Emerging health threat and cost of Fusarium mycotoxins in European wheat.

Mycotoxins harm human and livestock health, while damaging economies. Here we reveal the changing threat of Fusarium head blight (FHB) mycotoxins in European wheat, using data from the European Food Safety Agency and agribusiness (BIOMIN, World Mycotoxin Survey) for ten years (2010-2019). We show persistent, high, single- and multi-mycotoxin contamination alongside changing temporal-geographical distributions, indicative of altering FHB disease pressure and pathogen populations, highlighting the potential synergistic negative health consequences and economic cost.

Multi-site fungicides suppress banana Panama disease, caused by Fusarium oxysporum f. sp. cubense Tropical Race 4.

Global banana production is currently challenged by Panama disease, caused by Fusarium oxysporum f.sp. cubense Tropical Race 4 (FocTR4).

The future of fungi: threats and opportunities.

The fungal kingdom represents an extraordinary diversity of organisms with profound impacts across animal, plant, and ecosystem health. Fungi simultaneously support life, by forming beneficial symbioses with plants and producing life-saving medicines, and bring death, by causing devastating diseases in humans, plants, and animals. With climate change, increased antimicrobial resistance, global trade, environmental degradation, and novel viruses altering the impact of fungi on health and disease, developing new approaches is now more crucial than ever to combat the threats posed by fungi and to harness their extraordinary potential for applications in human health, food supply, and environmental remediation.

Zymoseptoria tritici white-collar complex integrates light, temperature and plant cues to initiate dimorphism and pathogenesis.

Transitioning from spores to hyphae is pivotal to host invasion by the plant pathogenic fungus Zymoseptoria tritici. This dimorphic switch can be initiated by high temperature in vitro (~27 °C); however, such a condition may induce cellular heat stress, questioning its relevance to field infections. Here, we study the regulation of the dimorphic switch by temperature and other factors.

Tackling the emerging threat of antifungal resistance to human health.

Invasive fungal infections pose an important threat to public health and are an under-recognized component of antimicrobial resistance, an emerging crisis worldwide. Across a period of profound global environmental change and expanding at-risk populations, human-infecting pathogenic fungi are evolving resistance to all licensed systemic antifungal drugs. In this Review, we highlight the main mechanisms of antifungal resistance and explore the similarities and differences between bacterial and fungal resistance to antimicrobial control.

Asynchronous development of Zymoseptoria tritici infection in wheat.

The fungus Zymoseptoria tritici causes Septoria tritici blotch of wheat. Pathogenicity begins with spore germination, followed by stomata invasion by hyphae, mesophyll colonization and fruiting body formation. It was previously found that entry into the plant via stomata occurs in a non-synchronized way over several days, while later developmental steps, such as early and late fruiting body formation, were reported to follow each other in time.

Conditional promoters to investigate gene function during wheat infection by Zymoseptoria tritici.

The fungus Zymoseptoria tritici causes Septoria tritici leaf blotch, which poses a serious threat to temperate-grown wheat. Recently, we described a raft of molecular tools to study the biology of this fungus in vitro. Amongst these are 5 conditional promoters (Pnar1, Pex1A, Picl1, Pgal7, PlaraB), which allow controlled over-expression or repression of target genes in cells grown in liquid culture.

Fungi, fungicide discovery and global food security.

Securing sufficient food for a growing world population is of paramount importance for social stability and the well-being of mankind. Recently, it has become evident that fungal pathogens pose the greatest biotic challenge to our calorie crops. Moreover, the loss of commodity crops to fungal disease destabilises the economies of developing nations, thereby increasing the dimension of the threat.

Geometry and evolution of the ecological niche in plant-associated microbes.

The ecological niche can be thought of as a volume in multidimensional space, where each dimension describes an abiotic condition or biotic resource required by a species. The shape, size, and evolution of this volume strongly determine interactions among species and influence their current and potential geographical distributions, but the geometry of niches is poorly understood. Here, we analyse temperature response functions and host plant ranges for hundreds of potentially destructive plant-associated fungi and oomycetes.

Threats to global food security from emerging fungal and oomycete crop pathogens.

Emerging fungal and oomycete pathogens infect staple calorie crops and economically important commodity crops, thereby posing a significant risk to global food security. Our current agricultural systems - with emphasis on intensive monoculture practices - and globalized markets drive the emergence and spread of new pathogens and problematic traits, such as fungicide resistance. Climate change further promotes the emergence of pathogens on new crops and in new places.

Threats Posed by the Fungal Kingdom to Humans, Wildlife, and Agriculture.

The fungal kingdom includes at least 6 million eukaryotic species and is remarkable with respect to its profound impact on global health, biodiversity, ecology, agriculture, manufacturing, and biomedical research. Approximately 625 fungal species have been reported to infect vertebrates, 200 of which can be human associated, either as commensals and members of our microbiome or as pathogens that cause infectious diseases. These organisms pose a growing threat to human health with the global increase in the incidence of invasive fungal infections, prevalence of fungal allergy, and the evolution of fungal pathogens resistant to some or all current classes of antifungals.

A lipophilic cation protects crops against fungal pathogens by multiple modes of action.

The emerging resistance of crop pathogens to fungicides poses a challenge to food security and compels discovery of new antifungal compounds. Here, we show that mono-alkyl lipophilic cations (MALCs) inhibit oxidative phosphorylation by affecting NADH oxidation in the plant pathogens Zymoseptoria tritici, Ustilago maydis and Magnaporthe oryzae. One of these MALCs, consisting of a dimethylsulfonium moiety and a long alkyl chain (C-SMe), also induces production of reactive oxygen species at the level of respiratory complex I, thus triggering fungal apoptosis.

Many unreported crop pests and pathogens are probably already present.

Invasive species threaten global biodiversity, food security and ecosystem function. Such incursions present challenges to agriculture where invasive species cause significant crop damage and require major economic investment to control production losses. Pest risk analysis (PRA) is key to prioritize agricultural biosecurity efforts, but is hampered by incomplete knowledge of current crop pest and pathogen distributions.

A new mechanistic model of weather-dependent Septoria tritici blotch disease risk.

We present a new mechanistic model for predicting Septoria tritici blotch (STB) disease, parameterized with experimentally derived data for temperature- and wetness-dependent germination, growth and death of the causal agent, Zymoseptoria tritici. The output of this model (A) was compared with observed disease data for UK wheat over the period 2002-2016. In addition, we compared the output of a second model (B), in which experimentally derived parameters were replaced by a modified version of a published Z.

Rapid loss of virulence during submergence of Z. tritici asexual spores.

Zymoseptoria tritici, the causal agent of Septoria tritici blotch, is a notable pathogen of temperate-grown wheat. To better understand the mechanisms underpinning pathogenicity, leaf infection assays are commonly used to compare either the virulence of Z. tritici wildtype or mutant strains, or the susceptibility of wheat cultivars.

Worldwide emergence of resistance to antifungal drugs challenges human health and food security.

The recent rate of emergence of pathogenic fungi that are resistant to the limited number of commonly used antifungal agents is unprecedented. The azoles, for example, are used not only for human and animal health care and crop protection but also in antifouling coatings and timber preservation. The ubiquity and multiple uses of azoles have hastened the independent evolution of resistance in many environments.

A role for random, humidity-dependent epiphytic growth prior to invasion of wheat by Zymoseptoria tritici.

Zymoseptoria tritici causes Septoria leaf blotch of wheat. The prevailing paradigm of the Z. tritici-wheat interaction assumes fungal ingress through stomata within 24-48h, followed by days of symptomless infection.

NOious gases and the unpredictability of emerging plant pathogens under climate change.

Emerging pathogens of crops threaten food security and are increasingly problematic due to intensive agriculture and high volumes of trade and transport in plants and plant products. The ability to predict pathogen risk to agricultural regions would therefore be valuable. However, predictions are complicated by multi-faceted relationships between crops, their pathogens, and climate change.

Investigating chitin deacetylation and chitosan hydrolysis during vegetative growth in Magnaporthe oryzae.

Chitin deacetylation results in the formation of chitosan, a polymer of β1,4-linked glucosamine. Chitosan is known to have important functions in the cell walls of a number of fungal species, but its role during hyphal growth has not yet been investigated. In this study, we have characterized the role of chitin deacetylation during vegetative hyphal growth in the filamentous phytopathogen Magnaporthe oryzae.

Emerging Fungal Threats to Plants and Animals Challenge Agriculture and Ecosystem Resilience.

While fungi can make positive contributions to ecosystems and agro-ecosystems, for example, in mycorrhizal associations, they can also have devastating impacts as pathogens of plants and animals. In undisturbed ecosystems, most such negative interactions will be limited through the coevolution of fungi with their hosts. In this article, we explore what happens when pathogenic fungi spread beyond their natural ecological range and become invasive on naïve hosts in new ecosystems.

Tackling emerging fungal threats to animal health, food security and ecosystem resilience.

Emerging infections caused by fungi have become a widely recognized global phenomenon. Their notoriety stems from their causing plagues and famines, driving species extinctions, and the difficulty in treating human mycoses alongside the increase of their resistance to antifungal drugs. This special issue comprises a collection of articles resulting from a Royal Society discussion meeting examining why pathogenic fungi are causing more disease now than they did in the past, and how we can tackle this rapidly emerging threat to the health of plants and animals worldwide.

Modelling coffee leaf rust risk in Colombia with climate reanalysis data.

Many fungal plant diseases are strongly controlled by weather, and global climate change is thus likely to have affected fungal pathogen distributions and impacts. Modelling the response of plant diseases to climate change is hampered by the difficulty of estimating pathogen-relevant microclimatic variables from standard meteorological data. The availability of increasingly sophisticated high-resolution climate reanalyses may help overcome this challenge.

Co-delivery of cell-wall-forming enzymes in the same vesicle for coordinated fungal cell wall formation.

Fungal cells are surrounded by an extracellular cell wall. This complex matrix of proteins and polysaccharides protects against adverse stresses and determines the shape of fungal cells. The polysaccharides of the fungal wall include 1,3-β-glucan and chitin, which are synthesized by membrane-bound synthases at the growing cell tip.

A role for the asexual spores in infection of Fraxinus excelsior by the ash-dieback fungus Hymenoscyphus fraxineus.

The invasive pathogen, ash dieback fungus Hymenoscyphus fraxineus, is spreading rapidly across Europe. It shows high levels of outcrossing and limited population structure, even at the epidemic front. The anamorphic (asexual) form produces prolific conidia, thought to function solely as spermatia (male gametes), facilitating gene flow between sympatric strains.