共查询到19条相似文献,搜索用时 171 毫秒
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对水稻品种D优527体内筛选到的优势细菌SR-15、SR-25、SL-37进行浸染、扫描电镜和透射电镜观察.结果表明。菌株主要在水稻组织的细胞间隙、细胞质内和液泡内定位。SR-15菌株通过质粒PUC-18转化和ERIC-PCR再分离实验验证,结果显示重组菌株在植株体内稳定定位,具有稳定的内生特性。生理、生化指标结合形态特点研究确定该菌株属盐敏芽孢杆菌Bacillus halmapalus 。致病性和促生性试验表明,菌株对水稻植株无致病性,在水稻生长中后期有明显促生作用。将带有Cry1Ac基因的质粒转入菌株SR-15,并经southern分析证明,其表达产物具有致死水稻二化螟84.7%的效应。 相似文献
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【背景】植物内生细菌可产生具有抑菌和促生活性的物质,既能抑制植物病原菌对寄主植物的侵染,也能促进植物的生长。沙棘根瘤内生细菌是根瘤内除共生固氮的弗兰克氏菌外,与沙棘共生的一大类微生物。研究具有抑菌和促生活性的植物内生菌,可为微生物菌肥的研究提供理论基础。【目的】筛选具有优良抑菌和促生活性的沙棘根瘤内生细菌,初步研究其抑菌和促生活性,并对菌株进行鉴定。【方法】采用双层琼脂法、琼脂扩散法、双层平板对峙法、牛津杯法进行沙棘根瘤拮抗性内生细菌的筛选。选取抑菌活性较高的内生细菌,分别采用Salkowski比色法、ChromeAzurolS(CAS)平板检测法和钼锑抗比色法进行产吲哚乙酸、铁载体及溶磷能力的测定。采用发酵液灌根法测定沙棘根瘤内生细菌SR308对黄瓜促生作用的盆栽效果。通过形态和培养特征、生理生化试验及16S rRNA基因序列分析法对菌株TT201和SR308进行鉴定。【结果】从131株沙棘根瘤内生细菌中筛选出9株具有较强抑菌活性的内生细菌,其中菌株TT201抑菌性最佳、抑菌谱广;菌株SR308的促生活性最好,其发酵液对黄瓜的生长具有较强的促进作用。对具有较强抑菌和促生活性的菌株TT201和SR308进行鉴定的结果表明,菌株TT201为侧孢短芽孢杆菌(Brevibacilluslaterosporus),菌株SR308为蕈状芽孢杆菌(Bacillusmycoides)。【结论】获得2株具有优良抑菌和促生活性的沙棘根瘤内生细菌,为进一步开发微生物农药及菌肥提供了资源。 相似文献
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广东省水稻纹枯病菌遗传多样性与致病力分化的研究 总被引:6,自引:0,他引:6
利用随机引物扩增多态性DNA(PAPD)分子标记技术分析了来自广东省7个县市48个水稻纹枯病菌菌株的遗传多样性,以筛选出的10个随机引物对菌株进行PAPD-PCR扩增,共产生了98个PAPD分子标记,其中89.9%的片段具有多态性。48菌株间的遗传相似性系数(以Nei基因一致度表示)在0.56-0.949之间,用UPGMA和类分析可将它们分为5个RAPD遗传聚类群(A、B、C、D、E),相同地区来源的菌株基本上聚类在同一组群内。在温室中对供试菌株进行致病性测定,结果表明所有菌株对水稻品种Tetep都有致病性,菌株间致病力差异显著(α=0.05),病情指数范围为0.73-18.7,平均感指病指数为5.24。试验分析结果表明水稻纹枯病菌具有丰富的遗传多样性,不同县市的菌株存在很大的遗传分化现象(FST=0.579),RAPD遗传聚类群的划分与菌株的地理来源有明显的相关性,但菌株的致病力差异与菌株的来源、遗传聚类组群的划分没有明显的相关性。 相似文献
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生防细菌对水稻的促生性及诱导抗性研究 总被引:1,自引:0,他引:1
《生物技术进展》2017,(1)
研究了4株生防菌对水稻白叶枯病的抑制作用和菌悬液浸种、浸芽、浇苗和包衣4种处理对水稻生长的促进作用,及对水稻体内过氧化物酶POD、多酚氧化酶PPO、苯丙氨酸解氨酶PAL 3种保护酶的诱导表达作用。结果表明,4个菌株均对水稻幼苗有促生及诱导抗病性的作用。其中,WY2菌株诱导水稻抗病性和对水稻的促生性都要优于其他3株菌株。水稻幼苗接种生防细菌24 h后再接种病原菌,生防细菌能促进植物体内保护酶PAL、POD、PPO活性的提高,进而诱导植物抗病性的提高。 相似文献
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本实验通过质粒pSUP501l及其辅助质粒RP4将Tn5-Mob随机插入苜蓿根瘤菌(Rhizo-bium meliloti 042B)的基因组中,得到86株接合子SR。随机选取4株SR,通过辅助质粒R68.45的三亲本杂交,将它们的DNA片段引入慢生型大豆根瘤菌(Bradyrhizobium,japo—nicum USDA 110),获得106株接合子BSR。大部分BSR菌株获得了生长快速的特性和耐盐性,一般能耐0.3—0.5m01/L Nacl,其中有些菌株能产生黑色素。将9o株BSR回接大豆和苜蓿植株,发现47株能在大豆和苜蓿植株结瘤,但在苜蓿卜无固氮活性;26株只能在大豆植株结瘤固氮;13株只能在苜蓿植株结瘤而不固氮;4株在大豆和菖蓿植株均不结瘤。其中,获得了4株耐盐性和固氮酶活性强的接合子。 相似文献
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内生拮抗细菌在哈密瓜植株体内的传导定殖和促生作用研究 总被引:10,自引:0,他引:10
采用抗生素标记的方法研究了内生拮抗细菌P38和B167菌株在哈密瓜植株体内的定殖动态和对植株生长的影响.结果表明,接种方法显著影响P38菌株在植株体内的定殖和传导,并以浸种处理最佳,蘸根和灌根处理次之,喷叶处理最差;浸种可使P38菌株在根、茎、叶中良好传导和稳定定殖,随着植株的生长,根内菌量呈下降趋势,而茎、叶内的含菌量先上升后下降;P38菌株还具有促进哈密瓜种子萌发和植株生长的作用.B167菌株只在根内定殖,在体内的扩展性较差,不能进入叶片;它对植株的生长表现出一定的抑制作用. 相似文献
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采用十二烷基硫酸钠(SDS)和提高生长温度结合法消除T1828菌株质粒后,筛选到无质粒突变株ZWL-15。以原始亲株T1828和无质粒突变株ZWL-15为出发菌株,考察了两者部分生物学特性。结果表明,菌株ZWL.15生长速率快于T1828,进入对数期和稳定期的时间分别提前1h和4h。在菌株ZWL-15发酵过程中添加0.01%的SDS有利于冠菌素的合成,最适发酵温度比T1828升高5℃,达到35℃,发酵周期提前4h,COR相对值是T1828的两倍左右。ZWL-15传代实验表明该突变株很稳定,且对氨苄青霉素敏感,氨苄青霉素基因初步定位于该菌属质粒上。 相似文献
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李颖龙长梅蒋标韩丽珍 《生物技术通报》2022,(9):237-247
为探讨2株根际促生菌耐酪氨酸束村氏菌P9和吡咯伯克霍尔德氏菌P10对花生的促生机制。利用GFP及利福平对2个菌株进行标记、结合扫描电镜观察,追踪了2株PGPR菌株在花生组织中的定殖动态;并通过16S rRNA全长测序对菌株接种花生根际土壤的细菌多样性进行分析。结果表明,利福平标记的P9和P10菌株具有良好的遗传稳定性,其生长和促生特性与原始菌株基本一致。GFP标记菌株可在花生的根尖及其分生区定殖;利福平标记菌株可稳定定殖在土壤及花生的根、茎部,且接菌30 d后定殖数仍保持在10CFU/g数量级。与未接菌植株根际土壤相比,P9、P10及混合菌株接种组的细菌群落相似性更高;接菌组的Flavihumibacter、unidentified_Rhizobiaceae的相对丰度显著增加,芽孢杆菌属、链霉菌属等的丰度较CK有不同程度增加,溶杆菌属、无色杆菌属及假黄单胞菌属等的丰度降低。2株PGPR菌株均可通过直接定殖在植株组织中、间接影响土壤细菌群落结构而发挥对花生的促生作用,混合菌株接种效果更优。研究结果明析了2株促生菌的促生机制,并为菌株的应用提供了科学依据。 相似文献
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由灰葡萄孢(Botrytis cinerea)引起的灰霉病是番茄生产中最重要的病害之一,当前使用的杀菌剂因药物残留、病原菌抗药性及食品安全等原因逐渐受到限制。因此,利用拮抗微生物的生物防治逐渐成为灰霉病防控的有效策略。【目的】从番茄植株体内筛选具有抗病促生特性内生菌株并对其生防潜力进行评估,为开发番茄灰霉病生物防治新策略提供理论依据。【方法】采用组织分离法在番茄植株不同部位分离出内生细菌、真菌,结合16SrRNA和ITS序列分析,对候选菌株进行初步鉴定;通过菌株对峙培养、果实离体接种筛选对灰葡萄孢具有拮抗活性的内生菌;进一步测定菌株分泌生长素、嗜铁素的能力及其对拟南芥和番茄幼苗生长的促生特性。【结果】从番茄植株不同部位共分离出72株内生细菌和31株内生真菌,通过平板对峙法筛选出1株对多种病原菌具有较好抑菌活性的内生细菌FQ-G3,分子鉴定为Bacillus velezensis。FQ-G3对灰葡萄孢抑菌率达80.93%,并显著抑制灰葡萄孢在番茄果实上的扩展。该菌株能够分泌生长素、蛋白酶和嗜铁素,且对拟南芥、番茄幼苗具有明显的促生效果。【结论】本研究表明分离自番茄植株的内生菌FQ-G3具... 相似文献
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Yung Choon Yoo Kumiko Yoshimatsu Ryu Yoshida Mizuho Tamura Ichiro Azuma Jiro Arikawa 《Microbiology and immunology》1993,37(7):557-562
Virulence of hantavirus strain of SR-11 Seoul virus and Hantaan 76–118 (HTN) of Hantaan virus were compared. Infections of both strains were lethal in newborn mice. However, inoculum required to cause lethal infection was about 4,000 times higher for strain HTN (1.65 × 103 PFU/mouse/LD50) than for strain SR-11 (0.36 PFU). Thus, both strains were considered pathogenic to newborn mice but they possessed different levels of virulence. The assay system used for these strains in newborn mice proved to be useful in the study of hantavirus vilurence. Growth curves of the two strains in CV-7 cell cultures were compared. Strain SR-11 was shown to have higher activity of virus replication and virus release into the culture fluids than strain HTN. The possibility of a relationship between replication activity and high levels of virulence in mice was suggested. 相似文献
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Efficiency of regulating serum cholesterol by cholesterol-7 alpha-hydroxylase was studied in pigeon strains hypo-(SR-39) and hypercholesterolemic (SR-37) with respect to dietary cholesterol. Diurnal hydroxylase activity in SR-37 was 10% of that in strain SR-39 adapted to a light-dark cycle and fed a non-cholesterol diet. Acrophase (6 p.m.) activity was 54-fold greater in SR-39 than in SR-37 pigeons. Dietary cholesterol elevated enzyme activity 2.8-fold in SR-37 pigeons. Dietary cholestyramine plus cholesterol increased hydroxylase activity 21-fold in SR-37 and 3-fold in SR-39 strain; yet, activity remained greater in SR-39. Cholestyramine feeding prevented elevated cholesterol levels in both groups. The circadian rhythms of hydroxylase and serum corticosterone were determined. The diurnal activity in SR-37 was 10% of that in SR-39 and acrophase activity was 34-fold greater in SR-39. Hormone levels were comparable. Programmed acrophase was asynchronous between strains. Hydroxylase activity was positively correlated with corticosterone levels and inversely correlated with serum cholesterol. A defect in the up-regulation of cholesterol-7 alpha-hydroxylase is proposed which limits the catabolism of cholesterol in strain SR-37. 相似文献
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Tanaka S Yamada K Yabumoto K Fujii S Huser A Tsuji G Koga H Dohi K Mori M Shiraishi T O'Connell R Kubo Y 《Molecular microbiology》2007,64(5):1332-1349
Fungal plant pathogens have evolved diverse strategies to overcome the multilayered plant defence responses that confront them upon host invasion. Here we show that pathogenicity of the cucumber anthracnose fungus, Colletotrichum lagenarium, and the rice blast fungus, Magnaporthe grisea, requires a gene orthologous to Saccharomyces cerevisiae SSD1, a regulator of cell wall assembly. Screening for C. lagenarium insertional mutants deficient in pathogenicity led to the identification of ClaSSD1. Following targeted gene replacement, appressoria of classd1 mutants retained the potential for penetration but were unable to penetrate into host epidermal cells. Transmission electron microscopy suggested that appressorial penetration by classd1 mutants was restricted by plant cell wall-associated defence responses, which were observed less frequently with the wild-type strain. Interestingly, on non-host onion epidermis classd1 mutants induced papilla formation faster and more abundantly than the wild type. Similarly, colonization of rice leaves by M. grisea was severely reduced after deletion of the orthologous MgSSD1 gene and attempted infection by the mutants was accompanied by the accumulation of reactive oxygen species within the host cell. These results suggest that appropriate assembly of the fungal cell wall as regulated by SSD1 allows these pathogens to establish infection by avoiding the induction of host defence responses. 相似文献
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F. Nazari B.M. Soltani M. Shams-Bakhsh M. Sharifi 《Archives Of Phytopathology And Plant Protection》2017,50(1-2):24-32
Surfactin secreted by bacilli has biological functions in plant. Surfactin C14 and C15 have the highest effect on inducing hydrogen peroxide species release in the plant. Surfactin production in the two Bacillus strains ACCT21332 and FKR3 were analysed by HPLC and the phytotoxicity of the Bacilli-derived surfactins was determined in Tobacco cell culture. Surfactin C14 and C15 were detected in ACCT21332 but not in FKR3 strain. Extracellular hydrogen peroxide produced by tobacco cell culture cells exposed to ATCC21332 and FKR3 strains increased compared to untreated ones. The Agrobacterium mediated transformation rate of tobacco cells drops from 4% transformed cells to 0.8 and 1.2% when pretreated with ATCC21332 or FKR3 strain, respectively. The strong drop in transformation rate of plant cell culture after FKR3 strain pre-treatment indicates that Surfactin C14 and C15 are not the major or the only cause in protecting plant cells from Agrobacterial infection and transformation. 相似文献
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Pseudomonas fluorescens enhances resistance and natural enemy population in rice plants against leaffolder pest 总被引:1,自引:0,他引:1
D. Saravanakumar N. Lavanya B. Muthumeena T. Raguchander S. Suresh & R. Samiyappan 《Journal of Applied Entomology》2008,132(6):469-479
Plant growth promoting fluorescent pseudomonad strains Pf1, TDK1 and PY15 were evaluated for their efficacy against leaffolder ( Cnaphalocrocis medinalis ) pest in rice plants under field conditions individually and in combinations. Application of mixtures of Pseudomonas fluorescens strains Pf1, TDK1 and PY15 significantly reduced the leaffolder damage in rice plants compared with untreated control. Interestingly, natural enemy population in plots treated with P. fluorescens was greater than the chemical and untreated controls. Further, support for these results was gathered by assaying activities of polyphenol oxidase (PPO) and lipoxygenase (LOX) under glasshouse conditions. The results showed the higher activity of PPO and LOX in plants treated with P. fluorescens mixtures (Pf1 + TDK1 + PY15) than the plants treated with individual strains, chemical and untreated controls. Further, fluorescent pseudomonad mixtures increased the rice yield compared with individual strain and non-bacterized treatments. The present study reveals that in addition to plant growth promotion, plant growth-promoting rhizobacterial (PGPR) strains-mediated induction of PPO and LOX in rice plants could be involved in enhanced natural enemy populations and resistance mechanisms against leaffolder attack. 相似文献
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Abstract Enterobacter agglomerans strains are able to form cell aggregates called symplasmata when grown in a liquid medium. The nitrogen-fixing E. agglomerans strain NO30, isolated from the rhizosphere soil of rice, was inoculated onto roots of axenically grown wheat and rice seedlings and could colonize the roots of both plants. The ability of NO30 cells to colonize the plant roots seemed comparable in the host and non-host plants, as far as colony forming units (cfu) measurements were concerned. Nevertheless, electron microscopy (SEM, TEM) revealed that, in the case of rice, the normal host plant for NO30, the colonization was characterized by the formation of symplasmata, whereas only individual cells were found on wheat roots. Symplasmata formation seems to be specific for colonization of the host plant, rice. This finding also means that colonization of the host plant may be largely underestimated when measured by conventional techniques. Symplasmata formed in liquid medium or on the roots of rice were stained using Thiery's and Swift's technique, and the presence of polysaccharides and proteins was revealed in the extracellular matrix as well as in fibrils anchoring symplasmata to other symplasmata or to plant cells. 相似文献
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N. Seenivasan P.M.M. David P. Vivekanandan R. Samiyappan 《Biocontrol Science and Technology》2012,22(6):611-632
The plant growth promoting rhizobacterium, Pseudomonas fluorescens strains PF1, TDK1, and PY15 were evaluated individually and in combinations for their efficacy against root-knot nematode, Meloidogyne graminicola, in rice plants under in vitro, glass house and field conditions. Culture filtrates of these strains either individually or as mixture inhibited egg hatching and caused mortality of juveniles of M. graminicola in vitro. The efficacy was more pronounced when filtrates of the strain were used as mixtures than as individual strains. Mixtures of P. fluorescens strains signficantly reduced M. graminicola infestation when applied as bacterial suspensions through seed treatment. The higher activity of peroxidase and chitinase enzymes was observed in plants treated with P. fluorescens mixtures than the plants treated with individual strains, two strain mixtures and untreated control. In field trials on rice, talc formulations of the P. fluorescens strains individually as well as mixtures were evaluated as seed treatment, soil treatment and combination of both. A mixture of the three strains was the most effective when applied either as seed + soil treatment or as seed treatment alone. The introduced P. fluorescens strains survived endophytically on rice roots. The application of the P. fluorescens mixture PF1 + TDK1 + PY15 in seed + soil treatment resulted in higher grain yield which provided a 27.3% increase over the control followed by P. fluorescens mixture PF1 + TDK1 + PY15 in seed treatment alone, which increased the grain yield of rice by 24.7% compared to the control. 相似文献
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M. Z. Liang L. J. Ou L. X. Deng S. Luan L. B. Chen 《Russian Journal of Plant Physiology》2008,55(5):694-698
The aim of this work was to develop a photoperiod-sensitive male sterile rice with stable sterility. We developed Changguang S, an indica rice strain, by using a short critical day length. Differences in the fertility responses of Changguang S strain pollen to temperature and photoperiod under natural and controlled conditions were studied. The results showed that Changguang S strain exhibited stable sterility under long-day and low-temperature conditions (22°C, 15 days). The stability of sterility was significantly higher than that of other such rice strains, Nongken 58S and 7001S. The critical photoperiod for inducing male sterility in Changguang S was 13 h or shorter, and its duration was significantly shorter than that required for rice strains Nongken 58S and 7001S. It is suggested that Changguang S is a typical photoperiod-sensitive male sterile rice strain with a shorter critical day length and a lower critical temperature. It is promising to apply this strain to two-line hybrid rice production. 相似文献