Publications by authors named "Bulman S"

Grapevine trunk diseases (GTDs) are a substantial challenge to viticulture, especially with a lack of available control measures. The lack of approved fungicides necessitates the exploration of alternative controls. One promising approach is the investigation of disease escape plants, which remain healthy under high disease pressure, likely due to their microbiome function.

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The bacterial microbiome of psyllids has been studied for decades, with a strong focus on the primary and secondary endosymbionts capable of providing essential amino acids for the insects' diet and therefore playing a key role in the insects' ability to radiate on novel plant hosts. Here, we combine metabarcoding analysis of the bacterial communities hosted by psyllids with a multi-gene phylogenetic analysis of the insect hosts to determine what factors influence the bacterial diversity of the psyllids' microbiomes, especially in the context of the dispersal and evolutionary radiation of these insects in Aotearoa New Zealand. Using multi-gene phylogenetics with COI, 18S and EF-1α sequences from 102 psyllid species, we confirmed for the first time monophyly for all the six genera of native/endemic Aotearoa New Zealand psyllids, with indications that they derive from at least six dispersal events to the country.

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Grapevine trunk diseases (GTDs) are a threat to grape production worldwide, with a diverse collection of fungal species implicated in disease onset. Due to the long-term and complex nature of GTDs, simultaneous detection of multiple microbial species can enhance understanding of disease development. We used DNA metabarcoding of ribosomal internal transcribed spacer 1 (ITS1) sequences, supported by specific PCR and microbial isolation, to establish the presence of trunk pathogens across 11 vineyards (11-26 years old) over three years in Marlborough, the largest wine producing region in New Zealand.

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Rapid and transient changes in pH frequently occur in soil, impacting dissolved organic matter (DOM) and other chemical attributes such as redox and oxygen conditions. Although we have detailed knowledge on microbial adaptation to long-term pH changes, little is known about the response of soil microbial communities to rapid pH change, nor how excess DOM might affect key aspects of microbial N processing. We used potassium hydroxide (KOH) to induce a range of soil pH changes likely to be observed after livestock urine or urea fertilizer application to soil.

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The plant pathogenic protist Plasmodiophora brassicae causes clubroot disease of Brassicaceae. This biotrophic organism can down-regulate plant defence responses. The previously characterised P.

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The superfamily Psylloidea (Hemiptera: Sternorrhyncha) lacks a robust multigene phylogeny. This impedes our understanding of the evolution of this group of insects and, consequently, an accurate identification of individuals, of their plant host associations, and their roles as vectors of economically important plant pathogens. The conserved nuclear gene elongation factor-1 alpha (EF-1α) has been valuable as a higher-level phylogenetic marker in insects and it has also been widely used to investigate the evolution of intron/exon structure.

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Article Synopsis
  • Fungi, nematodes, and oomycetes are major groups of eukaryotic organisms that cause diseases in plants.
  • The review explores not only these common pathogens but also includes unicellular organisms known as protists that can infect plants.
  • It highlights recent research developments regarding plant pathogenic protists, including the role of algae in the infection processes of oomycetes.
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Manuka honey (MH) is used as an antibacterial agent in bioactive wound dressings via direct impregnation onto a suitable substrate. MH provides unique antibacterial activity when compared with conventional honeys, owing partly to one of its constituents, methylglyoxal (MGO). Aiming to investigate an antibiotic-free antimicrobial strategy, we studied the antibacterial activity of both MH and MGO (at equivalent MGO concentrations) when applied as a physical coating to a nonwoven fabric wound dressing.

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Silvopastoral systems aim to enhance economic, cultural and social principles by sustainably combining forest management with agriculture. In these typically high-nitrogen (N) environments, plant species selection can profoundly influence N fluxes. For grazed pastures, plants may be exposed to urine patches that have received the equivalent of up to 1000 kg N ha.

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The myrtaceae family has a cosmopolitan distribution and includes the Australasian native species Leptospermum scoparium (mānuka) and Kunzea robusta (kānuka), which are of economic interest for the production of high-value honey and essential oils. Potentially, these species could be established on low-fertility or degraded soils that have been amended with biowastes, including biosolids and sawdust. We aimed to determine the effect of these biowastes on nitrate leaching and the growth and chemical composition of these plant species compared to Pinus radiata (pine), a common forestry species.

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Background: Detection and preventing entry of exotic viruses and viroids at the border is critical for protecting plant industries trade worldwide. Existing post entry quarantine screening protocols rely on time-consuming biological indicators and/or molecular assays that require knowledge of infecting viral pathogens. Plants have developed the ability to recognise and respond to viral infections through Dicer-like enzymes that cleave viral sequences into specific small RNA products.

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Increasing production of biowastes, particularly biosolids (sewage sludge), requires sustainable management strategies for their disposal. Biosolids can contain high concentrations of nutrients; hence, land application can have positive effects on plant growth and soil fertility, especially when applied to degraded soils. However, high rates of biosolids application may result in excessive nitrogen (N) leaching, which can be mitigated by blending biosolids with other biowastes, such as sawdust.

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Land application of biosolids to low-fertility soil can improve soil quality by increasing concentrations of macronutrients and trace elements. Mixing biosolids with sawdust could reduce the risks of contaminant accumulation posed by rebuilding soils using biosolids alone. We aimed to determine the effects of biosolids and biosolids-sawdust on the plant quality and chemical composition of sorghum, rapeseed, and ryegrass.

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Article Synopsis
  • Biosolids can enhance soil quality and nutrient levels in plants, but their application may pose risks due to certain trace elements.
  • Mixing biosolids with sawdust reduces risks, particularly cadmium uptake, while still increasing essential micronutrients in plants.
  • In a study involving ryegrass, blending sawdust with biosolids led to moderate growth benefits and a balance of nutrient availability over a 5-month period.
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Introduction: Local delivery of mesenchymal stem cells (MSCs) to the acutely injured or osteoarthritic joint retards cartilage destruction. However, in the absence of assistive materials the efficiency of engraftment of MSCs to either intact or fibrillated cartilage is low and localization is further reduced by natural movement of the joint surfaces. It is hypothesised that enhanced engraftment of the delivered MSCs at the cartilage surface will increase their reparative effect and that the application of a bioadhesive to the degraded cartilage surface will provide improved cell retention.

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As problems of antibiotic resistance increase, a continuing need for effective bioactive wound dressings is anticipated for the treatment of infected chronic wounds. Naturally derived antibacterial agents, such as Manuka honey, consist of a mixture of compounds, more than one of which can influence antimicrobial potency. The non-peroxide bacteriostatic properties of Manuka honey have been previously linked to the presence of methylglyoxal.

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The obligate biotrophic pathogen Plasmodiophora brassicae causes clubroot disease in Arabidopsis thaliana, which is characterized by large root galls. Salicylic acid (SA) production is a defence response in plants, and its methyl ester is involved in systemic signalling. Plasmodiophora brassicae seems to suppress plant defence reactions, but information on how this is achieved is scarce.

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Background: Phytomyxids (plasmodiophorids and phagomyxids) are cosmopolitan, obligate biotrophic protist parasites of plants, diatoms, oomycetes and brown algae. Plasmodiophorids are best known as pathogens or vectors for viruses of arable crops (e.g.

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Spongospora subterranea is a soil-borne obligate parasite responsible for potato powdery scab disease. S. subterranea is a member of the order Plasmodiophorida, a protist taxa that is related to Cercozoa and Foraminifera but the fine details of these relationships remain unresolved.

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At least 15 species of aphids are now recognised as New Zealand natives and most of these are very likely to be endemic. Most native aphids belong in the subfamily Aphidinae (Aphidini), with a possible single species in Aphidinae-Macrosiphini, at least two in Neophyllaphidinae and one in Taiwanaphidinae. With one exception, native aphids are restricted to a single host plant genus, and these hosts are from 13 genera and 12 plant families in the Pinales and Angiospermae-Eudicotyledonae, suggesting that the aphids are a remnant fauna.

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Articular cartilage is a complex, multilayered biological composite material, comprised of chondrocytes encapsulated in a water-based glycosaminoglycan matrix reinforced with collagen fibers. Once damaged by osteoarthritis or traumatic injury, this aneural, avascular tissue has little self-repair capacity. Over the last 20 years, cell therapies and tissue-engineering strategies have shown significant promise for the repair or regeneration of damaged cartilage.

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The plasmodiophorids are a phylogenetically distinct group of parasitic protists that infect plants and stramenopiles, causing several important agricultural diseases. Because of the obligate intracellular part of their lifecycle, none of the plasmodiophorids has been axenically cultured. Further, the molecular biology of the plasmodiophorids is poorly understood because pure cultures are not available from any species.

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Background: Recent phylogenomic analyses have revolutionized our view of eukaryote evolution by revealing unexpected relationships between and within the eukaryotic supergroups. However, for several groups of uncultivable protists, only the ribosomal RNA genes and a handful of proteins are available, often leading to unresolved evolutionary relationships. A striking example concerns the supergroup Rhizaria, which comprises several groups of uncultivable free-living protists such as radiolarians, foraminiferans and gromiids, as well as the parasitic plasmodiophorids and haplosporids.

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ABSTRACT The development of specific oligonucleotide primers for Plasmodiophora brassicae has led to a nested polymerase chain reaction (PCR) detection method for P. brassicae in soil and water. Initially, the PCR was used to amplify a section of the rDNA repeat.

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Plasmodiophora brassicae, a pathogen of Brassicaceae plants, is grouped within the eukaryotic supergroup, the Rhizaria. Although a large diversity of protists is found in the Rhizaria, genomes of organisms within the group have barely been examined. In this study, we identified DNA sequences spanning or flanking 24 P.

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