The influence of nitrification inhibitor(NI) 3,4 dimethylpyrazole phosphate(DMPP) on nitrate accumulation in greengrocery( Brassica campestris L. ssp. chinensis ) and vegetable soil at surface layer were investigated ...The influence of nitrification inhibitor(NI) 3,4 dimethylpyrazole phosphate(DMPP) on nitrate accumulation in greengrocery( Brassica campestris L. ssp. chinensis ) and vegetable soil at surface layer were investigated in field experiments in 2002 and 2003 Results showed that NI DMPP took no significant effect on yields of edible parts of greengrocery, but it could significantly decrease NO - 3 N concentration in greengrocery and in vegetable soil at surface layer. In addition, NI DMPP could reduce the NO - 3 N concentration during the prophase stage of storage.展开更多
Glucosinolates (GSs) are a group of plant secondary metabolites containing abundant nitrogen (N) and sulfur (S) mainly in Brassica and have the beneficial effects on human health including anti-carcinogenic, cho...Glucosinolates (GSs) are a group of plant secondary metabolites containing abundant nitrogen (N) and sulfur (S) mainly in Brassica and have the beneficial effects on human health including anti-carcinogenic, cholesterol-reducing and other pharmacological effects. The objective of this study was to investigate the effect of different concentrations of N (5, 10, and 20 mmol L-a, denoted by N5, N10 and N20) and S (0,5, 1, and 2 mmol L^-1, denoted by S0.5, S1 and S2) on the yield and GSs in pakchoi (Brassica campestris L. ssp. chinensis var. communis) in hydroponics. Results showed that N10 and N20 significantly enhanced the yield compared with N5, however, N20 had a negative effect relative to N10. Only with N10 and N20 low S supply (S0.5) reduced the yield. The concentrations of aliphatic GSs, aromatic GS and total GSs were enhanced by N5 and indolyl GSs were enhanced by N20. S2 enhanced the concentration of individual GS and total GSs. The concentrations of indolyl GSs were maximized in N20S2 treatment, whereas the highest concentrations of aliphatic GSs, aromatic GS and total GSs were found in N5S2 treatment. Effects of N and S on aliphatic GSs were higher than on indolyl GSs. The results suggest that the accumulation of aliphatic GSs and aromatic GS could be enhanced by low N and high S and restricted by high N while that of indolyl GSs could be enhanced by high N and high S.展开更多
A molecular genetic map of Chinese cabbage was constructed with a 102 recombinant inbred (RI) population from a cross of two cultivated Chinese cabbage lines 177 and 276, using AFLP and RAPD markers. 352 markers inclu...A molecular genetic map of Chinese cabbage was constructed with a 102 recombinant inbred (RI) population from a cross of two cultivated Chinese cabbage lines 177 and 276, using AFLP and RAPD markers. 352 markers including 265 AFLP markers and 87 RAPD markers were integrated into 17 linkage groups. It covered a total of 2 665. 7 cM with an average interval of 7. 6 cM. AFLP marker is efficient for map construction while it easily forms clusters to cause big gaps in map. A total of 13.92 % abnormal segregation markers distributed in the map. The molecular genetic map is fundamental for gene localization, comparative genomics, and QTL mapping of important agronomic traits.展开更多
Black rot, caused by Xanthomonas campestris pv. campestris (Xcc) is possibly the most important disease of Brassica worldwide. To compare chromosomal positions of Xcc resistance loci in Brassica oleracea between the p...Black rot, caused by Xanthomonas campestris pv. campestris (Xcc) is possibly the most important disease of Brassica worldwide. To compare chromosomal positions of Xcc resistance loci in Brassica oleracea between the present and published studies and to develop marker assisted selection (MAS) to resistance against Xcc race 1, we constructed a B. oleracea map, including pW, pX and BoCL markers that were closely linked to previously reported Xcc resistance QTLs. We also analyzed Xcc resistance QTLs by improving our previously reported map derived from the cross of a susceptible double-haploid line (GC P09) with a resistant double-haploid line (Reiho P01). In the nine linkage groups obtained (C1-C9), the major QTL, XccBo(Reiho)2, was derived from Reiho with a maximum LOD score (7.7) in C8. The QTL (LOD 4.4) located in C9, XccBo(GC)1 was derived from the susceptible GC. The other QTL (LOD 4.4), XccBo(Reiho)1, was found in C5. Based on common markers, it was possible to compare our finding Xcc resistance QTLs with the B. oleraceaXcc loci reported by previous authors;XccBo(Reiho)1 and XccBo(GC)1 may be identical to the Xcc resistance QTLs reported previously or a different member contained in the same resistance gene cluster. Our map includes public SSR markers linked to Xcc resistance genes that will promote pyramiding Xcc resistance genes in B. oleracea. The present study will also contribute to a better understanding of genetic control of Xcc resistance.展开更多
To determine differential expression of genie male sterility A/B lines in Chinese cabbage-pak-choi (Brassica campestris ssp. chinensis Makino var. communis Tsen et Lee), we used the RNA fingerprinting technique, cDNA-...To determine differential expression of genie male sterility A/B lines in Chinese cabbage-pak-choi (Brassica campestris ssp. chinensis Makino var. communis Tsen et Lee), we used the RNA fingerprinting technique, cDNA-AFLP analysis, in different developmental stages and different tissues. While no obvious differential expressions were observed in rosette leaves, florescence leaves, and scapes, some differential expressions were found in alabstrums of A/B lines and among leaves, scapes and alabstrums. We analyzed the al-abstrums collected in different developmental stages with 10 primer combinations. We got a unique band between middle size alabstrums and large alabstrums in B line in one of the ten pair primers, and in another one pair, one band reflecting a higher gene-expression level in A line than that in B line was obtained. No unique bands were found with the other primer combinations. The bands reflecting different gene-expression level were confirmed by Northern hybridization. The results indicated that cDNA-AFLP was a suitable tool for studying differential expression of genie male sterility in plants. SDS-polyacrylamide gel electrophoresis patterns of soluble proteins further verified the difference in A/B lines.展开更多
This article investigates the responses of Brassica campestris seedlings to an acute level of nitrogen dioxide (NO2) exposure in a plant growth chamber, and examines whether pretreating plants with hydrogen peroxide...This article investigates the responses of Brassica campestris seedlings to an acute level of nitrogen dioxide (NO2) exposure in a plant growth chamber, and examines whether pretreating plants with hydrogen peroxide (H2O2) will alleviate NO2-caused injury. Twenty-eight-day-old B. campestris plants sprayed with 10 mmol L^-1 H2O2 aqueous solution (corresponding to approximate 1.0 mg H2O2 per single plant) were exposed to different concentrations of NO2 (0.25, 0.5, 1.0, and 2.0 μL L^-1, respectively) for 24 h under controlled environment. To measure the plant biomass, the plants were fumigated with the same NO2 concentrations as mentioned above for 7 h per day (8.00-15.00) for 7 days. As a control, charcoal filtered air alone was applied. Data were collected on plant biomass, total chlorophyll, photosynthetic rate, stomatal conductance, nitrate and nitrate reductase (NR), antioxidative enzymes, ascorbate (ASA), and malondialdehyde (MDA), immediately after exposure. The results showed that exposure to a moderate dose of NO2 (e.g., 0.25 μL L^-1) had a favorable effect on plants, and the dry weight of the above-ground part increased, whereas the exposure to high NO2 concentrations (e.g., 0.5 μL L^-1 or higher) caused a reduction in the plant biomass and the total chlorophyll, when compared with the control. In addition, at 0.5 μL L^-1 or higher NO2 concentrations, prominent increases in the MDA level and superoxide dismutase (SOD) and NR activities were observed. Exposure to 1 μL L^-1 and higher NO2 resulted in necroses appearing on older leaves, and an increase in catalase (CAT) activity, decrease in ASA content, increased accumulation of NO3^-, and reduction in photosynthesis, when compared with the controls. No changes were detected in stomatal conductance under NO2 fumigation. The pretreatment with 10 mmol L^-1 H2O2 alleviated significantly NO2- caused biomass decrease and photosynthetic inhibition when compared with H2O2-untreated plants. Under NO2 fumigation, further induction in SOD and CAT activities occurred in H2O2 treated plants when compared with H2O2- untreated plants. The effect of NO2 on the ASA and MDA contents was also absent in H2O2-treated plants. However, the H2O2 treatment did not alter the nitrate content and NR activity in plants under NO2 fumigation. The H2O2 treatment caused a lower rate of stomatal conductance. Taken together, these data suggest that fumigation with an acute level of NO2 causes oxidative damage to B. campestris seedlings. The H2O2 pretreatment markedly protects plants against NO2 stress and this may be associated with inducible antioxidative level. NO2 fumigation contributes, at least in part, to the enhanced levels of nitrate in B. campestris leaves.展开更多
The study analyzed the silencing of BcMF12 gene regulated by BcA9 promoter in the transgenic pakchoi and confirmed the effect of antisense BcMF12 gene on the pollen development. A conserved BcMF12 gene fragment was am...The study analyzed the silencing of BcMF12 gene regulated by BcA9 promoter in the transgenic pakchoi and confirmed the effect of antisense BcMF12 gene on the pollen development. A conserved BcMF12 gene fragment was amplified from the cDNA of flower buds in pakchoi (Brassica campestris L. ssp. chinensis, syn. B. rapa L. ssp. chinensis) and was fused to the anther specific BcA9 promoter. The plant antisense expression vector was constructed and then introduced into pakchoi via Agrobacterium-mediated transformation. The transgenic plants were screened by antibiotics and molecular analysis. PCR and Southern blot revealed that the antisense BcMF12-GUS fusion gene regulated by BcA9 promoter was integrated into transgenic plants. Northern blot suggested that the expression of BcMF12 gene was down-regulated significantly. The pollen germination rate of transgenic plants with antisense BcMF12 gene decreased as compared with that of the control plants. The expression of the gene BcMF12 related to the pollen development was inhibited by the antisense BcMF12 driven by BcA9 promoter, which consequently affected the pollen development in pakchoi.展开更多
The plant immune system is divided into two branches;one branch is based on the recognition of pathogenassociated molecular patterns(PAMP-triggered immunity),and the other relies on pathogenic effector detection(effec...The plant immune system is divided into two branches;one branch is based on the recognition of pathogenassociated molecular patterns(PAMP-triggered immunity),and the other relies on pathogenic effector detection(effector-triggered immunity).Despite each branch being involved in different complex mechanisms,both lead to transcription reprogramming and,thus,changes in plant metabolism.To study the defense mechanisms involved in the Brassica oleracea–Xanthomonas campestris pv.campestris(Xcc)interaction,we analyzed the plant transcriptome dynamics at 3 and 12 days postinoculation(dpi)by using massive analysis of 3′-cDNA ends.We identified more induced than repressed transcripts at both 3 and 12 dpi,although the response was greater at 12 dpi.Changes in the expression of genes related to the early infection stages were only detected at 12 dpi,suggesting that the timing of triggered defenses is crucial to plant survival.qPCR analyses in susceptible and resistant plants allowed us to highlight the potential role of two calcium-signaling proteins,CBP60g and SARD1,in the resistance against Xcc.This role was subsequently confirmed using Arabidopsis knockout mutants.展开更多
Using three varieties of Brassica campestris, Hauarad (708), Maoshan-3 (714) and Youbai (715),as the maternal plants and one variety of Brassica oleracea Jingfeng-1 (6012) as paternalplants, crosses were made to produ...Using three varieties of Brassica campestris, Hauarad (708), Maoshan-3 (714) and Youbai (715),as the maternal plants and one variety of Brassica oleracea Jingfeng-1 (6012) as paternalplants, crosses were made to produce interspecific hybrids through ovary culture techniques.The ovaries from the cross between B. campestrisB.oleracea (7086012 and 7146012) werecultured and ovary culture was more effective in terms of obtained seeds when ovaries werecultured in vitro at 9 d after pollination (DAP). While for the cross of 7156012, it wasbetter when ovaries in vitro cultured at 12 DAP. Among three cross combinations, the cross of7146012 showed the best response and 43 seeds per ovary were obtained. Among the mediastudied, the ovaries from the cross of 7086012 cultured on MS media supplemented with 3.0 mgL-1 BA0.1 mg L-1 NAA showed better response, and its rate of seeds per ovary reached 44.0%.While the ovaries from the other two crosses (7146012 and 7156012) showed the best responsewhen cultured on B5 media supplemented with 3.0 mg L-1 BA + 0.2 mg L-1 NAA, and the rates of seedsper ovary reached 72.0 and 60.0%, respectively. All seeds obtained from the three crosscombinations were cultured on the MS media supplemented with 1.0 mg L-1 BA + 0.05 mg L-1 NAA,and the seeds from the cross of 7156012 showed the best germination response and thepercentage of germinations reached 66.7%. The regenerated plantlets were obtained from theseseedlings after cultured on the MS media supplemented with 0.05 mg L-1 NAA. Cytological studyshowed that these regenerated plants were all true hybrids of B.campestrisB.oleracea.展开更多
Bacterial spot(BS)is a severe bacterial disease induced by Xanthomonas campestris pv.vesicatoria(Xcv),a pathogen that causes serious damage to pepper growth and yield.It is therefore important to study the mechanisms ...Bacterial spot(BS)is a severe bacterial disease induced by Xanthomonas campestris pv.vesicatoria(Xcv),a pathogen that causes serious damage to pepper growth and yield.It is therefore important to study the mechanisms of pepper resistance to Xcv and to breed and promote Xcvresistant pepper varieties.However,studies of the responses to Xcv infection in peppers at the protein level are limited.Here,we examined Xcv-induced proteomic changes in leaves of the BS susceptible bell pepper ECW and the resistant bell pepper VI037601 using the isobaric tags for relative and absolute quantitation(iTRAQ)-based protein labeling technology.A total of 6,120 distinct proteins were identified,and there were 1,289 significantly differentially accumulated proteins(DAPs)in ECW and VI037601 leaves after Xcv inoculation.Among these,339(250up-and 89 down-regulated)and 479(300 up-and 179 down-regulated)DAPs were specifically identified in ECW and VI037601,respectively,with 459(364 up-and 95 down-regulated)similarly expressed DAPs being shared by ECW and VI037601.Based on bioinformatics analysis,many defense-associated proteins were identified as up-regulated in ECW and VI037601,especially the proteins involved in plant-pathogen interaction,phenylpropanoid biosynthesis,protein processing in the endoplasmic reticulum,and MAPK signaling pathway-plant.Moreover,we evaluated transcript levels of six differentially expressed genes from the iTRAQ results by q RT-PCR.The analysis revealed transcriptional changes that were consistent with the changes at the protein level.This study will provide a valuable resource for understanding the molecular basis of pepper resistance to Xcv infection and for improving the disease resistance of pepper cultivars.展开更多
Lettuce yields can be reduced by the disease bacterial leaf spot(BLS)caused by the pathogen Xanthomonas campestris pv.vitians(Xcv)and host resistance is the most feasible method to reduce disease losses.The cultivars ...Lettuce yields can be reduced by the disease bacterial leaf spot(BLS)caused by the pathogen Xanthomonas campestris pv.vitians(Xcv)and host resistance is the most feasible method to reduce disease losses.The cultivars La Brillante,Pavane and Little Gem express an incompatible host–pathogen interaction as a hypersensitive response(HR)to California strains of Xcv resulting in resistance.Little was known about the inheritance of resistance;however,resistance to other lettuce pathogens is often determined by resistance gene candidates(RGCs)encoding nucleotide-binding leucine-rich repeat(NB-LRR)proteins.Therefore,we determined the inheritance of BLS resistance in the cultivars La Brillante,Little Gem and Pavane and mapped it relative to RGCs.The reaction to Xcv was analyzed in nine F_(1),F_(2) and recombinant inbred line populations of lettuce from HR3compatible or HR3HR crosses.The HR in La Brillante,Pavane and Little Gem is conditioned by single dominant genes,which are either allelic or closely linked genes.The resistance gene in La Brillante was designated Xanthomonas resistance 1(Xar1)and mapped to lettuce linkage group 2.Xar1 is present in a genomic region that contains numerous NB-LRR encoding RGCs and functional pathogen resistance loci in the RGC2 family.The Xar1 gene confers a high level of BLS resistance in the greenhouse and field that can be introgressed into commercial lettuce cultivars to reduce BLS losses using molecular markers.展开更多
In this work, the localization, density, morphology and ultrastructure of secretory structures in aerial organs of Flourensia campestris (FC) and F. oolepis (FO) (Asteraceae) by means of a combination of light, fluore...In this work, the localization, density, morphology and ultrastructure of secretory structures in aerial organs of Flourensia campestris (FC) and F. oolepis (FO) (Asteraceae) by means of a combination of light, fluorescence, transmission (TEM) and scanning electron microscopy (SEM) were examined. The possible role of secretory structures in the production and secretion of the phytotoxic sesquiterpene (-)-hamanasic acid A ((-)HAA) in both species was also assessed. Capitate glandular trichomes were found in all reproductive organs of FC and FO, and were being reported for the first time. These glandular trichomes, typically associated to edges and veins, were of the same type as those already described for vegetative organs, and were abundant in involucral bracts and corolla of tubulose and ligulate flowers. Their density in reproductive organs of both species was similar (ca. 30/mm2) and lower than that found in leaves (ca. 100/mm2) and stems (ca. 160/mm2 in FC, and up to 650/mm2 in FO). Glandular trichomes in vegetative organs followed a species-specific pattern of distribution. TEM and SEM observations suggest that each species differs in the way in which secretory materials are released to the outside: through cracks or pores in FC, or through a loose cuticle in FO. Similar inspections of the secretory ducts revealed lipophilic vacuoles localized in subepithelial and epithelial cells, in which secretions accumulated before being transferred to the duct. The presence of wall ingrowths in subepithelial cells suggests that granulocrine secretion operates in these species. Secretory ducts varied in density and diameter among the organs in both species, with the combination being maximal in woody stems. (-)HAA was only detected in surface secreted resins of both species, and its concentration (2D-TLC, GC-FID) was intimately associated with the distribution and density of glandular trichomes in each organ (capitula, leaves, and stems with primary or secondary growth). In addition, no (-)HAA was detected internally in the resins collected from secretory ducts. The composition of these resins showed distinctive profiles for FC and FO, and only four from ca. 30 compounds detected (GC/MS) were shared by both species. In addition to the elucidation of ultrastructural traits, distribution and density of secretory structures in aerial organs of FC and FO, present findings suggest a functional role for glandular trichomes in the secretion of the putative phytotoxic allelochemical (-)HAA.展开更多
Experiments were carried out to evaluate the effect of seed treatment on germination of Cuscuta campestris. This may provide the possible ways to overcome the problem of dormancy in Cuscuta campestris. The experiments...Experiments were carried out to evaluate the effect of seed treatment on germination of Cuscuta campestris. This may provide the possible ways to overcome the problem of dormancy in Cuscuta campestris. The experiments were conducted in the Laboratory of Crop Production and Horticulture, Modibbo Adama University of Technology, Yola, Adamawa State, Nigeria, using mechanical scarification and tetraoxosulphate (VI) acid (H2SO4). For the mechanical scarification the treatments were unscarified, scarified using sandpaper and scarified using gravel arranged in a completely randomized design (CRD) and replicated four times. For the tetraoxosulphate (VI) acid (H2SO4) scarification, the treatment of control, 9:1, 7:3, 1:1, 4:6, 3:7, 2:8 and 1:9 H2SO4 were laid out in a Split plot design and replicated three times. The mechanical scarification was not significant (P ≤ 0.05), a rapid increase of germination from day 3 to day 9 was observed, and the highest rate of germination percentage (14% - 22%) obtained on day 9. Tetraoxosulphate (VI) acid treatment of 4:6 concentrations significantly gave the highest C. campestris seeds germination percentage (40.07%) compared with the rest of the treatments, while the time of soaking the seeds in the tetraoxosulphate (VI) acid showed that soaking the seeds for 1 minute significantly gave the highest percentage germination (39.98%) of C. campestris compared with the 3 and 5 minutes soaking treatments. It can be concluded that sulphuric acid of 4:6 concentrations treatments has the potentiality to break dormancy of C. campestris seeds.展开更多
The effects of different Cd (Cadmium) levels on generation of active oxygen speceies(AOS) and H2O2-scavenging system in the leaves of Brassica campestris L. ssp. chinensiswere studied. The results showed that generat...The effects of different Cd (Cadmium) levels on generation of active oxygen speceies(AOS) and H2O2-scavenging system in the leaves of Brassica campestris L. ssp. chinensiswere studied. The results showed that generation rate, and H2O2 content were enhancedand malondialdehyde (MDA) content increased with the increase of Cd concentrations inthe growth medium. The activities of ascorbate peroxidase (APX), dehydroascorbatereductase (DR) and glutathione reductase (GR) were promoted by the addition of Cd.Exposed to Cd also increased the contents of ascorbate (AsA) and glutathione (GSH) in theleaves.展开更多
Different sterile cytoplasm types of nine cabbage cytoplasmic male sterile materials were identified by molecular marker in the study, in order to better use molecular marker to conduct the assisted breeding in the fu...Different sterile cytoplasm types of nine cabbage cytoplasmic male sterile materials were identified by molecular marker in the study, in order to better use molecular marker to conduct the assisted breeding in the future. Genomic DNA was isolated from Chinese cabbage by CTAB method. The design of two pairs of specific primers was performed on conserved flanking region of orf138 gene in the GenBank. PCR was performed with genomic DNA of the nine Chinese cabbage materials. The bands were sequenced. The homologous comparison was conducted in NCBI, and finally, the type of sterile cytoplasm was determined. The results showed that the bands were amplified only in four Chinese cabbage male sterile materials with two pairs of specific primers PUPIl and PIII/PIV, while the other five materials did not obtain the relative bands. The result was consistent with the field sterility identification. And then four molecular markers of Chinese cabbage Ogura cytoplasmic male sterility (CMS) were obtained. After conducting a homologous comparative analysis with BLAST in GenBank, it was found that the homologous degree was 100% in specific segments of tbe tbree sterility materials (L1-CI, L3-CI and L3- F1 ) and Ogu orf138 gene (GenBank accession No. : HQ149728) of the reported broccoli Ogu CMS. The homologous degree of L1-F1 was 99% with a variation point. The type of cytoplasmic male sterility of the other five materials needed further research. Four materials of the nine were identified as the radish cytoplasmic male sterility materials and four molecular markers were obtained.展开更多
Mango bacterial canker is caused by Xanthomonas campestris pv. mangiferaeindicae. During 2009 and 2013,leaves,twigs and fruits of mango were collected from commercial and experimental mango fields with typical canker ...Mango bacterial canker is caused by Xanthomonas campestris pv. mangiferaeindicae. During 2009 and 2013,leaves,twigs and fruits of mango were collected from commercial and experimental mango fields with typical canker symptoms in Hainan,Guangxi,Guangdong and Szechwan Provinces of China. The causal agent was identified as X. campestris pv. mangiferaeindicae through KC semi-selective medium isolation,pathogenicity tests,and sequencing of the gyrB gene.展开更多
文摘The influence of nitrification inhibitor(NI) 3,4 dimethylpyrazole phosphate(DMPP) on nitrate accumulation in greengrocery( Brassica campestris L. ssp. chinensis ) and vegetable soil at surface layer were investigated in field experiments in 2002 and 2003 Results showed that NI DMPP took no significant effect on yields of edible parts of greengrocery, but it could significantly decrease NO - 3 N concentration in greengrocery and in vegetable soil at surface layer. In addition, NI DMPP could reduce the NO - 3 N concentration during the prophase stage of storage.
文摘Glucosinolates (GSs) are a group of plant secondary metabolites containing abundant nitrogen (N) and sulfur (S) mainly in Brassica and have the beneficial effects on human health including anti-carcinogenic, cholesterol-reducing and other pharmacological effects. The objective of this study was to investigate the effect of different concentrations of N (5, 10, and 20 mmol L-a, denoted by N5, N10 and N20) and S (0,5, 1, and 2 mmol L^-1, denoted by S0.5, S1 and S2) on the yield and GSs in pakchoi (Brassica campestris L. ssp. chinensis var. communis) in hydroponics. Results showed that N10 and N20 significantly enhanced the yield compared with N5, however, N20 had a negative effect relative to N10. Only with N10 and N20 low S supply (S0.5) reduced the yield. The concentrations of aliphatic GSs, aromatic GS and total GSs were enhanced by N5 and indolyl GSs were enhanced by N20. S2 enhanced the concentration of individual GS and total GSs. The concentrations of indolyl GSs were maximized in N20S2 treatment, whereas the highest concentrations of aliphatic GSs, aromatic GS and total GSs were found in N5S2 treatment. Effects of N and S on aliphatic GSs were higher than on indolyl GSs. The results suggest that the accumulation of aliphatic GSs and aromatic GS could be enhanced by low N and high S and restricted by high N while that of indolyl GSs could be enhanced by high N and high S.
文摘A molecular genetic map of Chinese cabbage was constructed with a 102 recombinant inbred (RI) population from a cross of two cultivated Chinese cabbage lines 177 and 276, using AFLP and RAPD markers. 352 markers including 265 AFLP markers and 87 RAPD markers were integrated into 17 linkage groups. It covered a total of 2 665. 7 cM with an average interval of 7. 6 cM. AFLP marker is efficient for map construction while it easily forms clusters to cause big gaps in map. A total of 13.92 % abnormal segregation markers distributed in the map. The molecular genetic map is fundamental for gene localization, comparative genomics, and QTL mapping of important agronomic traits.
文摘Black rot, caused by Xanthomonas campestris pv. campestris (Xcc) is possibly the most important disease of Brassica worldwide. To compare chromosomal positions of Xcc resistance loci in Brassica oleracea between the present and published studies and to develop marker assisted selection (MAS) to resistance against Xcc race 1, we constructed a B. oleracea map, including pW, pX and BoCL markers that were closely linked to previously reported Xcc resistance QTLs. We also analyzed Xcc resistance QTLs by improving our previously reported map derived from the cross of a susceptible double-haploid line (GC P09) with a resistant double-haploid line (Reiho P01). In the nine linkage groups obtained (C1-C9), the major QTL, XccBo(Reiho)2, was derived from Reiho with a maximum LOD score (7.7) in C8. The QTL (LOD 4.4) located in C9, XccBo(GC)1 was derived from the susceptible GC. The other QTL (LOD 4.4), XccBo(Reiho)1, was found in C5. Based on common markers, it was possible to compare our finding Xcc resistance QTLs with the B. oleraceaXcc loci reported by previous authors;XccBo(Reiho)1 and XccBo(GC)1 may be identical to the Xcc resistance QTLs reported previously or a different member contained in the same resistance gene cluster. Our map includes public SSR markers linked to Xcc resistance genes that will promote pyramiding Xcc resistance genes in B. oleracea. The present study will also contribute to a better understanding of genetic control of Xcc resistance.
基金supported by the National Natural Science Foundation of China(39670512)
文摘To determine differential expression of genie male sterility A/B lines in Chinese cabbage-pak-choi (Brassica campestris ssp. chinensis Makino var. communis Tsen et Lee), we used the RNA fingerprinting technique, cDNA-AFLP analysis, in different developmental stages and different tissues. While no obvious differential expressions were observed in rosette leaves, florescence leaves, and scapes, some differential expressions were found in alabstrums of A/B lines and among leaves, scapes and alabstrums. We analyzed the al-abstrums collected in different developmental stages with 10 primer combinations. We got a unique band between middle size alabstrums and large alabstrums in B line in one of the ten pair primers, and in another one pair, one band reflecting a higher gene-expression level in A line than that in B line was obtained. No unique bands were found with the other primer combinations. The bands reflecting different gene-expression level were confirmed by Northern hybridization. The results indicated that cDNA-AFLP was a suitable tool for studying differential expression of genie male sterility in plants. SDS-polyacrylamide gel electrophoresis patterns of soluble proteins further verified the difference in A/B lines.
基金the National Natural Science Foundation of China (30570445) Natural Science Foundation of Liaoning Province, China (20021022)+1 种基金 Tackle Key Problem of Science and Technology, Education Department of Liaoning Province, China (2004D005)and Director Foundation of ExperimentalCentre, Shenyang Normal University, China (SY200406).
文摘This article investigates the responses of Brassica campestris seedlings to an acute level of nitrogen dioxide (NO2) exposure in a plant growth chamber, and examines whether pretreating plants with hydrogen peroxide (H2O2) will alleviate NO2-caused injury. Twenty-eight-day-old B. campestris plants sprayed with 10 mmol L^-1 H2O2 aqueous solution (corresponding to approximate 1.0 mg H2O2 per single plant) were exposed to different concentrations of NO2 (0.25, 0.5, 1.0, and 2.0 μL L^-1, respectively) for 24 h under controlled environment. To measure the plant biomass, the plants were fumigated with the same NO2 concentrations as mentioned above for 7 h per day (8.00-15.00) for 7 days. As a control, charcoal filtered air alone was applied. Data were collected on plant biomass, total chlorophyll, photosynthetic rate, stomatal conductance, nitrate and nitrate reductase (NR), antioxidative enzymes, ascorbate (ASA), and malondialdehyde (MDA), immediately after exposure. The results showed that exposure to a moderate dose of NO2 (e.g., 0.25 μL L^-1) had a favorable effect on plants, and the dry weight of the above-ground part increased, whereas the exposure to high NO2 concentrations (e.g., 0.5 μL L^-1 or higher) caused a reduction in the plant biomass and the total chlorophyll, when compared with the control. In addition, at 0.5 μL L^-1 or higher NO2 concentrations, prominent increases in the MDA level and superoxide dismutase (SOD) and NR activities were observed. Exposure to 1 μL L^-1 and higher NO2 resulted in necroses appearing on older leaves, and an increase in catalase (CAT) activity, decrease in ASA content, increased accumulation of NO3^-, and reduction in photosynthesis, when compared with the controls. No changes were detected in stomatal conductance under NO2 fumigation. The pretreatment with 10 mmol L^-1 H2O2 alleviated significantly NO2- caused biomass decrease and photosynthetic inhibition when compared with H2O2-untreated plants. Under NO2 fumigation, further induction in SOD and CAT activities occurred in H2O2 treated plants when compared with H2O2- untreated plants. The effect of NO2 on the ASA and MDA contents was also absent in H2O2-treated plants. However, the H2O2 treatment did not alter the nitrate content and NR activity in plants under NO2 fumigation. The H2O2 treatment caused a lower rate of stomatal conductance. Taken together, these data suggest that fumigation with an acute level of NO2 causes oxidative damage to B. campestris seedlings. The H2O2 pretreatment markedly protects plants against NO2 stress and this may be associated with inducible antioxidative level. NO2 fumigation contributes, at least in part, to the enhanced levels of nitrate in B. campestris leaves.
基金the National Natural Science Foundation of China(30671426)the Key Sci-Technology Project of Zhejiang Province,China(2005C12019-02)
文摘The study analyzed the silencing of BcMF12 gene regulated by BcA9 promoter in the transgenic pakchoi and confirmed the effect of antisense BcMF12 gene on the pollen development. A conserved BcMF12 gene fragment was amplified from the cDNA of flower buds in pakchoi (Brassica campestris L. ssp. chinensis, syn. B. rapa L. ssp. chinensis) and was fused to the anther specific BcA9 promoter. The plant antisense expression vector was constructed and then introduced into pakchoi via Agrobacterium-mediated transformation. The transgenic plants were screened by antibiotics and molecular analysis. PCR and Southern blot revealed that the antisense BcMF12-GUS fusion gene regulated by BcA9 promoter was integrated into transgenic plants. Northern blot suggested that the expression of BcMF12 gene was down-regulated significantly. The pollen germination rate of transgenic plants with antisense BcMF12 gene decreased as compared with that of the control plants. The expression of the gene BcMF12 related to the pollen development was inhibited by the antisense BcMF12 driven by BcA9 promoter, which consequently affected the pollen development in pakchoi.
基金supported by project AGL2015-66256-C2-R and RTI2018-096591-B-I00,by the European Regional Development Fund(ERDF)and by A Xunta de Galicia(IN607A 2016/13).M.T.
文摘The plant immune system is divided into two branches;one branch is based on the recognition of pathogenassociated molecular patterns(PAMP-triggered immunity),and the other relies on pathogenic effector detection(effector-triggered immunity).Despite each branch being involved in different complex mechanisms,both lead to transcription reprogramming and,thus,changes in plant metabolism.To study the defense mechanisms involved in the Brassica oleracea–Xanthomonas campestris pv.campestris(Xcc)interaction,we analyzed the plant transcriptome dynamics at 3 and 12 days postinoculation(dpi)by using massive analysis of 3′-cDNA ends.We identified more induced than repressed transcripts at both 3 and 12 dpi,although the response was greater at 12 dpi.Changes in the expression of genes related to the early infection stages were only detected at 12 dpi,suggesting that the timing of triggered defenses is crucial to plant survival.qPCR analyses in susceptible and resistant plants allowed us to highlight the potential role of two calcium-signaling proteins,CBP60g and SARD1,in the resistance against Xcc.This role was subsequently confirmed using Arabidopsis knockout mutants.
基金supported by the Science and Technology Department of Zhej iang Province(021102109)Hangzhou Municipality(2003132E32)China-Sweden Cooperation Project(C08).
文摘Using three varieties of Brassica campestris, Hauarad (708), Maoshan-3 (714) and Youbai (715),as the maternal plants and one variety of Brassica oleracea Jingfeng-1 (6012) as paternalplants, crosses were made to produce interspecific hybrids through ovary culture techniques.The ovaries from the cross between B. campestrisB.oleracea (7086012 and 7146012) werecultured and ovary culture was more effective in terms of obtained seeds when ovaries werecultured in vitro at 9 d after pollination (DAP). While for the cross of 7156012, it wasbetter when ovaries in vitro cultured at 12 DAP. Among three cross combinations, the cross of7146012 showed the best response and 43 seeds per ovary were obtained. Among the mediastudied, the ovaries from the cross of 7086012 cultured on MS media supplemented with 3.0 mgL-1 BA0.1 mg L-1 NAA showed better response, and its rate of seeds per ovary reached 44.0%.While the ovaries from the other two crosses (7146012 and 7156012) showed the best responsewhen cultured on B5 media supplemented with 3.0 mg L-1 BA + 0.2 mg L-1 NAA, and the rates of seedsper ovary reached 72.0 and 60.0%, respectively. All seeds obtained from the three crosscombinations were cultured on the MS media supplemented with 1.0 mg L-1 BA + 0.05 mg L-1 NAA,and the seeds from the cross of 7156012 showed the best germination response and thepercentage of germinations reached 66.7%. The regenerated plantlets were obtained from theseseedlings after cultured on the MS media supplemented with 0.05 mg L-1 NAA. Cytological studyshowed that these regenerated plants were all true hybrids of B.campestrisB.oleracea.
基金supported by grants of the National Key R&D Program of China (Grants Nos.2016YFE0205500 and 2017YFD0101903)the earmarked fund for China Agriculture Research System (Grant No.CARS-23-G28)+2 种基金the China Postdoctoral Science Foundation (Grant No.2017M620305)Natural Science Foundation of Hubei Province (Grant No.2020CFA010)Youth Fund of Hubei Academy of Agricultural Sciences (Grant No.2021NKYJJ04)。
文摘Bacterial spot(BS)is a severe bacterial disease induced by Xanthomonas campestris pv.vesicatoria(Xcv),a pathogen that causes serious damage to pepper growth and yield.It is therefore important to study the mechanisms of pepper resistance to Xcv and to breed and promote Xcvresistant pepper varieties.However,studies of the responses to Xcv infection in peppers at the protein level are limited.Here,we examined Xcv-induced proteomic changes in leaves of the BS susceptible bell pepper ECW and the resistant bell pepper VI037601 using the isobaric tags for relative and absolute quantitation(iTRAQ)-based protein labeling technology.A total of 6,120 distinct proteins were identified,and there were 1,289 significantly differentially accumulated proteins(DAPs)in ECW and VI037601 leaves after Xcv inoculation.Among these,339(250up-and 89 down-regulated)and 479(300 up-and 179 down-regulated)DAPs were specifically identified in ECW and VI037601,respectively,with 459(364 up-and 95 down-regulated)similarly expressed DAPs being shared by ECW and VI037601.Based on bioinformatics analysis,many defense-associated proteins were identified as up-regulated in ECW and VI037601,especially the proteins involved in plant-pathogen interaction,phenylpropanoid biosynthesis,protein processing in the endoplasmic reticulum,and MAPK signaling pathway-plant.Moreover,we evaluated transcript levels of six differentially expressed genes from the iTRAQ results by q RT-PCR.The analysis revealed transcriptional changes that were consistent with the changes at the protein level.This study will provide a valuable resource for understanding the molecular basis of pepper resistance to Xcv infection and for improving the disease resistance of pepper cultivars.
基金This research was supported by the California Leafy Greens Research Program,the California Department of Food and Agriculture,USDA NRI(grant no.2008-35300-004447)USDA NIFA SCRI(grant no.2010-51181-21631).
文摘Lettuce yields can be reduced by the disease bacterial leaf spot(BLS)caused by the pathogen Xanthomonas campestris pv.vitians(Xcv)and host resistance is the most feasible method to reduce disease losses.The cultivars La Brillante,Pavane and Little Gem express an incompatible host–pathogen interaction as a hypersensitive response(HR)to California strains of Xcv resulting in resistance.Little was known about the inheritance of resistance;however,resistance to other lettuce pathogens is often determined by resistance gene candidates(RGCs)encoding nucleotide-binding leucine-rich repeat(NB-LRR)proteins.Therefore,we determined the inheritance of BLS resistance in the cultivars La Brillante,Little Gem and Pavane and mapped it relative to RGCs.The reaction to Xcv was analyzed in nine F_(1),F_(2) and recombinant inbred line populations of lettuce from HR3compatible or HR3HR crosses.The HR in La Brillante,Pavane and Little Gem is conditioned by single dominant genes,which are either allelic or closely linked genes.The resistance gene in La Brillante was designated Xanthomonas resistance 1(Xar1)and mapped to lettuce linkage group 2.Xar1 is present in a genomic region that contains numerous NB-LRR encoding RGCs and functional pathogen resistance loci in the RGC2 family.The Xar1 gene confers a high level of BLS resistance in the greenhouse and field that can be introgressed into commercial lettuce cultivars to reduce BLS losses using molecular markers.
文摘In this work, the localization, density, morphology and ultrastructure of secretory structures in aerial organs of Flourensia campestris (FC) and F. oolepis (FO) (Asteraceae) by means of a combination of light, fluorescence, transmission (TEM) and scanning electron microscopy (SEM) were examined. The possible role of secretory structures in the production and secretion of the phytotoxic sesquiterpene (-)-hamanasic acid A ((-)HAA) in both species was also assessed. Capitate glandular trichomes were found in all reproductive organs of FC and FO, and were being reported for the first time. These glandular trichomes, typically associated to edges and veins, were of the same type as those already described for vegetative organs, and were abundant in involucral bracts and corolla of tubulose and ligulate flowers. Their density in reproductive organs of both species was similar (ca. 30/mm2) and lower than that found in leaves (ca. 100/mm2) and stems (ca. 160/mm2 in FC, and up to 650/mm2 in FO). Glandular trichomes in vegetative organs followed a species-specific pattern of distribution. TEM and SEM observations suggest that each species differs in the way in which secretory materials are released to the outside: through cracks or pores in FC, or through a loose cuticle in FO. Similar inspections of the secretory ducts revealed lipophilic vacuoles localized in subepithelial and epithelial cells, in which secretions accumulated before being transferred to the duct. The presence of wall ingrowths in subepithelial cells suggests that granulocrine secretion operates in these species. Secretory ducts varied in density and diameter among the organs in both species, with the combination being maximal in woody stems. (-)HAA was only detected in surface secreted resins of both species, and its concentration (2D-TLC, GC-FID) was intimately associated with the distribution and density of glandular trichomes in each organ (capitula, leaves, and stems with primary or secondary growth). In addition, no (-)HAA was detected internally in the resins collected from secretory ducts. The composition of these resins showed distinctive profiles for FC and FO, and only four from ca. 30 compounds detected (GC/MS) were shared by both species. In addition to the elucidation of ultrastructural traits, distribution and density of secretory structures in aerial organs of FC and FO, present findings suggest a functional role for glandular trichomes in the secretion of the putative phytotoxic allelochemical (-)HAA.
文摘Experiments were carried out to evaluate the effect of seed treatment on germination of Cuscuta campestris. This may provide the possible ways to overcome the problem of dormancy in Cuscuta campestris. The experiments were conducted in the Laboratory of Crop Production and Horticulture, Modibbo Adama University of Technology, Yola, Adamawa State, Nigeria, using mechanical scarification and tetraoxosulphate (VI) acid (H2SO4). For the mechanical scarification the treatments were unscarified, scarified using sandpaper and scarified using gravel arranged in a completely randomized design (CRD) and replicated four times. For the tetraoxosulphate (VI) acid (H2SO4) scarification, the treatment of control, 9:1, 7:3, 1:1, 4:6, 3:7, 2:8 and 1:9 H2SO4 were laid out in a Split plot design and replicated three times. The mechanical scarification was not significant (P ≤ 0.05), a rapid increase of germination from day 3 to day 9 was observed, and the highest rate of germination percentage (14% - 22%) obtained on day 9. Tetraoxosulphate (VI) acid treatment of 4:6 concentrations significantly gave the highest C. campestris seeds germination percentage (40.07%) compared with the rest of the treatments, while the time of soaking the seeds in the tetraoxosulphate (VI) acid showed that soaking the seeds for 1 minute significantly gave the highest percentage germination (39.98%) of C. campestris compared with the 3 and 5 minutes soaking treatments. It can be concluded that sulphuric acid of 4:6 concentrations treatments has the potentiality to break dormancy of C. campestris seeds.
文摘The effects of different Cd (Cadmium) levels on generation of active oxygen speceies(AOS) and H2O2-scavenging system in the leaves of Brassica campestris L. ssp. chinensiswere studied. The results showed that generation rate, and H2O2 content were enhancedand malondialdehyde (MDA) content increased with the increase of Cd concentrations inthe growth medium. The activities of ascorbate peroxidase (APX), dehydroascorbatereductase (DR) and glutathione reductase (GR) were promoted by the addition of Cd.Exposed to Cd also increased the contents of ascorbate (AsA) and glutathione (GSH) in theleaves.
基金Supported by National Staple Vegetable Industrial Technology System(CARS-23-G37)Breeding and Industrialization Demonstration of New Varieties of Cruciferae Vegetables(Brassica pekinensis Rupr.,Raphanus sativus L.,Brassica oleracea L.)in Yunnan Province(2015BB007)Basic Research Project of Yunnan Science and Technology Plan(2017FD200)
文摘Different sterile cytoplasm types of nine cabbage cytoplasmic male sterile materials were identified by molecular marker in the study, in order to better use molecular marker to conduct the assisted breeding in the future. Genomic DNA was isolated from Chinese cabbage by CTAB method. The design of two pairs of specific primers was performed on conserved flanking region of orf138 gene in the GenBank. PCR was performed with genomic DNA of the nine Chinese cabbage materials. The bands were sequenced. The homologous comparison was conducted in NCBI, and finally, the type of sterile cytoplasm was determined. The results showed that the bands were amplified only in four Chinese cabbage male sterile materials with two pairs of specific primers PUPIl and PIII/PIV, while the other five materials did not obtain the relative bands. The result was consistent with the field sterility identification. And then four molecular markers of Chinese cabbage Ogura cytoplasmic male sterility (CMS) were obtained. After conducting a homologous comparative analysis with BLAST in GenBank, it was found that the homologous degree was 100% in specific segments of tbe tbree sterility materials (L1-CI, L3-CI and L3- F1 ) and Ogu orf138 gene (GenBank accession No. : HQ149728) of the reported broccoli Ogu CMS. The homologous degree of L1-F1 was 99% with a variation point. The type of cytoplasmic male sterility of the other five materials needed further research. Four materials of the nine were identified as the radish cytoplasmic male sterility materials and four molecular markers were obtained.
基金Supported by the Ministry of Science and Technology and the Ministry of Agriculture of China(2014hzs1J007-2)
文摘Mango bacterial canker is caused by Xanthomonas campestris pv. mangiferaeindicae. During 2009 and 2013,leaves,twigs and fruits of mango were collected from commercial and experimental mango fields with typical canker symptoms in Hainan,Guangxi,Guangdong and Szechwan Provinces of China. The causal agent was identified as X. campestris pv. mangiferaeindicae through KC semi-selective medium isolation,pathogenicity tests,and sequencing of the gyrB gene.