Several quantitative trait genes(QTGs)related to rice heading date,a key factor for crop development and yield,have been identified,along with complex interactions among genes.However,a comprehensive genetic interacti...Several quantitative trait genes(QTGs)related to rice heading date,a key factor for crop development and yield,have been identified,along with complex interactions among genes.However,a comprehensive genetic interaction network for these QTGs has not yet been established.In this study,we use 18K-rice lines to identify QTGs and their epistatic interactions affecting rice heading date.We identify 264 pairs of interacting quantitative trait loci(QTL)and construct a comprehensive genetic network of these QTL.On average,the epistatic effects of QTL pairs are estimated to be approximately 12.5%of additive effects of identified QTL.Importantly,epistasis varies among different alleles of several heading date genes.Additionally,57 pairs of interacting QTGs are also significant in their epistatic effects on 12 other agronomic traits.The identified QTL genetic interactions are further validated using near-isogenic lines,yeast two-hybrid,and split-luciferase complementation assays.Overall,this study provides a genetic network of rice heading date genes,which plays a crucial role in regulating rice heading date and influencing multiple related agronomic traits.This network serves as a foundation for understanding the genetic mechanisms of rice quantitative traits and for advancing rice molecular breeding.展开更多
Rice,a critical global staple crop,relies heavily on heading date,a key agronomic trait marking the transition from vegetative to reproductive growth.Understanding the genetic regulation of heading date is vital for e...Rice,a critical global staple crop,relies heavily on heading date,a key agronomic trait marking the transition from vegetative to reproductive growth.Understanding the genetic regulation of heading date is vital for enhancing the adaptability of high-quality rice varieties across diverse geographical regions and for bolstering local food security.In this study,we uncovered a novel role for OsCATA,a catalase gene,in the regulation of photoperiodic flowering in rice.We identified a novel allele of OsELF3.1,whose mutation resulted in delayed heading.Further analyses revealed that OsELF3.1 physically interacted with OsCATA.Notably,OsCATA exhibited rhythmic expression patterns similar to OsELF3.1 and,when mutated,also delayed flowering.Expression analyses showed that the delayed heading phenotype could be attributed to elevated Ghd7 expression under both long-day and short-day conditions,with OsCATA expression positively regulated by OsELF3.1.Double mutants of OsELF3.1 and OsCATA displayed a heading delay similar to that of oself3.1 single mutants.Additionally,OsELF3.1 could interact with Ghd7 in vivo,alleviating its suppression of Ehd1.Luciferase assays confirmed that Ghd7 repressed Ehd1 expression,while OsELF3.1 mitigated this repression.Collectively,our findings reveal that OsCATA is critical in suppressing Ghd7 expression through the OsELF3.1-OsCATA-Ghd7 transcriptional pathway,thereby regulating rice heading.展开更多
Obtaining accurate ship positions and headings in remote sensing images plays a crucial role in various applications.However,current deep learning-based methods primarily focus on ship position detection,while the det...Obtaining accurate ship positions and headings in remote sensing images plays a crucial role in various applications.However,current deep learning-based methods primarily focus on ship position detection,while the detection of ship wakes relies on traditional non-deep learning approaches,which often underperform in complex marine environments.We proposed a novel,simple,and efficient method called Point-Vector Net.The proposed method leverages convolutional neural networks(CNN)for feature extraction and subsequently integrates multi-scale features to generate high-resolution feature maps.In the final stage,ship positions and headings are represented using a combination of points and vectors.Comparative experiments with results from automatic identification system(AIS)reports demonstrate that our method achieved impressive performance in two-class ship target detection,with an average precision of 96.4%,recall rate of 94.3%,and an F 1 score of 95.2%.Notably,the average heading error was 3.3°.The proposed model achieved a practical inference speed(FPS>30),and the average processing time for inferring a large-scale Sentinel-2 remote sensing image was 11.4 s.展开更多
Heading date is one of the most important agronomic traits that directly affect rice yield and determines the regional adaptability in specific growing environments.As a short-day plant,rice can grow under long-day(LD...Heading date is one of the most important agronomic traits that directly affect rice yield and determines the regional adaptability in specific growing environments.As a short-day plant,rice can grow under long-day(LD)conditions due to the synergistic regulation of many photosensitive genes.Using a set of chromosome segment substitution lines(CSSLs)with the indica cultivar Huanghuazhan(HHZ)as the recipient parent and Basmati Surkh 89-15(BAS)as the donor parent,we identified a QTL locus.展开更多
Plant height and heading date are important agronomic traits in wheat(Triticum aestivum L.)that affect final grain yield.In wheat,knowledge of pseudo-response regulator(PRR)genes on agronomic traits is limited.Here,we...Plant height and heading date are important agronomic traits in wheat(Triticum aestivum L.)that affect final grain yield.In wheat,knowledge of pseudo-response regulator(PRR)genes on agronomic traits is limited.Here,we identify a wheat TaPRR95 gene by genome-wide association studies to be associated with plant height.Triple allele mutant plants produced by CRISPR/Cas9 show increased plant height,particularly the peduncle,with an earlier heading date.The longer peduncle is mainly caused by the increased cell elon-gation at its upper section,whilst the early heading date is accompanied by elevated expression of flow-ering genes,such as TaFT and TacO1.A peduncle-specific transcriptome analysis reveals up-regulated photosynthesis genes and down-regulated IAAVAux genes for auxin signaling inpr95abad plants that may act as a regulatory mechanism to promote robust plant growth.A haplotype analysis identifies a TaPRR95-B haplotype(Hap2)to be closely associated with reduced plant height and increased thousand-grain weight.Moreover,the Hap2 frequency is higher in cultivars than that in landraces,suggesting the artifi-cial selection on the allele during wheat breeding.These findings suggest that TaPRR95 is a regulator for plant height and heading date,thereby providing an important target for wheat yield improvement.展开更多
In order to study the problems of unreasonable airflow distribution and serious dust pollution in a heading surface,an experimental platform for forced ventilation and dust removal was built based on the similar princ...In order to study the problems of unreasonable airflow distribution and serious dust pollution in a heading surface,an experimental platform for forced ventilation and dust removal was built based on the similar principles.Through the similar experiment and numerical simulation,the distribution of airflow field in the roadway and the spatial and temporal evolution of dust pollution under the conditions of forced ventilation were determined.The airflow field in the roadway can be divided into three zones:jet zone,vortex zone and reflux zone.The dust concentration gradually decreases from the head to the rear of the roadway.Under the forced ventilation conditions,there is a unilateral accumulation of dust,with higher dust concentrations away from the ducts.The position of the equipment has an interception effect on the dust.The maximum error between the test value and the simulation result is 12.9%,which verifies the accuracy of the experimental results.The research results can provide theoretical guidance for the application of dust removal technology in coal mine.展开更多
Panicle size is one of the important factors in shaping yield potential in rice,but it shows plasticity in different environments,which leads to yieldfluctuation.Variations in panicle size among varieties are largely d...Panicle size is one of the important factors in shaping yield potential in rice,but it shows plasticity in different environments,which leads to yieldfluctuation.Variations in panicle size among varieties are largely determined by quantitative trait loci(QTLs).QTL analysis could elaborate on the environmental impact on trait plasticity using nearly isogenic lines(NILs)of different QTLs.Two QTLs,ipa1-2D and qPL6 are identified to have pleio-tropic contributions to panicle size and plant architecture,but their responses to different growth conditions are still unclear.In this study,we developed NILs harboring a single locus or both loci of ipa1-2D and qPL6 and sub-sequently evaluated these QTL effects under different nitrogen treatments or heading periods.Trait comparison showed that panicle length was highly responsive to the high nitrogen treatment independent of qPL6.At the same time,ipa1-2D reduced the response of plant height,panicle number,and grain yield to the treatment.The background of long heading periods decreased the stem diameter for any genotype combinations but enhanced the performance of ipa1-2D for the panicle primary branch number.Moreover,the middle heading background could better balance the pleiotropic effect of the two QTLs and showed the highest yield potential.In-parallel analysis of the QTL contributions under different nitrogen treatments or heading periods confirmed the significant effect of ipa1-2D in increasing stem diameter,panicle primary branch number,and spikelet number per panicle.We proved that the two individual QTLs had a stable effect in increasing the yield potential but com-peted to decrease the panicle secondary branch number,panicle number,and yield potential when they were pyr-amided.This work provides a full view of the plasticity of two QTLs in shaping yield-related traits and lays the foundation for the rational design of rice breeding in the future.展开更多
QTLs for heading date of rice （Oryza sativa L.） with additive, epistatic, and QTL × environment （QE） interaction effects were studied using a mixed-model-based composite interval mapping （MCIM） method and a...QTLs for heading date of rice （Oryza sativa L.） with additive, epistatic, and QTL × environment （QE） interaction effects were studied using a mixed-model-based composite interval mapping （MCIM） method and a double haploid （DH） population derived from IR64/Azucena in two crop seasons. Fourteen QTLs conferring heading date in rice, which were distributed on ten chromosomes except for chromosomes 5 and 9, were detected. Among these QTLs, eight had single-locus effects, five pairs had double-locus interaction effects, and two single-loci and one pair of double-loci showed QTL × environment interaction effects. All predicted values of QTL effects varied from 1.179 days to 2.549 days, with corresponding contribution ratios of 1.04%-4.84%. On the basis of the effects of the QTLs, the total genetic effects on rice heading date for the two parents and the two superior lines were predicted, and the putative reasons for discrepancies between predicted values and observed values, and the genetic potentiality in the DH population for improvement of heading date were discussed. These results are in agreement with previous results for heading date in rice, and the results provide further information, which indicate that both epistasis and QE interaction are important genetic basis for determining heading date in rice.展开更多
[Objective]The study aimed to map QTLs（Quantitative trait loci）of heading stage for phtopeiod-thermo sensitive male sterile line BS366 in wheat.[Method] A population of 234 doubled haploid derived from the cross bet...[Objective]The study aimed to map QTLs（Quantitative trait loci）of heading stage for phtopeiod-thermo sensitive male sterile line BS366 in wheat.[Method] A population of 234 doubled haploid derived from the cross between BS366 and Baiyu149 was planted in Beijing and Funan in 2007,respectively.We used composite interval mapping（CIM）method to analyse the QTLs for heading stage.[Result]We detected 15 QTLs for heading stage.8 QTLs were detected in both Beijing and Funan,which were located on 1B,2A,2D,3B（2 loci）,6B（2 loci）and 7B.A single QTL accounted for 2.42%-10.98% of pheotypic varience.[Conclusion] Eight QTLs which were detected under two environments could be applied for marker-assisted breeding and improvement of BS366.The QTL on chromosome 1B was new for heading stage,which enriches the QTL resource.展开更多
Sterility changeover induced by low temperature in male sterility line CMS7311 of heading Chinese cabbage ( Brassica campestris L. ssp. penkinsis) was investigated under constant temperature, day/night alternating tem...Sterility changeover induced by low temperature in male sterility line CMS7311 of heading Chinese cabbage ( Brassica campestris L. ssp. penkinsis) was investigated under constant temperature, day/night alternating temperature in light-growth-incubator and outdoor natural day/night alternating temperature respectively. It showed that the sterility of CMS7311 has significant change with temperature. The constant temperature of 6 - 12 degreesC was suitable to induce the changeover of sterility (CGS) of CMS7311 ; the shortest treatment time for CGS induction at this temperature was 3 d. The significant value of sterility changeover of CMS7311 occurred at the constant temperature of 6 - 9 degreesC after treatment for 6 - 9 d. The intensity of CGS was stronger under constant temperature than under alternate temperature, but the shortest treatment time inducing CGS has no difference between them. When treated for 9 d under the day/night alternating temperature of 11/7 degreesC, its sterility could also turn to normal fertility (near to sterile grade I or zero). In normal condition, the interval from the end of temperature treatment to the beginning of CGS induction was 10 - 16 d. In the condition of natural day/night alternating temperature, the lower limit of temperature for effective CGS induction was at the daily mean temperature ( DMT) of 3. 5 - 6. 8 degreesC, and the shortest treatment time which could induce the sterility changeover was also longer than that under constant temperature, being 11d at DMT of 1.5 - 3.1 degreesC. In addition, for the apical dominance, the flower bud on the first lateral branch showed the CGS 8 - 10 d later than the flower bud on the main stem under the same temperature with the same days of treatment. The intensity of CGS of CMS7311 on the first lateral branch was also weaker than the flower bud on the main stem.展开更多
USSR5, a japonica rice variety from the former Soviet Union, is an extremely early maturing rice variety. To elucidate the genetic basis for its early heading, genetic analysis was carried out by crossing it with a se...USSR5, a japonica rice variety from the former Soviet Union, is an extremely early maturing rice variety. To elucidate the genetic basis for its early heading, genetic analysis was carried out by crossing it with a set of major gene nearly isogenic lines （NIL） and QTL-isogenic lines. The early heading of USSR5 was attributed to the presence of photoperiod-insensitive alleles at E1 and Se-1 gene, the photoperiod-sensitive inhibitor gene i-Se-1, and the dominant earliness gene Ef-1. Analysis of a backcrossed population （BCIF1） derived from the cross USSR5 x N22 indicated that two quantitative trait loci （QTL） for early heading were located on chromosomes 7 and 8, accounting for 27.4% and 11.2% of the phenotypic variance, respectively, with both early alleles originating from USSRS. From an F2 population of the same cross, early heading QTLs were detected on chromosomes 1, 2, 7, 9, and 10, with individual QTL accounting for between 4.1% and 15.4% of the phenotypic variance. Early heading alleles at four of these five QTLs originated from USSRS. A comparison of chromosomal locations suggests that one of these QTLs may be identical with the known gene Hd4 （E1）. The relationship between the other QTLs and known genes for heading date are not clear. USSR5 is a promising source for propagating earliness for the development of improved early heading rice varieties.展开更多
The seed setting rates of total 198 rice cultivars （lines） at heading and flowering stage were investigated under the condition of extreme natural high tem- perature in 2013 so as to analyze the effect of extreme na...The seed setting rates of total 198 rice cultivars （lines） at heading and flowering stage were investigated under the condition of extreme natural high tem- perature in 2013 so as to analyze the effect of extreme natural high temperature on seed setting rate of different rice cultivar （line）. The results showed that the contin- uous high temperature showed certain effects on the seed setting rates of tested materials, and significant differences were shown in seed setting rate among differ- ent rice cultivars （lines）. The seed setting rates differed significantly among indica F1 hybrids derived from different sterile and restorer lines, indicating that the sterile and restorer lines had great effects on heat tolerances of different F~ hybrids. The cor- relation analysis showed that the seed setting rates of conventional indica restorer lines and conventional japonica rice cultivars （lines） were negatively related to the daily highest temperature （P〉0.05）, and the seed setting rates of indica F1 hybrids were positively related to the seed setting rates of their restorer lines. Total four in- dica restorer lines, including Ninghuiguangkangzhan, Shuhui 527, Chenghui 3203 and Xianyin-8, and four new japonica rice cultivars （lines）, including Wuyinjinghui （B2）, Nanjing 4//W3660/Nanjing 44 （B12） and Wuyun 2330/JD6011 （B22） were pre- liminarily screened, and their seed setting rates were all close to the normal level （90%）. The screened rice cultivars （lines） showed higher heat tolerances.展开更多
[Objective] This study was conducted to discuss influence factors for safety full heading of machine-transplanted rice seedlings in cool-warm rice area. [Method] Effects of variety, seedling age and nitrogen fertilize...[Objective] This study was conducted to discuss influence factors for safety full heading of machine-transplanted rice seedlings in cool-warm rice area. [Method] Effects of variety, seedling age and nitrogen fertilizer dosage and strategy of machine-transplanted seedlings on safety full heading of machine-transplanted seedlings were investigated. [Result] During mechanized rice production in coolwarm rice area, mid-early-maturing cold-resistant varieties with growth periods no longer than 180 d could selected, and seedling age could controlled within 30-35 d; and the total amount of pure nitrogen should be less than 300 kg/hm^2, and the proportion of nitrogen fertilizer applied in later stages should be properly reduced. [Conclusion] Under this condition, safety full heading of rice is ensured, and the target yield is realized.展开更多
Nida's famous notion of Dynamic Equivalence in translation process is characterized by three stages - analysis, transfer and restructuring, which are explained in detail. The application of these principles are il...Nida's famous notion of Dynamic Equivalence in translation process is characterized by three stages - analysis, transfer and restructuring, which are explained in detail. The application of these principles are illustrated by providing step-by-step explanation on the translation process of headings of two news reports, which are selected from Far Eastern Economic Review.展开更多
Heading date determines the seasonal and regional adaptation of rice(Oryza sativa L.)varieties and is mainly controlled by photoperiod sensitivity(PS).The core heading date genes Hd1,Ghd7,DTH8,and PRR37 act synergisti...Heading date determines the seasonal and regional adaptation of rice(Oryza sativa L.)varieties and is mainly controlled by photoperiod sensitivity(PS).The core heading date genes Hd1,Ghd7,DTH8,and PRR37 act synergistically in regulating the PS.In this study,we systematically analyze the heading date,PS,and agronomic traits of eight homozygous lines with various combinations of Hd1,Ghd7,and DTH8 alleles in the prr37 background under long-day(LD)and short-day(SD)conditions,respectively.We find that Hd1 alone promotes heading,regardless of the day length.However,under LDs,Hd1 suppresses flowering,in coordination with functional Ghd7 or with Ghd7 and DTH8.These loci cooperate to negatively regulate the Ehd1-Hd3 a/RFT1 pathway and delay heading.Under SDs,Hd1 competes with various heading suppressors to promote heading.Therefore,the dual function of Hd1 is vital for PS.The lines carrying Hd1 alone show reduced plant height with fewer primary and secondary branches in panicles.Lines carrying Ghd7 and DTH8(with hd1)show delayed heading and improve agronomic traits.Overall,our results reveal the regulation of rice PS flowering by the core heading date genes and their effects on agronomic traits,providing valuable information for the selection of rice varieties for adaptation to different light and temperature conditions.展开更多
Non-heading Chinese cabbage(NHCC)is an important leafy vegetable cultivated worldwide.Here,we report the first high-quality,chromosome-level genome of NHCC001 based on PacBio,Hi-C,and Illumina sequencing data.The asse...Non-heading Chinese cabbage(NHCC)is an important leafy vegetable cultivated worldwide.Here,we report the first high-quality,chromosome-level genome of NHCC001 based on PacBio,Hi-C,and Illumina sequencing data.The assembled NHCC001 genome is 405.33 Mb in size with a contig N50 of 2.83 Mb and a scaffold N50 of 38.13 Mb.Approximately 53%of the assembled genome is composed of repetitive sequences,among which long terminal repeats(LTRs,20.42%of the genome)are the most abundant.Using Hi-C data,97.9%(396.83 Mb)of the sequences were assigned to 10 pseudochromosomes.Genome assessment showed that this B.rapa NHCC001 genome assembly is of better quality than other currently available B.rapa assemblies and that it contains 48,158 protein-coding genes,99.56%of which are annotated in at least one functional database.Comparative genomic analysis confirmed that B.rapa NHCC001 underwent a whole-genome triplication(WGT)event shared with other Brassica species that occurred after the WGD events shared with Arabidopsis.Genes related to ascorbic acid metabolism showed little variation among the three B.rapa subspecies.The numbers of genes involved in glucosinolate biosynthesis and catabolism were higher in NHCC001 than in Chiifu and Z1,due primarily to tandem duplication.The newly assembled genome will provide an important resource for research on B.rapa,especially B.rapa ssp.chinensis.展开更多
Effects of rolling and cooling conditions on microstructure and mechanical properties of low carbon cold heading steel were investigated on a laboratory hot rolling mill. The results have shown that the mechanical pro...Effects of rolling and cooling conditions on microstructure and mechanical properties of low carbon cold heading steel were investigated on a laboratory hot rolling mill. The results have shown that the mechanical proper ties of low carbon steels exceed the standard requirements of ML30, ML35, ML40, and ML45 steel, respectively due to thermomechanical controlled processing （TMCP）. This is attributed to a significant amount of pearlite and the ferrite-grain refinement. Under the condition of relatively low temperature rolling, the mechanical properties exceed standard requirements of ML45 and ML30 steel after water cooling and air cooling, respectively. Fast cooling which leads to more pearlite and finer ferrite grains is more critical than finish rolling temperatures for low carbon cold heading steel. The specimen at high finish rolling temperature exhibits very good mechanical properties due to fast cooling. This result has great significance not only for energy saving and emission reduction, but also for low-carbon economy, because the goals of the replacement of medium-carbon by low-carbon are achieved with TMCP.展开更多
Non-heading Chinese cabbage(Brassica rapa ssp.chinensis)is one of the main green leafy vegetables in the world,especially in China,with significant economic value.Hyaloperonospora parasitica is a fungal pathogen respo...Non-heading Chinese cabbage(Brassica rapa ssp.chinensis)is one of the main green leafy vegetables in the world,especially in China,with significant economic value.Hyaloperonospora parasitica is a fungal pathogen responsible for causing downy mildew disease in Chinese cabbage,which greatly affects its production.The objective of this study was to identify transcriptionally regulated genes during incompatible interactions between non-heading Chinese cabbage and H.parasitica using complementary DNA-amplified fragment length polymorphism(cDNA-AFLP).We obtained 129 reliable differential transcript-derived fragments(TDFs)in a resistant line‘Suzhou Qing’.Among them,121 upregulated TDFs displayed an expression peak at 24–48 h post inoculation(h.p.i.).Fifteen genes were further selected for validation of cDNA-AFLP expression patterns using quantitative reverse transcription PCR.Results confirmed the altered expression patterns of 13 genes(86.7%)revealed by the cDNA-AFLP.We identified four TDFs related to fungal resistance among the 15 TDFs.Furthermore,comparative analysis of four TDFs between resistant line‘Suzhou Qing’and susceptible line‘Aijiao Huang’showed that transcript levels of TDF14(BcLIK1_A01)peaked at 48 h.p.i.and 25.1-fold increased in the resistant line compared with the susceptible line.Similarly,transcript levels of the other three genes,TDF42(BcCAT3_A07),TDF75(BcAAE3_A06)and TDF88(BcAMT2_A05)peaked at 24,48 and 24 h.p.i.with 25.1-,100-and 15.8-fold increases,respectively.The results suggested that the resistance genes tended to transcribe at higher levels in the resistance line than in the susceptible line,which may provide resistance against pathogen infections.The present study might facilitate elucidating the molecular basis of the infection process and identifying candidate genes for resistance improvement of susceptible cultivars.展开更多
Heading Chinese cabbage(Brassica rapa L.syn.B.campestris L.ssp.chinensis Makino var.pekinensis(Rupr.)J.Cao et Sh.Cao)is a cruciferous Brassica vegetable that has a triplicate genome,owing to an ancient genome duplicat...Heading Chinese cabbage(Brassica rapa L.syn.B.campestris L.ssp.chinensis Makino var.pekinensis(Rupr.)J.Cao et Sh.Cao)is a cruciferous Brassica vegetable that has a triplicate genome,owing to an ancient genome duplication event.It is unclear whether the duplicated homologs have conserved or diversi fied functions.Hydrogen sulfide(H_(2)S)is a plant gasotransmitter that plays important physiological roles in growth,development,and responses to environmental stresses.The modification of cysteines through S-sulfhydration is an important mechanism of H_(2)S,which regulates protein functions.H?S promotes flowering in Arabidopsis and heading Chinese cabbage.Here we investigated the molecular mechanisms of H_(2)S used to promote flowering in the latter.Four,five,and four BraFLC,BraSOC I,and BraFT homologs were identi fi ed in heading Chinese cabbage.Different BraFLC proteins were bound to different CArG boxes in the promoter regions of the BraSOC I and BraFT homologs,producing different binding patterns.Thus,there may be functionally diverse BraFLC homologs in heading Chinese cabbage.Exogenous H_(2)S at 100μmol L^(-1) significantly promoted flowering by compensating for insuf fi cient vernalization.BraFLC 1 and BraFLC_(3) underwent S-sulfhydration by H_(2)S,after which their abilities to bind most BraSOC I or BraFT promoter probes weakened or even disappeared.These changes in binding ability were consistent with the expression pattern of the BraFT and BraSOC I homologs in seedlings treated with H_(2)S.These results indicated that H_(2)S signaling regulates flowering time.In summary,H_(2)S signaling promoted plant flowering by weakening or eliminating the binding abilities of BraFLCs to downstream promoters through S-sulfhydration.展开更多
Previous study showed that a linkage drag between a blast resistance gene Pi25（t） and QTLs conditioning spikelet fertility （qSF-6） and number of filled grains per panicle （qNFGP-6） was detected on the short arm ...Previous study showed that a linkage drag between a blast resistance gene Pi25（t） and QTLs conditioning spikelet fertility （qSF-6） and number of filled grains per panicle （qNFGP-6） was detected on the short arm of chromosome 6. A larger population was used for further verification, and the results confirmed the linkage drag between the blast resistance gene and QTL conditioning spikelet fertility, other than QTL conditioning number of filled grains per panicle. Breakdown or avoidance of the linkage drag could be achieved by selection against the genotype background of a heading-date gene （qHD-7） that resided in the region between RM2 and RM214 on chromosome 7. For further validation, two lines with almost identical genotypes on all chromosomal regions except the Pi25（t） region on chromosome 6 were chosen to develop a new population The results showed that qSF-6 could be further subdivided into qSF-6-1 and qSF-6-2. When the genotype of the region between RM2 and RM214 was from rice variety Zhong 156, the linkage drag between Pi25（t） and qSF-6-2 was detected and the allele of qSF-6-2 from rice variety Gumei 2 reduced the spikelet fertility. When the genotype of the region between RM2 and RM214 was from Gumei 2, no linkage drag was detected. This indicates that the linkage drag between the blast resistance gene and the QTL conditioning spikelet fertility could be broken down or avoided under a certain background genotype selection against heading-date and provides a marker aided solution for high level of blast resistance and yield breeding in rice and other crops as well.展开更多
基金supported by the National Natural Science Foundation of China(32222064 and 32341030)the Natural Science Foundation of Shanghai(22ZR1445800)Zhejiang Provincial Natural Science Foundation of China(LQ24C130008).
文摘Several quantitative trait genes(QTGs)related to rice heading date,a key factor for crop development and yield,have been identified,along with complex interactions among genes.However,a comprehensive genetic interaction network for these QTGs has not yet been established.In this study,we use 18K-rice lines to identify QTGs and their epistatic interactions affecting rice heading date.We identify 264 pairs of interacting quantitative trait loci(QTL)and construct a comprehensive genetic network of these QTL.On average,the epistatic effects of QTL pairs are estimated to be approximately 12.5%of additive effects of identified QTL.Importantly,epistasis varies among different alleles of several heading date genes.Additionally,57 pairs of interacting QTGs are also significant in their epistatic effects on 12 other agronomic traits.The identified QTL genetic interactions are further validated using near-isogenic lines,yeast two-hybrid,and split-luciferase complementation assays.Overall,this study provides a genetic network of rice heading date genes,which plays a crucial role in regulating rice heading date and influencing multiple related agronomic traits.This network serves as a foundation for understanding the genetic mechanisms of rice quantitative traits and for advancing rice molecular breeding.
基金funded by the Biological Breeding-National Science and Technology Major Projects,China(Grant No.2023ZD04066)the Zhejiang Provincial Natural Science Foundation of China(Grant Nos.LZ24C130006,LTGN24C130007)+5 种基金the Open Project Program of the State Key Laboratory of Rice Biology and Breeding,China(Grant No.20240107)the Xi’nan League Science and Technology Project,China(Grant No.2023DXZD0001)the Joint Research and Development Program on Rice Breeding in Inner Mongolia Autonomous Region,China(Grant No.YZ2023004)the China Agriculture Research System(Grant No.CARS-01)the Central Public-interest Scientific Institution Basal Research Fund,China(Grant No.CPSIBRF-CNRRI-202301)the Agricultural Science and Technology Innovation Program(ASTIP).
文摘Rice,a critical global staple crop,relies heavily on heading date,a key agronomic trait marking the transition from vegetative to reproductive growth.Understanding the genetic regulation of heading date is vital for enhancing the adaptability of high-quality rice varieties across diverse geographical regions and for bolstering local food security.In this study,we uncovered a novel role for OsCATA,a catalase gene,in the regulation of photoperiodic flowering in rice.We identified a novel allele of OsELF3.1,whose mutation resulted in delayed heading.Further analyses revealed that OsELF3.1 physically interacted with OsCATA.Notably,OsCATA exhibited rhythmic expression patterns similar to OsELF3.1 and,when mutated,also delayed flowering.Expression analyses showed that the delayed heading phenotype could be attributed to elevated Ghd7 expression under both long-day and short-day conditions,with OsCATA expression positively regulated by OsELF3.1.Double mutants of OsELF3.1 and OsCATA displayed a heading delay similar to that of oself3.1 single mutants.Additionally,OsELF3.1 could interact with Ghd7 in vivo,alleviating its suppression of Ehd1.Luciferase assays confirmed that Ghd7 repressed Ehd1 expression,while OsELF3.1 mitigated this repression.Collectively,our findings reveal that OsCATA is critical in suppressing Ghd7 expression through the OsELF3.1-OsCATA-Ghd7 transcriptional pathway,thereby regulating rice heading.
基金Supported by the National Key R&D Program of China(No.2022YFB3902400)the China High Resolution Earth Observation System Program(No.41-Y30F07-9001-20/22)。
文摘Obtaining accurate ship positions and headings in remote sensing images plays a crucial role in various applications.However,current deep learning-based methods primarily focus on ship position detection,while the detection of ship wakes relies on traditional non-deep learning approaches,which often underperform in complex marine environments.We proposed a novel,simple,and efficient method called Point-Vector Net.The proposed method leverages convolutional neural networks(CNN)for feature extraction and subsequently integrates multi-scale features to generate high-resolution feature maps.In the final stage,ship positions and headings are represented using a combination of points and vectors.Comparative experiments with results from automatic identification system(AIS)reports demonstrate that our method achieved impressive performance in two-class ship target detection,with an average precision of 96.4%,recall rate of 94.3%,and an F 1 score of 95.2%.Notably,the average heading error was 3.3°.The proposed model achieved a practical inference speed(FPS>30),and the average processing time for inferring a large-scale Sentinel-2 remote sensing image was 11.4 s.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(Grant Nos.LZ24C130004 and LQ24C130008)。
文摘Heading date is one of the most important agronomic traits that directly affect rice yield and determines the regional adaptability in specific growing environments.As a short-day plant,rice can grow under long-day(LD)conditions due to the synergistic regulation of many photosensitive genes.Using a set of chromosome segment substitution lines(CSSLs)with the indica cultivar Huanghuazhan(HHZ)as the recipient parent and Basmati Surkh 89-15(BAS)as the donor parent,we identified a QTL locus.
基金We are grateful for the funding from STI 2030-Major Projects(2023ZD0406802)the National Natural Science Foundation of China(32072066,32172050,3220151460)+2 种基金Hainan Yazhou Bay Seed Lab(B21HJ0215)CAAS Agricultural Science and Technology Innovation Program(CAAS-ZDRW202002,CAAS-ZDRW202201)Hebei Natural Science Foundation(C2021205013).
文摘Plant height and heading date are important agronomic traits in wheat(Triticum aestivum L.)that affect final grain yield.In wheat,knowledge of pseudo-response regulator(PRR)genes on agronomic traits is limited.Here,we identify a wheat TaPRR95 gene by genome-wide association studies to be associated with plant height.Triple allele mutant plants produced by CRISPR/Cas9 show increased plant height,particularly the peduncle,with an earlier heading date.The longer peduncle is mainly caused by the increased cell elon-gation at its upper section,whilst the early heading date is accompanied by elevated expression of flow-ering genes,such as TaFT and TacO1.A peduncle-specific transcriptome analysis reveals up-regulated photosynthesis genes and down-regulated IAAVAux genes for auxin signaling inpr95abad plants that may act as a regulatory mechanism to promote robust plant growth.A haplotype analysis identifies a TaPRR95-B haplotype(Hap2)to be closely associated with reduced plant height and increased thousand-grain weight.Moreover,the Hap2 frequency is higher in cultivars than that in landraces,suggesting the artifi-cial selection on the allele during wheat breeding.These findings suggest that TaPRR95 is a regulator for plant height and heading date,thereby providing an important target for wheat yield improvement.
基金National Key R&D Program of China(2022YFC2503200,2022YFC2503201)National Natural Science Foundation of China(52074012,52204191)+5 种基金Anhui Provincial Natural Science Foundation(2308085J19)University Distinguished Youth Foundation of Anhui Province(2022AH020057)Anhui Province University Discipline(Major)Top Talent Academic Support Project(gxbjZD2022017)Funding for academic research activities of reserve candidates for academic and technological leaders in Anhui Province(2022H301)Independent Research fund of Key Laboratory of Industrial Dust Prevention and Control&Occupational Health and Safety,Ministry of Education(Anhui University of Science and Technology)(EK20211004)Graduate Innovation Fund of Anhui University of Science and Technology(2023CX1003).
文摘In order to study the problems of unreasonable airflow distribution and serious dust pollution in a heading surface,an experimental platform for forced ventilation and dust removal was built based on the similar principles.Through the similar experiment and numerical simulation,the distribution of airflow field in the roadway and the spatial and temporal evolution of dust pollution under the conditions of forced ventilation were determined.The airflow field in the roadway can be divided into three zones:jet zone,vortex zone and reflux zone.The dust concentration gradually decreases from the head to the rear of the roadway.Under the forced ventilation conditions,there is a unilateral accumulation of dust,with higher dust concentrations away from the ducts.The position of the equipment has an interception effect on the dust.The maximum error between the test value and the simulation result is 12.9%,which verifies the accuracy of the experimental results.The research results can provide theoretical guidance for the application of dust removal technology in coal mine.
基金This work was supported by grants from the National Natural Science Foundation of China(32072037)the grant“Postgraduate Research&Practice Innovation Program of Jiangsu Province(Yangzhou University SJCX22_1786)”+1 种基金the grant from the Ministry of Science and Technology of the People’s Republic of China(DL2022014009L)the grants from Jiangsu Province Government(BZ2021017 and 20KJA210002).
文摘Panicle size is one of the important factors in shaping yield potential in rice,but it shows plasticity in different environments,which leads to yieldfluctuation.Variations in panicle size among varieties are largely determined by quantitative trait loci(QTLs).QTL analysis could elaborate on the environmental impact on trait plasticity using nearly isogenic lines(NILs)of different QTLs.Two QTLs,ipa1-2D and qPL6 are identified to have pleio-tropic contributions to panicle size and plant architecture,but their responses to different growth conditions are still unclear.In this study,we developed NILs harboring a single locus or both loci of ipa1-2D and qPL6 and sub-sequently evaluated these QTL effects under different nitrogen treatments or heading periods.Trait comparison showed that panicle length was highly responsive to the high nitrogen treatment independent of qPL6.At the same time,ipa1-2D reduced the response of plant height,panicle number,and grain yield to the treatment.The background of long heading periods decreased the stem diameter for any genotype combinations but enhanced the performance of ipa1-2D for the panicle primary branch number.Moreover,the middle heading background could better balance the pleiotropic effect of the two QTLs and showed the highest yield potential.In-parallel analysis of the QTL contributions under different nitrogen treatments or heading periods confirmed the significant effect of ipa1-2D in increasing stem diameter,panicle primary branch number,and spikelet number per panicle.We proved that the two individual QTLs had a stable effect in increasing the yield potential but com-peted to decrease the panicle secondary branch number,panicle number,and yield potential when they were pyr-amided.This work provides a full view of the plasticity of two QTLs in shaping yield-related traits and lays the foundation for the rational design of rice breeding in the future.
文摘QTLs for heading date of rice （Oryza sativa L.） with additive, epistatic, and QTL × environment （QE） interaction effects were studied using a mixed-model-based composite interval mapping （MCIM） method and a double haploid （DH） population derived from IR64/Azucena in two crop seasons. Fourteen QTLs conferring heading date in rice, which were distributed on ten chromosomes except for chromosomes 5 and 9, were detected. Among these QTLs, eight had single-locus effects, five pairs had double-locus interaction effects, and two single-loci and one pair of double-loci showed QTL × environment interaction effects. All predicted values of QTL effects varied from 1.179 days to 2.549 days, with corresponding contribution ratios of 1.04%-4.84%. On the basis of the effects of the QTLs, the total genetic effects on rice heading date for the two parents and the two superior lines were predicted, and the putative reasons for discrepancies between predicted values and observed values, and the genetic potentiality in the DH population for improvement of heading date were discussed. These results are in agreement with previous results for heading date in rice, and the results provide further information, which indicate that both epistasis and QE interaction are important genetic basis for determining heading date in rice.
基金Supported by the Program of Beijing Basic Research and Innovation Platform for Agricultural Breeding Ⅱ(No.D080705006900801)National"863"Program(No.2009AA101102,2006AA100102)Beijing Natural Science Foundation(No.5091001)~~
文摘[Objective]The study aimed to map QTLs（Quantitative trait loci）of heading stage for phtopeiod-thermo sensitive male sterile line BS366 in wheat.[Method] A population of 234 doubled haploid derived from the cross between BS366 and Baiyu149 was planted in Beijing and Funan in 2007,respectively.We used composite interval mapping（CIM）method to analyse the QTLs for heading stage.[Result]We detected 15 QTLs for heading stage.8 QTLs were detected in both Beijing and Funan,which were located on 1B,2A,2D,3B（2 loci）,6B（2 loci）and 7B.A single QTL accounted for 2.42%-10.98% of pheotypic varience.[Conclusion] Eight QTLs which were detected under two environments could be applied for marker-assisted breeding and improvement of BS366.The QTL on chromosome 1B was new for heading stage,which enriches the QTL resource.
文摘Sterility changeover induced by low temperature in male sterility line CMS7311 of heading Chinese cabbage ( Brassica campestris L. ssp. penkinsis) was investigated under constant temperature, day/night alternating temperature in light-growth-incubator and outdoor natural day/night alternating temperature respectively. It showed that the sterility of CMS7311 has significant change with temperature. The constant temperature of 6 - 12 degreesC was suitable to induce the changeover of sterility (CGS) of CMS7311 ; the shortest treatment time for CGS induction at this temperature was 3 d. The significant value of sterility changeover of CMS7311 occurred at the constant temperature of 6 - 9 degreesC after treatment for 6 - 9 d. The intensity of CGS was stronger under constant temperature than under alternate temperature, but the shortest treatment time inducing CGS has no difference between them. When treated for 9 d under the day/night alternating temperature of 11/7 degreesC, its sterility could also turn to normal fertility (near to sterile grade I or zero). In normal condition, the interval from the end of temperature treatment to the beginning of CGS induction was 10 - 16 d. In the condition of natural day/night alternating temperature, the lower limit of temperature for effective CGS induction was at the daily mean temperature ( DMT) of 3. 5 - 6. 8 degreesC, and the shortest treatment time which could induce the sterility changeover was also longer than that under constant temperature, being 11d at DMT of 1.5 - 3.1 degreesC. In addition, for the apical dominance, the flower bud on the first lateral branch showed the CGS 8 - 10 d later than the flower bud on the main stem under the same temperature with the same days of treatment. The intensity of CGS of CMS7311 on the first lateral branch was also weaker than the flower bud on the main stem.
基金This work was supported by the National Natural Science Foundation of China (No. 30571142), the 948 Project from the Ministry of Agricultue (No. 2004-Z24), Jiangsu Province High Technology Foundation (No. BG2004303), the Key Technology of Agricultural Structural Adjustment (No. 05-01-05B) and PCSIRT.
文摘USSR5, a japonica rice variety from the former Soviet Union, is an extremely early maturing rice variety. To elucidate the genetic basis for its early heading, genetic analysis was carried out by crossing it with a set of major gene nearly isogenic lines （NIL） and QTL-isogenic lines. The early heading of USSR5 was attributed to the presence of photoperiod-insensitive alleles at E1 and Se-1 gene, the photoperiod-sensitive inhibitor gene i-Se-1, and the dominant earliness gene Ef-1. Analysis of a backcrossed population （BCIF1） derived from the cross USSR5 x N22 indicated that two quantitative trait loci （QTL） for early heading were located on chromosomes 7 and 8, accounting for 27.4% and 11.2% of the phenotypic variance, respectively, with both early alleles originating from USSRS. From an F2 population of the same cross, early heading QTLs were detected on chromosomes 1, 2, 7, 9, and 10, with individual QTL accounting for between 4.1% and 15.4% of the phenotypic variance. Early heading alleles at four of these five QTLs originated from USSRS. A comparison of chromosomal locations suggests that one of these QTLs may be identical with the known gene Hd4 （E1）. The relationship between the other QTLs and known genes for heading date are not clear. USSR5 is a promising source for propagating earliness for the development of improved early heading rice varieties.
基金Supported by National Natural Science Foundation of China(31201181)Earmarked Fund for China Agriculture Research System(CARS-01-47)Project for Breeding and Demonstration of New Super Rice Varieties~~
文摘The seed setting rates of total 198 rice cultivars （lines） at heading and flowering stage were investigated under the condition of extreme natural high tem- perature in 2013 so as to analyze the effect of extreme natural high temperature on seed setting rate of different rice cultivar （line）. The results showed that the contin- uous high temperature showed certain effects on the seed setting rates of tested materials, and significant differences were shown in seed setting rate among differ- ent rice cultivars （lines）. The seed setting rates differed significantly among indica F1 hybrids derived from different sterile and restorer lines, indicating that the sterile and restorer lines had great effects on heat tolerances of different F~ hybrids. The cor- relation analysis showed that the seed setting rates of conventional indica restorer lines and conventional japonica rice cultivars （lines） were negatively related to the daily highest temperature （P〉0.05）, and the seed setting rates of indica F1 hybrids were positively related to the seed setting rates of their restorer lines. Total four in- dica restorer lines, including Ninghuiguangkangzhan, Shuhui 527, Chenghui 3203 and Xianyin-8, and four new japonica rice cultivars （lines）, including Wuyinjinghui （B2）, Nanjing 4//W3660/Nanjing 44 （B12） and Wuyun 2330/JD6011 （B22） were pre- liminarily screened, and their seed setting rates were all close to the normal level （90%）. The screened rice cultivars （lines） showed higher heat tolerances.
文摘[Objective] This study was conducted to discuss influence factors for safety full heading of machine-transplanted rice seedlings in cool-warm rice area. [Method] Effects of variety, seedling age and nitrogen fertilizer dosage and strategy of machine-transplanted seedlings on safety full heading of machine-transplanted seedlings were investigated. [Result] During mechanized rice production in coolwarm rice area, mid-early-maturing cold-resistant varieties with growth periods no longer than 180 d could selected, and seedling age could controlled within 30-35 d; and the total amount of pure nitrogen should be less than 300 kg/hm^2, and the proportion of nitrogen fertilizer applied in later stages should be properly reduced. [Conclusion] Under this condition, safety full heading of rice is ensured, and the target yield is realized.
文摘Nida's famous notion of Dynamic Equivalence in translation process is characterized by three stages - analysis, transfer and restructuring, which are explained in detail. The application of these principles are illustrated by providing step-by-step explanation on the translation process of headings of two news reports, which are selected from Far Eastern Economic Review.
基金supported by grants from the National Natural Science Foundation of China (31921004 and 31871596)the Major Program of Guangdong Basic and Applied Research (2019B030302006)the Laboratory of Lingnan Modern Agriculture Project (NT2021002)
文摘Heading date determines the seasonal and regional adaptation of rice(Oryza sativa L.)varieties and is mainly controlled by photoperiod sensitivity(PS).The core heading date genes Hd1,Ghd7,DTH8,and PRR37 act synergistically in regulating the PS.In this study,we systematically analyze the heading date,PS,and agronomic traits of eight homozygous lines with various combinations of Hd1,Ghd7,and DTH8 alleles in the prr37 background under long-day(LD)and short-day(SD)conditions,respectively.We find that Hd1 alone promotes heading,regardless of the day length.However,under LDs,Hd1 suppresses flowering,in coordination with functional Ghd7 or with Ghd7 and DTH8.These loci cooperate to negatively regulate the Ehd1-Hd3 a/RFT1 pathway and delay heading.Under SDs,Hd1 competes with various heading suppressors to promote heading.Therefore,the dual function of Hd1 is vital for PS.The lines carrying Hd1 alone show reduced plant height with fewer primary and secondary branches in panicles.Lines carrying Ghd7 and DTH8(with hd1)show delayed heading and improve agronomic traits.Overall,our results reveal the regulation of rice PS flowering by the core heading date genes and their effects on agronomic traits,providing valuable information for the selection of rice varieties for adaptation to different light and temperature conditions.
基金supported by the National Key Research and Development Program(2016YFD0101701)the National Vegetable Industry Technology System(CARS-23-A-06)+1 种基金the National Natural Science Foundation of China(31872106)the National Key Programs for Bok Choy Breeding of China(111821301354052283).
文摘Non-heading Chinese cabbage(NHCC)is an important leafy vegetable cultivated worldwide.Here,we report the first high-quality,chromosome-level genome of NHCC001 based on PacBio,Hi-C,and Illumina sequencing data.The assembled NHCC001 genome is 405.33 Mb in size with a contig N50 of 2.83 Mb and a scaffold N50 of 38.13 Mb.Approximately 53%of the assembled genome is composed of repetitive sequences,among which long terminal repeats(LTRs,20.42%of the genome)are the most abundant.Using Hi-C data,97.9%(396.83 Mb)of the sequences were assigned to 10 pseudochromosomes.Genome assessment showed that this B.rapa NHCC001 genome assembly is of better quality than other currently available B.rapa assemblies and that it contains 48,158 protein-coding genes,99.56%of which are annotated in at least one functional database.Comparative genomic analysis confirmed that B.rapa NHCC001 underwent a whole-genome triplication(WGT)event shared with other Brassica species that occurred after the WGD events shared with Arabidopsis.Genes related to ascorbic acid metabolism showed little variation among the three B.rapa subspecies.The numbers of genes involved in glucosinolate biosynthesis and catabolism were higher in NHCC001 than in Chiifu and Z1,due primarily to tandem duplication.The newly assembled genome will provide an important resource for research on B.rapa,especially B.rapa ssp.chinensis.
基金Item Sponsored by National Natural Science Foundation of China(50334010)
文摘Effects of rolling and cooling conditions on microstructure and mechanical properties of low carbon cold heading steel were investigated on a laboratory hot rolling mill. The results have shown that the mechanical proper ties of low carbon steels exceed the standard requirements of ML30, ML35, ML40, and ML45 steel, respectively due to thermomechanical controlled processing （TMCP）. This is attributed to a significant amount of pearlite and the ferrite-grain refinement. Under the condition of relatively low temperature rolling, the mechanical properties exceed standard requirements of ML45 and ML30 steel after water cooling and air cooling, respectively. Fast cooling which leads to more pearlite and finer ferrite grains is more critical than finish rolling temperatures for low carbon cold heading steel. The specimen at high finish rolling temperature exhibits very good mechanical properties due to fast cooling. This result has great significance not only for energy saving and emission reduction, but also for low-carbon economy, because the goals of the replacement of medium-carbon by low-carbon are achieved with TMCP.
基金The research was supported by the following:the Independent Innovation Fund for Agricultural Science and Technology of Jiangsu Province(CX(15)1015)the Science-technology Support Plan of Jiangsu Province(BE2012325,BE2013429)+1 种基金Natural Science Foundation of China(31272173)and Jiangsu Natural Science Foundation(BK20140704).
文摘Non-heading Chinese cabbage(Brassica rapa ssp.chinensis)is one of the main green leafy vegetables in the world,especially in China,with significant economic value.Hyaloperonospora parasitica is a fungal pathogen responsible for causing downy mildew disease in Chinese cabbage,which greatly affects its production.The objective of this study was to identify transcriptionally regulated genes during incompatible interactions between non-heading Chinese cabbage and H.parasitica using complementary DNA-amplified fragment length polymorphism(cDNA-AFLP).We obtained 129 reliable differential transcript-derived fragments(TDFs)in a resistant line‘Suzhou Qing’.Among them,121 upregulated TDFs displayed an expression peak at 24–48 h post inoculation(h.p.i.).Fifteen genes were further selected for validation of cDNA-AFLP expression patterns using quantitative reverse transcription PCR.Results confirmed the altered expression patterns of 13 genes(86.7%)revealed by the cDNA-AFLP.We identified four TDFs related to fungal resistance among the 15 TDFs.Furthermore,comparative analysis of four TDFs between resistant line‘Suzhou Qing’and susceptible line‘Aijiao Huang’showed that transcript levels of TDF14(BcLIK1_A01)peaked at 48 h.p.i.and 25.1-fold increased in the resistant line compared with the susceptible line.Similarly,transcript levels of the other three genes,TDF42(BcCAT3_A07),TDF75(BcAAE3_A06)and TDF88(BcAMT2_A05)peaked at 24,48 and 24 h.p.i.with 25.1-,100-and 15.8-fold increases,respectively.The results suggested that the resistance genes tended to transcribe at higher levels in the resistance line than in the susceptible line,which may provide resistance against pathogen infections.The present study might facilitate elucidating the molecular basis of the infection process and identifying candidate genes for resistance improvement of susceptible cultivars.
基金the National Natural Science Foundation of China(31972428 and 31672140)the Shanxi Province Natural Science Foundation(201801D121191 and 201801D121197).
文摘Heading Chinese cabbage(Brassica rapa L.syn.B.campestris L.ssp.chinensis Makino var.pekinensis(Rupr.)J.Cao et Sh.Cao)is a cruciferous Brassica vegetable that has a triplicate genome,owing to an ancient genome duplication event.It is unclear whether the duplicated homologs have conserved or diversi fied functions.Hydrogen sulfide(H_(2)S)is a plant gasotransmitter that plays important physiological roles in growth,development,and responses to environmental stresses.The modification of cysteines through S-sulfhydration is an important mechanism of H_(2)S,which regulates protein functions.H?S promotes flowering in Arabidopsis and heading Chinese cabbage.Here we investigated the molecular mechanisms of H_(2)S used to promote flowering in the latter.Four,five,and four BraFLC,BraSOC I,and BraFT homologs were identi fi ed in heading Chinese cabbage.Different BraFLC proteins were bound to different CArG boxes in the promoter regions of the BraSOC I and BraFT homologs,producing different binding patterns.Thus,there may be functionally diverse BraFLC homologs in heading Chinese cabbage.Exogenous H_(2)S at 100μmol L^(-1) significantly promoted flowering by compensating for insuf fi cient vernalization.BraFLC 1 and BraFLC_(3) underwent S-sulfhydration by H_(2)S,after which their abilities to bind most BraSOC I or BraFT promoter probes weakened or even disappeared.These changes in binding ability were consistent with the expression pattern of the BraFT and BraSOC I homologs in seedlings treated with H_(2)S.These results indicated that H_(2)S signaling regulates flowering time.In summary,H_(2)S signaling promoted plant flowering by weakening or eliminating the binding abilities of BraFLCs to downstream promoters through S-sulfhydration.
基金supported by the Science and Technology Program of Zhejiang Province, China (Grant No. 2005C24007)National High Technology Research and Development Program of China (Grant Nos. 2006AA10Z1E8 and 2006AA100101)
文摘Previous study showed that a linkage drag between a blast resistance gene Pi25（t） and QTLs conditioning spikelet fertility （qSF-6） and number of filled grains per panicle （qNFGP-6） was detected on the short arm of chromosome 6. A larger population was used for further verification, and the results confirmed the linkage drag between the blast resistance gene and QTL conditioning spikelet fertility, other than QTL conditioning number of filled grains per panicle. Breakdown or avoidance of the linkage drag could be achieved by selection against the genotype background of a heading-date gene （qHD-7） that resided in the region between RM2 and RM214 on chromosome 7. For further validation, two lines with almost identical genotypes on all chromosomal regions except the Pi25（t） region on chromosome 6 were chosen to develop a new population The results showed that qSF-6 could be further subdivided into qSF-6-1 and qSF-6-2. When the genotype of the region between RM2 and RM214 was from rice variety Zhong 156, the linkage drag between Pi25（t） and qSF-6-2 was detected and the allele of qSF-6-2 from rice variety Gumei 2 reduced the spikelet fertility. When the genotype of the region between RM2 and RM214 was from Gumei 2, no linkage drag was detected. This indicates that the linkage drag between the blast resistance gene and the QTL conditioning spikelet fertility could be broken down or avoided under a certain background genotype selection against heading-date and provides a marker aided solution for high level of blast resistance and yield breeding in rice and other crops as well.
