The fatty acid elongase 1 (FAE1) genes of Brassic napus were cloned from two cultivars, i.e. Zhong- shuan No. 9 with low erucic acid content, and Zhongyou 821 with high erucic acid content, using the degenerate PCR pr...The fatty acid elongase 1 (FAE1) genes of Brassic napus were cloned from two cultivars, i.e. Zhong- shuan No. 9 with low erucic acid content, and Zhongyou 821 with high erucic acid content, using the degenerate PCR primers. The sequence analysis showed that there was no intron within the FAE1 genes. The FAE1 genes from Zhongyou 821 contained a coding sequence of 1521 nucleotides, and those cloned from Zhongshuan No. 9 contained a 1517 bp coding sequence. Alignment of the FAE1 sequences from Brassica rapa, B. oleracea and B. napus detected 31 single nucleotide polymorphic sites (2.03%), which resulted in 7 amino-acid substitutions. Further analysis indicated that 19 SNPs were genome-specific, of which, 95% were synonymous mutations. The nucleotide substitution at po- sition 1217 in the FAE1 genes led to a specific site of restricted cleavage. An AvrII cleavage site was present only in the C genome genes and absent in the A genome FAE1 genes. Digestion profile of the FAE1 sequences from B. rapa, B. oleracea and B. napus produced with AvrII confirmed that the FAE1 genes of B. oleracea origin was recognized and digested, while that of B. rapa origin could not. The results indicated that by AvrII cleavage it was possible to distinguish B. rapa from B. oleracea and be- tween the A and C genome of B. napus. In addition, the FAE1 genes could be used as marker genes to detect the pollen flow of B. napus, thus providing an alternative method for risk assessment of gene flow.展开更多
The Nsa cytoplasmic male sterility(CMS) system confers stable male sterility and offers great potential for production of hybrid seeds in oilseed rape. However, genes responsible for male sterility in Nsa CMS have not...The Nsa cytoplasmic male sterility(CMS) system confers stable male sterility and offers great potential for production of hybrid seeds in oilseed rape. However, genes responsible for male sterility in Nsa CMS have not been identified. By mitochondrial genome sequencing of Nsa CMS and its maintainer line,we identified in an Nsa CMS line several chimeric genes encoding hypothetical proteins harboring transmembrane domains. One novel chimeric gene orf346 showed high identity with cox1 at the 50 terminal region and was co-transcribed with nad3 and rps12 genes. Transgenic plants of orf346 fused with or without mitochondrial targeting peptide conferred complete male sterility in Arabidopsis. ORF346 was mitochondrion-localized. Expression of orf346 in Escherichia coli inhibited bacterial growth, with excessive accumulation of reactive oxygen species and decreased ATP content. These results reveal a link between the newly identified mitochondrial gene orf346 and the abortion of Nsa CMS. Inadequate energy supply and excessive accumulation of reactive oxygen species may account for pollen abortion in Nsa CMS plants.展开更多
Interspecific and intergeneric hybridizations have been widely used in plant genetics and breeding to construct stocks for genetic analysis and to introduce into crops the desirable traits and genes from their relativ...Interspecific and intergeneric hybridizations have been widely used in plant genetics and breeding to construct stocks for genetic analysis and to introduce into crops the desirable traits and genes from their relatives. The intergeneric crosses between Brassica juncea (L.) Czern. & Coss., B. carinata A. Braun and Orychophragmus violaceus (L.) O. E. Schulz were made and the plants produced were subjected to genomic in situ hybridization analysis. The mixoploids from the cross with B. juncea were divided into three groups. The partially fertile mixoploids in the first group (2n = 36—42) mainly contained the somatic cells and pollen mother cells (PMCs) with the 36 chromosomes of B. juncea and additional chromosomes of O. violaceus. The mixoploids (2n = 30—36) in the second and third groups were morphologically quite similar to the mother plants B. juncea and showed nearly normal fertility. The plants in the second group produced the majority of PMCs (2n = 36) with their chromosomes paired and segregated normally, but 1—4 pairs of the O. violaceus chromosomes were included in some PMCs. The plants in the third group produced only PMCs with the 36 B. juncea chromosomes, which were paired and segregated normally. The mixoploids (2n = 29—34) from the cross with B. carinata produced the majority of PMCs (2n = 34) with normal chromosome pairing and segregation, but some plants had some PMCs with 1—3 pairs of chromosomes from O. violaceus and other plants had only PMCs with the B. carinata chromosomes. The Brassica homozygous plants and aneuploids with complete or partial chromo-some complements of Brassica parents and various numbers of O. violaceus chromosomes were derived from these progeny plants. The results in this study provided the molecular cytogenetic evidence for the separation of parental genomes which was previously proposed to occur in the hybridizations of these two genera.展开更多
In this paper the salt tolerance in Brassicas and some related species was compared. When seedlings germinated on sand cultures with liquid MS medium were considered, the relative germination rate, root length, shoot ...In this paper the salt tolerance in Brassicas and some related species was compared. When seedlings germinated on sand cultures with liquid MS medium were considered, the relative germination rate, root length, shoot length and fresh seedling weight were significantly correlated with each other (P 0.01), and only the relative shoot lengths were significantly different among the tested genotypes (P 0.05);When both seedlings germinated on MS and MS plus 0.4% NaCl were considered, only the relative shoot length of seedlings germinated on MS was significantly different from that germinated on MS + 0.4% NaCl (P 0.05), and also only the relative shoot lengths were significantly different among the tested genotypes (P 0.01). Raphanus sativa cv. Changfeng, B. juncea cv. JC and Brassica napus cv. ZS 10 showed low salt tolerance in terms of relative germination rate, root length, shoot length and fresh seedling weight;B. oleracea cv. JF-1, Sinapis alba cv. HN-2 showed high salt tolerance in terms of relative germination rate, root length, shoot length and fresh seedling weight. Based on our result we suggest that relative shoot length might be convenient to rank the salt tolerance but cluster analysis based on multiple parameters of relative germination rate, root length, shoot length and fresh seedling weight might be more accurate in screening for salt tolerance in Brassicas and related species.展开更多
A narrow genetic base has hindered improvement of Brassica juncea(A^(j)A^(j)B^(j)B^(j)).In this study,large-scale genomic components were introduced from diploid ancestor species into modern B.juncea using a digenomic...A narrow genetic base has hindered improvement of Brassica juncea(A^(j)A^(j)B^(j)B^(j)).In this study,large-scale genomic components were introduced from diploid ancestor species into modern B.juncea using a digenomic hexaploid strategy.The hexaploids A^(j)A^(j)A^(r)A^(r)B^(j)B^(j) and A^(j)A^(j)B^(j)B^(j)B^(n)B^(n) were first developed from B.juncea×B.rapa(A^(r)A^(r))and B.juncea×B.nigra(B^(n)B^(n)),and then crossed with dozens of B.nigra and B.rapa,respectively.Both types of hexaploid showed high pollen fertility and moderate seed set throughout the S_(1) to S_(3) generations,and could be crossed with diploid progenitor species under field conditions,in particular for the combination of A^(j)A^(j)B^(j)B^(j)B^(n)B^(n)×B.rapa.Thirty A^(j)A^(r)B^(n)B^(j)-type and 31 A^(j)A^(r)B^(n)B^(j)-type B.juncea resources were generated,of which the A^(j)A^(r)B^(n)B^(j) type showed higher fertility.Of these new-type B.juncea resources,97 individual plants were genotyped with 42 simple sequence repeat markers,together with 16 current B.juncea accessions and 30 hexaploid plants.Based on 180 polymorphic loci,the new-type B.juncea resources and current B.juncea were separated clearly into distinct groups,with large genetic distance between the new-type B.juncea resources and current B.juncea.Our study provides a novel approach to introducing large-scale genomic components from diploid ancestor species into B.juncea.展开更多
基金the National Natural Science Foundation of China (Grant No. 30471099)Development Plan of the State Key Fundamental Research of China (Grant No. 2006CB101600)the National High Technology and Development Program of China (Grant No. 2006AA10A113)
文摘The fatty acid elongase 1 (FAE1) genes of Brassic napus were cloned from two cultivars, i.e. Zhong- shuan No. 9 with low erucic acid content, and Zhongyou 821 with high erucic acid content, using the degenerate PCR primers. The sequence analysis showed that there was no intron within the FAE1 genes. The FAE1 genes from Zhongyou 821 contained a coding sequence of 1521 nucleotides, and those cloned from Zhongshuan No. 9 contained a 1517 bp coding sequence. Alignment of the FAE1 sequences from Brassica rapa, B. oleracea and B. napus detected 31 single nucleotide polymorphic sites (2.03%), which resulted in 7 amino-acid substitutions. Further analysis indicated that 19 SNPs were genome-specific, of which, 95% were synonymous mutations. The nucleotide substitution at po- sition 1217 in the FAE1 genes led to a specific site of restricted cleavage. An AvrII cleavage site was present only in the C genome genes and absent in the A genome FAE1 genes. Digestion profile of the FAE1 sequences from B. rapa, B. oleracea and B. napus produced with AvrII confirmed that the FAE1 genes of B. oleracea origin was recognized and digested, while that of B. rapa origin could not. The results indicated that by AvrII cleavage it was possible to distinguish B. rapa from B. oleracea and be- tween the A and C genome of B. napus. In addition, the FAE1 genes could be used as marker genes to detect the pollen flow of B. napus, thus providing an alternative method for risk assessment of gene flow.
基金supported by the National Key Research and Development Program of China (2016YFD0101300)the Natural Science Foundation of China (30871553)+3 种基金the Fundamental Research Funds for Central Nonprofit Scientific Institution (1610172017005)the Agricultural Science and Technology Innovation Program of CAAS (Group No. 118)the Hubei Agricultural Science and Technology Innovation Center (201620000001048)the China Agriculture Research System (CARS-12)。
文摘The Nsa cytoplasmic male sterility(CMS) system confers stable male sterility and offers great potential for production of hybrid seeds in oilseed rape. However, genes responsible for male sterility in Nsa CMS have not been identified. By mitochondrial genome sequencing of Nsa CMS and its maintainer line,we identified in an Nsa CMS line several chimeric genes encoding hypothetical proteins harboring transmembrane domains. One novel chimeric gene orf346 showed high identity with cox1 at the 50 terminal region and was co-transcribed with nad3 and rps12 genes. Transgenic plants of orf346 fused with or without mitochondrial targeting peptide conferred complete male sterility in Arabidopsis. ORF346 was mitochondrion-localized. Expression of orf346 in Escherichia coli inhibited bacterial growth, with excessive accumulation of reactive oxygen species and decreased ATP content. These results reveal a link between the newly identified mitochondrial gene orf346 and the abortion of Nsa CMS. Inadequate energy supply and excessive accumulation of reactive oxygen species may account for pollen abortion in Nsa CMS plants.
基金supported by the National Natural Science Foundation of China (Grant No. 30070413) and China Scholarship Council. References
文摘Interspecific and intergeneric hybridizations have been widely used in plant genetics and breeding to construct stocks for genetic analysis and to introduce into crops the desirable traits and genes from their relatives. The intergeneric crosses between Brassica juncea (L.) Czern. & Coss., B. carinata A. Braun and Orychophragmus violaceus (L.) O. E. Schulz were made and the plants produced were subjected to genomic in situ hybridization analysis. The mixoploids from the cross with B. juncea were divided into three groups. The partially fertile mixoploids in the first group (2n = 36—42) mainly contained the somatic cells and pollen mother cells (PMCs) with the 36 chromosomes of B. juncea and additional chromosomes of O. violaceus. The mixoploids (2n = 30—36) in the second and third groups were morphologically quite similar to the mother plants B. juncea and showed nearly normal fertility. The plants in the second group produced the majority of PMCs (2n = 36) with their chromosomes paired and segregated normally, but 1—4 pairs of the O. violaceus chromosomes were included in some PMCs. The plants in the third group produced only PMCs with the 36 B. juncea chromosomes, which were paired and segregated normally. The mixoploids (2n = 29—34) from the cross with B. carinata produced the majority of PMCs (2n = 34) with normal chromosome pairing and segregation, but some plants had some PMCs with 1—3 pairs of chromosomes from O. violaceus and other plants had only PMCs with the B. carinata chromosomes. The Brassica homozygous plants and aneuploids with complete or partial chromo-some complements of Brassica parents and various numbers of O. violaceus chromosomes were derived from these progeny plants. The results in this study provided the molecular cytogenetic evidence for the separation of parental genomes which was previously proposed to occur in the hybridizations of these two genera.
文摘In this paper the salt tolerance in Brassicas and some related species was compared. When seedlings germinated on sand cultures with liquid MS medium were considered, the relative germination rate, root length, shoot length and fresh seedling weight were significantly correlated with each other (P 0.01), and only the relative shoot lengths were significantly different among the tested genotypes (P 0.05);When both seedlings germinated on MS and MS plus 0.4% NaCl were considered, only the relative shoot length of seedlings germinated on MS was significantly different from that germinated on MS + 0.4% NaCl (P 0.05), and also only the relative shoot lengths were significantly different among the tested genotypes (P 0.01). Raphanus sativa cv. Changfeng, B. juncea cv. JC and Brassica napus cv. ZS 10 showed low salt tolerance in terms of relative germination rate, root length, shoot length and fresh seedling weight;B. oleracea cv. JF-1, Sinapis alba cv. HN-2 showed high salt tolerance in terms of relative germination rate, root length, shoot length and fresh seedling weight. Based on our result we suggest that relative shoot length might be convenient to rank the salt tolerance but cluster analysis based on multiple parameters of relative germination rate, root length, shoot length and fresh seedling weight might be more accurate in screening for salt tolerance in Brassicas and related species.
基金financially the National Key Research and Development Program of China(2018YFE0108000)the Natural Science Foundation of Chongqing(cstc2019jcyj-zdxm X0012)the Fundamental Research Funds for the Central Universities(XDJK2018B022,XDJK2018AA004)。
文摘A narrow genetic base has hindered improvement of Brassica juncea(A^(j)A^(j)B^(j)B^(j)).In this study,large-scale genomic components were introduced from diploid ancestor species into modern B.juncea using a digenomic hexaploid strategy.The hexaploids A^(j)A^(j)A^(r)A^(r)B^(j)B^(j) and A^(j)A^(j)B^(j)B^(j)B^(n)B^(n) were first developed from B.juncea×B.rapa(A^(r)A^(r))and B.juncea×B.nigra(B^(n)B^(n)),and then crossed with dozens of B.nigra and B.rapa,respectively.Both types of hexaploid showed high pollen fertility and moderate seed set throughout the S_(1) to S_(3) generations,and could be crossed with diploid progenitor species under field conditions,in particular for the combination of A^(j)A^(j)B^(j)B^(j)B^(n)B^(n)×B.rapa.Thirty A^(j)A^(r)B^(n)B^(j)-type and 31 A^(j)A^(r)B^(n)B^(j)-type B.juncea resources were generated,of which the A^(j)A^(r)B^(n)B^(j) type showed higher fertility.Of these new-type B.juncea resources,97 individual plants were genotyped with 42 simple sequence repeat markers,together with 16 current B.juncea accessions and 30 hexaploid plants.Based on 180 polymorphic loci,the new-type B.juncea resources and current B.juncea were separated clearly into distinct groups,with large genetic distance between the new-type B.juncea resources and current B.juncea.Our study provides a novel approach to introducing large-scale genomic components from diploid ancestor species into B.juncea.
