Sequence-related amplification polymorphism (SRAP) markers closely linked to stem nematode resistance gene were developed in sweetpotato, lpomoea batatas (L.) Lam. Using bulked segregant analysis (BSA), 200 SRAP...Sequence-related amplification polymorphism (SRAP) markers closely linked to stem nematode resistance gene were developed in sweetpotato, lpomoea batatas (L.) Lam. Using bulked segregant analysis (BSA), 200 SRAP primer combinations were screened with the resistant and susceptible bulked DNA from the 196 progenies of an F1 single-cross population of resistant parent Xu 781xsusceptible parent Xushu 18, 77 of them showed polymorphic bands between resistant and susceptible DNA. Primer combinations detecting polymorphism between the two bulks were used to screen both parents and 10 individuals from each of the bulks. The results showed that primer combination A9B4 produced 3 specific bands in the resistant plants but not in the susceptible plants, suggesting that the markers, named Nspl, Nsp2 and Nsp3, respectively, linked to a gene for stem nematode resistance. Primer combination A3B6 also produced a SRAP marker named Nsp4 linking to the resistance gene. Amplified analysis of the 196 F1 individuals indicated that the genetic distance between these markers and the resistance gene was 4.7, 4.7, 6.3, and 9.6 cM, respectively.展开更多
Allelopathic compounds have the potential to inhibit the growth and development of other organisms in a diverse manner ranging from shifting nutrients and enhancing their growth to inflicting diseases. In addition, th...Allelopathic compounds have the potential to inhibit the growth and development of other organisms in a diverse manner ranging from shifting nutrients and enhancing their growth to inflicting diseases. In addition, these compounds influence seedling growth and seed germination of various crops. The goal of this study was to identify and quantify different allelochemicals in various sweet potato cultivars through high-performance liquid chromatography techniques. Selected sweet potato slips (weight: 2.0 - 2.5 grams/slip) were propagated in separate glass tubes filled with 10.0 mL distilled water. Water extract from each glass tube was collected after 2, 4, and 6 weeks after transplanting (WAP) to identify and quantify allelochemical compounds by comparing their peaks with the retention time of standards. Results show that the concentration of allelochemicals in water extract was increased from 2 to 4 WAP but remained constant in the sixth week. Quantitative analysis revealed that the amount of chlorogenic acid was higher in all sweet potato cultivars compared to other allelochemicals. Some sweet potato cultivars, A5 and A39, exhibited higher allelopathy (18.28 - 19.37 ppm/slip) and reduced the height and biomass of Palmer amaranth the most due to the presence of increased concentration of combined allelochemicals, while other cultivars produced lesser allelochemicals (10.90 ppm/slip) and did not reduce the growth of the weed species. Allelopathic sweet potato cultivars high in chlorogenic acid production can effectively suppress Palmer amaranth with minimal dependence on chemicals to manage weeds and harmful pests under sustainable agricultural system.展开更多
Iron-sulfur cluster biosynthesis involving the nitrogen fixation(Nif) proteins has been proposed as a general mechanism acting in various organisms.NifU-like protein may play an important role in protecting plants a...Iron-sulfur cluster biosynthesis involving the nitrogen fixation(Nif) proteins has been proposed as a general mechanism acting in various organisms.NifU-like protein may play an important role in protecting plants against abiotic and biotic stresses.Based on the EST sequence selected from salt-stressed suppression subtractive hybridization(SSH) cDNA library constructed with a salt-tolerant mutant LM79,a NFU gene,termed IbNFU1,was cloned from sweetpotato(Ipomoea batatas(L.) Lam.) via rapid amplification of cDNA ends(RACE).The cDNA sequence of 1 117 bp contained an 846 bp open reading frame encoding a 281 amino acids polypeptide with a molecular weight of 30.5 kDa and an isoelectric point(pI) of 5.12.IbNFU1 gene contained a conserved Cys-X-X-Cys motif in C-terminal of the iron-sulfur cluster domain.The deduced amino acid sequence had 66.08 to 71.99% sequence identity to NFU genes reported in Arabidopsis thaliana,Eucalyptus grandis and Vitis vinifera.Real-time quantitative PCR analysis revealed that the expression level of IbNFU1 gene was significantly higher in the roots of the mutant LM79 compared to the wild-type Lizixiang.Transgenic tobacco(cv.Wisconsin 38) plants expressing IbNFU1 gene exhibited significantly higher salt tolerance compared to the untransformed control plants.It is proposed that IbNFU1 gene has an important function for salt tolerance of plants.展开更多
AFLP fingerprinting of the 98 main sweetpotato varieties planted in China has been constructed. Using 17 AFLP primer combinations which were selected from 1 208 primer combinations and generated the most amounts of po...AFLP fingerprinting of the 98 main sweetpotato varieties planted in China has been constructed. Using 17 AFLP primer combinations which were selected from 1 208 primer combinations and generated the most amounts of polymorphic bands, AFLP analysis of the 98 main sweetpotato varieties gave a total of 410 clear polymorphic bands with an average of 24.12 polymorphic bands per primer combination. Each one of the 98 sweetpotato varieties could be clearly distinguished by EcoR I-cta/Mse I-ggc primer combination which generated the most polymorphic bands. AFLP-based genetic distance ranged from 0.0546 to 0.5709 with an average of 0.3799. The dendrogram based on AFLP markers indicated that sweetpotato varieties coming from the same regions or having same parents were clustered in the same groups. Analysis of molecular variance (AMOVA) revealed greater variations within regions (94.08%) than among regions (5.92%). Thus, the genetic variations mainly existed within regions, while the variations among regions were very low in the tested sweetpotato varieties. Significant genetic variations existed between "Northern" and "Southern" sweetpotato varieties when Yangtze River was used as the dividing line.展开更多
Sweetpotato,Ipomoea batatas(L.) Lam.,is a globally important food crop and usually grown on arid-and semi-arid lands.Therefore,investigating the molecular mechanism of drought tolerance will provide important informat...Sweetpotato,Ipomoea batatas(L.) Lam.,is a globally important food crop and usually grown on arid-and semi-arid lands.Therefore,investigating the molecular mechanism of drought tolerance will provide important information for the improvement of drought tolerance in this crop.In this study,transcriptome analysis of the drought-tolerant sweetpotato line Xushu 55-2 was conducted on Illumina HiSeq 2500 platform.A total of 86.69 Gb clean data were generated and assembled into 2 671 693 contigs,222 073 transcripts,and 73 636 unigenes.In total,11 359 differentially expressed genes(DEGs) were identified after PEG6000 treatment,in which 7 666 were up-regulated and 3 693 were down-regulated.Of the 11 359 DEGs,10 192 DEGs were annotated in at least one database,and the remaining 1 167 DEGs were unknown.Abscisic acid(ABA),ethylene(ETH),and jasmonic acid(JA) signalling pathways play a major role in drought tolerance of sweetpotato.Drought-inducible transcription factors were identified,some of which have been reported to be associated with drought tolerance and others are unknown in plants.In addition,7 643 SSRs were detected.This study not only reveals insights into the molecular mechanism of drought tolerance in sweetpotato but also provides the candidate genes involved in drought tolerance of this crop.展开更多
Enhanced stem nematode resistance of transgenic sweetpotato (cv. Lizixiang) was achieved using Oryzacystatin-I (OCI) gene with Agrobacterium tumefaciens-mediated transformation. A. tumefaciens strain EHA105 harbor...Enhanced stem nematode resistance of transgenic sweetpotato (cv. Lizixiang) was achieved using Oryzacystatin-I (OCI) gene with Agrobacterium tumefaciens-mediated transformation. A. tumefaciens strain EHA105 harbors a binary vector pCAMBIA1301 with OCI gene, gusA gene and hptII gene. Selection culture was conducted using 25 mg L-1 hygromycin. A total of 1 715 plants were produced from the inoculated 1 450 cell aggregates of Lizixiang via somatic embryogenesis. GUS assay and PCR analysis of the putative transgenic plants randomly sampled showed that 90.54% of them were transgenic plants. Transgenic plants exhibited significantly enhanced resistance to stem nematodes compared to the untransformed control plants by the field evaluation with stem nematodes. Stable integration of the OCI gene into the genome of resistant transgenic plants was confirmed by Southern blot analysis, and the copy number of integrated OCI gene ranged from 1 to 4. Transgene overexpression in stem nematode-resistant plants was demonstrated by quantitative real-time PCR analysis. This study provides a way for improving stem nematode resistance in sweetpotato.展开更多
Trehalose plays an important role in metabolic regulation and abiotic stress tolerance in a variety of organisms. In plants, its biosynthesis is catalyzed by two key enzymes: trehalose-6-phosphate synthase(TPS) and...Trehalose plays an important role in metabolic regulation and abiotic stress tolerance in a variety of organisms. In plants, its biosynthesis is catalyzed by two key enzymes: trehalose-6-phosphate synthase(TPS) and trehalose-6-phosphate phosphatase(TPP). In the present study, a TPS gene, named IbTPS, was first isolated from sweetpotato(Ipomoea batatas(L.) Lam.) cv. Lushu 3 by rapid amplification of cDNA ends(RACE). The open reading frame(ORF) contained 2 580 nucleotides encoding 859 amino acids with a molecular weight of 97.433 kDa and an isoelectric point(pI) of 5.7. The deduced amino acid sequence showed high identities with TPS of other plants. Real-time quantitative PCR analysis revealed that the expression level of IbTPS gene was significantly higher in stems of Lushu 3 than in its leaves and roots. Subcellular localization analysis in onion epidermal cells indicated that IbTPS gene was located in the nucleus. Transgenic tobacco(cv. Wisconsin 38) plants over-expressing IbTPS gene exhibited significantly higher salt tolerance compared with the control plant. Trehalose and proline content was found to be significantly more accumulated in transgenic tobacco plants than in the wild-type and several stress tolerance related genes were up-regulated. These results suggest that IbTPS gene may enhance salt tolerance of plants by increasing the amount of treahalose and proline and regulating the expression of stress tolerance related genes.展开更多
Geranylgeranyl pyrophosphate synthase(GGPS) plays an important role in the biosynthesis of carotenoids. In a previous study, the IbGGPS gene was isolated from a sweetpotato, Ipomoea batatas(L.) Lam., line Nongdafu 14 ...Geranylgeranyl pyrophosphate synthase(GGPS) plays an important role in the biosynthesis of carotenoids. In a previous study, the IbGGPS gene was isolated from a sweetpotato, Ipomoea batatas(L.) Lam., line Nongdafu 14 with high carotenoid contents, but its role and underlying mechanisms in carotenoid biosynthesis in sweetpotato were not investigated. In the present study, the IbGGPS gene was introduced into a sweetpotato cv. Lizixiang and the contents of β-carotene, β-cryptoxanthin, zeaxanthin and lutein were significantly increased in the storage roots of the IbGGPSoverexpressing sweetpotato plants. Further analysis showed that IbGGPS gene overexpression systematically upregulated the genes involved in the glycolytic, 2-C-methyl-D-erythritol-4-phosphate(MEP) and carotenoid pathways,which increased the carotenoid contents in the transgenic plants. These results indicate that the IbGGPS gene has the potential for use in improving the carotenoid contents in sweetpotato and other plants.展开更多
Fusarium wilt,a disease caused by Fusarium oxysporum f.sp batatas(Fob)is an important disease in sweet potato production.Using endophytic bacteria for biological control of sweet potato diseases is one of the importan...Fusarium wilt,a disease caused by Fusarium oxysporum f.sp batatas(Fob)is an important disease in sweet potato production.Using endophytic bacteria for biological control of sweet potato diseases is one of the important ways.A Bacillus subtilis with antagonistic effect on Fusarium wilt of sweet potato was isolated from soil by confrontation culture.According to the biological characteristics,16S rDNA sequence analysis,and physiological and biochemical analysis,the Bacillus subtilis HAAS01 was named.A pot experiment was conducted for the biological control experiment of strain HAAS01,and the endogenous hormone content,antioxidant enzyme activity,soluble protein content,and related gene expressions of sweet potato plants were detected.The results showed that the HAAS01 strain could promote the production of endogenous hormones and resist the infection of plant diseases together with defensive enzymes and upregulation of related gene expressions.In summary,Bacillus subtilis HAAS01 was effective in controlling Fusarium wilt of sweet potato and has potential for application and development.展开更多
基金supported by China Agriculture Research System (CARS-11, Sweetpotato)the National 863 Program of China (2012AA101204)
文摘Sequence-related amplification polymorphism (SRAP) markers closely linked to stem nematode resistance gene were developed in sweetpotato, lpomoea batatas (L.) Lam. Using bulked segregant analysis (BSA), 200 SRAP primer combinations were screened with the resistant and susceptible bulked DNA from the 196 progenies of an F1 single-cross population of resistant parent Xu 781xsusceptible parent Xushu 18, 77 of them showed polymorphic bands between resistant and susceptible DNA. Primer combinations detecting polymorphism between the two bulks were used to screen both parents and 10 individuals from each of the bulks. The results showed that primer combination A9B4 produced 3 specific bands in the resistant plants but not in the susceptible plants, suggesting that the markers, named Nspl, Nsp2 and Nsp3, respectively, linked to a gene for stem nematode resistance. Primer combination A3B6 also produced a SRAP marker named Nsp4 linking to the resistance gene. Amplified analysis of the 196 F1 individuals indicated that the genetic distance between these markers and the resistance gene was 4.7, 4.7, 6.3, and 9.6 cM, respectively.
文摘Allelopathic compounds have the potential to inhibit the growth and development of other organisms in a diverse manner ranging from shifting nutrients and enhancing their growth to inflicting diseases. In addition, these compounds influence seedling growth and seed germination of various crops. The goal of this study was to identify and quantify different allelochemicals in various sweet potato cultivars through high-performance liquid chromatography techniques. Selected sweet potato slips (weight: 2.0 - 2.5 grams/slip) were propagated in separate glass tubes filled with 10.0 mL distilled water. Water extract from each glass tube was collected after 2, 4, and 6 weeks after transplanting (WAP) to identify and quantify allelochemical compounds by comparing their peaks with the retention time of standards. Results show that the concentration of allelochemicals in water extract was increased from 2 to 4 WAP but remained constant in the sixth week. Quantitative analysis revealed that the amount of chlorogenic acid was higher in all sweet potato cultivars compared to other allelochemicals. Some sweet potato cultivars, A5 and A39, exhibited higher allelopathy (18.28 - 19.37 ppm/slip) and reduced the height and biomass of Palmer amaranth the most due to the presence of increased concentration of combined allelochemicals, while other cultivars produced lesser allelochemicals (10.90 ppm/slip) and did not reduce the growth of the weed species. Allelopathic sweet potato cultivars high in chlorogenic acid production can effectively suppress Palmer amaranth with minimal dependence on chemicals to manage weeds and harmful pests under sustainable agricultural system.
基金supported by the China Agricultural Research System (Sweetpotato)the National High-Tech Research and Development Program of China(2009AA10Z102)+1 种基金the National Transgenic Plants Project of China (2009ZX08009-064B)the National Natural Science Foundation of China (31071468)
文摘Iron-sulfur cluster biosynthesis involving the nitrogen fixation(Nif) proteins has been proposed as a general mechanism acting in various organisms.NifU-like protein may play an important role in protecting plants against abiotic and biotic stresses.Based on the EST sequence selected from salt-stressed suppression subtractive hybridization(SSH) cDNA library constructed with a salt-tolerant mutant LM79,a NFU gene,termed IbNFU1,was cloned from sweetpotato(Ipomoea batatas(L.) Lam.) via rapid amplification of cDNA ends(RACE).The cDNA sequence of 1 117 bp contained an 846 bp open reading frame encoding a 281 amino acids polypeptide with a molecular weight of 30.5 kDa and an isoelectric point(pI) of 5.12.IbNFU1 gene contained a conserved Cys-X-X-Cys motif in C-terminal of the iron-sulfur cluster domain.The deduced amino acid sequence had 66.08 to 71.99% sequence identity to NFU genes reported in Arabidopsis thaliana,Eucalyptus grandis and Vitis vinifera.Real-time quantitative PCR analysis revealed that the expression level of IbNFU1 gene was significantly higher in the roots of the mutant LM79 compared to the wild-type Lizixiang.Transgenic tobacco(cv.Wisconsin 38) plants expressing IbNFU1 gene exhibited significantly higher salt tolerance compared to the untransformed control plants.It is proposed that IbNFU1 gene has an important function for salt tolerance of plants.
基金China Agriculture Research System (Sweetpotato) and Chinese Universities Scientific Fund (2012YJ008)
文摘AFLP fingerprinting of the 98 main sweetpotato varieties planted in China has been constructed. Using 17 AFLP primer combinations which were selected from 1 208 primer combinations and generated the most amounts of polymorphic bands, AFLP analysis of the 98 main sweetpotato varieties gave a total of 410 clear polymorphic bands with an average of 24.12 polymorphic bands per primer combination. Each one of the 98 sweetpotato varieties could be clearly distinguished by EcoR I-cta/Mse I-ggc primer combination which generated the most polymorphic bands. AFLP-based genetic distance ranged from 0.0546 to 0.5709 with an average of 0.3799. The dendrogram based on AFLP markers indicated that sweetpotato varieties coming from the same regions or having same parents were clustered in the same groups. Analysis of molecular variance (AMOVA) revealed greater variations within regions (94.08%) than among regions (5.92%). Thus, the genetic variations mainly existed within regions, while the variations among regions were very low in the tested sweetpotato varieties. Significant genetic variations existed between "Northern" and "Southern" sweetpotato varieties when Yangtze River was used as the dividing line.
基金supported by the earmarked fund for China Agriculture Research System (CARS-10,Sweetpotato)
文摘Sweetpotato,Ipomoea batatas(L.) Lam.,is a globally important food crop and usually grown on arid-and semi-arid lands.Therefore,investigating the molecular mechanism of drought tolerance will provide important information for the improvement of drought tolerance in this crop.In this study,transcriptome analysis of the drought-tolerant sweetpotato line Xushu 55-2 was conducted on Illumina HiSeq 2500 platform.A total of 86.69 Gb clean data were generated and assembled into 2 671 693 contigs,222 073 transcripts,and 73 636 unigenes.In total,11 359 differentially expressed genes(DEGs) were identified after PEG6000 treatment,in which 7 666 were up-regulated and 3 693 were down-regulated.Of the 11 359 DEGs,10 192 DEGs were annotated in at least one database,and the remaining 1 167 DEGs were unknown.Abscisic acid(ABA),ethylene(ETH),and jasmonic acid(JA) signalling pathways play a major role in drought tolerance of sweetpotato.Drought-inducible transcription factors were identified,some of which have been reported to be associated with drought tolerance and others are unknown in plants.In addition,7 643 SSRs were detected.This study not only reveals insights into the molecular mechanism of drought tolerance in sweetpotato but also provides the candidate genes involved in drought tolerance of this crop.
基金supported by the Earmarked Fund for Modern Agro-Industry Technology Research System(Sweetpotato), Chinathe National High-Tech R&D Pro-gram of China (2009AA10Z102)+2 种基金the National Transgenic Plants Project of China (2009ZX08009-064B)the Natinal NaturalScience Foundation of China(30871570)the Scientific Fund to Graduate Re-search and Innovation Projects of China Agricultural University (15059201-kycx09018)
文摘Enhanced stem nematode resistance of transgenic sweetpotato (cv. Lizixiang) was achieved using Oryzacystatin-I (OCI) gene with Agrobacterium tumefaciens-mediated transformation. A. tumefaciens strain EHA105 harbors a binary vector pCAMBIA1301 with OCI gene, gusA gene and hptII gene. Selection culture was conducted using 25 mg L-1 hygromycin. A total of 1 715 plants were produced from the inoculated 1 450 cell aggregates of Lizixiang via somatic embryogenesis. GUS assay and PCR analysis of the putative transgenic plants randomly sampled showed that 90.54% of them were transgenic plants. Transgenic plants exhibited significantly enhanced resistance to stem nematodes compared to the untransformed control plants by the field evaluation with stem nematodes. Stable integration of the OCI gene into the genome of resistant transgenic plants was confirmed by Southern blot analysis, and the copy number of integrated OCI gene ranged from 1 to 4. Transgene overexpression in stem nematode-resistant plants was demonstrated by quantitative real-time PCR analysis. This study provides a way for improving stem nematode resistance in sweetpotato.
基金supported by the National Natural Science Foundation of China (31271777)the China Agriculture Research System (CARS-11, Sweetpotato)+1 种基金the National High-Tech R&D Program of China (2012AA101204)the Beijing Key Discipline Program, China
文摘Trehalose plays an important role in metabolic regulation and abiotic stress tolerance in a variety of organisms. In plants, its biosynthesis is catalyzed by two key enzymes: trehalose-6-phosphate synthase(TPS) and trehalose-6-phosphate phosphatase(TPP). In the present study, a TPS gene, named IbTPS, was first isolated from sweetpotato(Ipomoea batatas(L.) Lam.) cv. Lushu 3 by rapid amplification of cDNA ends(RACE). The open reading frame(ORF) contained 2 580 nucleotides encoding 859 amino acids with a molecular weight of 97.433 kDa and an isoelectric point(pI) of 5.7. The deduced amino acid sequence showed high identities with TPS of other plants. Real-time quantitative PCR analysis revealed that the expression level of IbTPS gene was significantly higher in stems of Lushu 3 than in its leaves and roots. Subcellular localization analysis in onion epidermal cells indicated that IbTPS gene was located in the nucleus. Transgenic tobacco(cv. Wisconsin 38) plants over-expressing IbTPS gene exhibited significantly higher salt tolerance compared with the control plant. Trehalose and proline content was found to be significantly more accumulated in transgenic tobacco plants than in the wild-type and several stress tolerance related genes were up-regulated. These results suggest that IbTPS gene may enhance salt tolerance of plants by increasing the amount of treahalose and proline and regulating the expression of stress tolerance related genes.
基金supported by the National Key Research and Development Program of China(2019YFD1001302 and 2019YFD1001300)the China Agriculture Research System of MOF and MARA(CARS-10-Sweetpotato)。
文摘Geranylgeranyl pyrophosphate synthase(GGPS) plays an important role in the biosynthesis of carotenoids. In a previous study, the IbGGPS gene was isolated from a sweetpotato, Ipomoea batatas(L.) Lam., line Nongdafu 14 with high carotenoid contents, but its role and underlying mechanisms in carotenoid biosynthesis in sweetpotato were not investigated. In the present study, the IbGGPS gene was introduced into a sweetpotato cv. Lizixiang and the contents of β-carotene, β-cryptoxanthin, zeaxanthin and lutein were significantly increased in the storage roots of the IbGGPSoverexpressing sweetpotato plants. Further analysis showed that IbGGPS gene overexpression systematically upregulated the genes involved in the glycolytic, 2-C-methyl-D-erythritol-4-phosphate(MEP) and carotenoid pathways,which increased the carotenoid contents in the transgenic plants. These results indicate that the IbGGPS gene has the potential for use in improving the carotenoid contents in sweetpotato and other plants.
基金the National Key R&D Program of China,2019YFD1001300 and 2019YFD1001305China Agriculture Research System of MOF and MARA,China.
文摘Fusarium wilt,a disease caused by Fusarium oxysporum f.sp batatas(Fob)is an important disease in sweet potato production.Using endophytic bacteria for biological control of sweet potato diseases is one of the important ways.A Bacillus subtilis with antagonistic effect on Fusarium wilt of sweet potato was isolated from soil by confrontation culture.According to the biological characteristics,16S rDNA sequence analysis,and physiological and biochemical analysis,the Bacillus subtilis HAAS01 was named.A pot experiment was conducted for the biological control experiment of strain HAAS01,and the endogenous hormone content,antioxidant enzyme activity,soluble protein content,and related gene expressions of sweet potato plants were detected.The results showed that the HAAS01 strain could promote the production of endogenous hormones and resist the infection of plant diseases together with defensive enzymes and upregulation of related gene expressions.In summary,Bacillus subtilis HAAS01 was effective in controlling Fusarium wilt of sweet potato and has potential for application and development.