The soil-resident pathogen, Plasmodiophora brassicae, infects cruciferous crops, causing obligate parasitic clubroot disease and posing a significant threat to the Brassica vegetable industry in China. To learn more a...The soil-resident pathogen, Plasmodiophora brassicae, infects cruciferous crops, causing obligate parasitic clubroot disease and posing a significant threat to the Brassica vegetable industry in China. To learn more about its pathogenesis, we reported a Nanopore sequencing-derived25.3 Mb high-quality genome sequence of P. brassicae pathotype 4 strain(P.b 4). Comparing the P.b 4 genome with that of the published P.brassicae e3 genome(P.b e3) identified single nucleotide polymorphisms, structural variations, and small insertions and deletions. We then carried out RNA-sequencing of root samples from a clubroot-susceptible line at 5, 14, and 28 days after inoculation(DAI), and classified genes into five categories based on their expression patterns. Interestingly, 158 genes were highly expressed at 14 DAI, which were enriched in budding cell isotropic bud growth, ascospore wall assembly, spore wall assembly, spore wall biogenesis, and ascospore wall biogenesis.Subsequently, we bioinformatically predicted 555 secreted effector candidates, among which only 125 were expressed during infection and had amino acid lengths less than 400. The putative effector Pb010018, which was highly expressed at 14 DAI, was validated to have a signal peptide using a yeast secretion system. Luciferase activity and co-immunoprecipitation assays demonstrated that Pb010018 interacts with serine hydroxymethyltransferase BrSHMT1, and expression analysis showed that SHMT1 was upregulated in both Arabidopsis and B. rapa during infection. Furthermore, after infection, the Arabidopsis shmt1 mutant(atshmt1) showed reduced severity of clubroot disease, together with downregulated expression of Pb010018. Our results offer new insights into plant-pathogen interaction mechanisms, and provide the possibility for improving Brassica resistance to clubroot disease.展开更多
Toxic arsenic(As)and trace element selenium(Se)are transformed by microorganisms but their complex interactions in soil-plant systems have not been fully understood.An Asand Se-oxidizing bacterium,Agrobacterium sp.T3F...Toxic arsenic(As)and trace element selenium(Se)are transformed by microorganisms but their complex interactions in soil-plant systems have not been fully understood.An Asand Se-oxidizing bacterium,Agrobacterium sp.T3F4,was applied to a native seleniferous As-polluted soil to investigate As/Se uptake by the vegetable Brassica rapa L.and As-Se interaction as mediated by strain T3F4.The Se content in the aboveground plants was significantly enhanced by 34.1%,but the As content was significantly decreased by 20.5% in the T3F4-inoculated pot culture compared to the control(P<0.05).Similar result was shown in treatment with additional 5 mg/kg of Se(IV)in soil.In addition,the As contents in roots were significantly decreased by more than 35% under T3F4 or Se(IV)treatments(P<0.05).Analysis of As-Se-bacterium interaction in a soil simulation experiment showed that the bioavailability of Se significantly increased and As was immobilized with the addition of the T3F4strain(P<0.05).Furthermore,an As/Se co-exposure hydroponic experiment demonstrated that As uptake and accumulation in plants was reduced by increasing Se(IV)concentrations.The 50% growth inhibition concentration(IC50)values for As in plants were increased about one-fold and two-fold under co-exposure with 5 and 10μmol/L Se(IV),respectively.In conclusion,strain T3F4 improves Se uptake but decreases As uptake by plants via oxidation of As and Se,resulting in decrease of soil As bioavailability and As/Se competitive absorption by plants.This provides a potential bioremediation strategy for Se biofortification and As immobilization in As-polluted soil.展开更多
Properly regulated flowering time is pivotal for successful plant reproduction.The floral transition from vegetative growth to reproductive growth is regulated by a complex gene regulatory network that integrates envi...Properly regulated flowering time is pivotal for successful plant reproduction.The floral transition from vegetative growth to reproductive growth is regulated by a complex gene regulatory network that integrates environmental signals and internal conditions to ensure that flowering takes place under favorable conditions.Brassica rapa is a diploid Cruciferae species that includes several varieties that are cultivated as vegetable or oil crops.Flowering time is one of the most important agricultural traits of B.rapa crops because of its influence on yield and quality.The transition to flowering in B.rapa is regulated by several environmental and developmental cues,which are perceived by several signaling pathways,including the vernalization pathway,the autonomous pathway,the circadian clock,the thermosensory pathway,and gibberellin(GA)signaling.These signals are integrated to control the expression of floral integrators BrFTs and BrSOC1s to regulate flowering.In this review,we summarized current research advances on the molecular mechanisms that govern flowering time regulation in B.rapa and compare this to what is known in Arabidopsis.展开更多
Turnip mosaic virus(TuMV)constitutes one of the primary diseases affecting Brassica rapa,severely impacting its production and resulting in crop failures in various regions worldwide.Recent research has demonstrated t...Turnip mosaic virus(TuMV)constitutes one of the primary diseases affecting Brassica rapa,severely impacting its production and resulting in crop failures in various regions worldwide.Recent research has demonstrated the significance of plant translation initiation factors,specifically the eIF4E and eIF4G family genes,as essential recessive disease resistance genes.In our study,we conducted evolutionary and gene expression studies,leading us to identify e IF(iso)4E.c as a potential TuMV-resistant gene.Leveraging CRISPR/Cas9 technology,we obtained mutant B.rapa plants with edited eIF(iso)4E.c gene.We confirmed eIF(iso)4E.c confers resistance against TuMV through phenotypic observations and virus content evaluations.Furthermore,we employed ribosome profiling assays on eif(iso)4e.c mutant seedlings to unravel the translation landscape in response to TuMV.Interestingly,we observed a moderate correlation between the fold changes in gene expression at the transcriptional and translational levels(R^(2)=0.729).Comparative analysis of ribosome profiling and RNA-seq data revealed that plant-pathogen interaction,and MAPK signaling pathway-plant pathways were involved in eIF(iso)4E.c-mediated TuMV resistance.Further analysis revealed that sequence features,coding sequence length,and normalized minimal free energy,influenced the translation efficiency of genes.Our study highlights that the loss of e IF(iso)4E.c can result in a highly intricate translation mechanism,acting synergistically with transcription to confer resistance against TuMV.展开更多
The Lateral Organ Boundaries Domain(LBD)genes encode highly conserved plant-specific LOB domain proteins which regulate growth and development in various species.However,members of the LBD gene family have yet to be i...The Lateral Organ Boundaries Domain(LBD)genes encode highly conserved plant-specific LOB domain proteins which regulate growth and development in various species.However,members of the LBD gene family have yet to be identified in Brassica rapa var.rapa.In the present study,fifty-nine LBD genes were identified and distributed on 10 chromosomes.The BrrLBD proteins are predicted to encode hydrophobic polypeptides between 118 and 394 amino acids in length and with molecular weights ranging from 13.31 to 44.24 kDa;the theoretical pi for these proteins varies from 4.83 to 9.68.There were 17 paralogous gene pairs in the BrrLBD family,suggesting that the amplification of the BrrLBD gene family involved largescale gene duplication events.Members of the BrrLBD family were divided into 7 subclades(class I a to e,class II a and b).Analysis of gene structure and conserved domains revealed that most BrrLBD genes of the same subclade had similar gene structures and protein motifs.The expression profiles of 59 BrrLBD genes were determined through Quantitative Real-time fluorescent PCR(qRT-PCR).Most BrrLBD genes in the same subclade had similar gene expression profiles.However,the expression patterns of 7 genes differed from their duplicates,indicating that although the gene function of most BrrLBD genes has been conserved,some BrrLBD genes may have undergone evolutionary change.展开更多
[Objective] The research aimed to study antifeedant activity of Phytolacca acinosa Roxb., Setaria viridis （L.） Beauv and Viola yedoensis Makino extracts against Pieris rapae. [Method] Activity material was extracted...[Objective] The research aimed to study antifeedant activity of Phytolacca acinosa Roxb., Setaria viridis （L.） Beauv and Viola yedoensis Makino extracts against Pieris rapae. [Method] Activity material was extracted from S. viridis （L.）, P. acinosa and V. yedoensis using acetone cold soak method, and non-selective antifeedant activity of extracts to Pieris rapae larva was determined by using lobular plate addition method. [Result] The results showed that the acetone leaching agent of P. acinosa had most obvious antifeedant effects on Pieris rapae. The antifeedant rate were 74.53% and 82.34% at 24 and 48 h respectively. With the concentration increasing, the antifeedant effect of P. acinosa extracts increased. The antifeedant rate of 0.050 g/ml treatment was the highest, being 74.53% and 82.34% at 24 and 48 h. [Conclusion] P. acinosa could be studied and utilized as potential botanical insecticide.展开更多
Polyploidy is pursued in plant breeding programs due mainly to its ability to yield larger vegetative or reproductive organs. In controlled growth chamber experiments, a tetraploid turnip （cv. Aijiaohuang, 4n） and i...Polyploidy is pursued in plant breeding programs due mainly to its ability to yield larger vegetative or reproductive organs. In controlled growth chamber experiments, a tetraploid turnip （cv. Aijiaohuang, 4n） and its diploid progenitor （cv. Aijiaohuang, 2n） were evaluated for their tolerance to salinity stress via investigations on a group of physiological parameters. The results indicate that the tetraploid turnip exhibit better adaptation to a high concentration salt medium （200 mmol L-1）, as evidenced by a less-affected germination rate and a healthier morphological appearance at the seedling stage. Furthermore, an extension of salinity stress up to a certain period of time at the 5-7-leaf stage shows differences between the tetraploid turnip and its diploid progenitor. The former had a higher K＋/Na＋ ratio in the roots, higher glutathione concentration and antioxidant activities in the leaves, and smaller reductions in photosynthetic capacity in terms of leaf chlorophyll content. Studies on the differences between an autopolyploid and its respective relative, from which the autopolyploid originated, in terms of their tolerance to salinity and/or other abiotic stresses, have remained rather limited. The comparison is interesting due to a homogenous genetic background.展开更多
目的:探讨抗人骨肉瘤人源化单链抗体(OS-mhscFv)联合雷帕霉素(RAPA)对人骨肉瘤MG-63细胞凋亡及HIF-1α、VEGF、MMP-2表达的影响及其作用机制。方法:将人骨肉瘤MG-63细胞分为生理盐水组、OS-mhscFv组、RAPA组和OSmhscFv+RAPA联合组,应用...目的:探讨抗人骨肉瘤人源化单链抗体(OS-mhscFv)联合雷帕霉素(RAPA)对人骨肉瘤MG-63细胞凋亡及HIF-1α、VEGF、MMP-2表达的影响及其作用机制。方法:将人骨肉瘤MG-63细胞分为生理盐水组、OS-mhscFv组、RAPA组和OSmhscFv+RAPA联合组,应用流式细胞仪检测OS-mhscFv联合RAPA对MG-63细胞凋亡的影响;应用Real time PCR法检测4组细胞中HIF-1α、VEGF、MMP-2的mRNA表达量。结果:与生理盐水组和单独给药组比较,OS-mhscFv+RAPA联合组能诱导MG-63细胞的凋亡,差异有统计学意义(P<0.01)。OS-mhscFv+RAPA联合组MG-63细胞中HIF-1α、VEGF、MMP-2的mRNA相对表达量均显著低于单独用药组和生理盐水组,差异有统计学意义(P<0.01)。结论:OS-mhscFv联合RAPA能够有效诱导MG-63细胞凋亡,其诱导机制可能是通过下调HIF-1α、VEGF、MMP-2的mRNA表达量完成。展开更多
In higher plants,sugars(mainly sucrose)are produced by photosynthetically assimilated carbon in mesophyll cells of leaves and translocated to heterotrophic organs to ensure plant growth and devel-opment.Sucrose transp...In higher plants,sugars(mainly sucrose)are produced by photosynthetically assimilated carbon in mesophyll cells of leaves and translocated to heterotrophic organs to ensure plant growth and devel-opment.Sucrose transporters,or sucrose carriers(SUCs),play an important role in the long-distance transportation of sucrose from source organs to sink organs,thereby affecting crop yield and quality.The identification,characterization,and molecular function analysis of sucrose transporter genes have been reported for monocot and dicot plants.However,no relevant study has been reported on sucrose transporter genes in Brassica rapa vat.rapa,a cruciferous root crop used mainly as vegetables and fodder.We identified and cloned 12 sucrose transporter genes from turnips,named BrrSUC1.1 to BrrSUCB.2 according to the SUC gene sequences of B.rapa pekinensis.We constructed a phylogenetic tree and analyzed conserved motifs for all 12 sucrose transporter genes identified.Real-time quantitative poly-merase chain reaction was conducted to understand the expression levels of SUC genes in different tissues and developmental phases of the turnip.These findings add to our understanding of the genetics and physiology of sugar transport during taproot formation in turnips.展开更多
A molecular genetic map of Chinese cabbage was constructed with a 102 recombinant inbred (RI) population from a cross of two cultivated Chinese cabbage lines 177 and 276, using AFLP and RAPD markers. 352 markers inclu...A molecular genetic map of Chinese cabbage was constructed with a 102 recombinant inbred (RI) population from a cross of two cultivated Chinese cabbage lines 177 and 276, using AFLP and RAPD markers. 352 markers including 265 AFLP markers and 87 RAPD markers were integrated into 17 linkage groups. It covered a total of 2 665. 7 cM with an average interval of 7. 6 cM. AFLP marker is efficient for map construction while it easily forms clusters to cause big gaps in map. A total of 13.92 % abnormal segregation markers distributed in the map. The molecular genetic map is fundamental for gene localization, comparative genomics, and QTL mapping of important agronomic traits.展开更多
8-Sphingolipid desaturase is the key enzyme that catalyses desaturation at the C8 position of the long-chain base of sphingolipids in higher plants. There have been no previous studies on the genes encoding AS-sphingo...8-Sphingolipid desaturase is the key enzyme that catalyses desaturation at the C8 position of the long-chain base of sphingolipids in higher plants. There have been no previous studies on the genes encoding AS-sphingolipid desaturases in Brassica rapa. In this study, four genes encoding AS-sphingolipid desaturases from B. rapa were isolated and characterised. Phylogenetic analyses indicated that these genes could be divided into two groups： BrD8A, BrD8C and BrD8D in group I, and BrD8B in group II. The two groups of genes diverged before the separation of Arabidopsis and Brassica. Though the four genes shared a high sequence similarity, and their coding desaturases all located in endoplasmic reticulum, they exhibited distinct expression patterns. Heterologous expression in Saccharomyces cerevisiae revealed that BrD8A/B/C/D were functionally diverse AS-sphingolipid desaturases that catalyse different ratios of the two products 8（Z）- and 8（E）-C18-phytosphingenine. The aluminium tolerance of transgenic yeasts expressing BrD8A/B/C/D was enhanced compared with that of control cells. Expression of BrD8A in Arabidopsis changed the ratio of 8（Z）：8（E）-C 18-phytosphingenine in transgenic plants. The information reported here provides new insights into the biochemical functional diversity and evolutionary relationship of AS-sphingolipid desaturase in plants and lays a foundation for further investigation of the mechanism of 8（Z）- and 8（E）-C18- phytosphingenine biosynthesis.展开更多
Parasitism by the endoparasitoid wasp Pteromalus puparum causes alterations in the plasma proteins of Pieris rapae. Analysis of plasma proteins using a proteomic approach showed that seven proteins were differentially...Parasitism by the endoparasitoid wasp Pteromalus puparum causes alterations in the plasma proteins of Pieris rapae. Analysis of plasma proteins using a proteomic approach showed that seven proteins were differentially expressed in the host pupae after 24-h parasitism. They were masquerade-like serine proteinase homolog (MSPH), enolase (Eno), bilin-binding protein (BBP), imaginal disc growth factor (IDGF), ornithine decarboxylase (ODC), cellular retinoic acid binding protein (CRABP), and one unknown function protein. The full length cDNA sequences of MSPH, Eno, and BBP were successfully cloned using rapid amplification of cDNA ends-polymerase chain reaction (RACE-PCR). Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis indicated that the transcript levels of MSPH and BBP in the fat bodies of host pupae were inducible in response to the parasitism and their variations were consistent with translational changes of these genes after parasitism, while the transcript levels of Eno and IDGF were not affected by parasitism. This study will contribute to the better understanding of the molecular bases of parasitoid-induced host alterations associated with innate immune responses, detoxification, and energy metabolism.展开更多
As a part of the Multinational Genome Sequencing Project of Brassica rapa, linkage group R9 and R3 were sequenced using a bacterial artificial chromosome （BAC） by BAC strategy. The current physical contigs are expec...As a part of the Multinational Genome Sequencing Project of Brassica rapa, linkage group R9 and R3 were sequenced using a bacterial artificial chromosome （BAC） by BAC strategy. The current physical contigs are expected to cover approximately 90% euchromatins of both chromosomes. As the project progresses, BAC selection for sequence extension becomes more limited because BAC libraries are restriction enzyme-specific. To support the project, a random sheared fosmid library was constructed. The library consists of 97536 clones with average insert size of approximately 40 kb corresponding to seven genome equivalents, assuming a Chinese cabbage genome size of 550 Mb. The library was screened with primers designed at the end of sequences of nine points of scaffold gaps where BAC clones cannot be selected to extend the physical contigs. The selected positive clones were end-sequenced to check the overlap between the fosmid clones and the adjacent BAC clones. Nine fosmid clones were selected and fully sequenced. The sequences revealed two completed gap filling and seven sequence extensions, which can be used for further selection of BAC clones confirming that the fosmid library will facilitate the sequence completion of B. rapa.展开更多
Simple sequence repeat （SSR） or microsatellite marker is a valuable tool for several purposes, such as mapping, fingerprinting, and breeding. In the present study, an intersimple sequence repeat （ISSR）-PCR techniq...Simple sequence repeat （SSR） or microsatellite marker is a valuable tool for several purposes, such as mapping, fingerprinting, and breeding. In the present study, an intersimple sequence repeat （ISSR）-PCR technique was applied for developing SSR markers in non-heading Chinese cabbage （Brassica rapa）. A total of 190 SSRs were obtained. Among these, AG or CT （54.7%） was the most frequent repeat, followed by AC or GT （31.6%） of the microsatellites. The average number of the SSRs length array was 16 and 10 times, respectively. Based on the determined SSR sequences, 143 SSR primer pairs were designed to evaluate their transferabilities among the related species of Brassica. The number of alleles produced per marker averaged 2.91, and the polymorphism information content （PIC） value ranged from 0 to 0.863 with an average of 0.540. Monomorphism was observed in 16 primer pairs. The transferability percentage in CC genome was higher than in BB genome. More loci occurred in the BBCC genome. This result supported the hypothesis that BB genome was divergent from A and C genomes, and AA and CC genomes were relatively close. The polymorphic primers can be exploited for further evolution, fingerprinting, and variety identification.展开更多
We obtained two lines of Chinese head cabbage(Brassica rapa L. ssp. pekinensis)selfed progenies containing both an anti-sense gene of BcpLH and a gene for resistance to kanamycin by micro-injecting buds of their prima...We obtained two lines of Chinese head cabbage(Brassica rapa L. ssp. pekinensis)selfed progenies containing both an anti-sense gene of BcpLH and a gene for resistance to kanamycin by micro-injecting buds of their primary transformants(T0)with Agrobacterium tumefaciens strain LBA4404. 31 positive plants resistant to kanamycien were recovered. Southern blot analysis confirmed the presence of T-DNA in two transgenic plants. One(DHZ-13-1)exhibits the characteristics of out-toward rosette and cauline leaves, and nested flower model in which secondary complete flower developed from the base of the primary ovary and the third flower from the ovary in the secondary flower, and so on, while another(DHZ-6-1)has no phenotype change. ABA and IAA affected the root growth of progeny of DHZ-13-1, but 6-BA was insensitive to hypocotyl growth during its seedling development.展开更多
基金supported by the Youth Foundation of Beijing Academy of Agriculture and Forestry Sciences[Grant No.QNJJ202242]the Excellent Young Scholars of Beijing Academy of Agriculture and Forestry Sciences[Grant No.YXQN202205]+3 种基金the Beijing Nova Program[Grant No.20220484052]the National Natural Science Foundation of China[Grant No.31801852]the Collaborative Innovation Center of Beijing Academy of Agriculture and Forestry Sciences[Grant No.KJCX201907-2]the Earmarked Fund for China Agriculture Research System[Grant No.CARS-23-A-05].
文摘The soil-resident pathogen, Plasmodiophora brassicae, infects cruciferous crops, causing obligate parasitic clubroot disease and posing a significant threat to the Brassica vegetable industry in China. To learn more about its pathogenesis, we reported a Nanopore sequencing-derived25.3 Mb high-quality genome sequence of P. brassicae pathotype 4 strain(P.b 4). Comparing the P.b 4 genome with that of the published P.brassicae e3 genome(P.b e3) identified single nucleotide polymorphisms, structural variations, and small insertions and deletions. We then carried out RNA-sequencing of root samples from a clubroot-susceptible line at 5, 14, and 28 days after inoculation(DAI), and classified genes into five categories based on their expression patterns. Interestingly, 158 genes were highly expressed at 14 DAI, which were enriched in budding cell isotropic bud growth, ascospore wall assembly, spore wall assembly, spore wall biogenesis, and ascospore wall biogenesis.Subsequently, we bioinformatically predicted 555 secreted effector candidates, among which only 125 were expressed during infection and had amino acid lengths less than 400. The putative effector Pb010018, which was highly expressed at 14 DAI, was validated to have a signal peptide using a yeast secretion system. Luciferase activity and co-immunoprecipitation assays demonstrated that Pb010018 interacts with serine hydroxymethyltransferase BrSHMT1, and expression analysis showed that SHMT1 was upregulated in both Arabidopsis and B. rapa during infection. Furthermore, after infection, the Arabidopsis shmt1 mutant(atshmt1) showed reduced severity of clubroot disease, together with downregulated expression of Pb010018. Our results offer new insights into plant-pathogen interaction mechanisms, and provide the possibility for improving Brassica resistance to clubroot disease.
基金supported by the National Natural Science Foundation of China(No.41771283)"Longyun Program"of the College of Life Science and Technology of Huazhong Agricultural University。
文摘Toxic arsenic(As)and trace element selenium(Se)are transformed by microorganisms but their complex interactions in soil-plant systems have not been fully understood.An Asand Se-oxidizing bacterium,Agrobacterium sp.T3F4,was applied to a native seleniferous As-polluted soil to investigate As/Se uptake by the vegetable Brassica rapa L.and As-Se interaction as mediated by strain T3F4.The Se content in the aboveground plants was significantly enhanced by 34.1%,but the As content was significantly decreased by 20.5% in the T3F4-inoculated pot culture compared to the control(P<0.05).Similar result was shown in treatment with additional 5 mg/kg of Se(IV)in soil.In addition,the As contents in roots were significantly decreased by more than 35% under T3F4 or Se(IV)treatments(P<0.05).Analysis of As-Se-bacterium interaction in a soil simulation experiment showed that the bioavailability of Se significantly increased and As was immobilized with the addition of the T3F4strain(P<0.05).Furthermore,an As/Se co-exposure hydroponic experiment demonstrated that As uptake and accumulation in plants was reduced by increasing Se(IV)concentrations.The 50% growth inhibition concentration(IC50)values for As in plants were increased about one-fold and two-fold under co-exposure with 5 and 10μmol/L Se(IV),respectively.In conclusion,strain T3F4 improves Se uptake but decreases As uptake by plants via oxidation of As and Se,resulting in decrease of soil As bioavailability and As/Se competitive absorption by plants.This provides a potential bioremediation strategy for Se biofortification and As immobilization in As-polluted soil.
基金supported by National Natural Science Foundation of China(Grant Nos.32372733,32172594)Natural Science Foundation of Hebei(Grant No.C2020204111)+2 种基金S&T Program of Hebei(Grant No.21326344D)State Key Laboratory of North China Crop Improvement and Regulation(Grant No.NCCIR2023ZZ-1)the Starting Grant from Hebei Agricultural University(Grant No.YJ201920).
文摘Properly regulated flowering time is pivotal for successful plant reproduction.The floral transition from vegetative growth to reproductive growth is regulated by a complex gene regulatory network that integrates environmental signals and internal conditions to ensure that flowering takes place under favorable conditions.Brassica rapa is a diploid Cruciferae species that includes several varieties that are cultivated as vegetable or oil crops.Flowering time is one of the most important agricultural traits of B.rapa crops because of its influence on yield and quality.The transition to flowering in B.rapa is regulated by several environmental and developmental cues,which are perceived by several signaling pathways,including the vernalization pathway,the autonomous pathway,the circadian clock,the thermosensory pathway,and gibberellin(GA)signaling.These signals are integrated to control the expression of floral integrators BrFTs and BrSOC1s to regulate flowering.In this review,we summarized current research advances on the molecular mechanisms that govern flowering time regulation in B.rapa and compare this to what is known in Arabidopsis.
基金supported by grants from the Scientist Training Program of BAAFS (Grant No.JKZX202406)the Innovation and Capacity-Building Project of BAAFS (Grant No.KJCX20230221)+2 种基金Collaborative innovation program of the Beijing Vegetable Research Center (Grant No.XTCX202302)the National Natural Science Foundation of China (Grant No.32072567)the China Agriculture Research System of MOF and MARA (Grant No.CARS-A03)。
文摘Turnip mosaic virus(TuMV)constitutes one of the primary diseases affecting Brassica rapa,severely impacting its production and resulting in crop failures in various regions worldwide.Recent research has demonstrated the significance of plant translation initiation factors,specifically the eIF4E and eIF4G family genes,as essential recessive disease resistance genes.In our study,we conducted evolutionary and gene expression studies,leading us to identify e IF(iso)4E.c as a potential TuMV-resistant gene.Leveraging CRISPR/Cas9 technology,we obtained mutant B.rapa plants with edited eIF(iso)4E.c gene.We confirmed eIF(iso)4E.c confers resistance against TuMV through phenotypic observations and virus content evaluations.Furthermore,we employed ribosome profiling assays on eif(iso)4e.c mutant seedlings to unravel the translation landscape in response to TuMV.Interestingly,we observed a moderate correlation between the fold changes in gene expression at the transcriptional and translational levels(R^(2)=0.729).Comparative analysis of ribosome profiling and RNA-seq data revealed that plant-pathogen interaction,and MAPK signaling pathway-plant pathways were involved in eIF(iso)4E.c-mediated TuMV resistance.Further analysis revealed that sequence features,coding sequence length,and normalized minimal free energy,influenced the translation efficiency of genes.Our study highlights that the loss of e IF(iso)4E.c can result in a highly intricate translation mechanism,acting synergistically with transcription to confer resistance against TuMV.
基金This study was supported by the Major Program of National Natural Science Foundation of China,China(31590820 and 31590823)the National Natural Science Foundation of China,China(41771123 and 31400244)the Natural Science Foundation of Yunnan Province(2017FB050).
文摘The Lateral Organ Boundaries Domain(LBD)genes encode highly conserved plant-specific LOB domain proteins which regulate growth and development in various species.However,members of the LBD gene family have yet to be identified in Brassica rapa var.rapa.In the present study,fifty-nine LBD genes were identified and distributed on 10 chromosomes.The BrrLBD proteins are predicted to encode hydrophobic polypeptides between 118 and 394 amino acids in length and with molecular weights ranging from 13.31 to 44.24 kDa;the theoretical pi for these proteins varies from 4.83 to 9.68.There were 17 paralogous gene pairs in the BrrLBD family,suggesting that the amplification of the BrrLBD gene family involved largescale gene duplication events.Members of the BrrLBD family were divided into 7 subclades(class I a to e,class II a and b).Analysis of gene structure and conserved domains revealed that most BrrLBD genes of the same subclade had similar gene structures and protein motifs.The expression profiles of 59 BrrLBD genes were determined through Quantitative Real-time fluorescent PCR(qRT-PCR).Most BrrLBD genes in the same subclade had similar gene expression profiles.However,the expression patterns of 7 genes differed from their duplicates,indicating that although the gene function of most BrrLBD genes has been conserved,some BrrLBD genes may have undergone evolutionary change.
文摘[Objective] The research aimed to study antifeedant activity of Phytolacca acinosa Roxb., Setaria viridis （L.） Beauv and Viola yedoensis Makino extracts against Pieris rapae. [Method] Activity material was extracted from S. viridis （L.）, P. acinosa and V. yedoensis using acetone cold soak method, and non-selective antifeedant activity of extracts to Pieris rapae larva was determined by using lobular plate addition method. [Result] The results showed that the acetone leaching agent of P. acinosa had most obvious antifeedant effects on Pieris rapae. The antifeedant rate were 74.53% and 82.34% at 24 and 48 h respectively. With the concentration increasing, the antifeedant effect of P. acinosa extracts increased. The antifeedant rate of 0.050 g/ml treatment was the highest, being 74.53% and 82.34% at 24 and 48 h. [Conclusion] P. acinosa could be studied and utilized as potential botanical insecticide.
基金supported by the Special Grand National Science and Technology Project, China(2009ZX08009-076B)the Natural Science Foundation of China (30971700)the Natural Science Foundation of Zhejiang Province, China (Z3100130)
文摘Polyploidy is pursued in plant breeding programs due mainly to its ability to yield larger vegetative or reproductive organs. In controlled growth chamber experiments, a tetraploid turnip （cv. Aijiaohuang, 4n） and its diploid progenitor （cv. Aijiaohuang, 2n） were evaluated for their tolerance to salinity stress via investigations on a group of physiological parameters. The results indicate that the tetraploid turnip exhibit better adaptation to a high concentration salt medium （200 mmol L-1）, as evidenced by a less-affected germination rate and a healthier morphological appearance at the seedling stage. Furthermore, an extension of salinity stress up to a certain period of time at the 5-7-leaf stage shows differences between the tetraploid turnip and its diploid progenitor. The former had a higher K＋/Na＋ ratio in the roots, higher glutathione concentration and antioxidant activities in the leaves, and smaller reductions in photosynthetic capacity in terms of leaf chlorophyll content. Studies on the differences between an autopolyploid and its respective relative, from which the autopolyploid originated, in terms of their tolerance to salinity and/or other abiotic stresses, have remained rather limited. The comparison is interesting due to a homogenous genetic background.
文摘目的:探讨抗人骨肉瘤人源化单链抗体(OS-mhscFv)联合雷帕霉素(RAPA)对人骨肉瘤MG-63细胞凋亡及HIF-1α、VEGF、MMP-2表达的影响及其作用机制。方法:将人骨肉瘤MG-63细胞分为生理盐水组、OS-mhscFv组、RAPA组和OSmhscFv+RAPA联合组,应用流式细胞仪检测OS-mhscFv联合RAPA对MG-63细胞凋亡的影响;应用Real time PCR法检测4组细胞中HIF-1α、VEGF、MMP-2的mRNA表达量。结果:与生理盐水组和单独给药组比较,OS-mhscFv+RAPA联合组能诱导MG-63细胞的凋亡,差异有统计学意义(P<0.01)。OS-mhscFv+RAPA联合组MG-63细胞中HIF-1α、VEGF、MMP-2的mRNA相对表达量均显著低于单独用药组和生理盐水组,差异有统计学意义(P<0.01)。结论:OS-mhscFv联合RAPA能够有效诱导MG-63细胞凋亡,其诱导机制可能是通过下调HIF-1α、VEGF、MMP-2的mRNA表达量完成。
基金supported by Major Program of National Natural Science Foundation of China (31590820,31590823)
文摘In higher plants,sugars(mainly sucrose)are produced by photosynthetically assimilated carbon in mesophyll cells of leaves and translocated to heterotrophic organs to ensure plant growth and devel-opment.Sucrose transporters,or sucrose carriers(SUCs),play an important role in the long-distance transportation of sucrose from source organs to sink organs,thereby affecting crop yield and quality.The identification,characterization,and molecular function analysis of sucrose transporter genes have been reported for monocot and dicot plants.However,no relevant study has been reported on sucrose transporter genes in Brassica rapa vat.rapa,a cruciferous root crop used mainly as vegetables and fodder.We identified and cloned 12 sucrose transporter genes from turnips,named BrrSUC1.1 to BrrSUCB.2 according to the SUC gene sequences of B.rapa pekinensis.We constructed a phylogenetic tree and analyzed conserved motifs for all 12 sucrose transporter genes identified.Real-time quantitative poly-merase chain reaction was conducted to understand the expression levels of SUC genes in different tissues and developmental phases of the turnip.These findings add to our understanding of the genetics and physiology of sugar transport during taproot formation in turnips.
文摘A molecular genetic map of Chinese cabbage was constructed with a 102 recombinant inbred (RI) population from a cross of two cultivated Chinese cabbage lines 177 and 276, using AFLP and RAPD markers. 352 markers including 265 AFLP markers and 87 RAPD markers were integrated into 17 linkage groups. It covered a total of 2 665. 7 cM with an average interval of 7. 6 cM. AFLP marker is efficient for map construction while it easily forms clusters to cause big gaps in map. A total of 13.92 % abnormal segregation markers distributed in the map. The molecular genetic map is fundamental for gene localization, comparative genomics, and QTL mapping of important agronomic traits.
基金supported by the National High-tech R&D Program(863 Program,No.2006AA10A113) of the Ministry of Science and Technology of Chinathe projects of Ministry of Agriculture of China for Transgenic Research (Nos.2009ZX08009-098B and 2008ZX08009-003)
文摘8-Sphingolipid desaturase is the key enzyme that catalyses desaturation at the C8 position of the long-chain base of sphingolipids in higher plants. There have been no previous studies on the genes encoding AS-sphingolipid desaturases in Brassica rapa. In this study, four genes encoding AS-sphingolipid desaturases from B. rapa were isolated and characterised. Phylogenetic analyses indicated that these genes could be divided into two groups： BrD8A, BrD8C and BrD8D in group I, and BrD8B in group II. The two groups of genes diverged before the separation of Arabidopsis and Brassica. Though the four genes shared a high sequence similarity, and their coding desaturases all located in endoplasmic reticulum, they exhibited distinct expression patterns. Heterologous expression in Saccharomyces cerevisiae revealed that BrD8A/B/C/D were functionally diverse AS-sphingolipid desaturases that catalyse different ratios of the two products 8（Z）- and 8（E）-C18-phytosphingenine. The aluminium tolerance of transgenic yeasts expressing BrD8A/B/C/D was enhanced compared with that of control cells. Expression of BrD8A in Arabidopsis changed the ratio of 8（Z）：8（E）-C 18-phytosphingenine in transgenic plants. The information reported here provides new insights into the biochemical functional diversity and evolutionary relationship of AS-sphingolipid desaturase in plants and lays a foundation for further investigation of the mechanism of 8（Z）- and 8（E）-C18- phytosphingenine biosynthesis.
基金supported by the National Basic Research Program (973) of China (No. 2006CB102005)the National Natural Science Foundation of China (Nos. 30571251 and 30971959)+1 种基金the Zhejiang Provincial Natural Science Foundation of China (No. Z3090191)and the Program for New Century Excellent Talents in University of the Ministry of Education of China (No. NCET-05-0513)
文摘Parasitism by the endoparasitoid wasp Pteromalus puparum causes alterations in the plasma proteins of Pieris rapae. Analysis of plasma proteins using a proteomic approach showed that seven proteins were differentially expressed in the host pupae after 24-h parasitism. They were masquerade-like serine proteinase homolog (MSPH), enolase (Eno), bilin-binding protein (BBP), imaginal disc growth factor (IDGF), ornithine decarboxylase (ODC), cellular retinoic acid binding protein (CRABP), and one unknown function protein. The full length cDNA sequences of MSPH, Eno, and BBP were successfully cloned using rapid amplification of cDNA ends-polymerase chain reaction (RACE-PCR). Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis indicated that the transcript levels of MSPH and BBP in the fat bodies of host pupae were inducible in response to the parasitism and their variations were consistent with translational changes of these genes after parasitism, while the transcript levels of Eno and IDGF were not affected by parasitism. This study will contribute to the better understanding of the molecular bases of parasitoid-induced host alterations associated with innate immune responses, detoxification, and energy metabolism.
基金This work was supported by grants from the National Academy of Agricultural Science(Code #200901FHT020508369)the BioGreen21 Program(Code #20050301034438 and Code #20070301034037),Rural Development Administration, Republic of Korea
文摘As a part of the Multinational Genome Sequencing Project of Brassica rapa, linkage group R9 and R3 were sequenced using a bacterial artificial chromosome （BAC） by BAC strategy. The current physical contigs are expected to cover approximately 90% euchromatins of both chromosomes. As the project progresses, BAC selection for sequence extension becomes more limited because BAC libraries are restriction enzyme-specific. To support the project, a random sheared fosmid library was constructed. The library consists of 97536 clones with average insert size of approximately 40 kb corresponding to seven genome equivalents, assuming a Chinese cabbage genome size of 550 Mb. The library was screened with primers designed at the end of sequences of nine points of scaffold gaps where BAC clones cannot be selected to extend the physical contigs. The selected positive clones were end-sequenced to check the overlap between the fosmid clones and the adjacent BAC clones. Nine fosmid clones were selected and fully sequenced. The sequences revealed two completed gap filling and seven sequence extensions, which can be used for further selection of BAC clones confirming that the fosmid library will facilitate the sequence completion of B. rapa.
文摘Simple sequence repeat （SSR） or microsatellite marker is a valuable tool for several purposes, such as mapping, fingerprinting, and breeding. In the present study, an intersimple sequence repeat （ISSR）-PCR technique was applied for developing SSR markers in non-heading Chinese cabbage （Brassica rapa）. A total of 190 SSRs were obtained. Among these, AG or CT （54.7%） was the most frequent repeat, followed by AC or GT （31.6%） of the microsatellites. The average number of the SSRs length array was 16 and 10 times, respectively. Based on the determined SSR sequences, 143 SSR primer pairs were designed to evaluate their transferabilities among the related species of Brassica. The number of alleles produced per marker averaged 2.91, and the polymorphism information content （PIC） value ranged from 0 to 0.863 with an average of 0.540. Monomorphism was observed in 16 primer pairs. The transferability percentage in CC genome was higher than in BB genome. More loci occurred in the BBCC genome. This result supported the hypothesis that BB genome was divergent from A and C genomes, and AA and CC genomes were relatively close. The polymorphic primers can be exploited for further evolution, fingerprinting, and variety identification.
文摘We obtained two lines of Chinese head cabbage(Brassica rapa L. ssp. pekinensis)selfed progenies containing both an anti-sense gene of BcpLH and a gene for resistance to kanamycin by micro-injecting buds of their primary transformants(T0)with Agrobacterium tumefaciens strain LBA4404. 31 positive plants resistant to kanamycien were recovered. Southern blot analysis confirmed the presence of T-DNA in two transgenic plants. One(DHZ-13-1)exhibits the characteristics of out-toward rosette and cauline leaves, and nested flower model in which secondary complete flower developed from the base of the primary ovary and the third flower from the ovary in the secondary flower, and so on, while another(DHZ-6-1)has no phenotype change. ABA and IAA affected the root growth of progeny of DHZ-13-1, but 6-BA was insensitive to hypocotyl growth during its seedling development.
