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Plant Pathogenic Bacteria (plant + pathogenic_bacteria)

Distribution by Scientific Domains

Life Sciences	70%
Chemistry	30%

Selected Abstracts

Control of Plant Pathogenic Bacteria of Xanthomonas spp. by the Essential Oil and Extracts of Metasequoia glyptostroboides Miki ex Hu In vitro and In vivo

JOURNAL OF PHYTOPATHOLOGY, Issue 7-8 2010
Vivek K. Bajpai
Abstract Plant diseases constitute an emerging threat to global food security. Many of the currently available antimicrobial agents for agriculture are highly toxic and non-biodegradable and cause extended environmental pollution. Therefore, this study was undertaken to assess the in vitro and in vivo antibacterial efficacy of the essential oil and organic extracts of Metasequoia glyptostroboides against plant pathogenic bacteria of Xanthomonas spp. The oil (1000 ,g/disc) and extracts (1500 ,g/disc) displayed potential antibacterial effect in vitro as a diameter of zones of inhibition against Xanthomonas campestris pv. campestris KC94-17-XCC, X. campestris pv. vesicatoria YK93-4-XCV, X. oryzae pv. oryzae KX019-XCO and X. sp SK12, which were found in the range of 10,14 and 8,12 mm, respectively. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of oil and the extracts were ranged from 125,250 and 125 500 ,g/ml and 250,1000 and 250,2000 ,g/ml, respectively. Also the oil had strong detrimental effect on the viable count of the tested bacteria. Further, the oil displayed remarkable in vivo antibacterial effect up to 65 to 100% disease suppression efficacy against the tested strains of Xanthomonas spp. on greenhouse-grown oriental melon plants (Cucumis melo L. var. makuwa). These results suggest that the oil and extracts of M. glyptostroboides could be potential source of natural antibacterials for applying in food and agriculture industries to control plant bacterial diseases caused by Xanthomonas spp. [source]

Laboratory Guide for Identification of Plant Pathogenic Bacteria, Third Edition.

PLANT PATHOLOGY, Issue 6 2001

No abstract is available for this article. [source]

Comparative genomics-guided loop-mediated isothermal amplification for characterization of Pseudomonas syringae pv. phaseolicola

JOURNAL OF APPLIED MICROBIOLOGY, Issue 3 2009
X. Li
Abstract Aims:, To design and evaluate a loop-mediated isothermal amplification (LAMP) protocol by combining comparative genomics and bioinformatics for characterization of Pseudomonas syringae pv. phaseolicola (PSP), the causal agent of halo blight disease of bean (Phaseolus vulgaris L.). Methods and Results:, Genomic sequences of Pseudomonas syringae pathovars, P. fluorescens and P. aeruginosa were analysed using multiple sequence alignment. A pathovar-specific region encoding pathogenicity-related secondary metabolites in the PSP genome was targeted for developing a LAMP assay. The final assay targeted a polyketide synthase gene, and readily differentiated PSP strains from other Pseudomonas syringae pathovars and other Pseudomonas species, as well as other plant pathogenic bacteria, e.g. species of Pectobacterium, Erwinia and Pantoea. Conclusion:, A LAMP assay has been developed for rapid and specific characterization and identification of PSP from other pathovars of P. syringae and other plant-associated bacteria. Significance and Impact of the Study:, This paper describes an approach combining a bioinformatic data mining strategy and comparative genomics with the LAMP technology for characterization and identification of a plant pathogenic bacterium. The LAMP assay could serve as a rapid protocol for microbial identification and detection with significant applications in agriculture and environmental sciences. [source]

Transmission of cotton seed and boll rotting bacteria by the southern green stink bug (Nezara viridula L.)

JOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2007
E.G. Medrano
Abstract Aims:, To determine the ability of the southern green stink bug (SGSB) (Nezara viridula L.) to transmit Pantoea agglomerans into cotton (Gossypium hirsutum) bolls. Methods and Results:, An SGSB laboratory colony was kept on fresh green beans. A P. agglomerans variant resistant to rifampicin (Rif) (strain Sc 1-R) was used as the opportunistic cotton pathogen. Adult insects were individually provided green beans that were sterilized and then soaked in either sterile water or in a suspension of strain Sc 1-R. Insects were individually caged with an unopened greenhouse-grown cotton boll. After 2 days, live SGSB were collected, surfaced sterilized, ground, serially diluted, and then plated on nonselective media and media amended with Rif. Exterior and interior evidence of feeding on bolls was recorded 2 weeks after exposure to insects. Seed and lint tissue were harvested, ground, serially diluted, and then plated on media with and without Rif. Bacteria were recovered on nonselective media from all insects, and from seed and lint with signs of insect feeding at concentrations ranging from 102 to 109 CFU g,1 tissue. The Sc 1-R strain was isolated only from insects exposed to the marked strain and from seed and lint of respective bolls showing signs of insect feeding. Evidence of insect feeding on the exterior wall of the carpel was not always apparent (47%), whereas feeding was always observed (100%) on the interior wall in association with bacterial infections of seed and lint. Conclusions:,Nezara viridula readily ingested the opportunistic P. agglomerans strain Sc 1-R and transmitted it into unopened cotton bolls. Infections by the transmitted Sc 1-R strain caused rotting of the entire locule that masked internal carpel wounds incurred by insect feeding. Bacteria were recovered from penetration points by insects not exposed to the pathogen, but locule damage was limited to the area surrounding the feeding site (c. 3 mm). Significance and Impact of the Study:, This is the first study that demonstrates the ability of SGSB to acquire and transmit plant pathogenic bacteria into cotton bolls. [source]

Control of Plant Pathogenic Bacteria of Xanthomonas spp. by the Essential Oil and Extracts of Metasequoia glyptostroboides Miki ex Hu In vitro and In vivo

Antibacterial activities of essential oils and extracts of Turkish Achillea, Satureja and Thymus species against plant pathogenic bacteria

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 1 2010
Recep Kotan
Abstract BACKGROUND: The aims of this study were to examine the chemical composition of the essential oils and hexane extracts of the aerial parts of Satureja spicigera (C. Koch) Boiss., Thymus fallax Fisch. & CA Mey, Achillea biebersteinii Afan, and Achillea millefolium L. by GC and GC,MS, and to test antibacterial efficacy of essential oils and n -hexane, chloroform, acetone and methanol extracts as an antibacterial and seed disinfectant against 25 agricultural plant pathogens. RESULTS: Thymol, carvacrol, p -cymene, thymol methyl ether and ,-terpinene were the main constituents of S. spicigera and T. fallax oils and hexane extracts. The main components of the oil of Achillea millefolium were 1,8-cineole, ,-cadinol and caryophyllene oxide, whereas the hexane extract of this species contained mainly n -hexacosane, n -tricosane and n -heneicosane. The oils and hexane extracts of S. spicigera and T. fallax exhibited potent antibacterial activity over a broad spectrum against 25 phytopathogenic bacterial strains. Carvacrol and thymol, the major constituents of S. spicigera and T. fallax oils, also showed potent antibacterial effect against the bacteria tested. The oils of Achillea species showed weak antibacterial activity. Our results also revealed that the essential oil of S. spicigera, thymol and carvacrol could be used as potential disinfection agents against seed-borne bacteria. CONCLUSION: Our results demonstrate that S. spicigera, T. fallax oils, carvacrol and thymol could become potentials for controlling certain important agricultural plant pathogenic bacteria and seed disinfectant. Copyright © 2009 Society of Chemical Industry [source]

Type III-dependent translocation of the Xanthomonas AvrBs3 protein into the plant cell

MOLECULAR MICROBIOLOGY, Issue 1 2002
Boris Szurek
Summary Many plant pathogenic bacteria utilize a conserved type III secretion system (TTSS) to deliver effector proteins into the host tissue. Indirect evidence has suggested that at least some effector proteins are translocated from the bacterial cytoplasm into the plant cell. Using an immunocytochemical approach, we demonstrate that the type III effector AvrBs3 from Xanthomonas campestris pv. vesicatoria localizes to nuclei of infected pepper leaves. Importantly, AvrBs3 translocation was observed in situ in native tissues of susceptible and resistant plants. AvrBs3 was detected in the nucleus as soon as 4 h post infection, which was dependent on a functional TTSS and the putative translocator HrpF. N-terminal AvrBs3 deletion derivatives are no longer secreted by the TTSS in vitro and could not be detected inside the host cells, suggesting that the N-terminus of AvrBs3 is important for secretion. Deletion of the nuclear localization signals in the AvrBs3 C-terminus, which are required for the AvrBs3-mediated induction of the hypersensitive reaction in resistant pepper plants, abolished AvrBs3 localization to the nucleus. This is the first report on direct evidence for translocation of a native type III effector protein from a plant pathogenic bacterium into the host cell. [source]

HrpN of Erwinia amylovora functions in the translocation of DspA/E into plant cells

MOLECULAR PLANT PATHOLOGY, Issue 4 2008
ANA M. BOCSANCZY
SUMMARY The type III secretion system (T3SS) is required by plant pathogenic bacteria for the translocation of certain bacterial proteins to the cytoplasm of plant cells or secretion of some proteins to the apoplast. The T3SS of Erwinia amylovora, which causes fire blight of pear, apple and other rosaceous plants, secretes DspA/E, which is an indispensable pathogenicity factor. Several other proteins, including HrpN, a critical virulence factor, are also secreted by the T3SS. Using a CyaA reporter system, we demonstrated that DspA/E is translocated into the cells of Nicotiana tabacum,Xanthi'. To determine if other T3-secreted proteins are needed for translocation of DspA/E, we examined its translocation in several mutants of E. amylovora strain Ea321. DspA/E was translocated by both hrpW and hrpK mutants, although with some delay, indicating that these two proteins are dispensable in the translocation of DspA/E. Remarkably, translocation of DspA/E was essentially abolished in both hrpN and hrpJ mutants; however, secretion of DspA/E into medium was not affected in any of the mentioned mutants. In contrast to the more virulent strain Ea273, secretion of HrpN was abolished in a hrpJ mutant of strain Ea321. In addition, HrpN was weakly translocated into plant cytoplasm. These results suggest that HrpN plays a significant role in the translocation of DspA/E, and HrpJ affects the translocation of DspA/E by affecting secretion or stability of HrpN. Taken together, these results explain the critical importance of HrpN and HrpJ to the development of fire blight. [source]

Analysis of bacterial lipodepsipeptides by matrix-assisted laser desorption/ionisation time-of-flight and high-performance liquid chromatography with electrospray mass spectrometry

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 8 2001
Simona Maria Monti
Strains of certain plant pathogenic bacteria, in particular several pathovars of Pseudomonas syringae, are known to produce cyclic lipodepsipeptides (LDPs) endowed with peculiar structural features and noticeable biological activities. In this study, a mass spectrometry procedure is proposed for screening LDP-producing bacterial strains and for identifying and assessing individual LDPs. After matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) screening of thirteen P. syringae strains for LDP production, the extracts from culture filtrates of eight positive strains were subjected to electrospray mass spectrometry for the identification of LDPs. Five strains were found to produce two forms of syringomycins (SR-E and SR-G) and two forms of syringopeptin 25 (SP25A and SP25B); two strains produced SR-E, SR-G and a new form of SP22; one strain produced syringotoxin (ST) and syringostatin A (SS-A) in addition to SP25A and SP25B. The yield in culture of two major LPDs: SR-G (3.2,13.8,mg L,1) and SP25A (41.6,231.5,mg L,1) was assessed by and high-performance liquid chromatography with electrospray mass spectrometry (HPLC/ESI-MS) in both scan and single ion monitoring (SIM) modes. Results of this investigation showed that the mass spectrometry protocol developed here is a precise and reliable method for screening bacterial strains for LDP production and for assessing the amount of each metabolite under various culture conditions. This could be of practical value in view of potential applications, e.g. biocontrol of post-harvest fungal diseases. Copyright © 2001 John Wiley & Sons, Ltd. [source]