Bio Protection Research Center

Canterbury, New Zealand

Bio Protection Research Center

Canterbury, New Zealand
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Mesarich C.H.,The New Zealand Institute for Plant and Food Research Ltd | Mesarich C.H.,Massey University | Mesarich C.H.,Bio Protection Research Center | Rees-George J.,The New Zealand Institute for Plant and Food Research Ltd | And 12 more authors.
PLoS ONE | Year: 2017

Pseudomonas syringae pv. actinidiae (Psa), the causal agent of kiwifruit canker, is one of the most devastating plant diseases of recent times. We have generated two mini-Tn5-based random insertion libraries of Psa ICMP 18884. The first, a 'phenotype of interest' (POI) library, consists of 10,368 independent mutants gridded into 96-well plates. By replica plating onto selective media, the POI library was successfully screened for auxotrophic and motility mutants. Lipopolysaccharide (LPS) biosynthesis mutants with 'Fuzzy-Spreader'-like morphologies were also identified through a visual screen. The second, a 'mutant of interest' (MOI) library, comprises around 96,000 independent mutants, also stored in 96-well plates, with approximately 200 individuals per well. The MOI library was sequenced on the Illumina MiSeq platform using Transposon-Directed Insertion site Sequencing (TraDIS) to map insertion sites onto the Psa genome. A grid-based PCR method was developed to recover individual mutants, and using this strategy, the MOI library was successfully screened for a putative LPS mutant not identified in the visual screen. The Psa chromosome and plasmid had 24,031 and 1,236 independent insertion events respectively, giving insertion frequencies of 3.65 and 16.6 per kb respectively. These data suggest that the MOI library is near saturation, with the theoretical probability of finding an insert in any one chromosomal gene estimated to be 97.5%. However, only 47% of chromosomal genes had insertions. This surprisingly low rate cannot be solely explained by the lack of insertions in essential genes, which would be expected to be around 5%. Strikingly, many accessory genes, including most of those encoding type III effectors, lacked insertions. In contrast, 94% of genes on the Psa plasmid had insertions, including for example, the type III effector HopAU1. These results suggest that some chromosomal sites are rendered inaccessible to transposon insertion, either by DNA-binding proteins or by the architecture of the nucleoid. © 2017 Mesarich et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Sizova O.V.,RAS N. D. Zelinsky Institute of Organic Chemistry | Kondakova A.N.,RAS N. D. Zelinsky Institute of Organic Chemistry | Shashkov A.S.,RAS N. D. Zelinsky Institute of Organic Chemistry | Knirel Y.A.,RAS N. D. Zelinsky Institute of Organic Chemistry | And 6 more authors.
Carbohydrate Research | Year: 2017

An O-polysaccharide was isolated from the lipopolysaccharide of an entomopathogenic bacterium Yersinia entomophaga MH96T by mild acid hydrolysis and studied by 2D NMR spectroscopy. The following structure of the branched tetrasaccharide repeating unit of the polysaccharide was established:[Figure presented] where Tyv indicates 3,6-dideoxy-D-arabino-hexose (tyvelose). The structure established is consistent with the gene content of the O-antigen gene cluster. The O-polysaccharide structure and gene cluster of Y. entomophaga are related to those of some Y. pseudotuberculosis serotypes. © 2017 Elsevier Ltd


Russell A.L.,Grand Valley State University | Cox M.P.,Massey University | Cox M.P.,Allan Wilson Center for Molecular Ecology and Evolution | Cox M.P.,Bio Protection Research Center | And 2 more authors.
BMC Evolutionary Biology | Year: 2011

Background: Human activities, such as agriculture, hunting, and habitat modification, exert a significant effect on native species. Although many species have suffered population declines, increased population fragmentation, or even extinction in connection with these human impacts, others seem to have benefitted from human modification of their habitat. Here we examine whether population growth in an insectivorous bat (Tadarida brasiliensis mexicana) can be attributed to the widespread expansion of agriculture in North America following European settlement. Colonies of T. b. mexicana are extremely large (∼10 6 individuals) and, in the modern era, major agricultural insect pests form an important component of their food resource. It is thus hypothesized that the growth of these insectivorous bat populations was coupled to the expansion of agricultural land use in North America over the last few centuries. Results: We sequenced one haploid and one autosomal locus to determine the rate and time of onset of population growth in T. b. mexicana. Using an approximate Maximum Likelihood method, we have determined that T. b. mexicana populations began to grow ∼220 kya from a relatively small ancestral effective population size before reaching the large effective population size observed today. Conclusions: Our analyses reject the hypothesis that T. b. mexicana populations grew in connection with the expansion of human agriculture in North America, and instead suggest that this growth commenced long before the arrival of humans. As T. brasiliensis is a subtropical species, we hypothesize that the observed signals of population growth may instead reflect range expansions of ancestral bat populations from southern glacial refugia during the tail end of the Pleistocene. © 2011 Russell et al; licensee BioMed Central Ltd.


PubMed | New Zealand Institute for Plant and Food Research, Unitec Institute of Technology and Bio Protection Research Center
Type: | Journal: PeerJ | Year: 2015

Widespread replacement of native ecosystems by productive land sometimes results in the outbreak of a native species. In New Zealand, the introduction of exotic pastoral plants has resulted in diet alteration of the native coleopteran species, Costelytra zealandica (White) (Scarabaeidae) such that this insect has reached the status of pest. In contrast, C. brunneum (Broun), a congeneric species, has not developed such a relationship with these novel host plants. This study investigated the feeding preferences and fitness performance of these two closely related scarab beetles to increase fundamental knowledge about the mechanisms responsible for the development of invasive characteristics in native insects. To this end, the feeding preference of third instar larvae of both Costelytra species was investigated using an olfactometer device, and the survival and larval growth of the invasive species C. zealandica were compared on native and exotic host plants. Costelytra zealandica, when sampled from exotic pastures, was unable to fully utilise its ancestral native host and showed higher feeding preference and performance on exotic plants. In contrast, C. zealandica sampled from native grasslands did not perform significantly better on either host and showed similar feeding preferences to C. brunneum, which exhibited no feeding preference. This study suggests the possibility of strong intraspecific variation in the ability of C. zealandica to exploit native or exotic plants, supporting the hypothesis that such ability underpins the existence of distinct host-races in this species.


Lefort M.-C.,Bio Protection Research Center | Lefort M.-C.,Unitec Institute of Technology | Boyer S.,Unitec Institute of Technology | Vereijssen J.,The New Zealand Institute for Plant and Food Research Ltd | And 3 more authors.
PeerJ | Year: 2015

Widespread replacement of native ecosystems by productive land sometimes results in the outbreak of a native species. In New Zealand, the introduction of exotic pastoral plants has resulted in diet alteration of the native coleopteran species, Costelytra zealandica (White) (Scarabaeidae) such that this insect has reached the status of pest. In contrast, C. brunneum (Broun), a congeneric species, has not developed such a relationship with these 'novel' host plants. This study investigated the feeding preferences and fitness performance of these two closely related scarab beetles to increase fundamental knowledge about the mechanisms responsible for the development of invasive characteristics in native insects. To this end, the feeding preference of third instar larvae of both Costelytra species was investigated using an olfactometer device, and the survival and larval growth of the invasive species C. zealandica were compared on native and exotic host plants. Costelytra zealandica, when sampled from exotic pastures, was unable to fully utilise its ancestral native host and showed higher feeding preference and performance on exotic plants. In contrast, C. zealandica sampled from native grasslands did not perform significantly better on either host and showed similar feeding preferences to C. brunneum, which exhibited no feeding preference. This study suggests the possibility of strong intraspecific variation in the ability of C. zealandica to exploit native or exotic plants, supporting the hypothesis that such ability underpins the existence of distinct host-races in this species. © 2015 Lefort et al.


Meffin R.,Bio Protection Research Center | Duncan R.P.,Bio Protection Research Center | Duncan R.P.,University of Canberra | Hulme P.E.,Bio Protection Research Center
Agriculture, Ecosystems and Environment | Year: 2015

To assess the biotic and abiotic drivers of feral crop persistence, the occurrence and size of alien Brassica populations across an agricultural landscape in Canterbury, New Zealand, were surveyed over three years. Measures related to propagule input and site conditions were recorded and their role in explaining population occurrence and persistence assessed through GLMs and proportional-hazard models. Many Brassica populations were transient, with about 60% of populations disappearing within two years. New populations were founded at a rate that compensated for those that disappeared, and were more likely to occur along transportation routes and near seed companies, suggesting they established from seed spillage. Larger populations and those growing where habitat conditions were similar to those in which Brassica are cultivated had higher probabilities of survival. Without anthropogenic seed input to found new populations, Brassica spp. are unlikely to persist in this landscape beyond ten years. To avoid overestimating the extent of naturalised populations over time it is important to account for local population extinctions. The abundance of feral crops that occur as casuals in the landscape, along with other aliens that are maintained by external seed inputs, could be controlled by managing propagule sources. In themselves, casual populations are unlikely to facilitate gene flow or act as sources of further population spread. © 2015 Elsevier B.V.

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