Correlation analysis and principal component analysis( PCA) were conducted for some agronomic traits of 139 recombinant inbred lines of Brassica juncea L. The results showed that under the environmental conditions in ...Correlation analysis and principal component analysis( PCA) were conducted for some agronomic traits of 139 recombinant inbred lines of Brassica juncea L. The results showed that under the environmental conditions in Guiyang,the flowering time,number of seeds per silique,plant height and thousand seed weight differed significantly among different lines. The results of principal component analysis showed that the lines could be classified into three groups. The results of Pearson correlation tests showed that the plant height was positively correlated with the flowering time( P < 0. 05),and the thousand seed weight was negatively correlated with the flowering time and number of seeds per silique( P < 0. 01).展开更多
Soil salinity is one of the major environmental constraints that limits crop yield and nearly 7%of the total area worldwide is affected by salinity.Salinity-induced oxidative stress causes membrane damage during germi...Soil salinity is one of the major environmental constraints that limits crop yield and nearly 7%of the total area worldwide is affected by salinity.Salinity-induced oxidative stress causes membrane damage during germination and seedling growth.Indian mustard is a major oilseed crop in India and its production and productivity are severely affected by salt stress.Breeding Brassica cultivars for salinity tolerance by conventional means is very difficult and time-consuming.Therefore,understanding the molecular components associated with salt tolerance is needed to facilitate breeding for salt tolerance in Brassica.In this investigation,quantitative trait loci(QTLs)associated with salt tolerance were identified using F_(2:3)mapping population developed from a cross between CS52(salinity tolerant)and RH30(salinity sensitive).Parents and F_(2:3)were evaluated under controlled and salinity stress conditions for 14 morpho-physiological traits for two consecutive generations(F2 and F_(2:3)),explaining proportion of the phenotypic variance under control condition.Simple sequence repeat(SSR)markers were used for mapping studies.A genetic linkage map based on 42 simple sequence repeats(SSRs)markers was constructed covering 2298.5 cM(Haldane)to identify the loci associated with salt tolerance in Brassica juncea.Forty-one SSRs showing polymorphism in the parents(CS52 and RH30)were mapped on 8 linkage groups(C1–C8).One marker(nga 129)did not map to any of the linkage group and was excluded from mapping.Linkage group 5(C5;317.9 cM)was longest and linkage group 1(C1,255.0 cM)was shortest.Further,we identified 15 QTLs controlling 8 traits using F_(2:3)population.These QTLs explained 12.44–60.63%of the phenotypic variation with a LOD score range of 3.62–5.97.Out of these QTLs,QMI4.1 related to membrane injury showed 51.28%phenotypic variance with a LOD score of 3.34.QTL QBYP8.1 related to biological yield per plant showed 60.63%phenotypic variance at a LOD score of 3.62.The highest LOD score of 5.97 was recorded for QTL related to seed yield per plant(QSYP4.1).Major QTLs were QTL for biological yield per plant(QBYP8.1),QTL for siliquae per plant(QSP4.1),QTL for primary branches(QPB4.1),QTLs for seed per siliqua(QSS4.1,QSS4.2),QTL for seed yield per plant(QSYP4.1),and QTL for membrane injury(QMI8.1)which showed more than 50%phenotypic variance.These QTLs identified in our study need to be confirmed in other populations as well so that these can be used in marker-assisted selection and breeding to enhance salt tolerance in Brassica juncea.展开更多
Photoperiod and temperature are crucial factors that trigger flowering in Brassica juncea(B.juncea).However,the underlying regulatory mechanisms remain poorly understood.The MADS-box transcription factor AGL18 acts as...Photoperiod and temperature are crucial factors that trigger flowering in Brassica juncea(B.juncea).However,the underlying regulatory mechanisms remain poorly understood.The MADS-box transcription factor AGL18 acts as a pivotal repressor of floral transition and functions redundantly with AGL15.In this study,we isolated BjuAGL18-1 from B.juncea and identified two unique transcripts,resulting in two distinct proteins:a full-length protein,BjuAGL18-1L,and a truncated protein,BjuAGL18-1S.Further investigation showed that the two isoforms had similar subcellular localizations but different expression patterns in various plant tissues.Notably,BjuAGL18-1L and BjuAGL18-1S were abundantly induced under short-and long-day photoperiods,respectively.BjuAGL18-1L overexpression in B.juncea and Arabidopsis thaliana(A.thaliana)led to late flowering,whereas BjuAGL18-1S overexpression resulted in early flowering.Yeast two-hybrid,bimolecular fluorescent complementation,and luciferase complementation assays showed that BjuAGL18-1L,but not BjuAGL18-1S(which lacked the EAR motif),interacted with the co-repressor BjuAFR2 and the histone deacetylase BjuHDA9 to form a multiprotein complex.Further analysis indicated that BjuAGL18-1L could also form a complex with BjuAGL15 and bind to the BjuFUL promoter,thus inhibiting its expression.However,BjuAGL18-1S interacted with BjuAGL18-1L to form heterodimers,which attenuated their activities,likely by disrupting their binding to target genes,resulting in accelerated flowering progression.These results suggest that BjuAGL18-1 is involved in photoperiod-induced flowering via different regulatory mechanisms in B.juncea.展开更多
The potherb mustard Xuecai(XC)cultivar is a cruciferous vegetable that is popular either fresh or pickled.Due to the deep notches in the edges of leaves in mustard XC,this plant can be said to have multipinnately lobe...The potherb mustard Xuecai(XC)cultivar is a cruciferous vegetable that is popular either fresh or pickled.Due to the deep notches in the edges of leaves in mustard XC,this plant can be said to have multipinnately lobed leaves.The net photosynthesis of lobed leaves is significantly greater than that of simple leaves.However,the molecular mechanism of leaf shape variation has not been determined.Here,we used HiFi and Hi-C data to assemble the XC genome.The genome was 961.72 Mb in size,with a contig N50 value of 6.565 Mb.The XC genome was compared with four previously sequenced mustard genomes,and the genomic collinearity regions,SNPs,and indels were identified.Five BjRCO genes were found on chromosome(Chr.)A10 in potherb mustard XC when the BjRCO gene locus was compared against other sequenced B.juncea genomes.Segmental duplication was found to contribute to the BjRCO gene copy number.The transcript expression of BjRCO genes was greater in multipinnately lobed leaves than in sawtooth-like leaves.Together,these findings indicate that both the greater copy number and the expression level of BjRCO genes regulate leaf shape from simple to complex in B.juncea.Gene editing of the BjRCO gene from XC changed the leaf shape from multipinnately lobed to simple.The high-quality XC genome sequence not only provides new insight into B.juncea leaf-type genomics but also helps in deciphering leaf shape variation.Our study provides insights into the variation and evolution of important traits in Brassica plants through a comparative analysis of the sequenced genomes.展开更多
Elucidating crops'physiological and molecular mechanisms to adapt to low nitrogen environment and promoting nitrogen transfer from senescent leaves to new leaves is crucial in improving Brassica's nitrogen use...Elucidating crops'physiological and molecular mechanisms to adapt to low nitrogen environment and promoting nitrogen transfer from senescent leaves to new leaves is crucial in improving Brassica's nitrogen use efficiency(NUE).Glutamine synthetase gene(GS)plays a vital role in helping plants reassimilate ammonium released from protein degradation in leaves,and it was the focus of our research on this topic.In this study,we identified high(H141)and low(L65)NUE genotypes of Brassica juncea with different responses to low-nitrogen stress.We found that H141 has a lower nitrate content but higher ammonium and free amino acid contents as well as higher nitrate reductase and GS activities in the shoots.These physiological indicators are responsible for the high NUE of H141.Wholegenome resequencing data revealed that 5,880 genes associated with NUE are polymorphic between H141 and L65.These genes participate in various amino acid,carbohydrate,and energy metabolic pathways.Haplotype analysis revealed two haplotypes for BjuB05.GS1.4,Hap1 and Hap2,which have multiple single nucleotide polymorphisms or insertions/deletions in the regulatory regions of the 5′and 3′untranslated regions and introns.Furthermore,the shoot NUE of Hap1 is significantly lower than that of Hap2.These two haplotypes of BjuB05.GS1.4 lead to differences in the shoot NUEs of different genetic populations of mustard and are associated with the local soil nitrogen content,suggesting that they might help mustard to adapt to different geographic localities.In conclusion,the results of our study shed light on the physiological and molecular mechanisms underlying different mustard NUE genotypes and demonstrate the enormous potential of NUE breeding in B.juncea.展开更多
Rapeseed mustard(Brassica juncea L.) is the third most important oilseed crop in the world, but the geneticmechanism underlying its massive phenotypic variation remains largely unexplored. In this study, specific leng...Rapeseed mustard(Brassica juncea L.) is the third most important oilseed crop in the world, but the geneticmechanism underlying its massive phenotypic variation remains largely unexplored. In this study, specific length amplified fragment sequencing(SLAF-Seq) was used to resequence a population comprising 197 F8recombinantinbred lines(RILs) derived from a cross between vegetable-type Qichi881 and oilseed-type YufengZC of B. juncea. In total, 438,895 high-quality SLAFs were discovered, 47,644 of which were polymorphic, and 3,887 of the polymorphic markers met the requirements for genetic map construction. The final map included 3,887 markers on 18 linkage groups and was 1,830.23 centiMorgan(cM) in length, with an average distance of 0.47 cM between adjacent markers. Using the newly constructed high-density genetic map, a total of 53 QTLs for erucicacid(EA), oleic acid(OA), and linolenic acid(LNA) were detected and integrated into eight consensus QTLswith two for each of these traits. For each of these three traits, two candidate genes were cloned and sequence analysis indicated colocalization with their respective consensus QTLs. The co-dominant allele-specific markers for Bju.FAD3.A03 and Bju.FAD3.B07 were developed and showed co-localization with their consensus QTLs andco-segregation with LNA content, further supporting the results of QTL mapping and bioinformatic analysis. Theexpression levels of the cloned homologous genes were also determined, and the genes were tightly correlatedwith the EA, OA and LNA contents of different lines. The results of this study will facilitate the improvement offatty acid traits and molecular breeding of B. juncea. Further uses of the high-density genetic map created in this study are also discussed.展开更多
In this study, Bacil us amyloliquefaciens A3 was continual y incubated in shake fIasks contalning wastewater from sweet potato starch production as an ef-fective biofertiIizer for cuItivation of Brassica juncea var. m...In this study, Bacil us amyloliquefaciens A3 was continual y incubated in shake fIasks contalning wastewater from sweet potato starch production as an ef-fective biofertiIizer for cuItivation of Brassica juncea var. multiceps（XueIihong）. Based on pot experiments in the greenhouse, the effects of chemical fertiIizers （CN）, biofertiIizer （BF）, inactivated broth （BI）, starch wastewater （SW） and the combination of biofertiIizer and chemical fertiIizer （BC） on the yield, NO3- content and NO2- con-tent of XueIihong, soiI physicochemical properties and N2O emission were investi-gated. The resuIts showed that the yield of XueIihong in BC and CN treatments was improved by five times compared with CK; BF and SW treatments had insignifi-cant impact on the yield of XueIihong. Compared with CN treatment, BCL treatment exhibited simiIar improving effects on the yield of XueIihong, in which NO3- content of XueIihong and soiI was reduced by 16.4%-73.6% and 22%-29%, which reduced the risk of nitrogen eIuviations in soiI; average N2O fIux （FPV30） in BCL treatment was reduced by 58.3%-73.1% compared with CN treatment. In concIusion, B. amy-loliquefaciens is a feasibIe Iow-cost biofertiIizer for sustalnabIe vegetabIe farming with a great potential for starch wastewater utiIization.展开更多
[Objective] The study aimed at exploring the relationship among the agronomic characters of B. juncea in western China, in order to provide scientific basis for the breeding of B. juncea in western China. [Method] 39 ...[Objective] The study aimed at exploring the relationship among the agronomic characters of B. juncea in western China, in order to provide scientific basis for the breeding of B. juncea in western China. [Method] 39 B. juncea materials from western China were used for the canonical correlation analysis, and canonical correlations between each pair of the four ecological character （containing 18 variables） were verified, including yield characters （5 variables）, caulis characters （6 variables）, branch characters （3 variables） and pod characters （3 variables）. [Result] Yield per plant of B. juncea in western China suffered a tremendous influence from effective pod number per plant while was not significantly affected by the total pod number per plant, seed number per pod and 1 000-seed weight; the most important character related with the yield character of B. juncea in western China was caulis character, followed by the branch character and pod character; yield characters, caulis characters, branch characters and pod characters of B. juncea in western China were closely correlated. [Conclusion] In order to improve the yield characters of B. juncea in western China, caulis characters should be focused on, followed by branch characters and pod characters; rapeseed varieties with high performance in total pod number per plant and effective pod number per plant should be chosen through the perspectives of effective branch number, plant height, pod number of main inflorescence, fruit stalk number of main inflorescence and other traits, while rapeseed varieties with high performance in seed number per pod and 1 000-seed weight should be chosen through the perspectives of beak length and other traits.展开更多
[Objective] This study was performed to screen functional genes related to the fertility conversion of thermo-sensitive genic male sterile （TGMS） lines of Brassica juncea L. [Method] A B. juncea TGMS line K121S was ...[Objective] This study was performed to screen functional genes related to the fertility conversion of thermo-sensitive genic male sterile （TGMS） lines of Brassica juncea L. [Method] A B. juncea TGMS line K121S was selected as the experimental material. The total RNAs were isolated from fertile and sterile pollens at different development stages, including mother cell stage, tetrad stage, tricellular pollen stage and maturity stage. DDRT-PCR was carried out to identify differentially expressed genes. [Result] A total of 44 differentially expressed cDNA fragments were identified with Dot blot. And seven candidate genes related to fertility conversion of K121S were screened out by BLASTN, including callose synthase gene, aldehyde dehydrogenase gene and RNA polymerase I transcription factor RRN3 gene which were differentially expressed at the transcriptional level, H＇-ATPase gene, fructose diphosphate aldolase -class I gene, teucine-rich repeat receptor-Jike serine/threonine- protein kinase gene and alkaline/neutral invertase gene, which were differentially expressed at the post-transcriptional level. [Conclusion] The results of this study will help to explain the molecular mechanism of thermo-sensitive genic male sterility of B. juncea.展开更多
Five commonly-used reference genes： ACT （actin）, UBE （ubiquitin-conjugating enzyme）, RPL2 （ribosomal protein L2）, BRP II （RNA polymerase II subunit）, and NADH （nicotinamide adenine dinucleotide） were examin...Five commonly-used reference genes： ACT （actin）, UBE （ubiquitin-conjugating enzyme）, RPL2 （ribosomal protein L2）, BRP II （RNA polymerase II subunit）, and NADH （nicotinamide adenine dinucleotide） were examined using geNorm software as reference genes for RT-qPCR. Among the tested reference genes, ACT and UBE were the most stable in all samples. In parallel, expression analysis of nitrilases in Brassica juncea var. tumida, was performed to preliminarily investigate the molecular interactions between nitrilase and clubroot development at 10, 15, 20, 25, 30, and 40 d postinoculation （dpi） with a suspension of resting spores of Plasmodiophora brassicae. The results showed that different gene expressions of nitrilases were regulated during the initial periods of clubroot development. The expression level of BjNIT1 increased sharply from 20 to 40 dpi in infected roots while there were no remarkable changes in healthy roots. From 15 to 30 dpi, the expression levels of BjNIT2 and BjNIT4 in infected roots were lower than those in non-infected roots. Finally, BjNIT2 in treatment was down approximately to control at 40 dpi. Our results suggest that BjNIT1, which promoted overproductions of auxin, might be involved in P. brassicae infection of B. juncea.展开更多
Polar auxin transport plays a divergent role in plant growth and developmental processes including root and embryo development, vascular pattern formation and cell elongation. Recently isolated Arabidopsis pin gene fa...Polar auxin transport plays a divergent role in plant growth and developmental processes including root and embryo development, vascular pattern formation and cell elongation. Recently isolated Arabidopsis pin gene family was believed to encode a component of auxin efflux carrier (G(?)lweiler et al, 1998). Based on the Arabidopsis pin1 sequence we have isolated a Brassica juncea cDNA (designated Bjpin1), which encoded a 70-kDa putative auxin efflux carrier. Deduced BjPIN1 shared 65% identities at protein level with AtPINl and was highly homologous to other putative PIN proteins of Arabidopsis (with highest homology to AtPIN3). Hydrophobic analysis showed similar structures between BjPINl and AtPIN proteins. Presence of 6 exons (varying in size between 65 bp and 1229 bp) and 5 introns (sizes between 89 bp and 463 bp) in the genomic fragment was revealed by comparing the genomic and cDNA sequences. Northern blot analysis indicated that Bjpin1 was expressed in most of the tissues tested, with a relatively higher level of transcript in flowers and a lower level in root tissues. Promoter-reporter gene fusion studies further revealed the expression of Bjpin1 in the mature pollen grains, young seeds, root tip, leaf vascular tissue and trace bundle, stem epidermis, cortex and vascular cells. BjPINl was localized on the plasma membrane as demonstrated through fusion expression of green fluorescent protein (GFP). Auxin efflux carrier activity was elevated in transgenic Arabidopsis expressing BjPIN1.展开更多
Allopolyploid Brassica juncea is particularly enriched in sinigrin,a kind of 3C aliphatic glucosinolates(GSLs),giving rise to characteristic taste after picking.However,the molecular mechanism underlying 3C aliphatic ...Allopolyploid Brassica juncea is particularly enriched in sinigrin,a kind of 3C aliphatic glucosinolates(GSLs),giving rise to characteristic taste after picking.However,the molecular mechanism underlying 3C aliphatic GSLs biosynthesis in this species remains unknown.In this study,we genome-widely identified GSLs metabolic genes,indicating different evolutionary rate of GSLs metabolic genes between subgenomes of B.juncea.Eight methythioalkylmalate synthase(MAMs)homologs were identified from B.juncea,in which six MAM1s were located in chloroplast and the other two were not detected with any expression.Furthermore,BjMAM1-4,BjMAM1-5,and BjMAM1-6 displayed higher expression levels in leaves than other tissues.Silenced expression analysis revealed that BjMAM1-4 and BjMAM1-6 function in 3C and 4C aliphatic GSLs accumulation.The specificity of the substrate selection for the second cycle reaction is much lower than that of the first cycle,suggesting these genes may preferentially catalyze 3C aliphatic GSLs biosynthesis.Our study provides insights into the molecular mechanism underlying the accumulation of 3C aliphatic GSLs,thereby facilitating the manipulation of aliphatic GSLs content in B.juncea.展开更多
Based on the sequence information of Arabidopsis PIN1, two cDNAs encoding PIN homologues fromBrassica juncea, Bjpin2 and Bjpin3, were isolated through cDNA library screening. Bjpin2 and Bjpin3encoded proteins containi...Based on the sequence information of Arabidopsis PIN1, two cDNAs encoding PIN homologues fromBrassica juncea, Bjpin2 and Bjpin3, were isolated through cDNA library screening. Bjpin2 and Bjpin3encoded proteins containing 640 and 635 amino acid residues, respectively, which shared 97.5% identities witheach other and were highly homologous to Arabidopsis PIN1, PIN2 and other putative PIN proteins. BjPIN2and BjPIN3 had similar structures as AtPIN proteins. Northern blot analysis indicated that Bjpin2 wasexpressed in stem, leaf and floral tissues, while Bjpin3 was expressed predominantly in stem and hypocotyls.Two promoter fragments of pin genes, Bjpin-X and Bjpin-Z, were isolated by 'genome walking' techniqueusing primers at 5'-end of pin cDNA. Promoter-gus fusion studies revealed the GUS activities driven byBjpin-X were at internal side of xylem and petal; while those driven by Bjpin-Z were detected at leaf vein,epidermal cell and cortex of stem, vascular tissues and anther. Results of the pin genes with differentexpression patterns in B. juncea suggested the presence of a gene family.展开更多
Soil contamination by toxic trace metal elements,like barium(Ba),may stimulate various undesirable changes in the metabolic activity of plants.The plant responses are fast and with,direct or indirect,generation of rea...Soil contamination by toxic trace metal elements,like barium(Ba),may stimulate various undesirable changes in the metabolic activity of plants.The plant responses are fast and with,direct or indirect,generation of reactive oxygen species(ROS).To cope with the stress imposed by the ROS production,plants developed a dual cellular system composed of enzymatic and non-enzymatic players that convert ROS,and their by-products,into stable nontoxic molecules.To assess the Ba stress response of two Brassicaceae species(Brassica juncea,a glycophyte,and Cakile maritime,a halophyte),plants were exposure to different Ba concentrations(0,100,200,300 and 500µM).The plants response was evaluated through their morphology and development,the determination of plant leaves antioxidant enzymatic activities and by the production of plants secondary metabolites.Results indicated that the two Brassicaceae species have the ability to survive in an environment containing Ba(even at 500µM).The biomass production of C.maritima was slightly affected whereas an increase in biomass B.juncea was noticed.The stress imposed by Ba activated the antioxidant defense system in the two species,noticed by the changes in the leaves activity of catalase(CAT),ascorbate peroxidase(APX)and guaicol peroxidase(GPX),and of the secondary metabolites,through the production of total phenols and flavonoids.The enzymatic response was not similar within the two plant species:CAT and APX seem to have a more important role against the oxidative stress in C.maritima while in B.juncea is GPX.Overall,total phenols and flavonoids production was more significant in the plants aerial part than in the roots,of the both species.Although the two Brassicaceae species response was different,in both plants catalytic and non-catalytic transformation of ROS occurs,and both were able to overcome the Ba toxicity and prevent the cell damage.展开更多
The release of mitochondrial genome sequences provides the basis for characterizing interspecific and intraspecific variation in Brassica mitochondrial genomes.However,few B.juncea(mustard)mitochondrial genomes have b...The release of mitochondrial genome sequences provides the basis for characterizing interspecific and intraspecific variation in Brassica mitochondrial genomes.However,few B.juncea(mustard)mitochondrial genomes have been published.We assembled the mitochondrial genomes of three B.juncea subspecies and compared them with previously published genomes.The genomes were phylogenetically classified into A,B,C,and Bna clades.Two variant sites,a transversion(C→A)at nt 79,573 and a 31-bp copy-number variation between nts 65,564 and 65,596,were identified.Based on these variant sites,mitotype-specific sequence markers were developed to characterize the variation among worldwide 558 B.juncea accessions.Three mitochondrial genome types(mitotypes MT1–MT3)were identified.In terms of geographical distribution,MT1 and MT2 accessions were distributed mainly to the north and MT3 to the south of 34°N.Root mustards carried only MT1,leaf and stem mustards carried mainly MT3,and seed mustards carried all three mitotypes,implying that the mitotypes underwent selection during B.juncea domestication.A new form of oil mustard evolved by hybridization between two gene pools in southwest China.展开更多
Chromosome identification and karyotype using fluorescence in situ hybridization(FISH)provides a technical platform for genome and cytogenetic studies. Brassica juncea(brown mustard, 2n = 4× = 36; genome AABB) is...Chromosome identification and karyotype using fluorescence in situ hybridization(FISH)provides a technical platform for genome and cytogenetic studies. Brassica juncea(brown mustard, 2n = 4× = 36; genome AABB) is an allopolyploid species that originated from a spontaneous hybridization of Brassica rapa and Brassica nigra and contains many valuable traits. In this study, a multicolor FISH procedure allowing the identification of all 18 chromosomal pairs was developed by two-step hybridizations with probes on the same metaphase chromosomes. The distribution patterns and chromosomal localizations of six repeat sequences(satellite repeat p Br STR, 5S r DNA, 45 S r DNA, B genome-specific repeat p BNBH35, and centromeric satellite repeats Cent Br1 and Cent Br2) on B. juncea chromosomes were characterized.Comparative karyotype analyses showed that the genome is relatively stable in comparison with its diploid progenitor species and revealed intraspecific karyotypic diversity among three accessions of B. juncea. This study provides valuable information about the genome evolution of B. juncea and a toolkit that will be helpful for chromosome identification.展开更多
基金Supported by National Natural Science Foundation of China:QTL Mapping Combined with GWAS Strategy to Explore Major Regulation Genes for Glucosinolate Metabolism in Brassica juncea(31560422)Science and Technology Foundation of Guizhou Province of China:Positioning,Mining and Metabolic Mechanism of Major Genes Regulating Glucosinolate from Leaves and Seeds of Brassica rapa[Qian Ke He J Zi(2015)2052]+2 种基金Scientific Research Foundation for Returned Scholars,Ministry of Education:Mining of Glucosinolate-regulated Genes in Brassica napus and Analysis of Its Expression Dynamics[Jiao Wai Si Liu(2015)1098]Doctoral Talent Introduction Fund of Guizhou University:Screening of Glucosinolate Content in Brassica Napus Varieties and Development of Associated Markers[Gui Da Ren Ji He Zi(2014)14]Construction Program of Biology First-class Discipline in Guizhou(GNYL[2017]009)
文摘Correlation analysis and principal component analysis( PCA) were conducted for some agronomic traits of 139 recombinant inbred lines of Brassica juncea L. The results showed that under the environmental conditions in Guiyang,the flowering time,number of seeds per silique,plant height and thousand seed weight differed significantly among different lines. The results of principal component analysis showed that the lines could be classified into three groups. The results of Pearson correlation tests showed that the plant height was positively correlated with the flowering time( P < 0. 05),and the thousand seed weight was negatively correlated with the flowering time and number of seeds per silique( P < 0. 01).
文摘Soil salinity is one of the major environmental constraints that limits crop yield and nearly 7%of the total area worldwide is affected by salinity.Salinity-induced oxidative stress causes membrane damage during germination and seedling growth.Indian mustard is a major oilseed crop in India and its production and productivity are severely affected by salt stress.Breeding Brassica cultivars for salinity tolerance by conventional means is very difficult and time-consuming.Therefore,understanding the molecular components associated with salt tolerance is needed to facilitate breeding for salt tolerance in Brassica.In this investigation,quantitative trait loci(QTLs)associated with salt tolerance were identified using F_(2:3)mapping population developed from a cross between CS52(salinity tolerant)and RH30(salinity sensitive).Parents and F_(2:3)were evaluated under controlled and salinity stress conditions for 14 morpho-physiological traits for two consecutive generations(F2 and F_(2:3)),explaining proportion of the phenotypic variance under control condition.Simple sequence repeat(SSR)markers were used for mapping studies.A genetic linkage map based on 42 simple sequence repeats(SSRs)markers was constructed covering 2298.5 cM(Haldane)to identify the loci associated with salt tolerance in Brassica juncea.Forty-one SSRs showing polymorphism in the parents(CS52 and RH30)were mapped on 8 linkage groups(C1–C8).One marker(nga 129)did not map to any of the linkage group and was excluded from mapping.Linkage group 5(C5;317.9 cM)was longest and linkage group 1(C1,255.0 cM)was shortest.Further,we identified 15 QTLs controlling 8 traits using F_(2:3)population.These QTLs explained 12.44–60.63%of the phenotypic variation with a LOD score range of 3.62–5.97.Out of these QTLs,QMI4.1 related to membrane injury showed 51.28%phenotypic variance with a LOD score of 3.34.QTL QBYP8.1 related to biological yield per plant showed 60.63%phenotypic variance at a LOD score of 3.62.The highest LOD score of 5.97 was recorded for QTL related to seed yield per plant(QSYP4.1).Major QTLs were QTL for biological yield per plant(QBYP8.1),QTL for siliquae per plant(QSP4.1),QTL for primary branches(QPB4.1),QTLs for seed per siliqua(QSS4.1,QSS4.2),QTL for seed yield per plant(QSYP4.1),and QTL for membrane injury(QMI8.1)which showed more than 50%phenotypic variance.These QTLs identified in our study need to be confirmed in other populations as well so that these can be used in marker-assisted selection and breeding to enhance salt tolerance in Brassica juncea.
基金supported by grants from the National Natural Science Foundation of China(32172547).
文摘Photoperiod and temperature are crucial factors that trigger flowering in Brassica juncea(B.juncea).However,the underlying regulatory mechanisms remain poorly understood.The MADS-box transcription factor AGL18 acts as a pivotal repressor of floral transition and functions redundantly with AGL15.In this study,we isolated BjuAGL18-1 from B.juncea and identified two unique transcripts,resulting in two distinct proteins:a full-length protein,BjuAGL18-1L,and a truncated protein,BjuAGL18-1S.Further investigation showed that the two isoforms had similar subcellular localizations but different expression patterns in various plant tissues.Notably,BjuAGL18-1L and BjuAGL18-1S were abundantly induced under short-and long-day photoperiods,respectively.BjuAGL18-1L overexpression in B.juncea and Arabidopsis thaliana(A.thaliana)led to late flowering,whereas BjuAGL18-1S overexpression resulted in early flowering.Yeast two-hybrid,bimolecular fluorescent complementation,and luciferase complementation assays showed that BjuAGL18-1L,but not BjuAGL18-1S(which lacked the EAR motif),interacted with the co-repressor BjuAFR2 and the histone deacetylase BjuHDA9 to form a multiprotein complex.Further analysis indicated that BjuAGL18-1L could also form a complex with BjuAGL15 and bind to the BjuFUL promoter,thus inhibiting its expression.However,BjuAGL18-1S interacted with BjuAGL18-1L to form heterodimers,which attenuated their activities,likely by disrupting their binding to target genes,resulting in accelerated flowering progression.These results suggest that BjuAGL18-1 is involved in photoperiod-induced flowering via different regulatory mechanisms in B.juncea.
基金supported by grants from the National Natural Science Foundation of China(32002056)the Science and Technology Research Key Project of Henan Province,China(242102111138)。
文摘The potherb mustard Xuecai(XC)cultivar is a cruciferous vegetable that is popular either fresh or pickled.Due to the deep notches in the edges of leaves in mustard XC,this plant can be said to have multipinnately lobed leaves.The net photosynthesis of lobed leaves is significantly greater than that of simple leaves.However,the molecular mechanism of leaf shape variation has not been determined.Here,we used HiFi and Hi-C data to assemble the XC genome.The genome was 961.72 Mb in size,with a contig N50 value of 6.565 Mb.The XC genome was compared with four previously sequenced mustard genomes,and the genomic collinearity regions,SNPs,and indels were identified.Five BjRCO genes were found on chromosome(Chr.)A10 in potherb mustard XC when the BjRCO gene locus was compared against other sequenced B.juncea genomes.Segmental duplication was found to contribute to the BjRCO gene copy number.The transcript expression of BjRCO genes was greater in multipinnately lobed leaves than in sawtooth-like leaves.Together,these findings indicate that both the greater copy number and the expression level of BjRCO genes regulate leaf shape from simple to complex in B.juncea.Gene editing of the BjRCO gene from XC changed the leaf shape from multipinnately lobed to simple.The high-quality XC genome sequence not only provides new insight into B.juncea leaf-type genomics but also helps in deciphering leaf shape variation.Our study provides insights into the variation and evolution of important traits in Brassica plants through a comparative analysis of the sequenced genomes.
基金supported by the National Natural Science Foundation of China(U21A20236,32072664)the Natural Science Foundation of Hunan Province,China(2022RC3053,2021JC0001,2021RC3086,2022NK2009)+1 种基金the China Agriculture Research System(CARS-01-30)the Innovation Foundation for Graduate of Hunan Agricultural University,China(2023XC116)。
文摘Elucidating crops'physiological and molecular mechanisms to adapt to low nitrogen environment and promoting nitrogen transfer from senescent leaves to new leaves is crucial in improving Brassica's nitrogen use efficiency(NUE).Glutamine synthetase gene(GS)plays a vital role in helping plants reassimilate ammonium released from protein degradation in leaves,and it was the focus of our research on this topic.In this study,we identified high(H141)and low(L65)NUE genotypes of Brassica juncea with different responses to low-nitrogen stress.We found that H141 has a lower nitrate content but higher ammonium and free amino acid contents as well as higher nitrate reductase and GS activities in the shoots.These physiological indicators are responsible for the high NUE of H141.Wholegenome resequencing data revealed that 5,880 genes associated with NUE are polymorphic between H141 and L65.These genes participate in various amino acid,carbohydrate,and energy metabolic pathways.Haplotype analysis revealed two haplotypes for BjuB05.GS1.4,Hap1 and Hap2,which have multiple single nucleotide polymorphisms or insertions/deletions in the regulatory regions of the 5′and 3′untranslated regions and introns.Furthermore,the shoot NUE of Hap1 is significantly lower than that of Hap2.These two haplotypes of BjuB05.GS1.4 lead to differences in the shoot NUEs of different genetic populations of mustard and are associated with the local soil nitrogen content,suggesting that they might help mustard to adapt to different geographic localities.In conclusion,the results of our study shed light on the physiological and molecular mechanisms underlying different mustard NUE genotypes and demonstrate the enormous potential of NUE breeding in B.juncea.
基金funded by the Scientific and Technological Key Program of Guizhou Province, China (Qiankehezhicheng [2022] Key 031)the National Natural Science Foundation of China (32160483 and 32360497)+2 种基金the Post-Funded Project for the National Natural Science Foundation of China from Guizhou University ([2023]093)the Key Laboratory of Molecular Breeding for Grain and Oil Crops in Guizhou Province, China (Qiankehezhongyindi [2023]008)the Key Laboratory of Functional Agriculture of Guizhou Provincial Higher Education Institutions, China (Qianjiaoji [2023] 007)。
文摘Rapeseed mustard(Brassica juncea L.) is the third most important oilseed crop in the world, but the geneticmechanism underlying its massive phenotypic variation remains largely unexplored. In this study, specific length amplified fragment sequencing(SLAF-Seq) was used to resequence a population comprising 197 F8recombinantinbred lines(RILs) derived from a cross between vegetable-type Qichi881 and oilseed-type YufengZC of B. juncea. In total, 438,895 high-quality SLAFs were discovered, 47,644 of which were polymorphic, and 3,887 of the polymorphic markers met the requirements for genetic map construction. The final map included 3,887 markers on 18 linkage groups and was 1,830.23 centiMorgan(cM) in length, with an average distance of 0.47 cM between adjacent markers. Using the newly constructed high-density genetic map, a total of 53 QTLs for erucicacid(EA), oleic acid(OA), and linolenic acid(LNA) were detected and integrated into eight consensus QTLswith two for each of these traits. For each of these three traits, two candidate genes were cloned and sequence analysis indicated colocalization with their respective consensus QTLs. The co-dominant allele-specific markers for Bju.FAD3.A03 and Bju.FAD3.B07 were developed and showed co-localization with their consensus QTLs andco-segregation with LNA content, further supporting the results of QTL mapping and bioinformatic analysis. Theexpression levels of the cloned homologous genes were also determined, and the genes were tightly correlatedwith the EA, OA and LNA contents of different lines. The results of this study will facilitate the improvement offatty acid traits and molecular breeding of B. juncea. Further uses of the high-density genetic map created in this study are also discussed.
基金Supported by Key Research Program of the Chinese Academy of Sciences(KZZD-EW-09-3,KZZD-EW-11-03)National Science and Technology Major Project(2014ZX07204-005)Special Fund of the National Academy Alliance(2012-1)~~
文摘In this study, Bacil us amyloliquefaciens A3 was continual y incubated in shake fIasks contalning wastewater from sweet potato starch production as an ef-fective biofertiIizer for cuItivation of Brassica juncea var. multiceps（XueIihong）. Based on pot experiments in the greenhouse, the effects of chemical fertiIizers （CN）, biofertiIizer （BF）, inactivated broth （BI）, starch wastewater （SW） and the combination of biofertiIizer and chemical fertiIizer （BC） on the yield, NO3- content and NO2- con-tent of XueIihong, soiI physicochemical properties and N2O emission were investi-gated. The resuIts showed that the yield of XueIihong in BC and CN treatments was improved by five times compared with CK; BF and SW treatments had insignifi-cant impact on the yield of XueIihong. Compared with CN treatment, BCL treatment exhibited simiIar improving effects on the yield of XueIihong, in which NO3- content of XueIihong and soiI was reduced by 16.4%-73.6% and 22%-29%, which reduced the risk of nitrogen eIuviations in soiI; average N2O fIux （FPV30） in BCL treatment was reduced by 58.3%-73.1% compared with CN treatment. In concIusion, B. amy-loliquefaciens is a feasibIe Iow-cost biofertiIizer for sustalnabIe vegetabIe farming with a great potential for starch wastewater utiIization.
基金Supported by National Natural Science Foundation(30760122)National High-Tech Research and Development Program(863Program)(2009AA101105)+1 种基金Faculty Construction of 211 Project(SZTD-211-02)Project of Introducing Advanced Agricultural Science and Technology of Ministry of Agriculture(948Program)(2010-Z54)~~
文摘[Objective] The study aimed at exploring the relationship among the agronomic characters of B. juncea in western China, in order to provide scientific basis for the breeding of B. juncea in western China. [Method] 39 B. juncea materials from western China were used for the canonical correlation analysis, and canonical correlations between each pair of the four ecological character （containing 18 variables） were verified, including yield characters （5 variables）, caulis characters （6 variables）, branch characters （3 variables） and pod characters （3 variables）. [Result] Yield per plant of B. juncea in western China suffered a tremendous influence from effective pod number per plant while was not significantly affected by the total pod number per plant, seed number per pod and 1 000-seed weight; the most important character related with the yield character of B. juncea in western China was caulis character, followed by the branch character and pod character; yield characters, caulis characters, branch characters and pod characters of B. juncea in western China were closely correlated. [Conclusion] In order to improve the yield characters of B. juncea in western China, caulis characters should be focused on, followed by branch characters and pod characters; rapeseed varieties with high performance in total pod number per plant and effective pod number per plant should be chosen through the perspectives of effective branch number, plant height, pod number of main inflorescence, fruit stalk number of main inflorescence and other traits, while rapeseed varieties with high performance in seed number per pod and 1 000-seed weight should be chosen through the perspectives of beak length and other traits.
基金Supported by National Natural Science Foundation of China(31160289)Rapeseed Industry Construction Program of Department of Agriculture of Yunnan ProvinceFund for Workstation of Academician Guan Chunyun from Department of Science and Technology of Yunnan Province~~
文摘[Objective] This study was performed to screen functional genes related to the fertility conversion of thermo-sensitive genic male sterile （TGMS） lines of Brassica juncea L. [Method] A B. juncea TGMS line K121S was selected as the experimental material. The total RNAs were isolated from fertile and sterile pollens at different development stages, including mother cell stage, tetrad stage, tricellular pollen stage and maturity stage. DDRT-PCR was carried out to identify differentially expressed genes. [Result] A total of 44 differentially expressed cDNA fragments were identified with Dot blot. And seven candidate genes related to fertility conversion of K121S were screened out by BLASTN, including callose synthase gene, aldehyde dehydrogenase gene and RNA polymerase I transcription factor RRN3 gene which were differentially expressed at the transcriptional level, H＇-ATPase gene, fructose diphosphate aldolase -class I gene, teucine-rich repeat receptor-Jike serine/threonine- protein kinase gene and alkaline/neutral invertase gene, which were differentially expressed at the post-transcriptional level. [Conclusion] The results of this study will help to explain the molecular mechanism of thermo-sensitive genic male sterility of B. juncea.
基金financially supported by the Natural Science Foundation of Chongqing Science and Technology Commission,China (2008BB1370)Fuling Agricultural Science Institute of Chongqing,China
文摘Five commonly-used reference genes： ACT （actin）, UBE （ubiquitin-conjugating enzyme）, RPL2 （ribosomal protein L2）, BRP II （RNA polymerase II subunit）, and NADH （nicotinamide adenine dinucleotide） were examined using geNorm software as reference genes for RT-qPCR. Among the tested reference genes, ACT and UBE were the most stable in all samples. In parallel, expression analysis of nitrilases in Brassica juncea var. tumida, was performed to preliminarily investigate the molecular interactions between nitrilase and clubroot development at 10, 15, 20, 25, 30, and 40 d postinoculation （dpi） with a suspension of resting spores of Plasmodiophora brassicae. The results showed that different gene expressions of nitrilases were regulated during the initial periods of clubroot development. The expression level of BjNIT1 increased sharply from 20 to 40 dpi in infected roots while there were no remarkable changes in healthy roots. From 15 to 30 dpi, the expression levels of BjNIT2 and BjNIT4 in infected roots were lower than those in non-infected roots. Finally, BjNIT2 in treatment was down approximately to control at 40 dpi. Our results suggest that BjNIT1, which promoted overproductions of auxin, might be involved in P. brassicae infection of B. juncea.
基金Studies were supported by "the National NaturalScience Foundation of China, No. 30070073", StateKey Project of Basic Research, No. G199901l604"and "National Natural Science Foundation of Pan-Deng". We thank Dr. Charles Brearley and JianXu for hel
文摘Polar auxin transport plays a divergent role in plant growth and developmental processes including root and embryo development, vascular pattern formation and cell elongation. Recently isolated Arabidopsis pin gene family was believed to encode a component of auxin efflux carrier (G(?)lweiler et al, 1998). Based on the Arabidopsis pin1 sequence we have isolated a Brassica juncea cDNA (designated Bjpin1), which encoded a 70-kDa putative auxin efflux carrier. Deduced BjPIN1 shared 65% identities at protein level with AtPINl and was highly homologous to other putative PIN proteins of Arabidopsis (with highest homology to AtPIN3). Hydrophobic analysis showed similar structures between BjPINl and AtPIN proteins. Presence of 6 exons (varying in size between 65 bp and 1229 bp) and 5 introns (sizes between 89 bp and 463 bp) in the genomic fragment was revealed by comparing the genomic and cDNA sequences. Northern blot analysis indicated that Bjpin1 was expressed in most of the tissues tested, with a relatively higher level of transcript in flowers and a lower level in root tissues. Promoter-reporter gene fusion studies further revealed the expression of Bjpin1 in the mature pollen grains, young seeds, root tip, leaf vascular tissue and trace bundle, stem epidermis, cortex and vascular cells. BjPINl was localized on the plasma membrane as demonstrated through fusion expression of green fluorescent protein (GFP). Auxin efflux carrier activity was elevated in transgenic Arabidopsis expressing BjPIN1.
基金The authors thank Prof.Q.Wang for GSLs analysis.This work was supported by grants from the National Natural Science Foundation of Zhejiang Province(Grant no.LZ20C150002)the National Natural Science Foundation of China(Grant no.31872095).
文摘Allopolyploid Brassica juncea is particularly enriched in sinigrin,a kind of 3C aliphatic glucosinolates(GSLs),giving rise to characteristic taste after picking.However,the molecular mechanism underlying 3C aliphatic GSLs biosynthesis in this species remains unknown.In this study,we genome-widely identified GSLs metabolic genes,indicating different evolutionary rate of GSLs metabolic genes between subgenomes of B.juncea.Eight methythioalkylmalate synthase(MAMs)homologs were identified from B.juncea,in which six MAM1s were located in chloroplast and the other two were not detected with any expression.Furthermore,BjMAM1-4,BjMAM1-5,and BjMAM1-6 displayed higher expression levels in leaves than other tissues.Silenced expression analysis revealed that BjMAM1-4 and BjMAM1-6 function in 3C and 4C aliphatic GSLs accumulation.The specificity of the substrate selection for the second cycle reaction is much lower than that of the first cycle,suggesting these genes may preferentially catalyze 3C aliphatic GSLs biosynthesis.Our study provides insights into the molecular mechanism underlying the accumulation of 3C aliphatic GSLs,thereby facilitating the manipulation of aliphatic GSLs content in B.juncea.
文摘Based on the sequence information of Arabidopsis PIN1, two cDNAs encoding PIN homologues fromBrassica juncea, Bjpin2 and Bjpin3, were isolated through cDNA library screening. Bjpin2 and Bjpin3encoded proteins containing 640 and 635 amino acid residues, respectively, which shared 97.5% identities witheach other and were highly homologous to Arabidopsis PIN1, PIN2 and other putative PIN proteins. BjPIN2and BjPIN3 had similar structures as AtPIN proteins. Northern blot analysis indicated that Bjpin2 wasexpressed in stem, leaf and floral tissues, while Bjpin3 was expressed predominantly in stem and hypocotyls.Two promoter fragments of pin genes, Bjpin-X and Bjpin-Z, were isolated by 'genome walking' techniqueusing primers at 5'-end of pin cDNA. Promoter-gus fusion studies revealed the GUS activities driven byBjpin-X were at internal side of xylem and petal; while those driven by Bjpin-Z were detected at leaf vein,epidermal cell and cortex of stem, vascular tissues and anther. Results of the pin genes with differentexpression patterns in B. juncea suggested the presence of a gene family.
基金This work has been supported by LISBOA-01-0145-FERDER-031863 project,cofunded by FEDER through POR Lisboa 2020(Programa Operacional de Lisboa)from Portugal 2020 and Fundação para a Ciência e a Tecnologia(PTDC/CTA-AMB/31863/2017).The authors also gratefully acknowledge the support of CERENA(strategic project FCT-UIDB/04028/2020)and MARE(strategic project FCT-UIDB/04292/2020).
文摘Soil contamination by toxic trace metal elements,like barium(Ba),may stimulate various undesirable changes in the metabolic activity of plants.The plant responses are fast and with,direct or indirect,generation of reactive oxygen species(ROS).To cope with the stress imposed by the ROS production,plants developed a dual cellular system composed of enzymatic and non-enzymatic players that convert ROS,and their by-products,into stable nontoxic molecules.To assess the Ba stress response of two Brassicaceae species(Brassica juncea,a glycophyte,and Cakile maritime,a halophyte),plants were exposure to different Ba concentrations(0,100,200,300 and 500µM).The plants response was evaluated through their morphology and development,the determination of plant leaves antioxidant enzymatic activities and by the production of plants secondary metabolites.Results indicated that the two Brassicaceae species have the ability to survive in an environment containing Ba(even at 500µM).The biomass production of C.maritima was slightly affected whereas an increase in biomass B.juncea was noticed.The stress imposed by Ba activated the antioxidant defense system in the two species,noticed by the changes in the leaves activity of catalase(CAT),ascorbate peroxidase(APX)and guaicol peroxidase(GPX),and of the secondary metabolites,through the production of total phenols and flavonoids.The enzymatic response was not similar within the two plant species:CAT and APX seem to have a more important role against the oxidative stress in C.maritima while in B.juncea is GPX.Overall,total phenols and flavonoids production was more significant in the plants aerial part than in the roots,of the both species.Although the two Brassicaceae species response was different,in both plants catalytic and non-catalytic transformation of ROS occurs,and both were able to overcome the Ba toxicity and prevent the cell damage.
基金China Agriculture Research System(CARS-12)National Natural Science Foundation of China(U20A2029)。
文摘The release of mitochondrial genome sequences provides the basis for characterizing interspecific and intraspecific variation in Brassica mitochondrial genomes.However,few B.juncea(mustard)mitochondrial genomes have been published.We assembled the mitochondrial genomes of three B.juncea subspecies and compared them with previously published genomes.The genomes were phylogenetically classified into A,B,C,and Bna clades.Two variant sites,a transversion(C→A)at nt 79,573 and a 31-bp copy-number variation between nts 65,564 and 65,596,were identified.Based on these variant sites,mitotype-specific sequence markers were developed to characterize the variation among worldwide 558 B.juncea accessions.Three mitochondrial genome types(mitotypes MT1–MT3)were identified.In terms of geographical distribution,MT1 and MT2 accessions were distributed mainly to the north and MT3 to the south of 34°N.Root mustards carried only MT1,leaf and stem mustards carried mainly MT3,and seed mustards carried all three mitotypes,implying that the mitotypes underwent selection during B.juncea domestication.A new form of oil mustard evolved by hybridization between two gene pools in southwest China.
基金supported by the National Natural Science Foundation of China (Nos. 31471173, 31560302)the Inner Mongolia Science & Technology Plan (No. 2014MS0305)+2 种基金the Program for Introducing Talents to University (No. 135121)the Inner Mongolia Innovation Guide Fund (No. 5153202)the Basic and Frontier Technology Research Program of Henan Province (No. 132300410284) to GX Tan
文摘Chromosome identification and karyotype using fluorescence in situ hybridization(FISH)provides a technical platform for genome and cytogenetic studies. Brassica juncea(brown mustard, 2n = 4× = 36; genome AABB) is an allopolyploid species that originated from a spontaneous hybridization of Brassica rapa and Brassica nigra and contains many valuable traits. In this study, a multicolor FISH procedure allowing the identification of all 18 chromosomal pairs was developed by two-step hybridizations with probes on the same metaphase chromosomes. The distribution patterns and chromosomal localizations of six repeat sequences(satellite repeat p Br STR, 5S r DNA, 45 S r DNA, B genome-specific repeat p BNBH35, and centromeric satellite repeats Cent Br1 and Cent Br2) on B. juncea chromosomes were characterized.Comparative karyotype analyses showed that the genome is relatively stable in comparison with its diploid progenitor species and revealed intraspecific karyotypic diversity among three accessions of B. juncea. This study provides valuable information about the genome evolution of B. juncea and a toolkit that will be helpful for chromosome identification.
