共查询到20条相似文献,搜索用时 15 毫秒
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Finnegan PM Brumbley SM O'Shea MG Nevalainen H Bergquist PL 《Archives of microbiology》2005,183(2):140-147
Genes encoding dextranolytic enzymes were isolated from Paenibacillus strains Dex40-8 and Dex50-2. Single, similar but non-identical dex1 genes were isolated from each strain, and a more divergent dex2 gene was isolated from strain Dex50-2. The protein deduced from the Dex40-8 dex1 gene sequence had 716 amino acids, with a predicted Mr of 80.8 kDa. The proteins deduced from the Dex50-2 dex1 and dex2 gene sequences had 905 and 596 amino acids, with predicted Mr of 100.1 kDa and 68.3 kDa, respectively. The deduced amino acid sequences of all three dextranolytic proteins had similarity to family 66 glycosyl hydrolases and were predicted to possess cleavable N-terminal signal peptides. Homology searches suggest that the Dex40-8 and Dex50-2 Dex1 proteins have one and two copies, respectively, of a carbohydrate-binding module similar to CBM_4_9 (pfam02018.11). The Dex50-2 Dex2 deduced amino acid sequence had highest sequence similarity to thermotolerant dextranases from thermophilic Paenibacillus strains, while the Dex40-8 and Dex50-2 Dex1 deduced protein sequences formed a distinct sequence clade among the family 66 proteins. Examination of seven Paenibacillus strains, using a polymerase chain reaction-based assay, indicated that multiple family 66 genes are common within this genus. The three recombinant proteins expressed in Escherichia coli possessed dextranolytic activity and were able to convert ethanol-insoluble blue dextran into an ethanol-soluble product, indicating they are endodextranases (EC 3.2.1.11). The reaction catalysed by each enzyme had a distinct temperature and pH dependence. 相似文献
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Qiguo Gao Songmei Shi Yudong Liu Quanming Pu Xiaohuan Liu Ying Zhang Liquan Zhu 《Sexual plant reproduction》2016,29(3):239-250
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Jian-Xia Zhang Kun-Lin Wu Li-Ning Tian Song-Jun Zeng Jun Duan 《Acta Physiologiae Plantarum》2011,33(2):409-417
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Plants are sensitive to D-serine, but functional expression of the dsdA gene, encoding D-serine ammonia lyase, from Escherichia coli can alleviate this toxicity. Plants, in contrast to many other organisms, lack the common pathway for oxidative deamination of D-amino acids. This difference in metabolism has major consequences for plant responses to D-amino acids, since several D-amino acids are toxic to plants even at relatively low concentrations. Therefore, introducing an enzyme specific for a phytotoxic D-amino acid should generate a selectable characteristic that can be screened. Here we present the use of the dsdA gene as a selectable marker for transformation of Arabidopsis. D-serine ammonia lyase catalyses the deamination of D-serine into pyruvate, water and ammonium. dsdA transgenic seedlings can be clearly distinguished from wild type, having an unambiguous phenotype immediately following germination when selected on D-serine containing medium. The dsdA marker allows flexibility in application of the selective agent: it can be applied in sterile plates, in foliar sprays or in liquid culture. Selection with D-serine resistance was compared with selection based on kanamycin resistance, and was found to generate similar transformation frequencies but also to be more unambiguous, more rapid and more versatile with respect to the way the selective agent can be supplied. 相似文献
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A total of 534 isolates were selectively obtained from different plant rhizospheres based on their growth on nitrogen-free medium and their resistance to 80 degrees C for 15 min. Of the 534 isolates, 23 isolates had nifH gene and exhibited nitrogenase activities. Based on 16S rDNA sequence, G + C content assay and DNA-DNA hybridization, by the 23 isolates, which were divided into four monophyletic clusters, all belonged to the Paenibacillus genus. NifH gene deduced amino acid alignment analysis revealed that cluster I, including 15 isolates, showed the highest NifH identity with Paenibacillus genus; while cluster II identified as P stellifer by DNA-DNA hybridization was consistent with four uncultured bacterial clones. This study suggested that the nitrogen-fixing Paenibacillus were distributed in various ecosystems and prevalent in different plant rhizospheres. It was the first demonstration that nitrogen fixation existed in P. jamilae and P. stellifer. In eight isolates identified as P. stellfer species, a novel nifH gene was detected in Paenibacillus. 相似文献
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Lihui Liu Tao Yuan Fei Yang Ziwei Liu Meiyan Yang Guixiang Peng Zhiyuan Tan 《Antonie van Leeuwenhoek》2018,111(12):2267-2273
A nitrogen-fixing, endospore-forming bacterium, designated strain L201T was isolated from the leaves of Bryophyllum pinnatum growing in South China Agricultural University. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain L201T is affiliated with the genus Paenibacillus, and closely related to Paenibacillus albidus Q4-3T (97.4%), Paenibacillus odorifer DSM 15391T (97.3%) and Paenibacillus borealis DSM 13188T (97.2%). The main fatty acids components was anteiso-C15:0 (48.1%). The predominant isoprenoid quinone was MK-7. The major polar lipids were found to be diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The G+C content of strain L201T was 43.9%. DNA–DNA relatedness between L201T and the reference strain was 29.8%. Biological and biochemical tests, protein patterns, genomic DNA fingerprinting and comparison of cellular fatty acids distinguished strain L201T from the closely related Paenibacillus species. Based on these data, the novel species Paenibacillus bryophyllum sp. nov. is proposed, with the type strain L201T(=?KCTC 33951 T?=?GDMCC 1.1251 T). 相似文献
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Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes. 相似文献
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Andrew T. Wiersma Jane A. Pulman Linda K. Brown Christina Cowger Eric L. Olson 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2017,130(6):1123-1133
Key message
A novel powdery mildew-resistance gene, designated Pm58, was introgressed directly from Aegilops tauschii to hexaploid wheat, mapped to chromosome 2DS, and confirmed to be effective under field conditions. Selectable KASP? markers were developed for MAS.Abstract
Powdery mildew caused by Blumeria graminis (DC.) f. sp. tritici (Bgt) remains a significant threat to wheat (Triticum aestivum L.) production. The rapid breakdown of race-specific resistance to Bgt reinforces the need to identify novel sources of resistance. The d-genome species, Aegilops tauschii, is an excellent source of disease resistance that is transferrable to T. aestivum. The powdery mildew-resistant Ae. tauschii accession TA1662 (2n?=?2x?=?DD) was crossed directly with the susceptible hard white wheat line KS05HW14 (2n?=?6x?=?AABBDD) followed by backcrossing to develop a population of 96 BC2F4 introgression lines (ILs). Genotyping-by-sequencing was used to develop a genome-wide genetic map that was anchored to the Ae. tauschii reference genome. A detached-leaf Bgt assay was used to screen BC2F4:6 ILs, and resistance was found to segregate as a single locus (χ?=?2.0, P value?=?0.157). The resistance gene, referred to as Pm58, mapped to chromosome 2DS. Pm58 was evaluated under field conditions in replicated trials in 2015 and 2016. In both years, a single QTL spanning the Pm58 locus was identified that reduced powdery mildew severity and explained 21% of field variation (P value?<?0.01). KASP? assays were developed from closely linked GBS-SNP markers, a refined genetic map was developed, and four markers that cosegregate with Pm58 were identified. This novel source of powdery mildew-resistance and closely linked genetic markers will support efforts to develop wheat varieties with powdery mildew resistance.11.
An actinomycete strain, designated YIM 60475T, was isolated from the roots of Maytenus austroyunnanensis and was characterized by using a polyphasic approach. The strain was determined to belong to the genus Streptomyces, based on its phenotypic and phylogenetic characteristics. The strain produced spiral spore chains on aerial mycelium. The
cell wall contained ll-diaminopimelic acid. Whole-cell hydrolysates contained galactose, glucose, and xylose. The phospholipid was type II. The
DNA G+C content of the type strain was 73.3 mol%. DNA–DNA hybridization and comparison of physiological and chemical characteristics
suggested that strain YIM 60475T is a new Streptomyces species, for which the name Streptomyces mayteni sp. nov. is proposed. The type strain is YIM 60475T (=CCTCC AA 207005T = KCTC 19383T).
Hua-Hong Chen and Sheng Qin contributed equally to this work. 相似文献
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Sarah P. Canova Tânia Petta Luciana F. Reyes Tiago D. Zucchi Luiz A. B. Moraes Itamar S. Melo 《World journal of microbiology & biotechnology》2010,26(12):2241-2247
The main aim was to identify the active compound against Rhizoctonia solani produced by the cassava endophyte Paenibacillus sp. IIRAC-30. The compounds produced were extracted with ethyl acetate and purified by Sephadex column prior to analysis
by Q-TOF mass spectrometry. A C15-lipopeptide with an estimated molecular weight of 1036 Da and homologues were identified. The lipopeptide had a cyclic structure,
which was deduced by interpreting the ESI–MS/MS spectra of main protonated homologues containing 15:0 FA, and the amino acid
composition was Glu-Leu-Leu-Val-Asp-Leu-Leu. Therefore, the lipopeptides produced by isolate IIRAC-30 was characterized as
a surfactin series. Thus, the main mechanism used by Paenibacillus sp. IIRAC-30 to suppress R. solani was elucidated. Furthermore, because lipopeptides active against phytopathogens generally show low toxicity to humans and
the environment, the positive findings presented here suggest that the isolate IIRAC-30 could be a possible candidate for
biocontrol of R. solani. 相似文献
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Biological nitrogen fixation plays an important role in the nitrogen balance of agricultural ecosystems and provides an essential part of nitrogen nutrition for plants, even in conditions of intensive fertilization. The main agrobiotechnological method for soybean cultivation (Glycine max (L.) Merril) is an application of microbial preparations based on Bradyrhizobium japonicum. Successful inoculation strongly depends on the interactions between the introduced microorganism and the aboriginal rhizosphere microorganisms. To evaluate the composition of diazotrophic communities, a study of the diversity of the molecular marker for nitrogen fixation, the nifH gene, in the samples of soybean rhizosphere soil was carried out. Experiments were performed in the variants when soybean was cultivated without inoculation and after adding bacterial preparations, as well as in enrichment cultures of diazotrophs. The revealed diazotrophic microorganisms demonstrated low level of similarity to the known microorganisms (74–95% identity by nucleotides), and were identified as species of the phyla Firmicutes and Proteobacteria. In the composition of nitrogen-fixing communities in the rhizosphere soil, the microorganisms of the genera Clostridium, Paenibacillus, and Spirochaeta were shown to prevail. 相似文献
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Perugini LD Murphy JP Marshall D Brown-Guedira G 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,116(3):417-425
Powdery mildew is an important foliar disease in wheat, especially in areas with a cool or maritime climate. A dominant powdery
mildew resistance gene transferred to the hexaploid germplasm line NC99BGTAG11 from T. timopheevii subsp. armeniacum was mapped distally on the long arm of chromosome 7A. Differential reactions were observed between the resistance gene in
NC99BGTAG11 and the alleles of the Pm1 locus that is also located on chromosome arm 7AL. Observed segregation in F2:3 lines from the cross NC99BGTAG11 × Axminster (Pm1a) demonstrate that germplasm line NC99BGTAG11 carries a novel powdery mildew resistance gene, which is now designated as Pm37. This new gene is highly effective against all powdery mildew isolates tested so far. Analyses of the population with molecular
markers indicate that Pm37 is located 16 cM proximal to the Pm1 complex. Simple sequence repeat (SSR) markers Xgwm332 and Xwmc790 were located 0.5 cM proximal and distal, respectively, to Pm37. In order to identify new markers in the region, wheat expressed sequence tags (ESTs) located in the distal 10% of 7AL that
were orthologous to sequences from chromosome 6 of rice were targeted. The two new EST-derived STS markers were located distal
to Pm37 and one marker was closely linked to the Pm1a region. These new markers can be used in marker-assisted selection schemes to develop wheat cultivars with pyramids of powdery
mildew resistance genes, including combinations of Pm37 in coupling linkage with alleles of the Pm1 locus. 相似文献
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Endospore-forming bacteria, Paenibacillus spp., have recently been isolated in association with insect pathogenic nematodes Heterorhabditis spp. Sporangia adhere to nematode infective juveniles (J3) and are carried with them into insects. Paenibacillus proliferates in the killed insect along with Heterorhabditis and its obligate bacterial symbiont, Photorhabdus, despite the antibiotic production of the latter. Nematode infective juveniles leave the insect cadaver with Paenibacillus sporangia attached. The specificity of the relationship between Paenibacillus and Heterorhabditis was investigated. Sporangia of nematode-associated Paenibacillus adhered to infective juveniles (but not other stages) of all Heterorhabditis species tested, and to infective juveniles of vertebrate parasitic Strongylida species, but not to a variety of other soil nematodes tested. Paenibacillus species that were not isolated from nematodes, but were phylogenetically close to the nematode-associated strains, did not adhere to Heterorhabditis, and they were also sensitive to Photorhabdus antibiotics in vitro, whereas the nematode-associated strains were not. Unusual longevity of the sporangium and resistance to Photorhabdus antibiotics may represent specific adaptations of the nematode-associated Paenibacillus strains to allow them to coexist with and be transported by Heterorhabditis. Adaptation to specific Heterorhabditis-Photorhabdus strains is evident among the three nematode-associated Paenibacillus strains (each from a different nematode strain). Paenibacillus NEM1a and NEM3 each developed best in cadavers with the nematode from which it was isolated and not at all with the nematode associate of the other strain. Differences between nematode-associated Paenibacillus strains in cross-compatibility with the various Heterorhabditis strains in cadavers could not be explained by differential sensitivity to antibiotics produced by the nematodes Photorhabdus symbionts in vitro. 相似文献
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Using rapid amplification of cDNA ends, a full length cDNA (CjLTI) was cloned from apical buds of Caragana jubata, a plant species that grows under extreme cold. The cDNA obtained was 573 bp long consisting of an open reading frame of
351 bp encoding 116 amino acids. Homology analysis did not exhibit significant similarity with any sequence at NCBI database,
therefore it was deduced as a novel gene. Secondary structure analysis suggested that the deduced CjLTI contained 25.86% α-helices,
4.31% β-turns, 6.90% extended strands, and 62.93% random coils. The hydropathy profile suggested CjLTI to be a hydrophobic
protein having characteristic features of signal peptides at N-terminus. The gene exhibited down-regulation at 5 min of exposure
to low temperature (LT, 4 ± 3°C) followed by a strong up-regulation after 15 min and onwards. Methyl jasmonate (MJ) lead to
up-regulation of CjLTI starting at 5 min onwards. The gene exhibited up- and down-regulation of expression pattern in response to abscisic acid
(ABA) and salicylic acid (SA). Mild drought stress slightly up-regulated gene expression and at severe drought (up to 115%
reduction in leaf water potential) slight down-regulation of gene expression was observed. These results suggested CjLTI to be a LT responsive gene wherein MJ, ABA and SA pathways might be involved in regulating the gene expression. 相似文献
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