共查询到20条相似文献,搜索用时 31 毫秒
1.
Katrin Konecki Marina Gernold Annette Wensing Klaus Geider 《Archives of microbiology》2013,195(10-11):759-764
Short-chain fatty acids (SCFAs) are used to preserve food and could be a tool for control of fire blight caused by Erwinia amylovora on apple, pear and related rosaceous plants. Neutralized acids were added to buffered growth media at 0.5–75 mM and tested at pHs ranging from 6.8 to 5.5. Particularly at low pH, SCFAs with a chain length exceeding that of acetic acid such as propionic acid were effective growth inhibitors of E. amylovora possibly due to uptake of free acid and its intracellular accumulation. We also observed high inhibition with monochloroacetic acid. An E. billingiae strain was as sensitive to the acids as E. amylovora or E. tasmaniensis. Fire blight symptoms on pear slices were reduced when the slices were pretreated with neutralized propionic acid. Propionic acid is well water soluble and could be applied in orchards as a control agent for fire blight. 相似文献
2.
Malnoy Mickaël Venisse Jean-Stéphane Brisset Marie-Noëlle Chevreau Elisabeth 《Molecular breeding : new strategies in plant improvement》2003,12(3):231-244
The siderophore produced by Erwinia amylovora, the causal agent of fire blight of Maloideae, is one of the virulence factors of this bacterium. The production of siderophores enables E. amylovora to overcome the conditions of iron limitation met in plant tissue, and may also protect the bacteria against active oxygen species produced through the Fenton reaction. In this paper, we have examined the ability of an iron chelator protein, encoded by the bovine lactoferrin gene, to reduce fire blight susceptibility in pear (Pyrus communis L.). Transgenic pear clones expressing this gene controlled by the CaMV35S promoter were produced by Agrobacterium tumefaciens mediated transformation. Transformants were analysed by RT-PCR and western blot to determine lactoferrin expression levels. Most transgenic clones demonstrated significant reduction of susceptibility to fire blight in vitro and in the greenhouse when inoculated by E. amylovora. These transgenic clones also showed a significant reduction of symptoms when inoculated with two other pear bacterial pathogens : Pseudomonas syringae pv. syringae and Agrobacterium tumefaciens. Moreover, we have shown that this increase in bacterial resistance was correlated with an increase in root ferric reductase level activity and leaf iron content. Despite negative effects on the growth of a few clones, our results indicate the potential of lactoferrin gene transformation to protect pear from fire blight through increased iron chelation. 相似文献
3.
Francesco Spinelli Joel L. Vanneste Guglielmo Costa 《Trees - Structure and Function》2012,26(1):247-257
Acylcyclohexanediones and antagonistic bacteria sprayed alone or in combination have been shown to suppress fire blight of
apple and pear. Acylcyclohexanediones, such as prohexadione-calcium and trinexapac-ethyl, increase plant resistance and are
effective against the shoot blight phase of the disease. Antagonistic bacteria, such as Pantoea agglomerans, compete with the pathogen (Erwinia amylovora) for space and nutrients on stigmas, which prevents blossom blight. Potential synergistic effects of acylcyclohexanediones
with P. agglomerans for fire blight suppression were investigated on leaves and flowers of apple and pear. Acylcyclohexanediones modified the
composition of apple nectar and stigmatic secretions, which resulted in moderately higher epiphytic populations of P. agglomerans strain P10c. In experiments in apple orchards, the combination of acylcyclohexanediones and P. agglomerans gave the greatest protection against blossom blight and shoot blight. In pear orchards, under natural infection conditions,
a similar result was obtained for the 3 of the 4 years of the experiment. 相似文献
4.
The rapid and effective activation of disease resistance responses is essential for plant defense against pathogen attack.
These responses are initiated when pathogen-derived molecules (elicitors) are recognized by the host. In order to create novel
mechanisms for fire blight resistance in pear, we have generated transgenic pears expressing the elicitor harpin Nea from Erwinia amylovora under the control of the constitutive promoter CaMV35S. The transient expression of hrpN
Ea
in pear cells did not provoke any apparent damage. Therefore, stable constitutive expression of hrpN
Ea
was studied in seventeen transgenic clones of the very susceptible cultivar “Passe Crassane.” Most transgenic clones displayed
significant reduction of susceptibility to fire blight in vitro when inoculated by E. amylovora, which was positively correlated to their degree of expression of the transgene hrpN
Ea
. These results indicate that ectopic expression of a bacterial elicitor such as harpin Nea is a promising way to improve pear resistance to fire blight. 相似文献
5.
Erwinia amylovora is a polyphagous bacterium causing fire blight on apple, pear and over 130 other plant species belonging mainly to the Rosaceae family. Although E. amylovora is regarded as a very homogenous species, the particular strains can differ in pathogenic ability as far as their host range
is concerned (e.g. those originating from Rubus or Maloidae plants) as well as by the extent of the disease they cause. It was found that strains originating from North America are
generally more genetically heterogeneous than those from Europe. Diversity of E. amylovora is also related to streptomycin resistance as a result of its application to control of fire blight. The level of genetic
heterogeneity of E. amylovora is so low (comparative genome analysis revealed a similarity of over 99% for the two genomes tested) that standard DNA-based
techniques fail in detection of intra-species variability. Amplified fragment length polymorphism was found to be most useful
for differentiation of strains of fire blight causal agent as well as techniques ensuing release of pan-genome sequences of
two E. amylovora strains: multi-locus variable number of tandem repeats analysis and clustered regularly interspaced short palindrome repeats. 相似文献
6.
Ana Palacio-Bielsa Montserrat Roselló Pablo Llop María M. López 《Trees - Structure and Function》2012,26(1):13-29
The number of described pathogenic and non-pathogenic Erwinia species associated with pome fruit trees, especially pear trees, has increased in recent years, but updated comparative information
about their similarities and differences is scarce. The causal agent of the fire blight disease of rosaceous plants, Erwinia amylovora, is the most studied species of this genus. Recently described species that are pathogenic to pear trees include Erwinia pyrifoliae in Korea and Japan, Erwinia spp. in Japan, and Erwinia piriflorinigrans in Spain. E. pyrifoliae causes symptoms that are indistinguishable from those of fire blight in Asian pear trees, Erwinia spp. from Japan cause black lesions on several cultivars of pear trees, and E. piriflorinigrans causes necrosis of only pear blossoms. All these novel species share some phenotypic and genetic characteristics with E. amylovora. Non-pathogenic Erwinia species are Erwinia billingiae and Erwinia tasmaniensis that have also been described on pome fruits; however, less information is available on these species. We present an updated
review on the phenotypic and molecular characteristics, habitat, pathogenicity, and epidemiology of E. amylovora, E. pyrifoliae, Erwinia spp. from Japan, E. piriflorinigrans, E. billingiae, and E. tasmaniensis. In addition, the interaction of these species with pome fruit trees is discussed. 相似文献
7.
First report on the presence of fire blight resistance in linkage group 11 ofPyrus ussuriensis Maxim
Fire blight, caused by the gram-negative bacteriumErwinia amylovora (Burrill) Winslow et al., is a dangerous disease of pome fruits, including pear. A pear breeding program for fire blight
resistance was initiated in 2003 at the Department of Pomology, Warsaw University of Life Sciences, Poland. Since several
Asian species are considered to be potential sources of resistance to fire blight, the susceptiblePyrus communis ‘Doyenne du Comice’ was crossed with the resistantP. ussuriensis. The F1 full-sib progeny composed of 155 seedlings was tested for susceptibility to fire blight by artificial shoot inoculation.
A framework linkage map of both parents was constructed based on 48 AFLP and 32 SSR markers and covered a length of 595 cM
and 680 cM in ‘Doyenne du Comice’ andP. ussuriensis, respectively. For the first time a putative QTL for fire blight resistance inP. ussuriensis linkage group 11 was identified. Another putative QTL in linkage group 4 of ‘Doyenne du Comice’ seems to indicate that sources
of fire blight resistance can be identified also in the susceptible cultivars. 相似文献
8.
Angela Baldo Jay L Norelli Robert E Farrell Carole L Bassett Herb S Aldwinckle Mickael Malnoy 《BMC plant biology》2010,10(1):1
Background
The necrogenic enterobacterium, Erwinia amylovora is the causal agent of the fire blight (FB) disease in many Rosaceaespecies, including apple and pear. During the infection process, the bacteria induce an oxidative stress response with kinetics similar to those induced in an incompatible bacteria-plant interaction. No resistance mechanism to E. amylovora in host plants has yet been characterized, recent work has identified some molecular events which occur in resistant and/or susceptible host interaction with E. amylovora: In order to understand the mechanisms that characterize responses to FB, differentially expressed genes were identified by cDNA-AFLP analysis in resistant and susceptible apple genotypes after inoculation with E. amylovora. 相似文献9.
10.
Vladimir Jakovljevic Susanne Jock Zhiqiang Du Klaus Geider 《Microbial biotechnology》2008,1(5):416-424
Fire blight caused by the Gram‐negative bacterium Erwinia amylovora can be controlled by antagonistic microorganisms. We characterized epiphytic bacteria isolated from healthy apple and pear trees in Australia, named Erwinia tasmaniensis, and the epiphytic bacterium Erwinia billingiae from England for physiological properties, interaction with plants and interference with growth of E. amylovora. They reduced symptom formation by the fire blight pathogen on immature pears and the colonization of apple flowers. In contrast to E. billingiae, E. tasmaniensis strains induced a hypersensitive response in tobacco leaves and synthesized levan in the presence of sucrose. With consensus primers deduced from lsc as well as hrpL, hrcC and hrcR of the hrp region of E. amylovora and of related bacteria, these genes were successfully amplified from E. tasmaniensis DNA and alignment of the encoded proteins to other Erwinia species supported a role for environmental fitness of the epiphytic bacterium. Unlike E. tasmaniensis, the epiphytic bacterium E. billingiae produced an acyl‐homoserine lactone for bacterial cell‐to‐cell communication. Their competition with the growth of E. amylovora may be involved in controlling fire blight. 相似文献
11.
Sara Montanari Laure Perchepied Déborah Renault Linda Frijters Riccardo Velasco Mary Horner Susan E. Gardiner David Chagné Vincent G. M. Bus Charles-Eric Durel Mickael Malnoy 《Molecular breeding : new strategies in plant improvement》2016,36(4):47
Fire blight, caused by the bacterium Erwinia amylovora (Burrill) Winslow et al., is one of the most serious diseases of pear. The development of pear cultivars with a durable resistance is extremely important for effective control of fire blight and is a key objective of most pear breeding programs throughout the world. We phenotyped seedlings from the interspecific pear population PEAR3 (PremP003, P. × bretschneideri × P. communis) × ‘Moonglow’ (P. communis) for fire blight resistance at two different geographic locations, in France and New Zealand, respectively, employing two local E. amylovora isolates. Using a genetic map constructed with single nucleotide polymorphism (SNP) and microsatellite (SSR) markers previously developed for this segregating population, we detected a major quantitative trait locus (QTL) on linkage group (LG)2 of ‘Moonglow’ (R 2 = 12.9–34.4 %), which was stable in both environments. We demonstrated that this QTL co-localizes with another major QTL for fire blight resistance previously detected in ‘Harrow Sweet’ and that the two favorable (i.e., resistant) alleles were not identical by descent. We also identified some smaller effect (R 2 = 8.1–14.8 %) QTLs derived from the susceptible parent PEAR3. We propose SNP and SSR markers linked to the large effect QTL on LG2 as candidates for marker-assisted breeding for fire blight resistance in pear. 相似文献
12.
Muhammad A. Khan Brion Duffy Cesare Gessler Andrea Patocchi 《Molecular breeding : new strategies in plant improvement》2006,17(4):299-306
Fire blight caused by the bacterium Erwinia amylovora is a severe threat to apple and pear orchards worldwide. Apple varieties exhibit a wide range of relative susceptibility/tolerance to fire blight. Although, no monogenic resistance against fire blight has been identified yet, recent evidence indicates the existence of quantitative resistance. Potential sources of fire blight resistance include several wild Malus species and some apple cultivars. F1 progenies of ‘Fiesta’בDiscovery’ were inoculated with the Swiss strain Ea 610 and studied under controlled conditions to identify quantitative trait loci (QTLs) for fire blight resistance. Disease was evaluated at four time points after inoculation. Shoot lesion length and the area under disease progress curve (AUDPC) values were used for QTL analysis. One significant (LOD score of 7.5–8.1, p<0.001) QTL was identified on the linkage group 7 of ‘Fiesta’ (F7). The F7 QTL explained about 37.5–38.6% of the phenotypic variation. 相似文献
13.
Mónica Ordax Jaime E. Piquer-Salcedo Ricardo D. Santander Beatriz Sabater-Mu?oz Elena G. Biosca María M. López Ester Marco-Noales 《PloS one》2015,10(5)
Monitoring the ability of bacterial plant pathogens to survive in insects is required for elucidating unknown aspects of their epidemiology and for designing appropriate control strategies. Erwinia amylovora is a plant pathogenic bacterium that causes fire blight, a devastating disease in apple and pear commercial orchards. Studies on fire blight spread by insects have mainly focused on pollinating agents, such as honeybees. However, the Mediterranean fruit fly (medfly) Ceratitis capitata (Diptera: Tephritidae), one of the most damaging fruit pests worldwide, is also common in pome fruit orchards. The main objective of the study was to investigate whether E. amylovora can survive and be transmitted by the medfly. Our experimental results show: i) E. amylovora can survive for at least 8 days inside the digestive tract of the medfly and until 28 days on its external surface, and ii) medflies are able to transmit the bacteria from inoculated apples to both detached shoots and pear plants, being the pathogen recovered from lesions in both cases. This is the first report on E. amylovora internalization and survival in/on C. capitata, as well as the experimental transmission of the fire blight pathogen by this insect. Our results suggest that medfly can act as a potential vector for E. amylovora, and expand our knowledge on the possible role of these and other insects in its life cycle. 相似文献
14.
Naturally-occurring epiphytic fluorescent pseudomonads were isolated and characterized in terms of their potential to control fire blight infection of hawthorn, caused by Erwinia amylovora. Preliminary testing and selection of antagonists using an immature pear fruit assay gave some inconsistency in the amount of pathogen suppression on the pear tissue and also in the prediction of biocontrol effectiveness on the intact plant. Selected antagonists provided significant but variable control of fire blight under protected (polythene tunnel and glasshouse) conditions, with isolates HL83 and HL99 giving control of both blossom-blight and shoot-blight. In some cases the degree of control was equal to that of chemical treatments, including agrimycin 17 and experimental bactericides, and was achieved without any numerical advantage of applied control agent over pathogen. The timing of pseudomonad application in relation to pathogen inoculation was found to have a significant effect on the level of control of blossom-blight. 相似文献
15.
The existence of different levels of susceptibility to fire blight (Erwinia amylovora) in European pear (Pyrus communis L.) cultivars suggests that it is possible to identify QTLs related to resistance in pear germplasm. Given the polygenic nature of this trait, we designed two genetic maps of the parental lines 'Passe Crassane' (susceptible) and 'Harrow Sweet' (resistant) using SSRs, MFLPs, AFLPs, RGAs and AFLP-RGAs markers. RGA-related markers should theoretically map in chromosome regions coding for resistance genes. The 'Passe Crassane' map includes 155 loci, for a total length of 912 cM organised in 18 linkage groups, and the 'Harrow Sweet' map 156 loci, for a total length of 930 cM divided in 19 linkage groups; both maps have a good genome coverage when compared to the more detailed apple maps. Four putative QTLs related to fire blight resistance were identified in the map. A suite of molecular markers, including two AFLP-RGAs, capable of defining resistant and susceptible haplotypes in the analysed population was developed. 相似文献
16.
VICTORIA DONAT ELENA G BIOSCA ARANTZA RICO JAVIER PEÑALVER MARISA BORRUEL DIONISIO BERRA TXARAN BASTERRETXEA JESÚS MURILLO MARÍA M LÓPEZ 《The Annals of applied biology》2005,146(1):105-114
One hundred and thirty strains of Erwinia amylovora recovered from Spanish foci of fire blight from 1995 to 2000 were characterised and compared to reference strains from different sources and origins. Their rapid identification was performed by double antibody sandwich indirect (DASI) ELISA, using specific monoclonal antibodies against E. amylovora, and molecular confirmation by PCR using primers specific to the native plasmid pEA29. The Spanish strains of E. amylovora grew on different general and selective media producing typical colonies, except one of them that was deficient in levan production, whereas none of them grew on minimal agar medium with copper sulphate and low content of asparagine. All of them were susceptible to tetracycline, streptomycin, kasugamycin and oxolinic acid. Biochemical characterisation of selected strains by API 20E system revealed a great homogeneity, with 80% of the Spanish strains showing one of the two majority API 20E profiles described for E. amylovora, and the remaining strains showing minor differences. Pathogenicity on pear fruits and hypersensitivity reaction was confirmed, but a delayed reaction was observed for two Spanish strains. This is the first characterisation of a large collection of Spanish strains of E. amylovora. 相似文献
17.
Leaf protoplasts of axenic shoot cultures of Pyrus communis L. cv. Williams' Bon Chretien (syn. Bartlett) underwent cell wall regeneration and division to give multicellular colonies in a modified Murashige and Skoog medium which lacked ammonium ions, but supplemented with 1-naphthaleneacetic acid (NAA), 4-indole-3yl-acetic acid, 6-benzylaminopurine (BAP) and casein hydrolysate. Protoplast-derived colonies gave callus on Murashige and Skoog salts medium with NAA and BAP and exhibited shoot regeneration on half-strength Murashige and Skoog medium supplemented with 0.2 mg 1–1 4-indole-3yl-butyric acid, 2.0 mg 1–1 BAP, 0.2 mg 1–1 gibberellic acid, 50 mg 1–1 casein hydrolysate and 10 mg 1–1 Ca-pantothenate. Following rooting, protoplast-derived plants of pear were transferred to the glasshouse where they completed acclimatization.Abbreviations BAP
6-benzylaminopurine
- FPE
final plating efficiency
- GA3
gibberellic acid
- IAA
4-indole-3yl-acetic acid
- IBA
4-indole-3yl-but yric acid
- IPE
initial plating efficiency
- NAA
1-naphthaleneacetic acid
- f.wt.
fresh weight
- MES
2-N-morpholinoethane sulfonic acid
- MS
Murashige and Skoog (1962)
- %PE
% plating efficiency
- PVP-10
polyvinylpyrrolidone (Av. MW 10,000)
- FDA
fluorescein diacetate 相似文献
18.
Comparative genomics of Spiraeoideae‐infecting Erwinia amylovora strains provides novel insight to genetic diversity and identifies the genetic basis of a low‐virulence strain 下载免费PDF全文
Quan Zeng Zhouqi Cui Jie Wang Kevin L. Childs George W. Sundin Daniel R. Cooley Ching‐Hong Yang Elizabeth Garofalo Alan Eaton Regan B. Huntley Xiaochen Yuan Neil P. Schultes 《Molecular Plant Pathology》2018,19(7):1652-1666
Erwinia amylovora is the causal agent of fire blight, one of the most devastating diseases of apple and pear. Erwinia amylovora is thought to have originated in North America and has now spread to at least 50 countries worldwide. An understanding of the diversity of the pathogen population and the transmission to different geographical regions is important for the future mitigation of this disease. In this research, we performed an expanded comparative genomic study of the Spiraeoideae‐infecting (SI) E. amylovora population in North America and Europe. We discovered that, although still highly homogeneous, the genetic diversity of 30 E. amylovora genomes examined was about 30 times higher than previously determined. These isolates belong to four distinct clades, three of which display geographical clustering and one of which contains strains from various geographical locations (‘Widely Prevalent’ clade). Furthermore, we revealed that strains from the Widely Prevalent clade displayed a higher level of recombination with strains from a clade strictly from the eastern USA, which suggests that the Widely Prevalent clade probably originated from the eastern USA before it spread to other locations. Finally, we detected variations in virulence in the SI E. amylovora strains on immature pear, and identified the genetic basis of one of the low‐virulence strains as being caused by a single nucleotide polymorphism in hfq, a gene encoding an important virulence regulator. Our results provide insights into the population structure, distribution and evolution of SI E. amylovora in North America and Europe. 相似文献
19.
An improved protocol for the culture of cassava leaf protoplasts 总被引:2,自引:0,他引:2
P. Anthony M. R. Davey J. B. Power K. C. Lowe 《Plant Cell, Tissue and Organ Culture》1995,42(3):299-302
Viable protoplasts (yield > 1.9 × 107 g–1 fresh weight; mean viability 85±2%, n=5) were isolated from leaves of axenic shoot cultures of Manihot esculenta Crantz. cv. M. Thai 8. Protoplasts were cultured for up to 50 days in liquid, ammonium-free MS medium, overlaying agarose-solidified B5 medium with short glass rods embedded perpendicularly within, and protruding from, the agarose layer. Control protoplasts were cultured identically, but without glass rods. Sustained protoplast division was observed only in the presence of glass rods, where the initial plating efficiency was almost 6-fold greater than control (p < 0.05). The mean final plating efficiency of treated cultures was 1.0±0.2% while, in contrast, significant colony formation was not observed in controls.Abbreviations BA
6-benzyladenine
- CPPU
N-(2-chloro-4-pyridyl)-N'-phenylurea
- MES
2[N-morpholino]ethane sulphonic acid
- MS
Murashige & Skoog (1962)
- NAA
-naphthaleneacetic acid
- IPE
initial plating efficiency
- FPE
final plating efficiency 相似文献