogen races. In this study, a new resistance gene against Pst race CYR34 was identified and predicted using the descendants of a cross between AS1676, a highly resistant Chinese landrace, and Avocet S, a susceptible cultivar. From a heterozygous plant from a F7recombinant inbred line(RIL) population lacking the Yr18 gene, a near-isogenic line(NIL) population was developed to map the resistance gene. An allstage resistance gene, YrAS1676, was identified on chromosome arm 1AL via bulked-segregant exomecapture sequencing. By analyzing a large NIL population consisting of 6537 plants, the gene was further mapped to the marker interval between KA1A_485.36 and KA1A_490.13, spanning 485.36–490.13 Mb on1AL. A total of 66 annotated genes have been reported in this region. To characterize and predict the candidate gene(s), an RNA-seq was performed using NIL-R and NIL-S seedlings 3 days after CYR34 inoculation. Compared to NIL-S plants, NIL-R plants showed stronger immune reaction and higher expression levels of genes encoding pathogenesis-associated proteins. These differences may help to explain why NIL-R plants were more resistant to Pst race CYR34 than NIL-S plants. By combining fine-mapping and transcriptome sequencing, a calcium-dependent protein kinase gene was finally predicted as the potential candidate gene of YrAS1676. This gene contained a single-nucleotide polymorphism. The candidate gene was more highly expressed in NIL-R than in NIL-S plants. In field experiments with Pst challenge,the YrAS1676 genotype showed mitigation of disease damage and yield loss without adverse effects on tested agronomic traits. These results suggest that YrAS1676 has potential use in wheat stripe rust resistance breeding.
基金supported by the National Natural Science Foundation of China(31971937 and 31970243)the International Science and Technology Cooperation and Exchanges Program of Science and Technology Department of Sichuan Province(2021YFH0083)+2 种基金the Applied Basic Research Programs of Science and Technology Department of Sichuan Province(2021YJ0503and 2020YJ0140)the Key Projects of Scientific and Technological Activities for Overseas Students of Sichuan Provincethe Basic Research Project of Science and Technology Plan of Guizhou Province(ZK2021 general 131)。
文摘Tiller angle(TA)strongly influences plant architecture and grain yield in cereals.However,the genetic basis of TA in wheat is largely unknown.We identified three TA-related quantitative trait loci(QTL).One of them was QTa.sau-2 B-769,a major QTL localized on chromosome arm 2 BL.QTa.sau-2 B-769 was detected in seven environments,explaining 18.1%–51.1%of phenotypic variance.We developed a linked Kompetitive Allele-Specific Polymerase chain reaction(KASP)marker,KASP-AX-108792274,to further validate this locus in three additional populations in multiple environments.QTa.sau-2 B-769 increased TA by up to 24.9%in these populations.There were significant and positive correlations between TA and flag leaf angle(FLANG).However,TA was not correlated with plant height or anthesis date,suggesting that expression of QTa.sau-2 B-769 is independent of vernalization.Traes CS2 B01 G583800,a gene known to be involved in leaf angle regulation,was identified as the most likely candidate gene for QTa.sau-2 B-769.These results enrich our understanding of the mechanisms regulating wheat TA at maturity and may support precise mapping and cloning of gene(s)underlying QTa.sau-2 B-769.
基金supported by grants from the National Key Research and Development Program of China(2016YFD0100100)the International Science and Technology Cooperation and Exchanges Programs of Science and Technology Department of Sichuan Province(2019YFH0063)the Applied Basic Research Programs of Sichuan Province(2021YJ0297)。
文摘Stripe rust,caused by Puccinia striiformis f.sp.tritici(Pst),is one of the most important diseases threatening the yield and stability of wheat production in China and many other countries.Identification and utilization of new genes for durable stripe rust resistance are important for ongoing control of this disease.The objectives of this study were to identify quantitative trait loci(QTL)associated with adult-plant stripe rust resistance in the Chinese wheat landrace Yibinzhuermai(YBZR)and to provide wheat breeders with new sources of potentially durable resistance.A total of 117 recombinant inbred lines(RILs)(F5:8)derived from a cross between YBZR and highly susceptible cultivar Taichung 29(TC29)were assessed for stripe rust severity in field experiments at Wenjiang in 2016 and 2017 and Chongzhou in 2016,2017,2018,and 2019 in Sichuan following inoculation with a mixture of current Pst races.The RILs were genotyped using the Wheat55K single nucleotide polymorphism(SNP)array.Three QTL were identified on chromosome arms 6AL,5BL and 7DS.QYr.YBZR-6AL and QYr.YBZR-7DS conferred major effects in all field environments,explaining 10.6%to 14.7%and 11.5%to 21.2%of phenotypic variation,respectively.The QTL on 5BL and 7DS likely correspond to previously known QTL,whereas QYr.YBZR-6AL is probably novel.Haplotype analysis revealed that the resistance allele at QYr.YBZR-6AL was present in 2.8%of 324 Chinese wheat landraces.SNP markers closely linked with QYr.YBZR-6AL were converted to kompetitive allele-specific PCR markers and validated in the RIL population and a subset of 92 wheat cultivars.QYr.YBZR-6AL and its markers should be useful in breeding programs to improve the level and durability of stripe rust resistance.
基金supported by grants from the Major Program of National Agricultural Science and Technology of China(NK20220607)the National Natural Science Foundation of China(32272059 and 31971883)the Science and Technology Department of Sichuan Province(2021YFYZ0002,2022ZDZX0014,and 2023NSFSC1995)。
文摘Stripe rust,caused by Puccinia striiformis f.sp.tritici(Pst),is a devastating disease in wheat worldwide.Discovering and characterizing new resistance genes/QTL is crucial for wheat breeding programs.In this study,we fine-mapped and characterized a stripe rust resistance gene,YRAYH,on chromosome arm 5BL in the Chinese wheat landrace Anyuehong(AYH).Evaluations of stripe rust response to prevalent Chinese Pst races in near-isogenic lines derived from a cross of Anyuehong and Taichung 29 showed that YrAYH conferred a high level of resistance at all growth stages.Fine mapping using a large segregating population of 9748 plants,narrowed the YRAYH locus to a 3.7 Mb interval on chromosome arm 5BL that included 61 annotated genes.Transcriptome analysis of two NIL pairs identified 64 upregulated differentially expressed genes(DEGs)in the resistant NILs(NILs-R).Annotations indicated that many of these genes have roles in plant disease resistance pathways.Through a combined approach of fine-mapping and transcriptome sequencing,we identified a serine/threonine-protein kinase SRPK as a candidate gene underlying YrAYH.A unique 25 bp insertion was identified in the NILs-R compared to the NILs-S and previously published wheat genomes.An InDel marker was developed and co-segregated with YrAYH.Agronomic trait evaluation of the NILs suggested that YrAYH not only reduces the impact of stripe rust but was also associated with a gene that increases plant height and spike length.
基金The authors are grateful for the support of the National Natural Science Foundation of China(Grant No.31901252)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20180276)+3 种基金Jiangsu Planned Projects for Postdoctoral Research Funds(Grant No.2020Z075)the Science and Technology Program of Jiangsu Housing and Construction Department(Grant Nos.2018ZD118 and 2020ZD29)Qing Lan Project of Jiangsu,the Yangzhou Science and Technology Project(Grant No.SGH2020010040)Yangzhou Polytechnic Institute Project(Grant No.2019xjzk007).
文摘A new beech and self-tapping screw composite dowel is proposed and studied,its performance being compared with that of beech dowels and self-tapping screws alone.The single shear performance of components connected by composite dowels was tested.Results show that the dowels are a good choice for components requiring high stiffness.Screws remain a good choice for components requiring excellent seismic performance.Combination group presents similar maximum load stiffness to those of composite dowels,but other ductility parameters are superior for composite dowels.The best connection mode was provided by two composite dowels.Based on connecting two points,structural elements with two composite dowels showed much better load bearing ability than when joined by two beech dowels or by two self-tapping screws separately.The structural element with two composite dowels not only presented better initial stiffness,but also exhibited a better ductility coeffi-cient and less energy consumption.So,the composite dowels can be used for beam column connection,dowel laminated timber,and restoration or enhancement of ancient buildings.
基金Research and Development Program of China(2023YFD1400200)the Natural Science Foundation of Fujian Province,China(2022J01125)+2 种基金the Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests,China(MIMCP-202301)the Fujian Provincial Science and Technology Key Project,China(2022NZ030014)the National Natural Science Foundation of China(NSFC31871914).
文摘The conserved DNA damage repair complex,MMS21-SMC5/6(Methyl methane sulfonate 21-Structural maintenance of chromosomes 5/6),has been extensively studied in yeast,animals,and plants.However,its role in phytopathogenic fungi,particularly in the highly destructive rice blast fungus Magnaporthe oryzae,remains unknown.In this study,we functionally characterized the homologues of this complex,MoMMS21 and MoSMC5,in M.oryzae.We first demonstrated the importance of DNA damage repair in M.oryzae by showing that the DNA damage inducer phleomycin inhibited vegetative growth,infection-related development and pathogenicity in this fungus.Additionally,we discovered that MoMMS21 and MoSMC5 interacted in the nuclei,suggesting that they also function as a complex in M.oryzae.Gene deletion experiments revealed that both MoMMS21 and MoSMC5 are required for infection-related development and pathogenicity in M.oryzae,while only MoMMS21 deletion affected growth and sensitivity to phleomycin,indicating its specific involvement in DNA damage repair.Overall,our results provide insights into the roles of MoMMS21 and MoSMC5 in M.oryzae,highlighting their functions beyond DNA damage repair.
文摘Electrical impedance tomography (EIT) aims to reconstruct the conductivity distribution using the boundary measured voltage potential. Traditional regularization based method would suffer from error propagation due to the iteration process. The statistical inverse problem method uses statistical inference to estimate unknown parameters. In this article, we develop a nonlinear weighted anisotropic total variation (NWATV) prior density function based on the recently proposed NWATV regularization method. We calculate the corresponding posterior density function, i.e., the solution of the EIT inverse problem in the statistical sense, via a modified Markov chain Monte Carlo (MCMC) sampling. We do numerical experiment to validate the proposed approach.
基金National Key Research_and Development Program of China(2024YFB3613900)National Natural Science Foundation of China(W2412044)+1 种基金Russian Science Foundation(25-49-00154)Fundamental Research Funds for the Central Universities(63253214).
文摘Femtosecond laser filamentation has attracted significant attention due to its applications in remote sensing of atmospheric pollutants and artificial weather intervention.Nitrogen is the most abundant gas in the atmosphere,and its stimulated ultraviolet emission is remarkably clean,distinctly different from the fluorescence obtained through electron impact or laser breakdown.
基金supported by the National Science Foundation of China(Grant Nos.12027807,12574418,12104241,62225501)Fundamental Research Funds for the Central Universities(Grant No.075-63253216).
文摘Photon upconversion through high harmonic generation,multiphoton absorption,Auger recombination and phonon scattering performs a vital role in energy conversion and renormalization.Considering the reduced dielectric screening and enhanced Coulomb interactions,semiconductor monolayers provide a promising platform to explore photon upconversion at room temperature.Additionally,two-photon upconversion was recently demonstrated as an emerging technique to probe the excitonic dark states due to the extraordinary selection rule compared with conventional excitation.However,highly efficient two-photon upconversion still remains challenging due to the limited multiphoton absorption efficiency and long radiative lifetimes.Here,a 2440-fold enhancement of two-photon luminescence(TPL)is achieved in doubly resonant plasmonic nanocavities due to the amplified light collection,enhanced excitation rate,and increased quantum efficiency.To gain more insight into the attractive doubly resonant enhancement in such a plasmon−exciton coupling system,the intriguing thermally tuned excitonic upconversion and optimized amplification factor>3000 are realized at 350 K.Meanwhile,the single resonance enhanced photoluminescence(PL)(~890-fold)and second-harmonic generation(SHG)(~134-fold)are elaborately demonstrated.These results establish a foundation for developing cost-effective,high-performance nonlinear photonic devices and probing fine excitonic states via configuring plasmonic nanocavities.
基金supported by the National Natural Science Foundation of China(Grant Nos.12102159,12462003)the Lanzhou Youth Science and Technology Talent Innovation Project(2023-QN-39)the postgraduate research exploration project(222080201023).
文摘Tooth breakage is a common issue in geared systems. The high-contact-ratio spur gear system (HCRSG) maintains continuoustransmission despite tooth breakage, but experiences increased impact vibration. In aviation, even if the gear teeth break, the gear'stransmission cannot be stopped immediately. Therefore, studying gear system dynamics with tooth breakage is crucial for assessing thereliability of mechanical equipment. This study treats the tooth-back contact induced by backlash as the tooth-back collision andpresents the multi-state meshing-collision pattern of HCRSG with one tooth breakage (OTB), including triple-tooth, double-tooth,single-tooth meshes, disengagement, and tooth-back collision. Time-varying meshing stiffness and load distribution coefficients ofHCRSG with OTB are calculated. Then a multi-state meshing-collision nonlinear dynamic model of HCRSG with OTB is established.The meshing forces of HCRSG with OTB and without OTB are calculated and compared to examine the effect of tooth breakage. Themulti-state meshing-collision nonlinear dynamics of HCRSG with OTB are studied via bifurcation diagram, phase portraits, andPoincaré maps by changing the transmission error amplitude. The results show that 3-2-3-2-3 meshing pattern of HCRSG is shifted to2-1-2-1-2 meshing pattern due to tooth breakage. The effect of tooth breakage on the meshing force and dynamic behavior significantlydepends on teeth disengagement or tooth-back collision. Tooth breakage greatly affects the bifurcation and chaos characteristics ofmultistate meshing-collision behavior of HCRSG. This study creates a framework to predict and assess the dynamics of gear transmissionsystems with tooth breakage in extreme aviation and aerospace environments.
基金supported by the National Science Foundation of China(Grant Nos.12027807,12104241,62225501)Fundamental Research Funds for the Central Universities(Grant No.075-63253216).
文摘Devices operating with excitons exhibit promising prospects for overcoming the dilemma of response time and integration in electron or/and photon based system.Strain engineering has emerged as an effective approach to modulate exciton transport and dynamics,with bubbles induced biaxial strain attracting particular attention for nanoscopic manipulation of exciton flux.However,the unintentionally produced bubbles are completely stochastic in dimensions and morphology,thereby the active and controllable bubbles formation still remain challenge,which is imperative for modulating excitonic and opt-electric performance on demand.Here,we propose the annealing-driven reassembly of micro-bubbles to create the controllable artificial potential landscapes in atomically thin semiconductor,facilitating the active manipulation of exciton flux at room temperature.Correlating micro PL mappings with strain maps calculated from AFM topography and strain modeling,demonstrates the efficient localized exciton emission and exciton funneling in spectral.The imaging of exciton transport and emission provide more intuitive evidence in spatial that excitons flow towards bubble center from excitation location driven by the conventional diffusion and strain gradient induced drift effect,supported by drift-diffusion model.These findings demonstrate the great potential to control exciton dynamics on-demand through annealing driven reassembled micro-bubbles,and lay the foundation for promising applications in high-performance sensing,energy harvesting,and quantum information processing.
基金supported by the National Natural Science Foundation of China(Nos.12074198,12204251,and 12061131010)the Russian Science Foundation(No.2149-00461)。
文摘Terahertz(THz)radiation generation by two-color femtosecond laser filamentation is a promising path for high-intensity THz source development.The intrinsic characteristics of the filament,especially its length,play a crucial role in determining the THz radiation strength.However,a detailed analysis of the underlying physical mechanism and the quantitative correlation between the laser filament length and the THz radiation intensity under a high-peak-power driving laser is still lacking.In this paper,the effect of filament length on the THz radiation is investigated by modulating the basic characteristics of the two-color laser field and changing the focal length.Experimental results show that the long filament length is advantageous for improving THz radiation intensity.The theoretical simulation indicates that enhancement of THz radiation arises from coherent accumulation of THz wave produced at each cross-section along the filament.These insights suggest that extending the filament length is an effective scheme to enhance the intensity of THz radiation generated by the two-color femtosecond laser filament.
基金supports from the National Key Research and Development Program of China(2020YFA0211300)National Science Foundation of China(grant Nos.62225501,12027807)+1 种基金Bejing Natural Science Foundation(grant Nos.Z180011)High-performance Computing Platform of Peking University.
文摘Phonon-assisted photon upconversion(UPC)is an anti-Stokes process in which incident photons achieve higher energy emission by absorbing phonons.This letter studies phonon-assisted UPC in twisted 2D semiconductors,in which an inverted contrast between UPC and conventional photoluminescence(PL)of WSe2 twisted bilayer is emergent.A 4-fold UPC enhancement is achieved in 5.5°twisted bilayer while PL weakens by half.Reduced interlayer exciton conversion efficiency driven by lattice relaxation,along with enhanced pump efficiency resulting from spectral redshift,lead to the rotation-angle-dependent UPC enhancement.The counterintuitive phenomenon provides a novel insight into a unique way that twisted angle affects UPC and light-matter interactions in 2D semiconductors.Furthermore,the UPC enhancement platform with various superimposable means offers an effective method for lighting bilayers and expanding the application prospect of 2D stacked van der Waals devices.
基金supported by National Key Research and Development Program of China(grant no.2017YFA0206000)Beijing Natural Science Foundation(grant nos.Z180011)+2 种基金National Key Research Program(2017YFA0205700,2019YFA0210203,2020YFA0211300)National Science Foundation of China(gant nos.12027807,21790364,12104241)High-performance Computing Platform of Peking University.
文摘Phonon-assisted upconverted emission is the heart of energy harvesting,bioimaging,optical cryptography,and optical refrigeration.It has been demonstrated that emerging two-dimensional(2D)semiconductors can provide an excellent platform for efficient phonon-assisted upconversion due to the enhanced optical transition strength and phonon-exciton interaction of 2D excitons.However,there is little research on the further enhancement of excitonic upconverted emission in 2D semiconductors.Here,we report the enhanced multiphoton upconverted emission of 2D excitons in doubly resonant plasmonic nanocavities.Owing to the enhanced light collection,enhanced excitation rate,and quantum efficiency enhancement arising from the Purcell effect,an upconverted emission amplification of>1000-fold and a decrease of 2~3 orders of magnitude in the saturated excitation power are achieved.These findings pave the way for the development of excitonic upconversion lasing,nanoscopic thermometry,and sensing,revealing the possibility of optical refrigeration in future 2D electronic or excitonic devices.
基金supported by the National Natural Science Foundation of China(Nos.12074198,12061131010,and 12304381)the Russian Science Foundation(RSF)(No.21-49-00023).
文摘Due to the promising applications of femtosecond laser filamentation in remote sensing,great demands exist for diagnosing the spatiotemporal dynamics of filamentation.However,until now,the rapid and accurate diagnosis of a femtosecond laser filament remains a severe challenge.Here,a novel filament diagnosing method is proposed,which can measure the longitudinal spatial distribution of the filament by a single laser shot-induced acoustic pulse.The dependences of the point-like plasma acoustic emission on the detection distance and angle are obtained experimentally.The results indicate that the temporal profile of the acoustic wave is independent of the detection distance and detection angle.Using the measured relation among the acoustic emission and the detection distance and angle,a single measurement of the acoustic emission generated by a single laser pulse can diagnose the spatial distribution of the laser filament through the Wiener filter deconvolution(WFD)algorithm.The results obtained by this method are in good agreement with those of traditional point-by-point acoustic diagnosis methods.These findings provide a new solution and idea for the rapid diagnosis of filament,thereby laying a firm foundation for femtosecond laser filament-based promising applications.
基金supported by the National Key Research and Development Program of China(No.2018YFB0504400)the Fundamental Research Funds for the Central Universities(No.63223052)。
文摘The effects of turbulence intensity and turbulence region on the distribution of femtosecond laser filaments are experimentally elaborated.Through the ultrasonic signals emitted by the filaments,it is observed that increasing turbulence intensity and an expanding turbulence active region cause an increase in the start position of the filament and a decrease in filament length,which can be well explained by theoretical calculation.It is also observed that the random perturbation of the air refractive index caused by atmospheric turbulence expands the spot size of the filament.Additionally,when the turbulence refractive index structure constant reaches 8.37×10^(-12)m^(-2/3),multiple filaments are formed.Furthermore,the standard deviation of the transverse displacement of filament is found to be proportional to the square root of the turbulent structure constant under the experimental turbulence parameters in this paper.These results contribute to the study of femtosecond laser propagation mechanisms in complex atmospheric turbulence conditions.
