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1.
【目的】明确印度梨形孢(Piriformospora indica)诱导小麦对根腐病产生抗性的作用机制。【方法】用印度梨形孢悬液浸种,以无菌培养液为对照,用病原菌禾谷镰孢菌(Fusarium graminearum)侵染小麦,对其相关生理生化指标及转录组变化进行分析。【结果】禾谷镰孢菌能诱导小麦产生过氧化氢,降低细胞内水含量,破坏细胞膜的稳定性;根部定殖印度梨形孢的小麦细胞内抗氧化酶活性增强,活性氧自由基含量降低,胞内水含量提高,细胞膜稳定性增强;印度梨形孢定殖能改变由于病原菌引起的mRNA转录组变化,抗性相关基因的表达增强。综合表明印度梨形孢定殖能有效地提高小麦对禾谷镰孢菌的抗性。【结论】研究结果为深入理解植物与微生物互作、开发新型高效环保抗根腐病生物制剂提供理论和实验依据。  相似文献   

2.
郝瑞颖  李亮  杨秀荣  马皓轩  史硕  冯宇 《微生物学报》1963,(收录汇总):3292-3309
【目的】明确印度梨形孢(Piriformospora indica)诱导小麦对根腐病产生抗性的作用机制。【方法】用印度梨形孢悬液浸种,以无菌培养液为对照,用病原菌禾谷镰孢菌(Fusarium graminearum)侵染小麦,对其相关生理生化指标及转录组变化进行分析。【结果】禾谷镰孢菌能诱导小麦产生过氧化氢,降低细胞内水含量,破坏细胞膜的稳定性;根部定殖印度梨形孢的小麦细胞内抗氧化酶活性增强,活性氧自由基含量降低,胞内水含量提高,细胞膜稳定性增强;印度梨形孢定殖能改变由于病原菌引起的mRNA转录组变化,抗性相关基因的表达增强。综合表明印度梨形孢定殖能有效地提高小麦对禾谷镰孢菌的抗性。【结论】研究结果为深入理解植物与微生物互作、开发新型高效环保抗根腐病生物制剂提供理论和实验依据。  相似文献   

3.
为探究印度梨形孢(Piriformospora indica)对铁皮石斛(Dendrobium officinale)种子萌发和原球茎生长的影响,在铁皮石斛种子离体培养和原球茎生长阶段分别接种印度梨形孢,对其形态发育特征和生理特性进行研究.结果表明,接种印度梨形孢的铁皮石斛种子的起始萌发时间提前,接种印度梨形孢的铁皮石...  相似文献   

4.
【背景】内生真菌印度梨形孢(Piriformospora indica)定殖植物可以显著促进植物生长发育。miRNA已被证实在植物体的生长发育中具有调控作用。【目的】揭示印度梨形孢定殖大麦促进大麦生长发育过程中miRNA对印度梨形孢定殖的响应及对大麦生长发育的调控作用。【方法】提取大麦总RNA,实施转录组测序并进行序列比对与数据挖掘;使用高效液相色谱检测大麦生长素等激素水平变化。【结果】印度梨形孢对大麦有显著促生作用;全转录组测序结果显示:印度梨形孢侵染3 d较空白对照有18个差异表达的miRNA,其中11个miRNA上调、7个miRNA下调;侵染7 d与空白对照相比24个差异表达的miRNA,其中11个miRNA上调、13个miRNA下调;侵染3 d与侵染7 d相比有3个miRNA上调、6个miRNA下调。GO功能富集分析与KEGG通路分析显示,差异表达miRNA的靶基因主要参与转录、细胞分裂、生长素信号的感知和转导、光合作用和激素刺激响应。靶基因所参与的途径与大麦生长发育密切相关,暗示miRNA对印度梨形孢定殖过程做出了积极响应。代谢产物分析表明miRNA参与的调控路径的代谢产物发生改变。【结论】本研究以miRNA为入手点,探究了miRNA对大麦生长发育的调控机制,为揭示印度梨形孢的促生机制提供了新的研究方向。  相似文献   

5.
重金属污染土壤的治理一直是全球热点问题,植物-微生物联合修复技术因其高效、经济和减少二次污染而被广泛关注.印度梨形孢是一种能够与植物共生的真菌,它能够通过与植物建立共生关系的方式来提高宿主植物的生长和耐胁迫能力.本文系统总结了印度梨形孢-植物体共生关系的建立过程,以及重金属胁迫下共生体的生长、光合作用、抗性生理指标、防...  相似文献   

6.
印度梨形孢是一种可在多种植物根部定殖的内生真菌,能与多种植物形成共生体,提高植物对外界营养的吸收能力,促进次生代谢产物的积累,提高植物对生物及非生物胁迫的抵抗能力,同时可增加植物的生物产量,对宿主植物产生许多有益影响。因此,印度梨形孢作为优良的生物防治和土壤改良因子,在农业生产方面显示出巨大的应用前景。本文结合本课题组近年研究结果及近10年间相关科学工作者的研究,系统总结了印度梨形孢在增强植物抗生物胁迫与非生物胁迫方面的研究进展,旨在为更好地发挥其潜在价值提供参考。  相似文献   

7.
目的:克隆并研究蒺藜苜蓿ROP基因的功能,为研究该基因家族在共生途径中的作用提供依据.方法:采用RACE方法,从蒺藜苜蓿中克隆MtROP基因,利用生物信息软件比对同源性及ROP蛋白特征结构分析,利用RT-PCR方法分析该基因的组织特异性表达,构建该基因的过表达载体并转化拟南芥.结果:获得了蒺藜苜蓿ROP家族中与拟南芥ROP10高度同源的MtROP10全长序列.氨基酸编码序列具有明显的ROP家族蛋白的结构域特征.该基因在花中高表达,根中低表达.拟南芥中过表达MtROP10,可导致根毛变粗、变短、分叉.结论:MtROP10属于植物ROP家族蛋白,可能在根毛的极性生长方面具有较为重要的功能.  相似文献   

8.
【目的】筛选出具有抗菌和抗肿瘤活性的蒺藜内生真菌。【方法】采用牛津杯法、稻瘟菌模型及肿瘤细胞模型评价蒺藜内生真菌PDB和察氏培养基发酵产物的抗菌活性和肿瘤细胞毒性。【结果】PDB培养基发酵液和察氏培养基发酵液抑菌圈直径大于10 mm的菌株分别占总菌株数的19.05%和23.81%。PDB培养基发酵液和察氏培养基发酵液对稻瘟菌的最小抑制浓度(MIC)低于10%的菌株分别占总菌株数的19.05%和47.61%。对肿瘤细胞抑制率高于50%的PDB发酵产物占PDB发酵产物总数的52.38%, 而对肿瘤细胞抑制率高于50%的察氏发酵产物占察氏发酵产物总数的28.57%。【结论】部分蒺藜内生真菌的发酵产物具有抗菌和抗肿瘤活性。  相似文献   

9.
苜蓿根瘤菌(Rhizobium meliloti)的耐盐性研究   总被引:3,自引:1,他引:3  
吴健  杨苏声 《微生物学报》1993,33(4):260-267
  相似文献   

10.
bHLH(Basic helix loop helix, bHLH)转录因子家族是植物最大的转录因子家族之一,广泛参与植物生长发育和盐胁迫应答机制。该研究利用同源克隆的方法克隆蒺藜苜蓿(Medicago truncatula)的MtbHLH148基因,采用qRT PCR方法分析MtbHLH148基因在蒺藜苜蓿中的表达特性,构建超表达载体并通过农杆菌侵染法转化拟南芥(Arabidopsis thaliana),对转基因拟南芥的耐盐性相关功能进行分析研究。结果显示:(1)从蒺藜苜蓿中获得MtbHLH148基因,该基因cDNA全长1 343 bp,包含开放阅读框为603 bp,编码 201 个氨基酸,蛋白分子量22.7 kD,等电点为11.76;蛋白结构分析显示,该蛋白无跨膜结构域,无信号肽,为亲水性蛋白;含有精氨酸/赖氨酸残基的保守结构域和典型的bHLH结构域;二级结构以α 螺旋和无规则卷曲为主。(2)亚细胞定位表明,MtbHLH148蛋白定位在细胞核。(3)进化树分析表明,MtbHLH148与大豆(Glycine max)的亲缘性最近;启动子分析发现,该基因启动子区域含有光响应元件、MYB结合位点以及ABA应答元件ABRE,可能参与非生物胁迫。(4)qRT PCR分析发现,MtbHLH148基因在蒺藜苜蓿的茎中表达量最高,叶中表达量最低,且MtbHLH148基因受ABA(100 μmol/L)诱导并在盐胁迫(200 mmol/L NaCl)处理8 h内表达量上调,而在低温(4 ℃)处理时表达量明显下调。(5)成功构建超表达载体pCAMBIA3301 MtbHLH148并转化拟南芥获得16个抗性株系,经鉴定有12个过表达株系,其中表达量最高的转基因株系为OE8;对OE8株系耐盐性功能分析发现,转基因拟南芥植株的发芽率明显高于野生型,盐胁迫下转基因拟南芥的根长是野生型的1.5倍,表明其耐盐性得到了增强。研究表明,MtbHLH148基因可能在盐胁迫调节机制中具有一定的调控作用。  相似文献   

11.
12.
AGAMOUS(AG)基因是控制高等植物花发育的重要基因,已在20多种植物基因组中发现同源基因。作为MADS-box家族的一员,AG基因结构具有高度的保守性。AG及其同源基因在植物生长发育中的功能已经十分清晰。本文研究AG同源基因在豆科几个代表物种中的分布,对其基因结构和蛋白序列进行分析比对。结果表明,AG同源基因在不同的豆科物种中具有高度的序列同源性及结构保守性。进一步通过蒺藜苜蓿Medicago truncatula的AG同源基因表达模式分析发现,其表达是与功能相互验证的。  相似文献   

13.
Medicago truncatula ssp Narbonensis and four genotypes of M. truncatula Gaertn cv. Jemalong were tested for their somatic embryogenesis potential using a two-step protocol. In the first step, embryogenic callus was induced in folioles isolated from shoots grown in vitro and cultured on Murashige and Skoog (MS) medium supplemented with 2,4-dichlorophenoxyacetic acid and zeatin. In the second step, somatic embryos were allowed to develop from the induced callus in MS growth-regulator-free medium. Individual somatic embryos were then isolated and transferred again to growth regulator free medium where they formed secondary somatic embryos in repetitive cycles. Conversion of somatic embryos into plantlets was achieved by isolating late-torpedo-phase somatic embryos with distinct cotyledons and reculturing them onto MS growth regulator free medium. The system of repetitive somatic embryogenesis in M. truncatula described here represents a permanent source of embryogenic material that can be used for the genetic modification of this species. Received: 7 August 1997 / Revision received: 22 December 1997 / Accepted: 20 January 1998  相似文献   

14.
    
Cyclophilins are widely distributed both in eukaryotes and prokaryotes and have a primary role as peptidyl‐prolyl cistrans isomerases (PPIases). This study focuses on the cloning, expression, purification and crystallization of a salinity‐stress‐induced cyclophilin A (CypA) homologue from the symbiotic fungus Piriformospora indica. Crystallization experiments in the presence of 56 mM sodium phosphate monobasic monohydrate, 1.34 M potassium phosphate dibasic pH 8.2 yielded crystals that were suitable for X‐ray diffraction analysis. The crystals belonged to the orthorhombic space group C2221, with unit‐cell parameters a = 121.15, b = 144.12, c = 110.63 Å. The crystals diffracted to a resolution limit of 2.0 Å. Analysis of the diffraction data indicated the presence of three molecules of the protein per asymmetric unit (VM = 4.48 Å3 Da−1, 72.6% solvent content).  相似文献   

15.
    
In order to research the relationship between endophytic fungus and active ingredients in medicinal Paeonia suffruticosa, a total of 57 fungal isolates were isolated from the roots, stems, leaves and buds of medicinal plant Paeonia ostii; mycelium was collected after these fungal isolates were fermented on PDA medium for a few days; then the mycelium products were extracted; their extracts were analyzed by gas chromatography–mass spectrometry. With this method, a strain endophytic fungi named J1-2 which can produce paeonol was screened. Paeonol produced by J1-2 was analyzed by using a high resolution mass spectrometer (HRMS) and nuclear magnetic resonance (NMR). The potential paeonol-procucing named J1-2 was identified Chaetomium based on morphological characteristics and ITS sequence analysis. The current research initially indicates that endophytic fungi can affect the potency of peony. At the same time it also indicates that the numerous endophytic fungi inside the medicinal Paeonia suffruticosa are precious resource for the pharmaceutical natural products that are originally from the Paeonia suffruticosa.  相似文献   

16.
    
《Fungal biology》2022,126(2):174-184
A fungus with biocontrol potential was isolated from the roots of hickory trees. The strain named sj18 was classified as a member of the genus Hypoxylon (Hypoxylaceae) after multigene phylogenetic analysis (beta-tubulin gene, internal transcribed spacer, 28S large subunit ribosomal RNA gene, and RNA polymerase II subunit gene). The strain grew well on a PDA with an optimum temperature range between 32 and 34 °C. The fungus had obvious inhibitory effects on Botryosphaeria dothidea, Colletotrichum gloeosporioides, and Gibberella moniliformis in fumigation experiments on solid agar plates. In an inoculation experiment of Chinese cabbage, the fungus was also found to have an obvious repellent effect on cabbage caterpillars. In vitro experiments on Petri dishes showed that the fermentation broth of the sj18 strain could kill 100% of Bursaphelenchus xylophilus within 8 h even if the fermentation broth was diluted 8 times. The inoculation test of Arabidopsis thaliana showed that the fungus could promote the lateral root formation of plants and significantly increase their aboveground biomass. Through the analysis of solid phase microextraction (SPME), it was found that the main volatile components of the fermentation products were azulene 65.39% (61.77% + 3.62%), caryophyllene 7.41%, and eucalyptol 6.83% according to the peak area ratio. Therefore, sj18 can be used as a candidate for the further research and development of biocontrol agents.  相似文献   

17.
  总被引:2,自引:0,他引:2  
  相似文献   

18.
    
(Iso)flavonoids are commonly accumulated as malonylated or acetylated glycoconjugates in legumes. Sequence analysis on EST database of the model legume Medicago truncatula enabled us to identify nine cDNA sequences encoding BAHD super-family enzymes that are distinct from the most of the characterized anthocyanin/flavonol acyltransferase genes in other species. Functional characterization revealed that three of these corresponding enzymes, MtMaT1, 2 and 3, specifically recognize malonyl CoA as an acyl donor and catalyze the malonylation of a range of isoflavone 7- O- glucosides in vitro . These malonyltransferase genes displayed distinct tissue-specific expression patterns and responded differentially to biotic and abiotic stresses. Consistent with gene expression, the level of the accumulated malonyl isoflavone glucoside was altered in the roots of M. truncatula grown under normal and drought-stressed conditions. Overexpression of the MtMaT1 gene in a previously engineered Arabidopsis line that accumulates genistein glycosides ( Proc. Natl Acad. Sci. USA , 99 , 2002:14578) led to a malonylated product. Confocal microscopy of the transiently expressed MtMaT1–GFP fusion revealed strong fluorescence in both the cytoplasm and nucleus of M. truncatula and tobacco leaf cells. A truncated MtMaT1 lacking the C-terminal polypeptide of 110 amino acid residues that include the DFGWG motif, the single conserved sequence signature of BAHD super-family members, retained considerable catalytic efficiency, but showed an altered optimum pH preference for maximum activity. Such C-terminal polypeptide deletion or deletion of the DFGWG motif alone led to improper folding of the transiently expressed GFP fusion protein in living cells, and impaired nuclear localization of the enzyme.  相似文献   

19.
    
Two new compounds, named as (Z)-7,4′-dimethoxy-6-hydroxy-aurone-4-O-β-glucopyranoside (1), and (1S,3R,4S)-1-(4′-hydroxyl-phenyl)-3,4-dihydro-3,4,5-trimethyl-1H-2-benzopyran-6,8-diol (2), were isolated from the endophytic fungus Penicillium citrinum of Bruguiera gymnorrhiza. Their structures were elucidated on the basis of spectroscopic analysis. Additionally, compound 1 exhibited potent neuroprotective activity in 1-methyl-4-phenylpyridinium-induced oxidative damage in PC12 cells.  相似文献   

20.
    
Nodulation is an extraordinary symbiotic interaction between leguminous plants and nitrogen‐fixing bacteria (rhizobia) that assimilate atmospheric nitrogen (in root nodules) and convert it into compounds suitable for the plant host. A class of plant hormones called cytokinins are involved in the nodulation process. In the model legume Medicago truncatula, nodulin 13 (MtN13), which belongs to the pathogenesis‐related proteins of class 10 (PR‐10), is expressed in the outer cortex of the nodules. In general, PR‐10 proteins are small and monomeric and have a characteristic fold with an internal hydrophobic cavity formed between a seven‐stranded antiparallel β‐sheet and a C‐terminal α‐helix. Previously, some PR‐10 proteins not related to nodulation were found to bind cytokinins such as trans‐zeatin. Here, four crystal structures of the MtN13 protein are reported in complexes with several cytokinins, namely trans‐zeatin, N6‐isopentenyladenine, kinetin and N6‐benzyladenine. All four phytohormones are bound in the hydrophobic cavity in the same manner and have excellent definition in the electron‐density maps. The binding of the cytokinins appears to be strong and specific and is reinforced by several hydrogen bonds. Although the binding stoichiometry is 1:1, the complex is actually dimeric, with a cytokinin molecule bound in each subunit. The ligand‐binding site in each cavity is formed with the participation of a loop element from the other subunit, which plugs the only entrance to the cavity. Interestingly, a homodimer of MtN13 is also formed in solution, as confirmed by small‐angle X‐ray scattering (SAXS).  相似文献   

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