When the contacts of a medium-voltage DC air circuit breaker(DCCB) are separated, the energy distribution of the arc is determined by the formation process of the near-electrode sheath. Therefore, the voltage drop thr...When the contacts of a medium-voltage DC air circuit breaker(DCCB) are separated, the energy distribution of the arc is determined by the formation process of the near-electrode sheath. Therefore, the voltage drop through the near-electrode sheath is an important means to build up the arc voltage, which directly determines the current-limiting performance of the DCCB. A numerical model to describe the near-electrode sheath formation process can provide insight into the physical mechanism of the arc formation, and thus provide a method for arc energy regulation. In this work, we establish a two-dimensional axisymmetric time-varying model of a medium-voltage DCCB arc when interrupted by high current based on a fluid-chemical model involving 16 kinds of species and 46 collision reactions. The transient distributions of electron number density, positive and negative ion number density, net space charge density, axial electric field, axial potential between electrodes, and near-cathode sheath are obtained from the numerical model. The computational results show that the electron density in the arc column increases, then decreases, and then stabilizes during the near-cathode sheath formation process, and the arc column's diameter gradually becomes wider. The 11.14 V–12.33 V drops along the17 μm space charge layer away from the cathode(65.5 k V/m–72.5 k V/m) when the current varies from 20 k A–80 k A.The homogeneous external magnetic field has little effect on the distribution of particles in the near-cathode sheath core,but the electron number density at the near-cathode sheath periphery can increase as the magnetic field increases and the homogeneous external magnetic field will lead to arc diffusion. The validity of the numerical model can be proven by comparison with the experiment.展开更多
This paper examines the occurrence regularity and comprehensive prevention and control techniques for sunflower downy mildew.It provides a detailed discussion of the pathogens,symptoms,and associated risks,as well as ...This paper examines the occurrence regularity and comprehensive prevention and control techniques for sunflower downy mildew.It provides a detailed discussion of the pathogens,symptoms,and associated risks,as well as the transmission pathways,underlying causes,and prevention and control techniques related to sunflower downy mildew.The aim is to offer valuable references and technical guidance for the effective management of this disease.展开更多
The Solar Upper Transition Region Imager(SUTRI)onboard the Space Advanced Technology demonstration satellite(SATech-01),which was launched to a Sun-synchronous orbit at a height of~500 km in 2022 July,aims to test the...The Solar Upper Transition Region Imager(SUTRI)onboard the Space Advanced Technology demonstration satellite(SATech-01),which was launched to a Sun-synchronous orbit at a height of~500 km in 2022 July,aims to test the on-orbit performance of our newly developed Sc/Si multi-layer reflecting mirror and the 2k×2k EUV CMOS imaging camera and to take full-disk solar images at the Ne VII 46.5 nm spectral line with a filter width of~3 nm.SUTRI employs a Ritchey-Chrétien optical system with an aperture of 18 cm.The on-orbit observations show that SUTRI images have a field of view of~416×416 and a moderate spatial resolution of~8″without an image stabilization system.The normal cadence of SUTRI images is 30 s and the solar observation time is about16 hr each day because the earth eclipse time accounts for about 1/3 of SATech-01's orbit period.Approximately15 GB data is acquired each day and made available online after processing.SUTRI images are valuable as the Ne VII 46.5 nm line is formed at a temperature regime of~0.5 MK in the solar atmosphere,which has rarely been sampled by existing solar imagers.SUTRI observations will establish connections between structures in the lower solar atmosphere and corona,and advance our understanding of various types of solar activity such as flares,filament eruptions,coronal jets and coronal mass ejections.展开更多
Histone H3 lysine 27 trimethylation(H3K27me3) is a histone modification associated with transcriptional repression. However, insights into the genome-wide pattern of H3K27me3 in grapevines are limited. Here, anti-H3K2...Histone H3 lysine 27 trimethylation(H3K27me3) is a histone modification associated with transcriptional repression. However, insights into the genome-wide pattern of H3K27me3 in grapevines are limited. Here, anti-H3K27 chromatin immunoprecipitation(ChIP), high-throughput sequencing, and transcriptome analysis were performed using leaves of Vitis amurensis. The leaves were treated at 4°C for 2 h and 24 h and used to investigate changes in H3K27me3 under chilling treatment. The results show that H3K27me3 is well-distributed both in gene regions(-50%) and in the intergenic region(-50%) in the grapevine genome(Vitis vinifera ‘Pinot Noir PN40024'). H3K27me3 was found to be localized in8 368 annotated gene regions in all detected samples(leaves at normal temperature and under chilling treatments) and mainly enriched in gene bodies with the adjacent promoter and downstream areas. The short-term chilling treatments(4°C for 2 h) induced 2 793 gains and 305losses in H3K27me3 modification. Subsequently, 97.3% of the alterations were restored to original levels after 24 h treatment. The ChIP-qPCR for five differential peaks showed similar results to the data for ChIP-seq, indicating that the chilling-induced H3K27me3 modification is reliable.Integrative analysis of transcriptome and ChIP-seq results showed that the expression of H3K27me3 target genes was significantly lower than those of non-target genes, indicating transcriptional repression of H3K27me3 in grapevine leaves. Furthermore, histone methylation alterations were detected in 82 genes and were related to either repression or activation of their expression during chilling stress. The findings provide the genome-wide H3K27me3 patterns in grapevines and shed light on uncovering its regulation in chilling stress responses.展开更多
Grape is a widely cultivated crop with high economic value.Most cultivars derived from mild or cooler climates may not withstand increasing heat stress.Therefore,dissecting the mechanisms of heat tolerance in grapes i...Grape is a widely cultivated crop with high economic value.Most cultivars derived from mild or cooler climates may not withstand increasing heat stress.Therefore,dissecting the mechanisms of heat tolerance in grapes is of particular significance.Here,we performed comparative transcriptome analysis of Vitis davidii‘Tangwei’(heat tolerant)and Vitis vinifera‘Jingxiu’(heat sensitive)grapevines after exposure to 25°C,40°C,or 45°C for 2 h.More differentially expressed genes(DEGs)were detected in‘Tangwei’than in‘Jingxiu’in response to heat stress,and the number of DEGs increased with increasing treatment temperatures.We identified a class B Heat Shock Factor,HSFB1,which was significantly upregulated in‘Tangwei’,but not in‘Jingxiu’,at high temperature.VdHSFB1 from‘Tangwei’and VvHSFB1 from‘Jingxiu’differ in only one amino acid,and both showed similar transcriptional repression activities.Overexpression and RNA interference of HSFB1 in grape indicated that HSFB1 positively regulates the heat tolerance.Moreover,the heat tolerance of HSFB1-overexpressing plants was positively correlated to HSFB1 expression level.The activity of the VdHSFB1 promoter is higher than that of VvHSFB1 under both normal and high temperatures.Promoter analysis showed that more TATA-box and AT∼TATA-box cis-elements are present in the VdHSFB1 promoter than the VvHSFB1 promoter.The promoter sequence variations between VdHSFB1 and VvHSFB1 likely determine the HSFB1 expression levels that inf luence heat tolerance of the two grape germplasms with contrasting thermotolerance.Collectively,we validated the role of HSFB1 in heat tolerance,and the knowledge gained will advance our ability to breed heat-tolerant grape cultivars.展开更多
Anthocyanins are essential for the quality of perennial horticultural crops,such as grapes.In grapes,ELONGATED HYPOCOTYL 5(HY5)and MYBA1 are two critical transcription factors that regulate anthocyanin biosynthesis.Ou...Anthocyanins are essential for the quality of perennial horticultural crops,such as grapes.In grapes,ELONGATED HYPOCOTYL 5(HY5)and MYBA1 are two critical transcription factors that regulate anthocyanin biosynthesis.Our previous work has shown that Vitis vinifera B-box protein 44(VvBBX44)inhibits anthocyanin synthesis and represses VvHY5 expression in grape calli.However,the regulatory mechanism underlying this regulation was unclear.In this study,we found that loss of VvBBX44 function resulted in increased anthocyanin accumulation in grapevine callus.VvBBX44 directly represses VvMYBA1,which activates VvBBX44.VvMYBA1,but not VvBBX44,directly modulates the expression of grape UDP flavonoid 3-O-glucosyltransferase(VvUFGT).We demonstrated that VvBBX44 represses the transcriptional activation of VvUFGT and VvBBX44 induced by VvMYBA1.However,VvBBX44 and VvMYBA1 did not physically interact in yeast.The application of exogenous anthocyanin stimulated VvBBX44 expression in grapevine suspension cells and tobacco leaves.These findings suggest that VvBBX44 and VvMYBA1 form a transcriptional feedback loop to prevent overaccumulation of anthocyanin and reduce metabolic costs.Our work sheds light on the complex regulatory network that controls anthocyanin biosynthesis in grapevine.展开更多
The quality of planting materials is the foundation for productivity,longevity,and berry quality of perennial grapevines with a long lifespan.Manipulating the nursery light spectrum may speed up the production of heal...The quality of planting materials is the foundation for productivity,longevity,and berry quality of perennial grapevines with a long lifespan.Manipulating the nursery light spectrum may speed up the production of healthy and high-quality planting vines but the underlying mechanisms remain elusive.Herein,the effects of different monochromatic lights(green,blue,and red)on grapevine growth,leaf photosynthesis,whole-plant carbon allocation,and transcriptome reprograming were investigated with white light as control.Results showed that blue and red lights were favorable for plantlet growth in comparison with white light.Blue light repressed excessive growth,significantly increased the maximum net photosynthetic rate(Pn)of leaves by 39.58%and leaf specific weight by 38.29%.Red light increased the dry weight of the stem by 53.60%,the starch content of the leaf by 53.63%,and the sucrose content of the stem by 230%.Green light reduced all photosynthetic indexes of the grape plantlet.Photosynthetic photon flux density(PPFD)/Ci–Pn curves indicated that blue light affected photosynthetic rate depending on the light intensity and CO2 concentration.RNA-seq analysis of different organs(leaf,stem,and root)revealed a systematic transcriptome remodeling and VvCOP1(CONSTITUTIVELY PHOTOMORPHOGENIC 1),VvHY5(ELONGATED HYPOCOTYL5),VvHYH(HY5 HOMOLOG),VvELIP(early light-induced protein)and VvPIF3(PHYTOCHROME INTERACTING FACTOR 3)may play important roles in this shoot-to-root signaling.Furthermore,the correlation network between differential expression genes and physiological traits indicated that VvpsbS(photosystem II subunit S),Vvpsb28(photosystem II subunit 28),VvHYH,VvSUS4(sucrose synthase 4),and VvALDA(fructose-bisphosphate aldolase)were pertinent candidate genes in responses to different light qualities.Our results provide a foundation for optimizing the light recipe of grape plantlets and strengthen the understanding of light signaling and carbon metabolism under different monochromatic lights.展开更多
Studies on Agrobacterium tumefaciens-mediated transformation of wild tobaccos Nicotiana debneyi, Nicotiana clevelandii, and Nicotiana glutinosa were conducted. Leaf disks were infected and co-cultivated with A. tumefa...Studies on Agrobacterium tumefaciens-mediated transformation of wild tobaccos Nicotiana debneyi, Nicotiana clevelandii, and Nicotiana glutinosa were conducted. Leaf disks were infected and co-cultivated with A. tumefaciens strain EHA105 carrying the binary vector pBISN1 with an intron interrupted β-glucuronidase (GUS) reporter gene (gusA) and the neomycin phosphotransferase gene (nptII). Selection and regeneration of kanamycin resistant shoots were conducted on regeneration medium containing 8.88 μM 6-benzylaminopurine (BAP), 0.57 μM indole-3-acetic acid (IAA), 50 mg·L<sup>-1</sup> kanamycin and 250 mg·L<sup>-1</sup> timentin. Kanamycin resistant shoots were rooted Murashige and Skoog (MS) medium containing 100 mg·L<sup>-1</sup> kanamycin and 250 mg·L<sup>-1</sup> timentin. Using this protocol, kanamycin-resistant plants were obtained from all three wild tobaccos at frequencies of 75.6% for N. debneyi, 25.0% for N. clevelandii, and 2.8% for N. glutinosa. Transcripts of nptII and gusA were detected in kanamycin-resistant T0 transformants (i.e., 2 for N. glutinosa and 5 for each of the N. debneyi and N. clevelandii) by the reverse transcript polymerase chain reaction (RT-PCR), and histochemical GUS assays confirmed expression of gusA in both T<sub>0</sub> plants and T<sub>1</sub> seedlings. The results indicate that the protocols are efficient for transformation of wild tobacco N. debneyi and N. clevelandii.展开更多
The Full-disk Magneto Graph(FMG),a payload onboard the Advanced Space Solar Observatory(ASO-S),will measure the vector magnetic field in the photosphere.The instrument consists of a frontwindow filter,a telescope,an L...The Full-disk Magneto Graph(FMG),a payload onboard the Advanced Space Solar Observatory(ASO-S),will measure the vector magnetic field in the photosphere.The instrument consists of a frontwindow filter,a telescope,an LCVR polarimeter,an image-stabilization system,a seven-stage tunable Lyot filter,a CMOS camera with 4096×4096 pixels and a pair of calibration/focus wheels.In this paper,we describe the design of the FMG instrument and provide a summary of test observations carried out with the FMG prototype.展开更多
The spherical agglomerated particles were fabricated by spray drying with the powders of NiO, Cr2O3 and TiO2. Plasma spray power, which has good property of flowability, was acquired by heat treatment from the particl...The spherical agglomerated particles were fabricated by spray drying with the powders of NiO, Cr2O3 and TiO2. Plasma spray power, which has good property of flowability, was acquired by heat treatment from the particles at 1200℃ in the reducing atmosphere. Dark and uniform coating of More than 50 μm thick was deposited on the copper sheet substrate by plasma spraying. It is found that the infrared normal total emissivity of the coating is up to 0.91 at 600℃ by infrared radiation testing. The X-ray diffraction analysis shows that the formation of （Cr0.88Ti0.12）2O3 and spinel structural NiCr2O4 in the coating is the main reason for high efficient infrared radiation, and the phase structure and performance of coating is favorable under the thermal cycle between room temperature and 600℃.展开更多
The efficacy of the CRISPR/Cas9 system in grapevine(Vitis vinifera L.)has been documented,but the optimization of this system,as well as CRISPR/Cas9-mediated multiplex genome editing,has not been explored in this spec...The efficacy of the CRISPR/Cas9 system in grapevine(Vitis vinifera L.)has been documented,but the optimization of this system,as well as CRISPR/Cas9-mediated multiplex genome editing,has not been explored in this species.Herein,we identified four VvU3 and VvU6 promoters and two ubiquitin(UBQ)promoters in grapevine and demonstrated that the use of the identified VvU3/U6 and UBQ2 promoters could significantly increase the editing efficiency in grape by improving the expression of sgRNA and Cas9,respectively.Furthermore,we conducted multiplex genome editing using the optimized CRISPR/Cas9 vector that contained the conventional multiple sgRNA expression cassettes or the polycistronic tRNA-sgRNA cassette(PTG)by targeting the sugar-related tonoplastic monosaccharide transporter(TMT)family members TMT1 and TMT2,and the overall editing efficiencies were higher than 10%.The simultaneous editing of TMT1 and TMT2 resulted in reduced sugar levels,which indicated the role of these two genes in sugar accumulation in grapes.Moreover,the activities of the VvU3,VvU6,and UBQ2 promoters in tobacco genome editing were demonstrated by editing the phytoene desaturase(PDS)gene in Nicotiana benthamiana leaves.Our study provides materials for the optimization of the CRISPR/Cas9 system.To our knowledge,our simultaneous editing of the grape TMT family genes TMT1 and TMT2 constitutes the first example of multiplex genome editing in grape.The multiplex editing systems described in this manuscript expand the toolbox of grape genome editing,which would facilitate basic research and molecular breeding in grapevine.展开更多
This paper considered a multi-relay distributed cooperative system in which not only the source communicates with the destination,but also the relays have communication requests with the destination.In order to achiev...This paper considered a multi-relay distributed cooperative system in which not only the source communicates with the destination,but also the relays have communication requests with the destination.In order to achieve the requirements of simultaneous communication for the source and relays,we propose a distributed cooperative system based on orthogonal frequency division multiplexing with index modulation(OFDM-IM).In this system,the relay can communicate with the destination by superimposing its own signal over the inactive subcarriers on the decoded OFDM-IM signal.Upper bounds on the bit error rates of the source and the active relay are both derived in closed form,whose tightness is verified through simulation results.展开更多
Selective laser melting(SLM) is a promising technique for additive manufacturing. During SLM of metallic powder, the temperature field and thermal history are important to understand physical phenomena involved. The p...Selective laser melting(SLM) is a promising technique for additive manufacturing. During SLM of metallic powder, the temperature field and thermal history are important to understand physical phenomena involved. The purpose of this study is to simulate the temperature field during the SLM process of a hollow cylinder shape part based on a fully threaded tree(FTT) technique, and to analyze the temperature variation with time in different regions of the part. A revised model for temperature field simulation in the SLM process was employed, which includes the transition of powder-to-dense sub-model and a moving volumetric Gaussian distribution heat source sub-model. The FTT technique is then adopted as an adaptive mesh strategy in the simulation. The simulation result shows that during the SLM process of cylinder part, the temperature of inner powder bed is obviously higher than external one. The temperature at the internal of the molten pool is also higher than external, which may lead to differences in microstructures and other properties between the two regions.展开更多
In this paper, we propose cooperative relay networks with non-orthogonal multiple access in order to design a near-optimal power allocation strategy. Like other next generation wireless technologies, spatially multipl...In this paper, we propose cooperative relay networks with non-orthogonal multiple access in order to design a near-optimal power allocation strategy. Like other next generation wireless technologies, spatially multiplexed transmissions are achieved by relay nodes which enables decode-and-forward relaying of a new superposition code after reception from the source. It is worth noting that, since it is hard to exactly prove the proposed PA scheme, due the fact that it is one kind of the approximate conjectures. Therefore, mathematical and numerical methods have been used to clarify the feasibility of the proposal. Numerical results indicate that it is able to asymptotically achieve the optimal sum rate at the higher signal-to-noise ratio region with the proposed strategy applied instead of negligible performance loss.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No.51977132)Key Special Science and Technology Project of Liaoning Province (Grant No.2020JH1/10100012)General Program of the Education Department of Liaoning Province (Grant No.LJKZ0126)。
文摘When the contacts of a medium-voltage DC air circuit breaker(DCCB) are separated, the energy distribution of the arc is determined by the formation process of the near-electrode sheath. Therefore, the voltage drop through the near-electrode sheath is an important means to build up the arc voltage, which directly determines the current-limiting performance of the DCCB. A numerical model to describe the near-electrode sheath formation process can provide insight into the physical mechanism of the arc formation, and thus provide a method for arc energy regulation. In this work, we establish a two-dimensional axisymmetric time-varying model of a medium-voltage DCCB arc when interrupted by high current based on a fluid-chemical model involving 16 kinds of species and 46 collision reactions. The transient distributions of electron number density, positive and negative ion number density, net space charge density, axial electric field, axial potential between electrodes, and near-cathode sheath are obtained from the numerical model. The computational results show that the electron density in the arc column increases, then decreases, and then stabilizes during the near-cathode sheath formation process, and the arc column's diameter gradually becomes wider. The 11.14 V–12.33 V drops along the17 μm space charge layer away from the cathode(65.5 k V/m–72.5 k V/m) when the current varies from 20 k A–80 k A.The homogeneous external magnetic field has little effect on the distribution of particles in the near-cathode sheath core,but the electron number density at the near-cathode sheath periphery can increase as the magnetic field increases and the homogeneous external magnetic field will lead to arc diffusion. The validity of the numerical model can be proven by comparison with the experiment.
基金Supported by Wujiaqu City Science and Technology Program Project of the Sixth Division(2214)Science and Technology Research Project in Key Areas of the Xinjiang Production and Construction Corps(2024AB014)+4 种基金Financial Program of the Ninth Division(2024JS007)"Strengthening Youth"Science and Technology Innovation Backbone Talent Program of the Xinjiang Production and Construction Corps(2023007-06)Key R&D Program of Xinjiang Autonomous Region(2023B02008-1)Excellence Youth Program of the Xinjiang Production and Construction CorpsEarmarked Fund for China Agriculture Research System(CARS-16).
文摘This paper examines the occurrence regularity and comprehensive prevention and control techniques for sunflower downy mildew.It provides a detailed discussion of the pathogens,symptoms,and associated risks,as well as the transmission pathways,underlying causes,and prevention and control techniques related to sunflower downy mildew.The aim is to offer valuable references and technical guidance for the effective management of this disease.
基金supported by the National Natural Science Foundation of China(NSFC)under Grants 11825301,12003016,12073077the National Key R&D Program of China No.2021YFA0718600+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences with the Grant No.XDA15018400the Youth Innovation Promotion Association of CAS(2023061)。
文摘The Solar Upper Transition Region Imager(SUTRI)onboard the Space Advanced Technology demonstration satellite(SATech-01),which was launched to a Sun-synchronous orbit at a height of~500 km in 2022 July,aims to test the on-orbit performance of our newly developed Sc/Si multi-layer reflecting mirror and the 2k×2k EUV CMOS imaging camera and to take full-disk solar images at the Ne VII 46.5 nm spectral line with a filter width of~3 nm.SUTRI employs a Ritchey-Chrétien optical system with an aperture of 18 cm.The on-orbit observations show that SUTRI images have a field of view of~416×416 and a moderate spatial resolution of~8″without an image stabilization system.The normal cadence of SUTRI images is 30 s and the solar observation time is about16 hr each day because the earth eclipse time accounts for about 1/3 of SATech-01's orbit period.Approximately15 GB data is acquired each day and made available online after processing.SUTRI images are valuable as the Ne VII 46.5 nm line is formed at a temperature regime of~0.5 MK in the solar atmosphere,which has rarely been sampled by existing solar imagers.SUTRI observations will establish connections between structures in the lower solar atmosphere and corona,and advance our understanding of various types of solar activity such as flares,filament eruptions,coronal jets and coronal mass ejections.
基金supported by the National Key Research and Development Program of China (Grant No. 2018YFD1000300)the National Natural Science Foundation of China (Grant No. 32025032)+1 种基金the Grape Breeding Project of Ningxia (Grant No. NXNYYZ202101-04)Major Program of Technological Innovation in Hubei Province (Grant No. 2019ABA093).
文摘Histone H3 lysine 27 trimethylation(H3K27me3) is a histone modification associated with transcriptional repression. However, insights into the genome-wide pattern of H3K27me3 in grapevines are limited. Here, anti-H3K27 chromatin immunoprecipitation(ChIP), high-throughput sequencing, and transcriptome analysis were performed using leaves of Vitis amurensis. The leaves were treated at 4°C for 2 h and 24 h and used to investigate changes in H3K27me3 under chilling treatment. The results show that H3K27me3 is well-distributed both in gene regions(-50%) and in the intergenic region(-50%) in the grapevine genome(Vitis vinifera ‘Pinot Noir PN40024'). H3K27me3 was found to be localized in8 368 annotated gene regions in all detected samples(leaves at normal temperature and under chilling treatments) and mainly enriched in gene bodies with the adjacent promoter and downstream areas. The short-term chilling treatments(4°C for 2 h) induced 2 793 gains and 305losses in H3K27me3 modification. Subsequently, 97.3% of the alterations were restored to original levels after 24 h treatment. The ChIP-qPCR for five differential peaks showed similar results to the data for ChIP-seq, indicating that the chilling-induced H3K27me3 modification is reliable.Integrative analysis of transcriptome and ChIP-seq results showed that the expression of H3K27me3 target genes was significantly lower than those of non-target genes, indicating transcriptional repression of H3K27me3 in grapevine leaves. Furthermore, histone methylation alterations were detected in 82 genes and were related to either repression or activation of their expression during chilling stress. The findings provide the genome-wide H3K27me3 patterns in grapevines and shed light on uncovering its regulation in chilling stress responses.
基金supported by the National Natural Science Foundation of China(Grant no.U21A20227)the National Key Research and Development Program of China(Grant no.2018YFD1000300)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant no.XDA23080602).
文摘Grape is a widely cultivated crop with high economic value.Most cultivars derived from mild or cooler climates may not withstand increasing heat stress.Therefore,dissecting the mechanisms of heat tolerance in grapes is of particular significance.Here,we performed comparative transcriptome analysis of Vitis davidii‘Tangwei’(heat tolerant)and Vitis vinifera‘Jingxiu’(heat sensitive)grapevines after exposure to 25°C,40°C,or 45°C for 2 h.More differentially expressed genes(DEGs)were detected in‘Tangwei’than in‘Jingxiu’in response to heat stress,and the number of DEGs increased with increasing treatment temperatures.We identified a class B Heat Shock Factor,HSFB1,which was significantly upregulated in‘Tangwei’,but not in‘Jingxiu’,at high temperature.VdHSFB1 from‘Tangwei’and VvHSFB1 from‘Jingxiu’differ in only one amino acid,and both showed similar transcriptional repression activities.Overexpression and RNA interference of HSFB1 in grape indicated that HSFB1 positively regulates the heat tolerance.Moreover,the heat tolerance of HSFB1-overexpressing plants was positively correlated to HSFB1 expression level.The activity of the VdHSFB1 promoter is higher than that of VvHSFB1 under both normal and high temperatures.Promoter analysis showed that more TATA-box and AT∼TATA-box cis-elements are present in the VdHSFB1 promoter than the VvHSFB1 promoter.The promoter sequence variations between VdHSFB1 and VvHSFB1 likely determine the HSFB1 expression levels that inf luence heat tolerance of the two grape germplasms with contrasting thermotolerance.Collectively,we validated the role of HSFB1 in heat tolerance,and the knowledge gained will advance our ability to breed heat-tolerant grape cultivars.
基金We thank professor Yu-Jin Hao(College of Horticulture Science and Engineering,Shandong Agricultural University)for providing the plasmid for the EMSA experiment.All data generated and analyzed in this study are shown in the article or attached as supplementary data.All the materials used in the study are available upon reasonable request fromthe corresponding author.This work was supported by the National Natural Science Foundation of China(Grant no.U21A20227)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant no.XDA23080602).Research conducted as part of the LIA INNOGRAPE International Associated Laboratory.
文摘Anthocyanins are essential for the quality of perennial horticultural crops,such as grapes.In grapes,ELONGATED HYPOCOTYL 5(HY5)and MYBA1 are two critical transcription factors that regulate anthocyanin biosynthesis.Our previous work has shown that Vitis vinifera B-box protein 44(VvBBX44)inhibits anthocyanin synthesis and represses VvHY5 expression in grape calli.However,the regulatory mechanism underlying this regulation was unclear.In this study,we found that loss of VvBBX44 function resulted in increased anthocyanin accumulation in grapevine callus.VvBBX44 directly represses VvMYBA1,which activates VvBBX44.VvMYBA1,but not VvBBX44,directly modulates the expression of grape UDP flavonoid 3-O-glucosyltransferase(VvUFGT).We demonstrated that VvBBX44 represses the transcriptional activation of VvUFGT and VvBBX44 induced by VvMYBA1.However,VvBBX44 and VvMYBA1 did not physically interact in yeast.The application of exogenous anthocyanin stimulated VvBBX44 expression in grapevine suspension cells and tobacco leaves.These findings suggest that VvBBX44 and VvMYBA1 form a transcriptional feedback loop to prevent overaccumulation of anthocyanin and reduce metabolic costs.Our work sheds light on the complex regulatory network that controls anthocyanin biosynthesis in grapevine.
基金supported by National Natural Science Foundation of China(U20A2041)the National Key R&D Program of China(2019YFD1000100,2021YFE0109500)+1 种基金the Agricultural Breeding Project of Ningxia Hui Autonomous Region(NXNYYZ202101)the CAS Youth Interdisciplinary Team(JCTD-2022-06).
文摘The quality of planting materials is the foundation for productivity,longevity,and berry quality of perennial grapevines with a long lifespan.Manipulating the nursery light spectrum may speed up the production of healthy and high-quality planting vines but the underlying mechanisms remain elusive.Herein,the effects of different monochromatic lights(green,blue,and red)on grapevine growth,leaf photosynthesis,whole-plant carbon allocation,and transcriptome reprograming were investigated with white light as control.Results showed that blue and red lights were favorable for plantlet growth in comparison with white light.Blue light repressed excessive growth,significantly increased the maximum net photosynthetic rate(Pn)of leaves by 39.58%and leaf specific weight by 38.29%.Red light increased the dry weight of the stem by 53.60%,the starch content of the leaf by 53.63%,and the sucrose content of the stem by 230%.Green light reduced all photosynthetic indexes of the grape plantlet.Photosynthetic photon flux density(PPFD)/Ci–Pn curves indicated that blue light affected photosynthetic rate depending on the light intensity and CO2 concentration.RNA-seq analysis of different organs(leaf,stem,and root)revealed a systematic transcriptome remodeling and VvCOP1(CONSTITUTIVELY PHOTOMORPHOGENIC 1),VvHY5(ELONGATED HYPOCOTYL5),VvHYH(HY5 HOMOLOG),VvELIP(early light-induced protein)and VvPIF3(PHYTOCHROME INTERACTING FACTOR 3)may play important roles in this shoot-to-root signaling.Furthermore,the correlation network between differential expression genes and physiological traits indicated that VvpsbS(photosystem II subunit S),Vvpsb28(photosystem II subunit 28),VvHYH,VvSUS4(sucrose synthase 4),and VvALDA(fructose-bisphosphate aldolase)were pertinent candidate genes in responses to different light qualities.Our results provide a foundation for optimizing the light recipe of grape plantlets and strengthen the understanding of light signaling and carbon metabolism under different monochromatic lights.
文摘Studies on Agrobacterium tumefaciens-mediated transformation of wild tobaccos Nicotiana debneyi, Nicotiana clevelandii, and Nicotiana glutinosa were conducted. Leaf disks were infected and co-cultivated with A. tumefaciens strain EHA105 carrying the binary vector pBISN1 with an intron interrupted β-glucuronidase (GUS) reporter gene (gusA) and the neomycin phosphotransferase gene (nptII). Selection and regeneration of kanamycin resistant shoots were conducted on regeneration medium containing 8.88 μM 6-benzylaminopurine (BAP), 0.57 μM indole-3-acetic acid (IAA), 50 mg·L<sup>-1</sup> kanamycin and 250 mg·L<sup>-1</sup> timentin. Kanamycin resistant shoots were rooted Murashige and Skoog (MS) medium containing 100 mg·L<sup>-1</sup> kanamycin and 250 mg·L<sup>-1</sup> timentin. Using this protocol, kanamycin-resistant plants were obtained from all three wild tobaccos at frequencies of 75.6% for N. debneyi, 25.0% for N. clevelandii, and 2.8% for N. glutinosa. Transcripts of nptII and gusA were detected in kanamycin-resistant T0 transformants (i.e., 2 for N. glutinosa and 5 for each of the N. debneyi and N. clevelandii) by the reverse transcript polymerase chain reaction (RT-PCR), and histochemical GUS assays confirmed expression of gusA in both T<sub>0</sub> plants and T<sub>1</sub> seedlings. The results indicate that the protocols are efficient for transformation of wild tobacco N. debneyi and N. clevelandii.
基金China Aerospace Science and Technology Corporation, the NO.771 InstituteChina Academy of Engineering Physics+4 种基金Changchun Institute of Optics, Fine Mechanics and Physics, CASNational Space Science Center, CASShanghai Engineering Center for Microsatellites, CASPurple Mountain Observatory, CASsupported by Grants:XDA15320102, 11427901 and XDA15052200
文摘The Full-disk Magneto Graph(FMG),a payload onboard the Advanced Space Solar Observatory(ASO-S),will measure the vector magnetic field in the photosphere.The instrument consists of a frontwindow filter,a telescope,an LCVR polarimeter,an image-stabilization system,a seven-stage tunable Lyot filter,a CMOS camera with 4096×4096 pixels and a pair of calibration/focus wheels.In this paper,we describe the design of the FMG instrument and provide a summary of test observations carried out with the FMG prototype.
文摘The spherical agglomerated particles were fabricated by spray drying with the powders of NiO, Cr2O3 and TiO2. Plasma spray power, which has good property of flowability, was acquired by heat treatment from the particles at 1200℃ in the reducing atmosphere. Dark and uniform coating of More than 50 μm thick was deposited on the copper sheet substrate by plasma spraying. It is found that the infrared normal total emissivity of the coating is up to 0.91 at 600℃ by infrared radiation testing. The X-ray diffraction analysis shows that the formation of （Cr0.88Ti0.12）2O3 and spinel structural NiCr2O4 in the coating is the main reason for high efficient infrared radiation, and the phase structure and performance of coating is favorable under the thermal cycle between room temperature and 600℃.
基金the National Natural Science Foundation of China(31772266 and 32001994)the Bureau of International Cooperation of the Chinese Academy of Sciences(151111KYSB20170032).
文摘The efficacy of the CRISPR/Cas9 system in grapevine(Vitis vinifera L.)has been documented,but the optimization of this system,as well as CRISPR/Cas9-mediated multiplex genome editing,has not been explored in this species.Herein,we identified four VvU3 and VvU6 promoters and two ubiquitin(UBQ)promoters in grapevine and demonstrated that the use of the identified VvU3/U6 and UBQ2 promoters could significantly increase the editing efficiency in grape by improving the expression of sgRNA and Cas9,respectively.Furthermore,we conducted multiplex genome editing using the optimized CRISPR/Cas9 vector that contained the conventional multiple sgRNA expression cassettes or the polycistronic tRNA-sgRNA cassette(PTG)by targeting the sugar-related tonoplastic monosaccharide transporter(TMT)family members TMT1 and TMT2,and the overall editing efficiencies were higher than 10%.The simultaneous editing of TMT1 and TMT2 resulted in reduced sugar levels,which indicated the role of these two genes in sugar accumulation in grapes.Moreover,the activities of the VvU3,VvU6,and UBQ2 promoters in tobacco genome editing were demonstrated by editing the phytoene desaturase(PDS)gene in Nicotiana benthamiana leaves.Our study provides materials for the optimization of the CRISPR/Cas9 system.To our knowledge,our simultaneous editing of the grape TMT family genes TMT1 and TMT2 constitutes the first example of multiplex genome editing in grape.The multiplex editing systems described in this manuscript expand the toolbox of grape genome editing,which would facilitate basic research and molecular breeding in grapevine.
基金supported in part by National Natural Science Foundation of China under Grants 61871190,U1809211 and 61771202in part by Key Program of Marine Economy Development(Six Marine Industries)Special Foundation of Department of Natural Resources of Guangdong Province(GDNRC[2020]009)in part by the Fundamental Research Funds for the Central Universities under No.2019SJ02。
文摘This paper considered a multi-relay distributed cooperative system in which not only the source communicates with the destination,but also the relays have communication requests with the destination.In order to achieve the requirements of simultaneous communication for the source and relays,we propose a distributed cooperative system based on orthogonal frequency division multiplexing with index modulation(OFDM-IM).In this system,the relay can communicate with the destination by superimposing its own signal over the inactive subcarriers on the decoded OFDM-IM signal.Upper bounds on the bit error rates of the source and the active relay are both derived in closed form,whose tightness is verified through simulation results.
基金supported by the Horrizon 2020"Efficient Manufacturing for Aerospace Components Using Additive Manufacturing,Net Shape HIP and Investment Casting(EMUSIC)"the State Key Laboratory of Materials Processing and Die&Mould Technology Research Project,China(2015-2017)
文摘Selective laser melting(SLM) is a promising technique for additive manufacturing. During SLM of metallic powder, the temperature field and thermal history are important to understand physical phenomena involved. The purpose of this study is to simulate the temperature field during the SLM process of a hollow cylinder shape part based on a fully threaded tree(FTT) technique, and to analyze the temperature variation with time in different regions of the part. A revised model for temperature field simulation in the SLM process was employed, which includes the transition of powder-to-dense sub-model and a moving volumetric Gaussian distribution heat source sub-model. The FTT technique is then adopted as an adaptive mesh strategy in the simulation. The simulation result shows that during the SLM process of cylinder part, the temperature of inner powder bed is obviously higher than external one. The temperature at the internal of the molten pool is also higher than external, which may lead to differences in microstructures and other properties between the two regions.
基金partly supported by the research funds of the National Natural Science Foundation of China (NO. 61371113, 61401241)the research funds of Chonbuk National University in 2017BK-21 of Korea and the Nantong University-Nantong Joint Research Center for Intelligent Information Technology (KFKT2016B04)
文摘In this paper, we propose cooperative relay networks with non-orthogonal multiple access in order to design a near-optimal power allocation strategy. Like other next generation wireless technologies, spatially multiplexed transmissions are achieved by relay nodes which enables decode-and-forward relaying of a new superposition code after reception from the source. It is worth noting that, since it is hard to exactly prove the proposed PA scheme, due the fact that it is one kind of the approximate conjectures. Therefore, mathematical and numerical methods have been used to clarify the feasibility of the proposal. Numerical results indicate that it is able to asymptotically achieve the optimal sum rate at the higher signal-to-noise ratio region with the proposed strategy applied instead of negligible performance loss.
