PSA Research Library

This collection of scientific papers has been collated to provide information for private study purposes on topics relevant to the genetics, epidemiology and control, including bio-control, of the bacterial pathogen Psa. The links listed alongside each publication provide free access to copies of the original scientific papers via the internet. Please note, we cannot guarantee that the original website hosting a specific scientific paper will maintain free access indefinitely.

Assessment of the importance of similarity in carbon source utilization profiles between the biological control agent and the pathogen in biological control of bacterial speck of Tomato.

Reference:
Ji and Wilson, (2002). Applied and Environmental Microbiology, 68(9):4383-4389.
Key Points:
Evaluates the utilization of carbon sources by bacterial strains for the bio-control of bacterial speck of tomato. Demonstrates that the suppression of bacterial speck was correlated with the nutritional similarity between the pathogenic and non-pathogenic bacteria.
Implications:
Suggests that preemptive utilization of carbon sources by bio-control bacteria could assist in the control of plant pathogenic bacteria.
Source: Click here

Biocontrol of Bacillus subtilis against infection of Arabidopsis roots by Pseudomonas syringae isfacilitated by biofilm formationand surfactinproduction.

Reference:
Bais et al., (2004). Plant Physiology, 134: 307-319.
Key Points:
Demonstrates the mechanism that the bio-control agent Bacillus subtilis uses to protect plant roots against pathogenic bacteria such as Pseudomonas syringae pv. tomato.
Implications:
Protective antibacterial bio-films on plant surfaces may provide control for Psa if such biofilms can be established on the plant surfaces that support pathogen population growth or provide entry points for the pathogen.
Source: Click here

Pseudomonas syringae pv. actinidiae: a re-emerging, multi-faceted, pandemic pathogen

Reference:
Scortichini et al., (2012) Molecular Plant Pathology DOI: 10.1111/J.1364-3703.2012.00788.X
Key Points:
Pseudomonas syringae pv. actinidiae can be considered as a pandemic disease of kiwifruit. This pathogen can easily colonise kiwifruit vines throughout the year.
Implications:
An integrated disease control approach will need to take into consideration the epidemiology of the pathogen and the environment that it is grown in. Ideally this should be based on solutions that dramatically reduce bacterium inoculum levels while recognizing that the disease will need to co-exist with a crop husbandry regime which minimises the environmental and food safety impacts.
Source: Click here

Bacteria in the leaf ecosystem with emphasis on Pseudomonas syringae - a pathogen, ice nucleus, and epiphyte.

Reference:
Hirano and Upper, (2000), Microbiology and Molecular Reviews. 64(3):
624-653.
Key Points:
Pseudomonas syringae on leaves is used as a case study to illustrate the ecology of bacteria on leaf surfaces. Demonstrates that competition for resources between bacteria rather than antimicrobial antagonism is the prevalent competitive strategy used to colonize leaves. Suggests that understanding the processes that lead to development of large population sizes may be more critical than understanding the mechanism by which bacteria causes leaf lesions.
Implications:
The application of competitive bacterial on leaves in the field can reduce the population size of pathogenic bacteria. Bacterial populations can increase when addition nutrients are applied to leaves. It would be prudent to ensure that existing foliar treatments do not contain nutrients that stimulate pathogenic strains of bacteria.
Source: Click here

Bacterial pathogens in plants: Life up against the walI.

Reference:
Alfano and Collmer, (1996). The Plant Cell, 8:
1683-1698.
Key Points:
Describes the lifecycle of bacterial pathogens such as pseudomonas that colonize the apoplast between cell walls.
Implications:
Effect and enduring control of Psa in kiwifruit will be dependent on understanding haow the bacteria systemically colonizes the kiwifruit tissues.
Source: Click here

Microbiology of the phyllosphere.

Reference:
Lindow and Brandl, (2003), Applied and Environmental Microbiology.
69(4): 1875-1883.
Key Points:
Describes the microbial communities on a leaf surface and discusses the leaf surface as a microbial habitat. Shows how microbial modification can occur to make the leaf surface more suitable habitat
Implications:
Leaf surfaces are a challenging microbial habitat. Some strategies used by bacterial to make a leaf more habitable are reliant on the production of compounds that are similar to agrochemicals applied by growers.
Source: Click here

Outbreak of bacterial canker on Hort16A (Actinidia chinensis Planchon)caused by Pseudomonas syringae pv. actinidiae in Korea.

Reference:
Koh et al., (2010). NZ J Crop and Horticultural
Science, 38(4):
275-282.
Key Points:
Bacterial canker was first observed on Hort16A in the spring 3006 on Jeju Province, Korea. The symptoms closely resemble those that occur on Hayward kiwifruit. Contaminated pruning shears and climatic conditions appear to be significant factors in the spread of the disease.
Implications:
Learning's from the disease and progress on control options in Korea are being are being used by research teams in New Zealand and Europe in the management of Psa.
Source: Click here

Pseudomonas content of cherry trees.

Reference:
Cameron, (1970). Phytopathology,
60:1343-1346.
Key Points:
Describes the distribution of pathogenic Pseudomonas spp. within diseased and healthy- appearing sweet cherry trees.
Implications:
Endophytic populations of bacteria within infected plants can reduce the ability of external protectant sprays to control bacterial diseases.
Source: Click here

Pseudomonas syringae phytotoxins: Mode of action, regulation, and biosynthesis by peptide and polyketide synthetases.

Reference:
Bender et al., (1999). Microbiology and Molecular Biology Reviews,
63(2):266-292.
Key Points:
Summarizes current understanding of the mechanism of action, biosynthesis, and regulation of four distinct classes of phytotoxins produced by Pseudomonas syringae.
Implications:
Phytotoxins such as the syringomycins are produced by Psa as part of its pathogenicity against kiwifruit.
Source: Click here

Raindrop momentum triggers growth of leaf-associated populations of Pseudomonas syringae onfield-grown snapbean plants.

Reference:
Hirano et al., (1996). Applied and Environmental Microbiology,
62(7):2560-2566.
Key Points:
Reports on the results of observational and microclimate modification experiments to determine the role of the physical environment on the population dynamics of Pseudomonas syringae in the phylloplane.
Implications:
Rainfall momentum plays a role in the growth triggering effect of intense rain on Pseudomonas syringae populations.
Source: Click here

Seasonal fuctuations in kiwifruit phyllosphereand ice nucleationactivity of Pseudomonas viridiflava.

Reference:
Balestra and Varvaro, (1998). J. Plant Pathology.
80(1), 151-156.
Key Points:
Describes the epidemiology of Pseudomonas viridiflava, the causal agent of bacterial blight, on kiwifruit.
Implications:
Provides insights into the lifecycle of a bacterial pathogen related to Psa on kiwifruit and highlights the interaction of climate and plant phenology on population dynamics.
Source: Click here

Survival, growth, and localization of epiphytic fitness mutants of Pseudomonas syningae on leaves.

Reference:
Beattie and
Lindow, (1994).
60(10):3790-
3798.
Key Points:
Uses epiphytic mutants of Pseudomonas syringae pv. syringae to understand survival and growth on leaf surfaces.
Implications:
The ability to locate, multiply in, and/or survive in protected sites on the leaf surface appears important for successful colonization of the leaf.
Source: Click here

Outbreak of bacterial canker onHort16A (Actinidia chinensis Planchon)caused by Pseudomonas syringae pv. actinidiae in Korea.

Reference:
Koh et al., (2010). NZ J Crop and Horticultural Science, 38(4):
275-282.
Key Points:
Bacterial canker was first observed on Hort16A in the spring 3006 on Jeju Province, Korea. The symptoms closely resemble those that occur on Hayward kiwifruit. Contaminated pruning shears and climatic conditions appear to be significant factors in the spread of the disease.
Implications:
Learning's from the disease and progress on control options in Korea are being are being used by research teams in New Zealand and Europe in the management of Psa.
Source: Click here

Raindrop momentum triggers growth of leaf-associated populations of Pseudomonas syringae onfield-grown snap bean plants.

Reference:
Hirano et al., (1996). Applied and Environmental Microbiology,
62(7):2560-2566.
Key Points:
Reports on the results of observational and microclimate modification experiments to determine the role of the physical environment on the population dynamics of Pseudomonas syringae in the phylloplane.
Implications:
Rainfall momentum plays a role in the growth triggering effect of intense rain on Pseudomonas syringae populations.
Source: Click here

First report of Pseudomonas syringae pv. actinidiae causing kiwifruit bacterial canker in New Zealand.

Reference:
Everett, K. R., Taylor, R. K., Romberg, M., Rees-George, J., Fullerton, R., Vanneste, J., Manning, M.A. (2011). Australasian Plant Disease Notes, 6, 67-71.
Key Points:
Provides details on the observation, isolation and identification of the first occurrence of Psa-V in NZ
Implications:
Koch's postulates were proven by pathogenicity tests on kiwifruit seedlings
Source: Click here

Comparative analysis of Pseudomonas syringae pv. actinidiae and pv. phaseolicola based on phaseolotoxin- resistant ornithine carbamoyltransfer ase gene (argK)

Reference:
Sawada, (1997). Applied and Environmental Microbiology,
63(1): 282-288.
Key Points:
Compares and contrasts phylogenetic development in Pseudomonas syringae pv. actinidiae and pv. phaseeolicola.
Implications:
Current work on the Psa genome will provide more knowledge on the origin and evolution of this pathogen.
Source: Click here

Genetic basis of copper resistance in New Zealand strains of Pseudomonas syringae.

Reference:
Vanneste and Voyle, (2003). NZ Plant Protection
56:109-112.
Key Points:
Strains of Pseudomonas syringae able to grow on a minimal media containing 500mg/litre of copper sulphate were selected from a collection of streptomycin- resistant strains.
Implications:
Resistance to both copper and streptomycin can occur in the same strain of Pseudomonas syringae.
Source: Click here

Comparative analysis of Pseudomonas syringae pv. actinidiae and pv. phaseolicola based on phaseolotoxin- resistant ornithine carbamoyltransfer ase gene (argK)and 16s-23s rRNAintergenic spacer sequences.

Reference:
Sawada, (1997). Applied and Environmental Microbiology,
63(1): 282-288.
Key Points:
Compares and contrasts phylogenetic development in Pseudomonas syringae pv. actinidiae and pv. phaseeolicola.
Implications:
Current work on the Psa genome will provide more knowledge on the origin and evolution of this pathogen.
Source: Click here

Genetic basis of copper resistance in NewZealand strains of Pseudomonas syringae.

Reference:
Vanneste and Voyle, (2003). NZ Plant Protection
56:109-112.
Key Points:
Strains of Pseudomonas syringae able to grow on a minimal media containing 500mg/litre of copper sulphate were selected from a collection of streptomycin- resistant strains.
Implications:
Resistance to both copper and streptomycin can occur in the same strain of Pseudomonas syringae.
Source: Click here

Genetic diversity, presence of the syrB gene, host preference and virulence of Pseudomonas syringaepv. syringae strains from woody and herbaceous host plants.

Reference:
Scortichini et al., (2003). Plant Pathology, 52:
277-286.
Key Points:
Describes the genetic relatedness for a range of Pseudomonas syringae pathovars, including Psa.
Implications:
Isolates obtained from kiwifruit exhibited similar but distinctive patterns according to the geographic region, California and Italy, where the isolates were collected. This is consistent with other research that shows the origin of particular Psa strains can be linked to specific geographic origins.
Source: Click here

Genetic relatedness among Pseudomonas avellanae,P. syringae pv. theae and P.s. pv. actinidiae, and their identification.

Reference:
Scortichini et al. (2002). European Journal of Plant Pathology, 108:
269-278.
Key Points:
Strains of Psa could be group on their basis of geographic origin. Pathogenicity tests clearly indicated that each of the Psuedomonas groups is specifically pathogenic only on the host plant species from which it was originally isolated.
Implications:
Psa could live as a symptomless non-pathogenic bacteria on other plant host species.
Source: Click here

Genomic and phenotypic characterization of the bacterium causing blight of kiwifruit in New Zealand.

Reference:
Young et al., (1997). Plant Pathology,
46:857-864.
Key Points:
Found that the bacterium responsible for causing kiwifruit bacterial blight in New Zealand that had previously been described as Pseudomonas viridifolia was more closely related to Pseudomonas savastanoi.
Implications:
The bacterial flower blight that occurs in New Zealand kiwifruit is distinctly different from the Psa strains that have been found in New Zealand.
Source: Click here

Molecular and phenotypic features of Pseudomonas syringae pv. actinidiae isolated during recent epidemics of bacterial cankeron yellow kiwifruit (Actinidia chinensis) in central Italy.

Reference:
Ferrante and Scortichini, (2010). Plant Pathology, 58(5):
954 -962.
Key Points:
Demonstrates that the Psa strains obtained in Italy during 2008-09 have a similar PCR fingerprint profile to each other but they differed from strains previously isolated in Italy and Japan. The recent Psa strains isolated in Italy all had the hopA1 effect or protein.
Implications:
The hopA1 effector protein has been associated with plant defense suppression in P. syringae pathovars in other crops. The hopA1 effector has been previously shown to suppress Jasmonic Acid and ethylene mediated plant defense/stress signaling systems.
Source: Click here

Quorum sensing: Cell-to-cell communication in bacteria

Reference:
Waters and Bassler, (2005). Annual Reviews in Cell Development and Biology,
21:319-346.
Key Points:
Reviews the architectures of bacterial chemical communication networks, including how within and between species communication is accomplished.
Implications:
Through recent insights in quorum sensing research teams are developing compounds as well as approaches to disrupt quorum sensing in bacterial and control infections.
Source: Click here

The application of polymerase chain reaction for characterising strains of pseudomonas syringaeisolated from NewZealand rivers.

Reference:
Vanneste et al., (2009). NZ Plant Protection 62:
256-261.
Key Points:
Describes the Polymerase Chain Reaction (PCR) protocols used to characterize Pseudomonas syringae strains. Demonstrates that P. syringae strains can be isolated from free flowing waterways in NZ.
Implications:
Although Psa was not isolated from the Waikato River or Whakapapnui stream it cannot be ruled out that pathogenic bacterium such as Psa are present or transported in NZ waterways.
Source: Click here

Comparative analysis of Pseudomonas syringae pv. actinidiae and pv. phaseolicola based on phaseolotoxin- resistant ornithine carbamoyltransfer ase gene (argK) and 16s-23s rRNA intergenic spacer sequences.

Reference:
Sawada, (1997). Applied and Environmental Microbiology,
63(1): 282-288.
Key Points:
Compares and contrasts phylogenetic development in Pseudomonas syringae pv. actinidiae and pv. phaseeolicola.
Implications:
Current work on the Psa genome will provide more knowledge on the origin and evolution of this pathogen.
Source: Click here

Genetic basis of copper resistance in NewZealand strains ofPseudomonas syringae.

Reference:
Vanneste and Voyle, (2003). NZ Plant Protection
56:109-112.
Key Points:
Strains of Pseudomonas syringae able to grow on a minimal media containing 500mg/litre of copper sulphate were selected from a collection of streptomycin- resistant strains.
Implications:
Resistance to both copper and streptomycin can occur in the same strain of Pseudomonas syringae.
Source: Click here

Genetic diversity, presence of the syrB gene, host preference and virulence of Pseudomonas syringaepv. syringaestrains from woody and herbaceous host plants.

Reference:
Scortichini et al., (2003). Plant Pathology, 52:
277-286.
Key Points:
Describes the genetic relatedness for a range of Pseudomonas syringae pathovars, including Psa.
Implications:
Isolates obtained from kiwifruit exhibited similar but distinctive patterns according to the geographic region, California and Italy, where the isolates were collected. This is consistent with other research that shows the origin of particular Psa strains can be linked to specific geographic origins.
Source: Click here

Genetic relatedness among Pseudomonas avellanae,P. syringae pv.theae and P.s. pv. actinidiae, and their identification.

Reference:
Scortichini et al. (2002). European Journal of Plant Pathology, 108:
269-278.
Key Points:
Strains of Psa could be group on their basis of geographic origin. Pathogenicity tests clearly indicated that each of the Psuedomonas groups is specifically pathogenic only on the host plant species from which it was originally isolated.
Implications:
Psa could live as a symptomless non-pathogenic bacteria on other plant host species.
Source: Click here

Pseudomonas syringae pv. actinidiae from RecentOutbreaks of Kiwifruit Bacterial Canker Belong toDifferent Clones That Originated in China

Reference:
Butler MI, Stockwell PA, Black MA, Day RC, Lamont IL, et al. (2013)
PLoS ONE 8(2): e57464
Key Points:
Provides gemonic evidence to indicate that the NZ Psa-V strain arrived in from China independent of introductions to the Italian and Chilean strains that also appear to have originated from China.
Implications:
Provides information that can be developed into tools to distinguish strains of Psa for bio-security management
Source: Click here

Genome for Pseudomonas syringae pv.

Reference:
Scortichini et al., (2011)
PLoS ONE, 6 (11):1-17.
Key Points:
Describes the genome for Pseudomonas syringae pv. actinidiae and the reputed origin of the pathogen, including closely related pathovars.
Implications:
Provides a genetic insight into the mode of action of this pathogen. This information will be valuable for understanding the epidemiology and opportunities for managing this pathogen.
Source: Click here