scholarly journals Antimicrobial and genetic strategies to defend kiwifruit against the bacterial pathogen Pseudomonas syringae pathovar actinidiae (Psa)

2021 ◽  
Author(s):  
◽  
Mathew Ambrose Storey

<p>A highly virulent strain of the bacterium Pseudomonas syringae pv. actinidiae (Psa-V), the causative agent of bacterial canker of kiwifruit, is threatening the $1.5 billion New Zealand kiwifruit industry. A strain of Psa-V was first identified in Italy in 2008 and related strain with a similar level of virulence arrived in New Zealand in November 2010. Since then it has been spreading rapidly throughout the country with devastating effects. Currently there is no effective treatment for growers to control Psa-V in their orchards and the potential impact of Psa-V on the New Zealand kiwifruit industry and growers is catastrophic. As part of a collaboration between Seeka Kiwifruit Industries, EastPack NZ, and a group of scientists nationwide (Taskforce Green) this work designed and implemented laboratory tests to quantify the effect of candidate antimicrobial sprays. Novel formulations with strong antimicrobial properties, including silver nanoparticles were also tested. This work was complemented by an investigation into the antibiotic resistance potential of Psa-V. A spontaneous streptomycin resistant mutant of Psa-V was generated and the molecular mechanism of resistance was elucidated. Further, gene knockout strategies aimed at facilitating the study of Psa-V virulence genes and ultimately developing a potential biocontrol agent were tested. Overall, this work together with several recent advances in the field should help advise the kiwifruit industry on best practice around the use of anti-Psa-V agents, and may make it possible to facilitate the generation and testing of candidate biocontrol agents in the near future.</p>

2021 ◽  
Author(s):  
◽  
Mathew Ambrose Storey

<p>A highly virulent strain of the bacterium Pseudomonas syringae pv. actinidiae (Psa-V), the causative agent of bacterial canker of kiwifruit, is threatening the $1.5 billion New Zealand kiwifruit industry. A strain of Psa-V was first identified in Italy in 2008 and related strain with a similar level of virulence arrived in New Zealand in November 2010. Since then it has been spreading rapidly throughout the country with devastating effects. Currently there is no effective treatment for growers to control Psa-V in their orchards and the potential impact of Psa-V on the New Zealand kiwifruit industry and growers is catastrophic. As part of a collaboration between Seeka Kiwifruit Industries, EastPack NZ, and a group of scientists nationwide (Taskforce Green) this work designed and implemented laboratory tests to quantify the effect of candidate antimicrobial sprays. Novel formulations with strong antimicrobial properties, including silver nanoparticles were also tested. This work was complemented by an investigation into the antibiotic resistance potential of Psa-V. A spontaneous streptomycin resistant mutant of Psa-V was generated and the molecular mechanism of resistance was elucidated. Further, gene knockout strategies aimed at facilitating the study of Psa-V virulence genes and ultimately developing a potential biocontrol agent were tested. Overall, this work together with several recent advances in the field should help advise the kiwifruit industry on best practice around the use of anti-Psa-V agents, and may make it possible to facilitate the generation and testing of candidate biocontrol agents in the near future.</p>


2017 ◽  
Vol 70 ◽  
pp. 310-314
Author(s):  
J.L. Tyson ◽  
S.J. Dobson ◽  
M.A. Manning

Pseudomonas syringae pv. actinidiae (Psa) causes bacterial canker of kiwifruit, which is an ongoing threat to New Zealand kiwifruit production. Disease control depends on orchard practices such as removal of visibly diseased material, pruning during low-risk periods, and the application of foliar bactericides. Although the use of copper compounds on Actinidia species (kiwifruit) can cause phytotoxicity, copper-based formulations remain a key component of Psa control in New Zealand. The effect of single copper applications on Psa infection of ‘Hort16A’ trap plants was studied over the Spring of 2014 (Sept—Nov). Psa leaf spots were observed at the beginning of October, appearing first on the untreated plants. Although the copper sprays did not achieve complete protection, particularly as the inoculum built up during November, the copper-sprayed plants always had less disease than the untreated plants.


2015 ◽  
Vol 68 ◽  
pp. 446-446
Author(s):  
D.J. Wilson ◽  
P.J. Gerard

Spiny snout mite (Neomolgus capillatus) is a potential biocontrol agent for clover flea (Sminthurus viridis) a white clover pest on dairy farms in warmer and wetter parts of New Zealand In the 1990s this mite was introduced from Brittany France into Tasmania for clover flea control Results during the release programme were highly promising and subsequent anecdotal farmer reports indicate widespread decreases in damage As N capillatus is a predatory mite and already known to attack nontarget organisms habitat specificity will determine whether it could be introduced into New Zealand without risk to native insects To assess this pastures on nine of the original Tasmanian release farms and adjacent nontarget habitats ranging from bush wetlands eucalypt stands to sand dune country were sampled in April 2014 Litter samples were collected heat extracted and mite species identified Neomolgus capillatus was found at effective densities in pastures that had good clover cover Where present it displaced Bdellodes spp mites that are ineffective against clover flea No N capillatus were found in the nontarget habitats all of which lacked clover and contained other predatory mites including Bdellodes spp Therefore the preference by N capillatus for lush pastures makes it an excellent prospect for introduction as a biocontrol agent into clover flea prone regions of New Zealand


2010 ◽  
Vol 5 (2) ◽  
Author(s):  
Andrew Speers ◽  
Allen Gale ◽  
Nancy Penney

This paper describes an international biosolids management initiative, known as the Australian and New Zealand Biosolids Partnership (ANZBP). The ANZBP - known formerly as the Australasian Biosolids Partnership – comprises 33 members dedicated to promoting the sustainable management of biosolids across the two nations. Two critical research projects are described, each of which contributes to the ANZBP goal of promoting the sustainable management of biosolids. The first is a review of community attitudes to biosolids management, the outcomes of which will be used to refine communication tools and methods of community consultation and which will provide input to policy development over time. The second is a review of regulations in place in Australia and New Zealand carried out to identify inconsistencies and improvements that could be made. An outcome of this initiative is potentially the development of a best practice manual. The relationship of the two projects to a sustainability framework adopted by the ANZBP is also described, as is the relationship of the two projects to each other.


Genetics ◽  
1999 ◽  
Vol 152 (1) ◽  
pp. 401-412 ◽  
Author(s):  
Randall F Warren ◽  
Peter M Merritt ◽  
Eric Holub ◽  
Roger W Innes

Abstract The RPS5 disease resistance gene of Arabidopsis mediates recognition of Pseudomonas syringae strains that possess the avirulence gene avrPphB. By screening for loss of RPS5-specified resistance, we identified five pbs (avrPphB susceptible) mutants that represent three different genes. Mutations in PBS1 completely blocked RPS5-mediated resistance, but had little to no effect on resistance specified by other disease resistance genes, suggesting that PBS1 facilitates recognition of the avrPphB protein. The pbs2 mutation dramatically reduced resistance mediated by the RPS5 and RPM1 resistance genes, but had no detectable effect on resistance mediated by RPS4 and had an intermediate effect on RPS2-mediated resistance. The pbs2 mutation also had varying effects on resistance mediated by seven different RPP (recognition of Peronospora parasitica) genes. These data indicate that the PBS2 protein functions in a pathway that is important only to a subset of disease-resistance genes. The pbs3 mutation partially suppressed all four P. syringae-resistance genes (RPS5, RPM1, RPS2, and RPS4), and it had weak-to-intermediate effects on the RPP genes. In addition, the pbs3 mutant allowed higher bacterial growth in response to a virulent strain of P. syringae, indicating that the PBS3 gene product functions in a pathway involved in restricting the spread of both virulent and avirulent pathogens. The pbs mutations are recessive and have been mapped to chromosomes I (pbs2) and V (pbs1 and pbs3).


Author(s):  
Armando Rocha Trinidade ◽  
Hermano Carmo ◽  
José Bidarra

Through the many documents regularly emitted by those dedicated to this activity, it is comparatively easy to describe factual developments in the field of open and distance education in different places in the world. However, it is much more difficult to produce judgements of value about their quality. Quality is a subjective rather than an absolute concept and may be examined from different analytical perspectives: consumers' satisfaction level, intrinsic value of scientific and technical content of learning materials, soundness of learning strategies, efficiency of organisation and procedures, adequate use of advanced technologies, reliability of student support mechanisms, etc. These parameters should be put into the context of specific objectives, nature of target populations and availability of different kinds of resources. In a specific geographic, social, economic and cultural situation a given set of solutions might be judged as adequate and deserving the qualification of "good practice", while in a different context it could be considered of rather poor quality. The selection of examples in this article is the sole responsibility of the authors: neither should the chosen cases be considered as clearly better than any other one, nor missing cases be interpreted as lack of appreciation or a negative judgement. Finally, the authors are aware of the risks of interpreting trends and trying to extrapolate them into the near future: readers should use their own judgement in accepting (or forcefully rejecting) these projections.


2002 ◽  
Vol 15 (7) ◽  
pp. 654-661 ◽  
Author(s):  
Jianxiong Li ◽  
Libo Shan ◽  
Jian-Min Zhou ◽  
Xiaoyan Tang

Tomato plants overexpressing the disease resistance gene Pto (35S∷Pto) exhibit spontaneous cell death, accumulation of salicylic acid (SA), elevated expression of pathogenesis-related genes, and enhanced resistance to a broad range of pathogens. Because salicylate plays an important role in the cell death and defense activation in many lesion mimic mutants, we investigated the interaction of SA-mediated processes and the 35S∷Pto-mediated defense pathway by introducing the nahG transgene that encodes salicylate hydroxylase. Here, we show that SA is not required for the 35S∷Pto-activated microscopic cell death and plays a minor role in defense gene activation and general disease resistance in 35S∷Pto plants. In contrast, temperature greatly affects the spontaneous cell death and general resistance in 35S∷Pto plants, and high temperature inhibits the cell death. The NahG tomato plants develop spontaneous, unconstrained necrotic lesions on leaves. These lesions also are initiated by the inoculation of a virulent strain of Pseudomonas syringae pv. tomato. However, the NahG-dependent necrotic lesions are inhibited in the NahG/35S∷Pto plants. This inhibition is most pronounced under conditions favoring the 35S∷Pto-mediated spontaneous cell death development. These results indicate that the signaling pathways activated by Pto overexpression suppress the cellular damage that is caused by SA depletion. We also found that ethylene is dispensable for the 35S∷Pto-mediated general defense.


2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
E Rawson

Abstract St John has been providing service in New Zealand for nearly 140 years since its arrival. It has now close to 4000 staff and nearly 20000 Members and over 8500 volunteers. In New Zealand the major work of St John is its Ambulance service providing front line first responders to crash, medical emergency and other life-threatening situations. St John New Zealand also provides a number of 'Community Health' initiatives focused on strengthening communities and prevention. In recent years St John has recognised that they have not engaged well with Indigenous communities and that their organisation in New Zealand must become skilled and relevant in addressing the needs of the Indigenous people of New Zealand, as they suffer the greater burden of disease and illness than any other population in the country. St John NZ Community and Health Services are embarking on a process of transformation through re-orienting its culture and practice by adopting Public Health approaches and an equity lens over all its programmes. They also have committed to understanding and using Indigenous knowledge to support this re-orientation to most effectively engage and implement programmes that will reduce Indigenous health inequities. This presentation will describe the process by which they will be implementing their strategy for change and highlight best practice for working with Indigenous communities. Key messages Indigenous Knowledge is key to addressing Indigenous Health inequities. Mainstream Public Health can learn from Indigenous Public Health approaches.


Author(s):  

Abstract A new distribution map is provided for Pseudomonas syringae pv. pisi (Sackett) Young, Dye & Wilkie. Hosts: Pea (Pisum sativum) and other Apiaceae. Information is given on the geographical distribution in Africa, Kenya, Malawi, Morocco, South Africa, Tanzania, Zimbabwe, Asia, India, Rajasthan, Himachal Pradesh, Indonesia, Israel, Japan, Lebanon, Nepal, Pakistan, Russia, Armenia, Kirghizistan, Australasia & Oceania, Australia, New South Wales, South Australia, Western Australia, Queensland, Tasmania, Victoria, New Zealand, Europe, Bulgaria, Denmark, France, Germany, Greece, Hungary, Italy, Netherlands, Romania, Russia, Ukraine, Voronezh, Moldavia, Switzerland, UK, England, Yugoslavia, North America, Bermuda, Canada, Alberta, British Columbia, Manitoba, Ontario, Quebec, Saskatchewan, Mexico, USA, New York, South America, Argentina, Colombia, Uruguay.


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