Publications by authors named "Peter N Dodds"

Article Synopsis
  • The population structure and evolution of basidiomycetes, such as rust fungi, are shaped by complex reproductive strategies that include both asexual and sexual reproduction, which enhance their adaptability.
  • Puccinia coronata f. sp. avenae (Pca), a significant oat pathogen, exhibits varied contributions from sexual reproduction, clonality, and genetic exchange to its evolution, leading to challenges in managing host resistance.
  • Recent genome sequencing of Pca isolates from the USA, Australia, Taiwan, and South Africa revealed genetic recombination and somatic hybridization, indicating increased genetic diversity and potential intercontinental movement of strains, highlighting the need for global pathogen monitoring.
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Effector proteins are central to the success of plant pathogens, while immunity in host plants is driven by receptor-mediated recognition of these effectors. Understanding the molecular details of effector-receptor interactions is key for the engineering of novel immune receptors. Here, we experimentally determined the crystal structure of the Puccinia graminis f.

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Plant Toll/interleukin-1 receptor/resistance protein (TIR) type nucleotide-binding and leucine-rich repeat immune receptors (NLRs) require enhanced disease susceptibility 1 (EDS1) family proteins and the helper NLRs NRG1 and ADR1 for immune activation. We show that the EDS1-SAG101b-NRG1 signaling pathway in is necessary for cell death signaling by TIR-NLRs from a range of plant species, suggesting a universal requirement for this module in TIR-NLR-mediated cell death in We also find that TIR domains physically associate with EDS1, PAD4, and SAG101 , independently of each other. Furthermore, NRG1 associates with SAG101b, but not with other EDS1 family members, via its C-terminal EP domain.

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Crop breeding for durable disease resistance is challenging due to the rapid evolution of pathogen virulence. While progress in resistance (R) gene cloning and stacking has accelerated in recent years, the identification of corresponding avirulence (Avr) genes in many pathogens is hampered by the lack of high-throughput screening options. To address this technology gap, we developed a platform for pooled library screening in plant protoplasts to allow rapid identification of interacting R-Avr pairs.

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Plant diseases are a constant and serious threat to agriculture and ecological biodiversity. Plants possess a sophisticated innate immunity system capable of detecting and responding to pathogen infection to prevent disease. Our understanding of this system has grown enormously over the past century.

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Crops are constantly exposed to pathogenic microbes. Rust fungi are examples of these harmful microorganisms, which have a major economic impact on wheat production. To protect themselves from pathogens like rust fungi, plants employ a multilayered immune system that includes immunoreceptors encoded by resistance genes.

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Article Synopsis
  • The study investigates the pathogen *f. sp.*, responsible for crown rust, which significantly hampers oat production globally, and compares the virulence profiles of isolates from Australia using different host differential sets.
  • Analysis revealed discrepancies in the virulence between the Australian and U.S. sets, suggesting that race assignments are inconsistent across countries.
  • Additionally, the research confirms that certain oat cultivars, including Volta, carry specific resistance genes and emphasizes the importance of molecular markers in breeding to enhance resistance to crown rust.
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In clonally reproducing dikaryotic rust fungi, non-sexual processes such as somatic nuclear exchange are postulated to play a role in diversity but have been difficult to detect due to the lack of genome resolution between the two haploid nuclei. We examined three nuclear-phased genome assemblies of Puccinia triticina, which causes wheat leaf rust disease. We found that the most recently emerged Australian lineage was derived by nuclear exchange between two pre-existing lineages, which originated in Europe and North America.

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The gene-for-gene model proposed by H. H. Flor has been one of the fundamental precepts of plant-pathogen interactions that has underpinned decades of research towards our current concepts of plant immunity.

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To infect plants, pathogenic fungi secrete small proteins called effectors. Here, we describe the catalytic activity and potential virulence function of the Nudix hydrolase effector AvrM14 from the flax rust fungus (Melampsora lini). We completed extensive in vitro assays to characterise the enzymatic activity of the AvrM14 effector.

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Functional characterization of effector proteins of fungal obligate biotrophic pathogens, especially confirmation of avirulence (Avr) properties, has been notoriously difficult, due to the experimental intractability of many of these organisms. Previous studies in wheat have shown promising data suggesting the type III secretion system (T3SS) of bacteria may be a suitable surrogate for delivery and detection of Avr properties of fungal effectors. However, these delivery systems were tested in the absence of confirmed Avr effectors.

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Rust fungi are characterized by large genomes with high repeat content and have two haploid nuclei in most life stages, which makes achieving high-quality genome assemblies challenging. Here, we described a pipeline using HiFi reads and Hi-C data to assemble a gigabase-sized fungal pathogen, Puccinia polysora f.sp.

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Plants deploy extracellular and intracellular immune receptors to sense and restrict pathogen attacks. Rapidly evolving pathogen effectors play crucial roles in suppressing plant immunity but are also monitored by intracellular nucleotide-binding, leucine-rich repeat immune receptors (NLRs), leading to effector-triggered immunity (ETI). Here, we review how NLRs recognize effectors with a focus on direct interactions and summarize recent research findings on the signalling functions of NLRs.

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Advances in sequencing technologies as well as development of algorithms and workflows have made it possible to generate fully phased genome references for organisms with nonhaploid genomes such as dikaryotic rust fungi. To enable discovery of pathogen effectors and further our understanding of virulence evolution, we generated a chromosome-scale assembly for each of the 2 nuclear genomes of the oat crown rust pathogen, Puccinia coronata f. sp.

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Filamentous plant pathogens cause disease in numerous economically important crops. These pathogens secrete virulence proteins, termed effectors, that modulate host cellular processes and promote infection. Plants have evolved immunity receptors that detect effectors and activate defence pathways, resulting in resistance to the invading pathogen.

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Background: Most animals and plants have more than one set of chromosomes and package these haplotypes into a single nucleus within each cell. In contrast, many fungal species carry multiple haploid nuclei per cell. Rust fungi are such species with two nuclei (karyons) that contain a full set of haploid chromosomes each.

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Pathogen effectors are crucial players during plant colonisation and infection. Plant resistance mostly relies on effector recognition to activate defence responses. Understanding how effector proteins escape from plant surveillance is important for plant breeding and resistance deployment.

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Many fungi and oomycete species are devasting plant pathogens. These eukaryotic filamentous pathogens secrete effector proteins to facilitate plant infection. Fungi and oomycete pathogens have diverse infection strategies and their effectors generally do not share sequence homology.

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Background: Silencing of transposable elements (TEs) is essential for maintaining genome stability. Plants use small RNAs (sRNAs) to direct DNA methylation to TEs (RNA-directed DNA methylation; RdDM). Similar mechanisms of epigenetic silencing in the fungal kingdom have remained elusive.

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Stem rust caused by the fungus Puccinia graminis f. sp. tritici (Pgt) is a devastating disease of the global staple crop wheat.

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Rust fungi (Pucciniales, Basidiomycota) are obligate biotrophic pathogens that cause rust diseases in plants, inflicting severe damage to agricultural crops. Pucciniales possess the most complex life cycles known in fungi. These include an alternation of generations, the development of up to five different sporulating stages, and, for many species, the requirement of infecting two unrelated host plants during different parts of their life cycle, termed heteroecism.

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Pathogen populations are expected to evolve virulence traits in response to resistance deployed in agricultural settings. However, few temporal datasets have been available to characterize this process at the population level. Here, we examined two temporally separated populations of Puccinia coronata f.

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