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
Transcription factor NAC102 plays an important role in the abiotic stress responses of plants.In this study,the promoter sequence of 3000 bp located in the upstream of the BjNAC102 gene was cloned from Brassica juncea...Transcription factor NAC102 plays an important role in the abiotic stress responses of plants.In this study,the promoter sequence of 3000 bp located in the upstream of the BjNAC102 gene was cloned from Brassica juncea‘Sichuan Yellow Seed’by using the homologous cloning method.The expression vector of the GUS gene driven by the BjNAC102 promoter was constructed by seamless cloning technology.The results showed that the sequence of the promoter of the BjNAC102 gene contained many cis-acting elements involved in light responsiveness,gibberellinresponsive element,and auxin-responsive element.It was speculated that BjNAC102 played an important role in the abiotic stress response in Brassica juncea.The expression vector of the promoter of the BjNAC102 gene was constructed,which layed a foundation for further studies of the expression pattern of the BjNAC102 gene in Brassica juncea.展开更多
1973年,本院发现芥菜型油菜雄性不育株后,经连续几年研究,1975年育成了欧新 A 不育系,欧新 B 保持系和74243—6恢复系,实现了芥菜型“三系”配套。多年来连续测定表明,育成的芥菜型“三系”表现育性稳定,欧新 A 不育系的不育株率达100%...1973年,本院发现芥菜型油菜雄性不育株后,经连续几年研究,1975年育成了欧新 A 不育系,欧新 B 保持系和74243—6恢复系,实现了芥菜型“三系”配套。多年来连续测定表明,育成的芥菜型“三系”表现育性稳定,欧新 A 不育系的不育株率达100%,单株自交结实指数平均在0.000—0.103之间。恢复株率为99.54～100%,F_1杂种有较强的苗期优势,也有种子产量和含油量优势。比芥菜型地方良种昆明高棵增产19.2～34.8%,含油量提高6.58～8.23%。芥菜型“三系”的育成,填补了我国芥菜型杂优利用的空白,势将推动芥菜型油菜杂优利用的研究。展开更多
芸薹属根肿菌(Plasmodiophora brassica)侵染引起的根肿病蔓延会严重影响芥菜[Brassica juncea(L.)Czern.]的产量和品质。丝裂原活化蛋白激酶(mitogen-activated protein kinases,MAPK)级联作为一种高度保守的信号通路,在植物的生物和...芸薹属根肿菌(Plasmodiophora brassica)侵染引起的根肿病蔓延会严重影响芥菜[Brassica juncea(L.)Czern.]的产量和品质。丝裂原活化蛋白激酶(mitogen-activated protein kinases,MAPK)级联作为一种高度保守的信号通路,在植物的生物和非生物胁迫中发挥重要作用。为了挖掘芥菜抗根肿病相关的MAPK基因,本研究对芥菜进行全基因组鉴定,并对芥菜MAPK基因家族的系统进化以及基因结构等进行生物信息学分析。筛选鉴定的66个BjuMAPK基因不均匀分布在17条染色体上。在基因组尺度上,发现基因的串联重复导致了芥菜MAPK基因数目增多。同一亚族成员之间具有相似的基因结构,不同亚族间差异较大。预测的顺式作用元件与植物激素、抗逆性以及植物的生长发育相关,表达分析显示BjuMAPK02、BjuMAPK15、BjuMAPK17和BjuMAPK19等基因在根肿菌侵染芥菜后具有不同的响应模式。以上结果为进一步研究BjuMAPK基因在芥菜应对根肿病生物胁迫中的功能奠定了理论基础。展开更多
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 Natural Science Foundation of Hunan Province(2023JJ50083,2023JJ50084)Excellent Youth Project of Hunan Provincial Department of Education(22B0844)Hunan Provincial Graduate Research Innovation Project(CX20231274)。
文摘Transcription factor NAC102 plays an important role in the abiotic stress responses of plants.In this study,the promoter sequence of 3000 bp located in the upstream of the BjNAC102 gene was cloned from Brassica juncea‘Sichuan Yellow Seed’by using the homologous cloning method.The expression vector of the GUS gene driven by the BjNAC102 promoter was constructed by seamless cloning technology.The results showed that the sequence of the promoter of the BjNAC102 gene contained many cis-acting elements involved in light responsiveness,gibberellinresponsive element,and auxin-responsive element.It was speculated that BjNAC102 played an important role in the abiotic stress response in Brassica juncea.The expression vector of the promoter of the BjNAC102 gene was constructed,which layed a foundation for further studies of the expression pattern of the BjNAC102 gene in Brassica juncea.
文摘1973年,本院发现芥菜型油菜雄性不育株后,经连续几年研究,1975年育成了欧新 A 不育系,欧新 B 保持系和74243—6恢复系,实现了芥菜型“三系”配套。多年来连续测定表明,育成的芥菜型“三系”表现育性稳定,欧新 A 不育系的不育株率达100%,单株自交结实指数平均在0.000—0.103之间。恢复株率为99.54～100%,F_1杂种有较强的苗期优势,也有种子产量和含油量优势。比芥菜型地方良种昆明高棵增产19.2～34.8%,含油量提高6.58～8.23%。芥菜型“三系”的育成,填补了我国芥菜型杂优利用的空白,势将推动芥菜型油菜杂优利用的研究。
文摘芸薹属根肿菌(Plasmodiophora brassica)侵染引起的根肿病蔓延会严重影响芥菜[Brassica juncea(L.)Czern.]的产量和品质。丝裂原活化蛋白激酶(mitogen-activated protein kinases,MAPK)级联作为一种高度保守的信号通路,在植物的生物和非生物胁迫中发挥重要作用。为了挖掘芥菜抗根肿病相关的MAPK基因,本研究对芥菜进行全基因组鉴定,并对芥菜MAPK基因家族的系统进化以及基因结构等进行生物信息学分析。筛选鉴定的66个BjuMAPK基因不均匀分布在17条染色体上。在基因组尺度上,发现基因的串联重复导致了芥菜MAPK基因数目增多。同一亚族成员之间具有相似的基因结构,不同亚族间差异较大。预测的顺式作用元件与植物激素、抗逆性以及植物的生长发育相关,表达分析显示BjuMAPK02、BjuMAPK15、BjuMAPK17和BjuMAPK19等基因在根肿菌侵染芥菜后具有不同的响应模式。以上结果为进一步研究BjuMAPK基因在芥菜应对根肿病生物胁迫中的功能奠定了理论基础。
