Aggressiveness and phylogenetic relationship of associated with crown and root rot in pyrethrum plants.

In Australia, pyrethrum (Tanacetum cinerariifolium) cultivation provides a significant portion of the global supply of natural insecticidal pyrethrins. However, crown and root rots, along with stunted plant growth and plant loss during winter, are significant issues affecting certain sites. Several isolates of the Fusarium oxysporum species complex (FOSC) have been identified as causal agents of crown and root rot in pyrethrum, highlighting these as key pathogens contributing to this decline.

Resolving spatially distinct phytohormone response zones in Arabidopsis thaliana roots colonized by Fusarium oxysporum.

Jasmonic acid (JA), ethylene (ET) and salicylic acid (SA) are the three major phytohormones coordinating plant defense responses, and all three are implicated in the defense against the fungal pathogen Fusarium oxysporum. However, their distinct modes of action and possible interactions remain unknown, in part because all spatial information on their activity is lacking. Here, we set out to probe this spatial aspect of plant immunity by using live-microscopy with newly developed fluorescence-based transcriptional reporter lines.

Taxonomic revision of fleshy species of , and (Thelephorales) from Australasia.

Stipitate Thelephorales are basidiomycetous, mostly hydnoid, ectomycorrhizal fungi. Some species have declined considerably, and some are threat-listed as vulnerable or endangered. These ecological concerns require a well-resolved taxonomy to understand diversity in this group of fungi and facilitate conservation.

Host Genetic Resistance in : A Valuable Tool for the Integrated Management of the Fungal Pathogen .

Management of plant disease in agro-ecosystems ideally relies on a combination of host genetic resistance, chemical control, and cultural practices. Growers increasingly rely on chemical and genetic options, but their relative benefits in disease control, yield, and economic outcomes are rarely quantified. We explore this relationship for blackleg crown canker disease (caused by ), a major biotic constraint limiting canola production globally.

The ilv2 gene, encoding acetolactate synthase for branched chain amino acid biosynthesis, is required for plant pathogenicity by Leptosphaeria maculans.

Background: Control of blackleg disease of canola caused by the fungus Leptosphaeria maculans relies on strategies such as the inhibition of growth with fungicides. However, other chemicals are used during canola cultivation, including fertilizers and herbicides. There is widespread use of herbicides that target the acetolactate synthase (ALS) enzyme involved in branched chain amino acid synthesis and low levels of these amino acids within leaves of Brassica species.

Genetic Transformation of Cryptococcus Species with Agrobacterium Transfer DNA.

Transformation of foreign DNA into Cryptococcus species is a powerful tool for exploring gene functions in these human pathogens. Agrobacterium tumefaciens-mediated transformation (AtMT) has been used for the stable introduction of exogenous DNA into Cryptococcus for over two decades, being particularly impactful for insertional mutagenesis screens to discover new genes involved in fungal biology. A detailed protocol to conduct this transformation method is provided in the chapter.

Hormonal and proteomic analyses of southern blight disease caused by and root chitosan priming on in an in vitro hydroponic system.

Southern blight disease, caused by the fungal pathogen , suppresses plant growth and reduces product yield in agriculture. Mechanisms of pathology of this soil-borne disease remain poorly understood, with disease management strategies reliant upon broad-spectrum antifungal use. Exposure to chitosan, a natural elicitor, has been proposed as an alternative method to control diverse fungal diseases in an eco-friendly manner.

Sequencing the Genomes of the First Terrestrial Fungal Lineages: What Have We Learned?

The first genome sequenced of a eukaryotic organism was for , as reported in 1996, but it was more than 10 years before any of the zygomycete fungi, which are the early-diverging terrestrial fungi currently placed in the phyla and , were sequenced. The genome for was completed in 2008; currently, more than 1000 zygomycete genomes have been sequenced. Genomic data from these early-diverging terrestrial fungi revealed deep phylogenetic separation of the two major clades-primarily plant-associated saprotrophic and mycorrhizal versus the primarily mycoparasitic or animal-associated parasites and commensals in the .

Isolation of strains and their genome sequencing to analyze the mating system of Ophiocordyceps robertsii.

The fungal genus Ophiocordyceps contains a number of insect pathogens. One of the best known of these is Ophiocordyceps sinensis, which is used in Chinese medicine and its overharvesting threatens sustainability; hence, alternative species are being sought. Ophiocordyceps robertsii, found in Australia and New Zealand, has been proposed to be a close relative to O.

are active eukaryotic transposable elements mobilized by a new family of tyrosine recombinases.

Transposable elements in eukaryotic organisms have historically been considered "selfish," at best conferring indirect benefits to their host organisms. The are a recently discovered feature in fungal genomes that are, in some cases, predicted to confer beneficial traits to their hosts and also have hallmarks of being transposable elements. Here, we provide experimental evidence that are indeed autonomous transposons, using the model , and identify the HhpA "Captain" tyrosine recombinase as essential for their mobilization into genomic sites with a specific target site consensus sequence.

and Species Associated with Yield Decline of Pyrethrum () in Australia.

Pyrethrum () cultivation in Australia, which accounts for the majority of global production of natural insecticidal pyrethrins, is affected by a persistent yield decline which in part is caused by a complex of pathogens. and species were isolated from crown and roots of pyrethrum plants showing stunting and brown discoloration of crown tissue, and from soil adjacent to diseased plants from yield-decline-affected sites in Tasmania and Victoria, Australia. Ten known species (, , , , , , , and var.

A Polyphasic Approach including Whole Genome Sequencing Reveals sp. nov. as a Cryptic Sister Species to .

Whole genome sequencing is rapidly increasing phylogenetic resolution across many groups of fungi. To improve sequencing coverage in the genus (), we report nine new genomes representing five different species. Phylogenetic comparison between these genomes and those reported previously showed that is a distinct species from its close relative .

Isolation of a fungal calcineurin A mutant suggests that amoebae can counter-select virulence attributes of microbes.

Evolutionary selection pressures that resulted in microbes found within environmental reservoirs that can cause diseases in animals are unknown. One hypothesis is that predatory organisms select microbes able to counteract animal immune cells. Here, a non-pathogenic yeast, Sporobolomyces primogenomicus, was exposed to predation by Acanthamoeba castellanii.

A new family of structurally conserved fungal effectors displays epistatic interactions with plant resistance proteins.

Recognition of a pathogen avirulence (AVR) effector protein by a cognate plant resistance (R) protein triggers a set of immune responses that render the plant resistant. Pathogens can escape this so-called Effector-Triggered Immunity (ETI) by different mechanisms including the deletion or loss-of-function mutation of the AVR gene, the incorporation of point mutations that allow recognition to be evaded while maintaining virulence function, and the acquisition of new effectors that suppress AVR recognition. The Dothideomycete Leptosphaeria maculans, causal agent of oilseed rape stem canker, is one of the few fungal pathogens where suppression of ETI by an AVR effector has been demonstrated.

Sexual reproduction is the null hypothesis for life cycles of rust fungi.

Sexual reproduction, mutation, and reassortment of nuclei increase genotypic diversity in rust fungi. Sexual reproduction is inherent to rust fungi, coupled with their coevolved plant hosts in native pathosystems. Rust fungi are hypothesised to exchange nuclei by somatic hybridisation with an outcome of increased genotypic diversity, independent of sexual reproduction.

Independent breakdown events of the Brassica napus Rlm7 resistance gene including via the off-target impact of a dual-specificity avirulence interaction.

Protection of many crops is achieved through the use of genetic resistance. Leptosphaeria maculans, the causal agent of blackleg disease of Brassica napus, has emerged as a model for understanding gene-for-gene interactions that occur between plants and pathogens. Whilst many of the characterized avirulence effector genes interact with a single resistance gene in the host, the AvrLm4-7 avirulence gene is recognized by two resistance genes, Rlm4 and Rlm7.

A large transposable element mediates metal resistance in the fungus Paecilomyces variotii.

The horizontal transfer of large gene clusters by mobile elements is a key driver of prokaryotic adaptation in response to environmental stresses. Eukaryotic microbes face similar stresses; however, a parallel role for mobile elements has not been established. A stress faced by many microorganisms is toxic metal ions in their environment.

Identification of the ergC gene involved in polyene drug sensitivity in the Mucorales species Phycomyces blakesleeanus.

Background: A strain of Phycomyces blakesleeanus (Mucorales, Mucoromycota) that was previously isolated after ultraviolet mutagenesis has altered responses to polyene antifungal drugs, sterol profiles, and phototropism of its sporangia. In this study, the genetic basis for these changes was sought.

Methods And Results: Two base pair substitutions were identified in the mutant within a P.