Ratoon rice,which refers to a second harvest of rice obtained from the regenerated tillers originating from the stubble of the first harvested crop,plays an important role in both food security and agroecology while r...Ratoon rice,which refers to a second harvest of rice obtained from the regenerated tillers originating from the stubble of the first harvested crop,plays an important role in both food security and agroecology while requiring minimal agricultural inputs.However,accurately identifying ratoon rice crops is challenging due to the similarity of its spectral features with other rice cropping systems(e.g.,double rice).Moreover,images with a high spatiotemporal resolution are essential since ratoon rice is generally cultivated in fragmented croplands within regions that frequently exhibit cloudy and rainy weather.In this study,taking Qichun County in Hubei Province,China as an example,we developed a new phenology-based ratoon rice vegetation index(PRVI)for the purpose of ratoon rice mapping at a 30 m spatial resolution using a robust time series generated from Harmonized Landsat and Sentinel-2(HLS)images.The PRVI that incorporated the red,near-infrared,and shortwave infrared 1 bands was developed based on the analysis of spectro-phenological separability and feature selection.Based on actual field samples,the performance of the PRVI for ratoon rice mapping was carefully evaluated by comparing it to several vegetation indices,including normalized difference vegetation index(NDVI),enhanced vegetation index(EVI)and land surface water index(LSWI).The results suggested that the PRVI could sufficiently capture the specific characteristics of ratoon rice,leading to a favorable separability between ratoon rice and other land cover types.Furthermore,the PRVI showed the best performance for identifying ratoon rice in the phenological phases characterized by grain filling and harvesting to tillering of the ratoon crop(GHS-TS2),indicating that only several images are required to obtain an accurate ratoon rice map.Finally,the PRVI performed better than NDVI,EVI,LSWI and their combination at the GHS-TS2 stages,with producer's accuracy and user's accuracy of 92.22 and 89.30%,respectively.These results demonstrate that the proposed PRVI based on HLS data can effectively identify ratoon rice in fragmented croplands at crucial phenological stages,which is promising for identifying the earliest timing of ratoon rice planting and can provide a fundamental dataset for crop management activities.展开更多
The yellow seed trait is preferred by breeders for its potential to improve the seed quality and commercial value of Brassica napus.In the present study,we produced yellow seed mutants using a CRISPR/Cas9 system when ...The yellow seed trait is preferred by breeders for its potential to improve the seed quality and commercial value of Brassica napus.In the present study,we produced yellow seed mutants using a CRISPR/Cas9 system when the two BnPAP2 homologs were knocked out.Histochemical staining of the seed coat demonstrated that proanthocyanidin accumulation was significantly reduced in the pap2 double mutants and decreased specifically in the endothelial and palisade layer cells of the seed coat.Transcriptomic and metabolite profiling analysis suggested that disruption of the BnPAP2 genes could reduce the expression of structural and regulated genes in the phenylpropanoid and flavonoid biosynthetic pathways.The broad suppression of these genes might hinder proanthocyanidin accumulation during seed development,and thereby causing the yellow seed trait in B.napus.These results indicate that BnPAP2 might play a vital role in the regulatory network controlling proanthocyanidin accumulation.展开更多
The two-line pollination control system,which usually depends on the utilization of thermosensitive or photoperiod genic male-sterile lines,has been widely used in various crops.However,this system is susceptible to i...The two-line pollination control system,which usually depends on the utilization of thermosensitive or photoperiod genic male-sterile lines,has been widely used in various crops.However,this system is susceptible to instability issues caused by uncontrollable weather fluctuations.A stable and handy two-line pollination control system is highly desirable in many crop species for heterosis exploitation.Oxophytodienoic acid reductase 3(OPR3)was proven to be involved in jasmonate biosynthesis.In the present study,CRISPR/Cas9(Clustered Regularly Interspaced Short Palindromic Repeat)was utilized to mutate two OPR3 homologs in Brassica napus.After two OPR3 homologs were simultaneously mutated,mutants exhibited complete male sterility,and fertility could be easily restored by exogenous MeJA treatment.Hybrids produced from crosses between the opr3 sterile lines and normal varieties exhibited heterosis.This new two-line system based on OPR3 mutation provides higher stability and convenience than traditional systems.By using exogenous MeJA treatment to restore fertility,the system enables more precise control of male fertility transition,which has great potential to significantly contribute to the maneuverable production of hybrid seeds in rapeseed as well as other Brassica species crops.展开更多
Rapeseed(Brassica napus L.) is the largest oilseed crop in China and accounts for about 20% of world production.For the last 10 years,the production,planting area,and yield of rapeseed have been stable,with improvemen...Rapeseed(Brassica napus L.) is the largest oilseed crop in China and accounts for about 20% of world production.For the last 10 years,the production,planting area,and yield of rapeseed have been stable,with improvement of seed quality and especially seed oil content.China is among the leading countries in rapeseed genomic research internationally,having jointly with other countries accomplished the whole genome sequencing of rapeseed and its two parental species,Brassica oleracea and Brassica rapa.Progress on functional genomics including the identification of QTL governing important agronomic traits such as yield,seed oil content,fertility regulation,disease and insect resistance,abiotic stress,nutrition use efficiency,and pod shattering resistance has been achieved.As a consequence,molecular markers have been developed and used in breeding programs.During 2005–2014,215 rapeseed varieties were registered nationally,including 210 winter-and 5 spring-type varieties.Mechanization across the whole process of rapeseed production was investigated and operating instructions for all relevant techniques were published.Modern techniques for rapeseed field management such as high-density planting,controlled-release fertilizer,and biocontrol of disease and pests combined with precision tools such as drones have been developed and are being adopted in China.With the application of advanced breeding and production technologies,in the near future,the oil yield and quality of rapeseed varieties will be greatly increased,and more varieties with desirable traits,especially early maturation,high yield,high resistance to biotic and abiotic stress,and suitability for mechanized harvesting will be developed.Application of modern technologies on the mechanized management of rapeseed will greatly increase grower profit.展开更多
Sequence-specific nucleases(SSN) that generate double-stranded DNA breaks(DSBs) in genes of interest are the key to site-specific genome editing in plants. Genome editing has developed into one method of reducing unde...Sequence-specific nucleases(SSN) that generate double-stranded DNA breaks(DSBs) in genes of interest are the key to site-specific genome editing in plants. Genome editing has developed into one method of reducing undesirable traits in crops by the induction of knockout mutations. Different SSN-mediated genome-editing systems, including LAGLIDADG homing endonucleases or meganucleases, zinc-finger nucleases, transcription activator-like effector nucleases and clustered regularly interspaced short palindromic repeats, are emerging as robust tools for introducing functional mutations in polyploid crops including citrus, wheat, cotton, soybean, rapeseed, potato, grapes, Camelina sativa,dandelion, and tobacco. The approach utilizes knowledge of biological mechanisms for targeted induction of DSBs and their error-prone repair, allowing highly specific changes at designated genome loci. In this review, we briefly describe genome-editing technologies and their application to genetic improvement of polyploid crops.展开更多
The Nsa cytoplasmic male sterility(CMS) system confers stable male sterility and offers great potential for production of hybrid seeds in oilseed rape. However, genes responsible for male sterility in Nsa CMS have not...The Nsa cytoplasmic male sterility(CMS) system confers stable male sterility and offers great potential for production of hybrid seeds in oilseed rape. However, genes responsible for male sterility in Nsa CMS have not been identified. By mitochondrial genome sequencing of Nsa CMS and its maintainer line,we identified in an Nsa CMS line several chimeric genes encoding hypothetical proteins harboring transmembrane domains. One novel chimeric gene orf346 showed high identity with cox1 at the 50 terminal region and was co-transcribed with nad3 and rps12 genes. Transgenic plants of orf346 fused with or without mitochondrial targeting peptide conferred complete male sterility in Arabidopsis. ORF346 was mitochondrion-localized. Expression of orf346 in Escherichia coli inhibited bacterial growth, with excessive accumulation of reactive oxygen species and decreased ATP content. These results reveal a link between the newly identified mitochondrial gene orf346 and the abortion of Nsa CMS. Inadequate energy supply and excessive accumulation of reactive oxygen species may account for pollen abortion in Nsa CMS plants.展开更多
Pod shattering causes severe yield loss in rapeseed(Brassica napus L.)under modern agricultural practice.Identification of highly shatter-resistant germplasm is desirable for the development of rapeseed cultivars for ...Pod shattering causes severe yield loss in rapeseed(Brassica napus L.)under modern agricultural practice.Identification of highly shatter-resistant germplasm is desirable for the development of rapeseed cultivars for mechanical harvesting.In the present study,an elite line OR88 with strong shatter resistance and a lignified-layer bridge(LLB)structure was identified.The LLB structure was unique to OR88 and co-segregated with high pod-shatter resistance.The LLB structure is differentiated at stage 12 of gynoecium development without any gynoecium defects.Genetic analysis showed that LLB is controlled by a single recessive gene.By BSA-Seq and map-based cloning,the resistance gene location was delimited to a0.688 Mb region on chromosome C09.Transcriptome analysis suggested Bn TCP8.C09 as the gene responsible for LLB.The expression of Bn TCP.C09 was strongly downregulated in OR88,suppressing cell proliferation in the pod valve margin.KASP markers linked to the candidate gene were developed.This pod shatter-resistant line could be used in rapeseed breeding programs by direct transfer of the gene with the assistance of the DNA markers.展开更多
Sinapis arvensis,belonging to the genus Sinapis of the family Brassicaceae,has good agronomic characters that make it a valuable genetic resource for crop improvement and is a cytoplasmic source of heterologous cytopl...Sinapis arvensis,belonging to the genus Sinapis of the family Brassicaceae,has good agronomic characters that make it a valuable genetic resource for crop improvement and is a cytoplasmic source of heterologous cytoplasmic male sterility(CMS).In addition,S.arvensis has played an important role in the evolution of the six major cultivated Brassica species involved in the triangle of U.Using next-generation sequencing,we assembled and revealed the gene composition of S.arvensis cytoplasmic genome.The chloroplast genome comprises 153,590 bp,with 112 individual genes,including 4 r RNA,29 t RNA,and 79 proteincoding genes.The mitochondrial genome comprises 240,024 bp,with 54 genes,including 18 t RNA,three r RNA and 33 protein-coding genes.Genome structure and evolutionary analysis indicated that the sequences of the S.arvensis organellar genomes were more similar to those of Brassica nigra and B.carinata than to those of other Brassicaceae species.Four mitochondrial open reading frames displaying chimeric structural features and encoding hypothetical proteins with transmembrane domains may account for the infertility of Nsa CMS previously derived from somatic cell hybridization between B.napus and S.arvensis.These results will not only contribute to utilize the germplasm resource of S.arvensis,and comprehend the evolution of organelle genomes within the Brassicaceae family,but also help to identify genes conditioning the alloplasmic male sterility of Nsa CMS in B.napus.展开更多
Branch angle is an important plant architecture trait and is considerably important for the ideal plant architecture of high density cultivation of rapeseed. In this study,12 representative rapeseed lines were first m...Branch angle is an important plant architecture trait and is considerably important for the ideal plant architecture of high density cultivation of rapeseed. In this study,12 representative rapeseed lines were first measured for whole-plant branch angles using image processing technology. Top branch angle (TBA) and basal branch angle (BBA) were significantly different in each line in which TBA was greater than BBA. Then, 156 rapeseed germplasm lines were evaluated for TBA and BBA in main cultivated regions of the Yangtze River Basin (Zunyi; Wuhan; Lu'an). In these three environments, the TBA and BBA of the rapeseed germplasm sources varied, in which ranges of 33.44°-73.17°and 18.73°-59.11°, 29.66°-61.91°and 22.32°-60.16°, and 28.47°-76.32°and 22.98°-72.68°, respectively. ANOVA showed that TBA and BBA were susceptible to environmental and had broadsense heritability (H2) values of 89.09%and 87.40%, respectively. Interactions of genotype by environment were also significant. There was diversity in branch angle among rapeseed genotypes. GGE biplot analysis showed that compact accession lines (Nilla, Purler and AV-SAPPHI) were the most desirable compact genotypes in all environments. Stability analysis showed that the genotype with the most minimum branch angle was stable for compact plant architecture.展开更多
[Objectives]To explore the antimicrobial and antioxidant activities of flavonoid and polysaccharide extracts from bulbs of Lycoris aurea.[Methods]The disc diffusion method was used to evaluate the antimicrobial activi...[Objectives]To explore the antimicrobial and antioxidant activities of flavonoid and polysaccharide extracts from bulbs of Lycoris aurea.[Methods]The disc diffusion method was used to evaluate the antimicrobial activity of flavonoid and polysaccharide extracts from the bulbs of L.aurea.The antioxidant activity was determined by scavenging of hydroxyl and 1,1-diphenyl-2-picrylhydrazine(DPPH)free radicals,and reducing ability.[Results]Flavonoids were effective on 7 microorganisms,but polysaccharides had no effect.Flavonoids had better hydroxyl free radical scavenging activity and reducing capacity than polysaccharides,but weaker than ascorbic acid.However,flavonoids had similar DPPH free radical activity to ascorbic acid.The strong antibacterial and antioxidant activities of flavonoids were mainly attributed to the high content of total phenols in the extract,which was(76.71±4.42)mg/g.[Conclusions]The study shows that flavonoids from bulbs of L.aurea could be regarded as a new potential source of natural bacterial inhibitors and antioxidants.展开更多
Plant organelle(plastid and mitochondrial)genomes contain substantial information for plant evolution and adaptation.Therefore,it’s important to reveal plant whole-genome sequences including plastid and mitochondrial...Plant organelle(plastid and mitochondrial)genomes contain substantial information for plant evolution and adaptation.Therefore,it’s important to reveal plant whole-genome sequences including plastid and mitochondrial genomes.To decode these sequences,it is required to efficiently separate organelle genomic DNA from nucleus genome,which is difficult and laborious.In this study,an efficient procedure was established to obtain plant organelle genomes without extraction of plastid and mitochondria.Organelle DNA was extracted from three materials including Sinapis arvensis var.‘Yeyou 18’,a cytoplasmic male sterile line(Nsa CMS)and its corresponding maintainer line‘Zhongshuang 4’.DNA was sequenced by Roche 454 FLXt and Illumina Miseq platforms.Organelle genomes were assembled using the generated reads and public organelle genome sequences.This research presented a procedure that efficiently assembled organelle genomes and subsequent fill gaps by extending the consensus contig terminals.This method enabled us to assemble plant plastid and mitochondrial genomes simultaneously.The obtained organelle genomes could accelerate understanding of mitochondrial rearrangements and laid a foundation for further study of Sinapis arvensis evolution and sterility gene of Nsa CMS.展开更多
Effective silique number per plant(ESN), seeds per silique(SS), thousand seeds weight(TSW), silique length(SL) and silique density(SD) are important seed yield potential determinant traits in rapeseed(Brassica napus L...Effective silique number per plant(ESN), seeds per silique(SS), thousand seeds weight(TSW), silique length(SL) and silique density(SD) are important seed yield potential determinant traits in rapeseed(Brassica napus L.), which are controlled by quantitative trait loci(QTL). Mapping QTL to delimited chromosomal region offers an effective method for genetic dissection of these traits. A set of 96 double haploid(DH) lines were developed by crossing 2 Brassica napus lines R1 and R2, and an immortalized F_2(IF_2) population containing 124 combinations was developed by crossing those DH lines. DH populations were planted at 2 locations for 2 years and IF_2 populations were planted in 2 locations for 1 year. Based on the established 2,217.2 cM length high density genetic map, 42 QTLs were identified, with 26 QTLs detected repeatedly in different environments or populations, including 8 for SL, 7 for TSW, 4 for ESN, 4 for SS and 3 for SD. Among these identified QTLs, 3, 4, 1, 1 and 3 QTLs were considered as major QTLs for SL, TSW, ESN, SS and SD, respectively. In addition, 2 QTLs on A9 chromosome which control multiple traits were identified. These results warrant further study of fine mapping for yield and yield components.展开更多
A novel method for HDDA-derived benzyne trapped by nitrone was developed. This research described a simple and efficient pathway for the synthesis of benzisoxazoles from arynes and PTIO(2-phenyl-4,4,5,5-tetramethylimi...A novel method for HDDA-derived benzyne trapped by nitrone was developed. This research described a simple and efficient pathway for the synthesis of benzisoxazoles from arynes and PTIO(2-phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl), C-C and C-O bonds were formed in a single step without catalyst under mild conditions. The unexpected cleavage of C-N bond contributed to the formation of isoxazole ring, as indicated by DFT studies. Furthermore, we obtained the structure of benzoxazolopyrrolidine when the trapping agent is DMPO(5,5-dimethyl-1-pyrroline N-oxide).展开更多
Xiao et al.(2017)在对比分析4个语料库的基础上,提出国内小学六年级学生的识词率增长不能令人满意的观点,建议人教版小学英语通用教材总词汇在原有726个的基础上再增加903个,并删除twelfth(序数词,第十二)这样的低频词。作为外语教师...Xiao et al.(2017)在对比分析4个语料库的基础上,提出国内小学六年级学生的识词率增长不能令人满意的观点,建议人教版小学英语通用教材总词汇在原有726个的基础上再增加903个,并删除twelfth(序数词,第十二)这样的低频词。作为外语教师和语言学家,我们赞同他们应用先进信息技术对传统词表进行评估的做法,但认为这项工作:1.在构建参考语料库时需重视语料抽样的合理性;2.在解读词频时需重视齐夫定律(Zipf’s law,即英语词频与词秩成反比)的作用——识字率增长随词汇量增加而减缓的情况是合理的;3.在提出教材选词策略时,需考虑小学生认知特点和课业负担等现实因素限制,以及语言教育的总体目标,不能随便删除twelfth这样承载文化的词汇;4.学龄儿童全国通用外语教材编写是项复杂的系统工程,需要各领域专家共同关注。展开更多
A novel poly(ethyleneimine)/Au nanoparticles/hemin nanocomposite(PEI-AuNPs-Hemin)acting for Methyl Orange(MO) removal has been synthesized. PEI-AuNPs was prepared firstly and it was then linked to hemin through the co...A novel poly(ethyleneimine)/Au nanoparticles/hemin nanocomposite(PEI-AuNPs-Hemin)acting for Methyl Orange(MO) removal has been synthesized. PEI-AuNPs was prepared firstly and it was then linked to hemin through the coupling between carboxyl groups in hemin and amino groups in PEI without the activation of carboxyl groups. The high reactivity and stability of AuNPs contributed greatly in the formation of the amido bonds in the nanocomposite. Fourier transform infrared spectroscopy, transmission electron microscopy and UV–visible spectroscopy were used to characterize the PEI-AuNPs-Hemin.Results show that PEI-AuNPs-Hemin has strong adsorption for MO. Adsorption and degradation experiments were carried out at different p Hs, nanocomposite concentrations and UV irradiation times. Removal of MO in acidic solutions was more effective than in basic solutions. The real-time study showed that the MO degradation with the nanocomposite under UV irradiation was a fast process. In addition, the photocatalytic degradation mechanism was proposed. The study suggests that the PEI-AuNPs-Hemin may have promising applications in environmental monitoring and protection.展开更多
This study presents a facile strategy for the formation of highly substituted butterfly 1,4-adducts/9,10-adducts via the Diels-Alder reaction of benzyne intermediates.The method achieves very good to excellent yields ...This study presents a facile strategy for the formation of highly substituted butterfly 1,4-adducts/9,10-adducts via the Diels-Alder reaction of benzyne intermediates.The method achieves very good to excellent yields of the respective anthracene derivative s under mild conditions.This practical protocol is compatible with a variety of sensitive functional groups and provides access to difunctionalized bridge 1,4-adducts/9,10-adducts.展开更多
A knowledge of the adsorption and desorption behavior of sorbates on surface adsorptive site(SAS)is the key to optimizing the chemical reactivity of catalysts.However,direct identification of the chemical reactivity o...A knowledge of the adsorption and desorption behavior of sorbates on surface adsorptive site(SAS)is the key to optimizing the chemical reactivity of catalysts.However,direct identification of the chemical reactivity of SASs is still a challenge due to the limitations of characterization techniques.Here,we present a new pathway to determine the kinetics of adsorption/desorption on SASs of graphene oxide(GO)based on total internal reflectance fluorescence microscopy.The switching on and off of the fluorescent signal of SAS lit by carbon dots(CDs)was used to trace the adsorption process and desorption process.We find that sodium pyrophosphate(PPi)could increase the adsorption equilibrium of CDs thermodynamically and promote the substrate-assisted desorption pathway kinetically.At the single turnover level,it was disclosed that the species that can promote desorption may also be an adsorption promoter.Such discovery provides significant guidance for improving the chemical reactivity of the heterogeneous catalyst.展开更多
基金supported by the National Natural Science Foundation of China(42271360 and 42271399)the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(CAST)(2020QNRC001)the Fundamental Research Funds for the Central Universities,China(2662021JC013,CCNU22QN018)。
文摘Ratoon rice,which refers to a second harvest of rice obtained from the regenerated tillers originating from the stubble of the first harvested crop,plays an important role in both food security and agroecology while requiring minimal agricultural inputs.However,accurately identifying ratoon rice crops is challenging due to the similarity of its spectral features with other rice cropping systems(e.g.,double rice).Moreover,images with a high spatiotemporal resolution are essential since ratoon rice is generally cultivated in fragmented croplands within regions that frequently exhibit cloudy and rainy weather.In this study,taking Qichun County in Hubei Province,China as an example,we developed a new phenology-based ratoon rice vegetation index(PRVI)for the purpose of ratoon rice mapping at a 30 m spatial resolution using a robust time series generated from Harmonized Landsat and Sentinel-2(HLS)images.The PRVI that incorporated the red,near-infrared,and shortwave infrared 1 bands was developed based on the analysis of spectro-phenological separability and feature selection.Based on actual field samples,the performance of the PRVI for ratoon rice mapping was carefully evaluated by comparing it to several vegetation indices,including normalized difference vegetation index(NDVI),enhanced vegetation index(EVI)and land surface water index(LSWI).The results suggested that the PRVI could sufficiently capture the specific characteristics of ratoon rice,leading to a favorable separability between ratoon rice and other land cover types.Furthermore,the PRVI showed the best performance for identifying ratoon rice in the phenological phases characterized by grain filling and harvesting to tillering of the ratoon crop(GHS-TS2),indicating that only several images are required to obtain an accurate ratoon rice map.Finally,the PRVI performed better than NDVI,EVI,LSWI and their combination at the GHS-TS2 stages,with producer's accuracy and user's accuracy of 92.22 and 89.30%,respectively.These results demonstrate that the proposed PRVI based on HLS data can effectively identify ratoon rice in fragmented croplands at crucial phenological stages,which is promising for identifying the earliest timing of ratoon rice planting and can provide a fundamental dataset for crop management activities.
基金supported by the National Natural Science Foundation of China(31971980,U19A2029)The science and technology innovation Program of Hunan Province,China(2023RC1077)+1 种基金the Agricultural Science and Technology Innovation Foundation of Hunan,China(2022CX55)the Scientific Research Fund of Hunan Provincial Science and Technology Department,China(2021JC0007)。
文摘The yellow seed trait is preferred by breeders for its potential to improve the seed quality and commercial value of Brassica napus.In the present study,we produced yellow seed mutants using a CRISPR/Cas9 system when the two BnPAP2 homologs were knocked out.Histochemical staining of the seed coat demonstrated that proanthocyanidin accumulation was significantly reduced in the pap2 double mutants and decreased specifically in the endothelial and palisade layer cells of the seed coat.Transcriptomic and metabolite profiling analysis suggested that disruption of the BnPAP2 genes could reduce the expression of structural and regulated genes in the phenylpropanoid and flavonoid biosynthetic pathways.The broad suppression of these genes might hinder proanthocyanidin accumulation during seed development,and thereby causing the yellow seed trait in B.napus.These results indicate that BnPAP2 might play a vital role in the regulatory network controlling proanthocyanidin accumulation.
基金This work was co-supported by the Guangdong Basic and Applied Basic Research Foundation(No.2022A1515010618)the Young Talent Support Project of Guangzhou Association for Science and Technology(No.QT-2023-009)+2 种基金the National Natural Science Foundation of China(No.21904026,21974031)the Guangzhou Science and Technology Project(No.202201010600,202201020170,202201000002)the Innovation Training Program for College Students of Guangzhou University(No.202211078113,S202111078031).
基金Thisworkwas supported by the Agricultural Science and Technology Innovation Project(CAAS-ZDRW202105)the Sci-Tech Innovation 2030 Agenda(2022ZD04009)+2 种基金the National Key Research and Development Program of China(2022YFD1200804)Key Research Projects of Hubei Province(No.2021EHB026 and 2022BBA0039)the Fundamental Research Funds for Central Non-profit Scientific Institution(No.1610172020001).
文摘The two-line pollination control system,which usually depends on the utilization of thermosensitive or photoperiod genic male-sterile lines,has been widely used in various crops.However,this system is susceptible to instability issues caused by uncontrollable weather fluctuations.A stable and handy two-line pollination control system is highly desirable in many crop species for heterosis exploitation.Oxophytodienoic acid reductase 3(OPR3)was proven to be involved in jasmonate biosynthesis.In the present study,CRISPR/Cas9(Clustered Regularly Interspaced Short Palindromic Repeat)was utilized to mutate two OPR3 homologs in Brassica napus.After two OPR3 homologs were simultaneously mutated,mutants exhibited complete male sterility,and fertility could be easily restored by exogenous MeJA treatment.Hybrids produced from crosses between the opr3 sterile lines and normal varieties exhibited heterosis.This new two-line system based on OPR3 mutation provides higher stability and convenience than traditional systems.By using exogenous MeJA treatment to restore fertility,the system enables more precise control of male fertility transition,which has great potential to significantly contribute to the maneuverable production of hybrid seeds in rapeseed as well as other Brassica species crops.
基金supported by the Agricultural Science and Technology Innovation Program of CAAS,the China Agriculture Research System(CARS-13)
文摘Rapeseed(Brassica napus L.) is the largest oilseed crop in China and accounts for about 20% of world production.For the last 10 years,the production,planting area,and yield of rapeseed have been stable,with improvement of seed quality and especially seed oil content.China is among the leading countries in rapeseed genomic research internationally,having jointly with other countries accomplished the whole genome sequencing of rapeseed and its two parental species,Brassica oleracea and Brassica rapa.Progress on functional genomics including the identification of QTL governing important agronomic traits such as yield,seed oil content,fertility regulation,disease and insect resistance,abiotic stress,nutrition use efficiency,and pod shattering resistance has been achieved.As a consequence,molecular markers have been developed and used in breeding programs.During 2005–2014,215 rapeseed varieties were registered nationally,including 210 winter-and 5 spring-type varieties.Mechanization across the whole process of rapeseed production was investigated and operating instructions for all relevant techniques were published.Modern techniques for rapeseed field management such as high-density planting,controlled-release fertilizer,and biocontrol of disease and pests combined with precision tools such as drones have been developed and are being adopted in China.With the application of advanced breeding and production technologies,in the near future,the oil yield and quality of rapeseed varieties will be greatly increased,and more varieties with desirable traits,especially early maturation,high yield,high resistance to biotic and abiotic stress,and suitability for mechanized harvesting will be developed.Application of modern technologies on the mechanized management of rapeseed will greatly increase grower profit.
基金supported by the National Natural Science Foundation of China(No.31700316)the Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences(Group No.118)+2 种基金the Earmarked Fund for China Agriculture Research System(CARS-12)the Fundamental Research Funds for Central Non-Profit Scientific Institution(1610172018009)Graduate School of Chinese Academy of Agricultural Sciences
文摘Sequence-specific nucleases(SSN) that generate double-stranded DNA breaks(DSBs) in genes of interest are the key to site-specific genome editing in plants. Genome editing has developed into one method of reducing undesirable traits in crops by the induction of knockout mutations. Different SSN-mediated genome-editing systems, including LAGLIDADG homing endonucleases or meganucleases, zinc-finger nucleases, transcription activator-like effector nucleases and clustered regularly interspaced short palindromic repeats, are emerging as robust tools for introducing functional mutations in polyploid crops including citrus, wheat, cotton, soybean, rapeseed, potato, grapes, Camelina sativa,dandelion, and tobacco. The approach utilizes knowledge of biological mechanisms for targeted induction of DSBs and their error-prone repair, allowing highly specific changes at designated genome loci. In this review, we briefly describe genome-editing technologies and their application to genetic improvement of polyploid crops.
基金supported by the National Key Research and Development Program of China (2016YFD0101300)the Natural Science Foundation of China (30871553)+3 种基金the Fundamental Research Funds for Central Nonprofit Scientific Institution (1610172017005)the Agricultural Science and Technology Innovation Program of CAAS (Group No. 118)the Hubei Agricultural Science and Technology Innovation Center (201620000001048)the China Agriculture Research System (CARS-12)。
文摘The Nsa cytoplasmic male sterility(CMS) system confers stable male sterility and offers great potential for production of hybrid seeds in oilseed rape. However, genes responsible for male sterility in Nsa CMS have not been identified. By mitochondrial genome sequencing of Nsa CMS and its maintainer line,we identified in an Nsa CMS line several chimeric genes encoding hypothetical proteins harboring transmembrane domains. One novel chimeric gene orf346 showed high identity with cox1 at the 50 terminal region and was co-transcribed with nad3 and rps12 genes. Transgenic plants of orf346 fused with or without mitochondrial targeting peptide conferred complete male sterility in Arabidopsis. ORF346 was mitochondrion-localized. Expression of orf346 in Escherichia coli inhibited bacterial growth, with excessive accumulation of reactive oxygen species and decreased ATP content. These results reveal a link between the newly identified mitochondrial gene orf346 and the abortion of Nsa CMS. Inadequate energy supply and excessive accumulation of reactive oxygen species may account for pollen abortion in Nsa CMS plants.
基金the National Natural Science Foundation of China(U19A2029)the National Key Research and Development Program of China(2018YFE0108000)+1 种基金Science and Technology Innovation Project of the Chinese Academy of Agricultural Sciences(CAAS-ZDRW202105)China Agriculture Research System of MOF and MARA。
文摘Pod shattering causes severe yield loss in rapeseed(Brassica napus L.)under modern agricultural practice.Identification of highly shatter-resistant germplasm is desirable for the development of rapeseed cultivars for mechanical harvesting.In the present study,an elite line OR88 with strong shatter resistance and a lignified-layer bridge(LLB)structure was identified.The LLB structure was unique to OR88 and co-segregated with high pod-shatter resistance.The LLB structure is differentiated at stage 12 of gynoecium development without any gynoecium defects.Genetic analysis showed that LLB is controlled by a single recessive gene.By BSA-Seq and map-based cloning,the resistance gene location was delimited to a0.688 Mb region on chromosome C09.Transcriptome analysis suggested Bn TCP8.C09 as the gene responsible for LLB.The expression of Bn TCP.C09 was strongly downregulated in OR88,suppressing cell proliferation in the pod valve margin.KASP markers linked to the candidate gene were developed.This pod shatter-resistant line could be used in rapeseed breeding programs by direct transfer of the gene with the assistance of the DNA markers.
基金supported by the National Natural Science Foundation of China(30871553)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(Group No.118)the Hubei Agricultural Science and Technology Innovation Center(201620000001048)。
文摘Sinapis arvensis,belonging to the genus Sinapis of the family Brassicaceae,has good agronomic characters that make it a valuable genetic resource for crop improvement and is a cytoplasmic source of heterologous cytoplasmic male sterility(CMS).In addition,S.arvensis has played an important role in the evolution of the six major cultivated Brassica species involved in the triangle of U.Using next-generation sequencing,we assembled and revealed the gene composition of S.arvensis cytoplasmic genome.The chloroplast genome comprises 153,590 bp,with 112 individual genes,including 4 r RNA,29 t RNA,and 79 proteincoding genes.The mitochondrial genome comprises 240,024 bp,with 54 genes,including 18 t RNA,three r RNA and 33 protein-coding genes.Genome structure and evolutionary analysis indicated that the sequences of the S.arvensis organellar genomes were more similar to those of Brassica nigra and B.carinata than to those of other Brassicaceae species.Four mitochondrial open reading frames displaying chimeric structural features and encoding hypothetical proteins with transmembrane domains may account for the infertility of Nsa CMS previously derived from somatic cell hybridization between B.napus and S.arvensis.These results will not only contribute to utilize the germplasm resource of S.arvensis,and comprehend the evolution of organelle genomes within the Brassicaceae family,but also help to identify genes conditioning the alloplasmic male sterility of Nsa CMS in B.napus.
基金supported by National Natural Science Foundation of China(No.31471535, 31771842)the Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences(Group No.118)+1 种基金the Earmarked Fund for China Agriculture Research System (CARS-13)Hubei Agricultural Science and Technology Innovation Center
文摘Branch angle is an important plant architecture trait and is considerably important for the ideal plant architecture of high density cultivation of rapeseed. In this study,12 representative rapeseed lines were first measured for whole-plant branch angles using image processing technology. Top branch angle (TBA) and basal branch angle (BBA) were significantly different in each line in which TBA was greater than BBA. Then, 156 rapeseed germplasm lines were evaluated for TBA and BBA in main cultivated regions of the Yangtze River Basin (Zunyi; Wuhan; Lu'an). In these three environments, the TBA and BBA of the rapeseed germplasm sources varied, in which ranges of 33.44°-73.17°and 18.73°-59.11°, 29.66°-61.91°and 22.32°-60.16°, and 28.47°-76.32°and 22.98°-72.68°, respectively. ANOVA showed that TBA and BBA were susceptible to environmental and had broadsense heritability (H2) values of 89.09%and 87.40%, respectively. Interactions of genotype by environment were also significant. There was diversity in branch angle among rapeseed genotypes. GGE biplot analysis showed that compact accession lines (Nilla, Purler and AV-SAPPHI) were the most desirable compact genotypes in all environments. Stability analysis showed that the genotype with the most minimum branch angle was stable for compact plant architecture.
基金Independent Application Project of Agricultural and Social Development Scientific Research in Hangzhou(20191203B31).
文摘[Objectives]To explore the antimicrobial and antioxidant activities of flavonoid and polysaccharide extracts from bulbs of Lycoris aurea.[Methods]The disc diffusion method was used to evaluate the antimicrobial activity of flavonoid and polysaccharide extracts from the bulbs of L.aurea.The antioxidant activity was determined by scavenging of hydroxyl and 1,1-diphenyl-2-picrylhydrazine(DPPH)free radicals,and reducing ability.[Results]Flavonoids were effective on 7 microorganisms,but polysaccharides had no effect.Flavonoids had better hydroxyl free radical scavenging activity and reducing capacity than polysaccharides,but weaker than ascorbic acid.However,flavonoids had similar DPPH free radical activity to ascorbic acid.The strong antibacterial and antioxidant activities of flavonoids were mainly attributed to the high content of total phenols in the extract,which was(76.71±4.42)mg/g.[Conclusions]The study shows that flavonoids from bulbs of L.aurea could be regarded as a new potential source of natural bacterial inhibitors and antioxidants.
基金supported by the National Key Research and Development Program of China(2016YFD0101300)the Natural Science Foundation of China(30871553)+3 种基金the Fundamental Research Funds for Central Non-profit Scientific Institution(1610172017005)the Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences(Group No.118)the Hubei Agricultural Science and Technology Innovation Center(201620000001048)the Earmarked Fund for China Agriculture Research System(CARS-12).
文摘Plant organelle(plastid and mitochondrial)genomes contain substantial information for plant evolution and adaptation.Therefore,it’s important to reveal plant whole-genome sequences including plastid and mitochondrial genomes.To decode these sequences,it is required to efficiently separate organelle genomic DNA from nucleus genome,which is difficult and laborious.In this study,an efficient procedure was established to obtain plant organelle genomes without extraction of plastid and mitochondria.Organelle DNA was extracted from three materials including Sinapis arvensis var.‘Yeyou 18’,a cytoplasmic male sterile line(Nsa CMS)and its corresponding maintainer line‘Zhongshuang 4’.DNA was sequenced by Roche 454 FLXt and Illumina Miseq platforms.Organelle genomes were assembled using the generated reads and public organelle genome sequences.This research presented a procedure that efficiently assembled organelle genomes and subsequent fill gaps by extending the consensus contig terminals.This method enabled us to assemble plant plastid and mitochondrial genomes simultaneously.The obtained organelle genomes could accelerate understanding of mitochondrial rearrangements and laid a foundation for further study of Sinapis arvensis evolution and sterility gene of Nsa CMS.
基金supported by the National Key Research and Development Program of China(No.2016YFD0101300)the Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences(Group No.118)+1 种基金the Earmarked Fund for China Agriculture Research System(CARS-12)Hubei Agricultural Science and Technology Innovation Center(201620000001048)
文摘Effective silique number per plant(ESN), seeds per silique(SS), thousand seeds weight(TSW), silique length(SL) and silique density(SD) are important seed yield potential determinant traits in rapeseed(Brassica napus L.), which are controlled by quantitative trait loci(QTL). Mapping QTL to delimited chromosomal region offers an effective method for genetic dissection of these traits. A set of 96 double haploid(DH) lines were developed by crossing 2 Brassica napus lines R1 and R2, and an immortalized F_2(IF_2) population containing 124 combinations was developed by crossing those DH lines. DH populations were planted at 2 locations for 2 years and IF_2 populations were planted in 2 locations for 1 year. Based on the established 2,217.2 cM length high density genetic map, 42 QTLs were identified, with 26 QTLs detected repeatedly in different environments or populations, including 8 for SL, 7 for TSW, 4 for ESN, 4 for SS and 3 for SD. Among these identified QTLs, 3, 4, 1, 1 and 3 QTLs were considered as major QTLs for SL, TSW, ESN, SS and SD, respectively. In addition, 2 QTLs on A9 chromosome which control multiple traits were identified. These results warrant further study of fine mapping for yield and yield components.
基金This research was supported by the National Basic Research Program of China （ 973 Program, 2011CB109302）；the National High - Tech R＆D Pro-gram of China （863 Program, 2011AA10A104, 2012AA101107） ； Natural Science Foundation of Hu-bei Province （2015CFA103） ； Hubei Agricultural Science and Technology Innovation Center.
基金the National Natural Science Foundation of China (No. 22071001)The Research Culture Funds of Anhui Normal UniversityDepartment of Human Resources of Anhui Province for financial support。
文摘A novel method for HDDA-derived benzyne trapped by nitrone was developed. This research described a simple and efficient pathway for the synthesis of benzisoxazoles from arynes and PTIO(2-phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl), C-C and C-O bonds were formed in a single step without catalyst under mild conditions. The unexpected cleavage of C-N bond contributed to the formation of isoxazole ring, as indicated by DFT studies. Furthermore, we obtained the structure of benzoxazolopyrrolidine when the trapping agent is DMPO(5,5-dimethyl-1-pyrroline N-oxide).
基金supported by the Fundamental Research Funds for the Central Universities,China(No.172220173)
文摘Xiao et al.(2017)在对比分析4个语料库的基础上,提出国内小学六年级学生的识词率增长不能令人满意的观点,建议人教版小学英语通用教材总词汇在原有726个的基础上再增加903个,并删除twelfth(序数词,第十二)这样的低频词。作为外语教师和语言学家,我们赞同他们应用先进信息技术对传统词表进行评估的做法,但认为这项工作:1.在构建参考语料库时需重视语料抽样的合理性;2.在解读词频时需重视齐夫定律(Zipf’s law,即英语词频与词秩成反比)的作用——识字率增长随词汇量增加而减缓的情况是合理的;3.在提出教材选词策略时,需考虑小学生认知特点和课业负担等现实因素限制,以及语言教育的总体目标,不能随便删除twelfth这样承载文化的词汇;4.学龄儿童全国通用外语教材编写是项复杂的系统工程,需要各领域专家共同关注。
基金supported by the National Natural Science Foundation of China(No.21575066)the Technology Foundation for Selected Overseas Scholar in Nanjing
文摘A novel poly(ethyleneimine)/Au nanoparticles/hemin nanocomposite(PEI-AuNPs-Hemin)acting for Methyl Orange(MO) removal has been synthesized. PEI-AuNPs was prepared firstly and it was then linked to hemin through the coupling between carboxyl groups in hemin and amino groups in PEI without the activation of carboxyl groups. The high reactivity and stability of AuNPs contributed greatly in the formation of the amido bonds in the nanocomposite. Fourier transform infrared spectroscopy, transmission electron microscopy and UV–visible spectroscopy were used to characterize the PEI-AuNPs-Hemin.Results show that PEI-AuNPs-Hemin has strong adsorption for MO. Adsorption and degradation experiments were carried out at different p Hs, nanocomposite concentrations and UV irradiation times. Removal of MO in acidic solutions was more effective than in basic solutions. The real-time study showed that the MO degradation with the nanocomposite under UV irradiation was a fast process. In addition, the photocatalytic degradation mechanism was proposed. The study suggests that the PEI-AuNPs-Hemin may have promising applications in environmental monitoring and protection.
基金the National Natural Science Foundation of China(Nos.21572002,21272005)The Research Culture Funds of Anhui Normal UniversityDepartment of Human Resources of Anhui Province for financial support。
文摘This study presents a facile strategy for the formation of highly substituted butterfly 1,4-adducts/9,10-adducts via the Diels-Alder reaction of benzyne intermediates.The method achieves very good to excellent yields of the respective anthracene derivative s under mild conditions.This practical protocol is compatible with a variety of sensitive functional groups and provides access to difunctionalized bridge 1,4-adducts/9,10-adducts.
基金This work was funded by the Research&Development Projects in Key Areas of Guangdong Province,China(2019B010933001)the National Natural Science Foundation of China(21974033,21904026)+1 种基金the National Basic Research Program of China(973 Program,2017YFE0197900)the Innovation Training Program for College Students of Guangzhou University(CX2019185).
文摘A knowledge of the adsorption and desorption behavior of sorbates on surface adsorptive site(SAS)is the key to optimizing the chemical reactivity of catalysts.However,direct identification of the chemical reactivity of SASs is still a challenge due to the limitations of characterization techniques.Here,we present a new pathway to determine the kinetics of adsorption/desorption on SASs of graphene oxide(GO)based on total internal reflectance fluorescence microscopy.The switching on and off of the fluorescent signal of SAS lit by carbon dots(CDs)was used to trace the adsorption process and desorption process.We find that sodium pyrophosphate(PPi)could increase the adsorption equilibrium of CDs thermodynamically and promote the substrate-assisted desorption pathway kinetically.At the single turnover level,it was disclosed that the species that can promote desorption may also be an adsorption promoter.Such discovery provides significant guidance for improving the chemical reactivity of the heterogeneous catalyst.
