David Pires

Bursaphelenchus xylophilus (pinewood nematode, PWN) responds transcriptionally to nematophagous fungi, but the earliest events preceding cuticle penetration are poorly characterized, and whether closely related fungal antagonists elicit comparable responses is unknown. Here, we compared PWN transcriptomic responses to Esteya floridanum V14639 (EF) and E. vermicola CCF3117 (EV) at 1 h post-inoculation (hpi), capturing the onset of host–fungus interaction. Despite their phylogenetic proximity, under our exposure conditions the two fungi elicited partly divergent host responses at 1 hpi. EF induced a broad transcriptional response enriched in peptidase activity and lysosomal pathways, accompanied by downregulation of cuticle structural components. In contrast, EV triggered a narrower response, without the proteolytic and lysosomal enrichment observed with EF. Direct comparison of the two treatments revealed no significantly enriched Gene Ontology categories, although pathway analysis identified DNA replication and repair pathways, comprising genes more highly expressed under EF. Enrichment analyses revealed a shared transcriptional signature in both interactions characterized by downregulation of xenobiotic- and central carbon-metabolism pathways, suggesting an early reduction in xenobiotic detoxification capacity rather than induction of detoxification programs. These findings suggest that phylogenetic proximity does not necessarily predict conserved early transcriptional responses, although comparisons of single isolates cannot separate species-level from isolate-level effects. Graphical

Pine wilt disease (PWD), caused by the pinewood nematode (PWN) Bursaphelenchus xylophilus, continues to expand globally despite decades of pathogen-focused management. Here, we propose that disruption of microbiome assembly within the pine holobiont may contribute to disease progression and help explain variation in disease outcomes and responses to microbial interventions. Drawing on recent advances in microbial ecology, multi-omics, and synthetic biology, we synthesize evidence of PWD-associated changes in host-associated microbial communities and examine how altered functional redundancy and pathobiome formation may contribute to disease progression. We propose that microbiome assembly, shaped by host traits, environmental filters, and biotic interactions, is a plausible and underexplored determinant of disease outcome. Building on this framework, we outline a shift from single-agent biocontrol toward assembly-informed microbiome engineering. To support reproducible design and future validation, we outline criteria for selecting candidate consortium members and assessing synthetic microbial community (SynCom) establishment, persistence and functional stability. We further propose experimentally testable strategies to compare assembly-informed versus conventional interventions and identify measurable indicators of microbiome stability and disease suppression. By reframing PWD as a problem of microbiome assembly and stability, this work provides a testable framework for developing durable, holobiont-level management strategies. Integrating ecological theory with applied microbiome engineering offers a path forward to move beyond inconsistent control outcomes and toward resilient forest health under ongoing environmental change.

BACKGROUND: Pine wilt disease, caused by Bursaphelenchus xylophilus , threatens pine forests worldwide, yet sustainable biological control strategies remain limited. We evaluated the effects of pre‐emptive inoculation with Esteya vermicola and E. floridanum on nematode reproduction and disease outcomes in Pinus pinaster seedlings under greenhouse conditions. RESULTS: Seedlings inoculated with E . vermicola or E . floridanum remained free of visible symptoms during the 5‐week pre‐challenge period. Fungi were subsequently re‐isolated from stem tissues at the experimental endpoint, and both treatments significantly reduced nematode reproduction relative to the inoculated control. However, reductions in nematode reproduction were not consistently accompanied by improvements across disease assessment endpoints, including symptom severity, disease progression, and survival. Symptom expression in nematode‐free controls indicated that environmental stress contributed to disease assessment endpoints, limiting interpretation of symptom‐based measures. Exploratory correlation and permutation analyses suggested treatment‐specific differences in the association between nematode reproduction and symptom severity; however, the endpoint design and restricted range of reproduction values following fungal treatment do not distinguish this interpretation from alternative explanations. CONCLUSION: Esteya spp. significantly reduced pinewood nematode reproduction in P . pinaster seedlings, but improvements in disease outcomes were inconsistent under the conditions tested. These findings highlight that pathogen reproduction and disease assessment endpoints should both be evaluated when assessing biological control strategies for pine wilt disease. © 2026 Society of Chemical Industry.

This paper focuses on how microbial diversity, soil organic matter, and soil structure influence the activities of soilborne pathogens and plant disease epidemiology. Microbial diversity, soil organic matter, and soil structure are soil components that can reshape plant–pathogen–soil interactions by altering nutrient dynamics and the composition of the soil microbiome. When beneficial microorganisms are enriched in soil ecosystems, suppression of soilborne pathogens may be enhanced, thereby decreasing disease incidence and severity. However, microbial diversity, soil organic matter, and soil structure may also promote pathogen growth or facilitate cooperative microbial interactions that improve pathogen persistence, thereby elevating disease risk. Future progress requires a shift from descriptive surveys toward functional and predictive approaches, as these soil components influence epidemiological processes that can either suppress or intensify the development of plant diseases caused by soilborne plant pathogens. Rather than acting as deterministic drivers of disease outcomes, microbial diversity, soil organic matter, and soil structure modify the ecological context in which host–pathogen interactions occur, altering the likelihood of pathogen establishment, persistence, and transmission. This paper highlights the importance of soil management in regulating microbial community dynamics and supporting plant disease control within this probabilistic ecological framework.

Pesticides play a critical role in food production by enhancing crop yields and protecting against pests and pathogens, such as insects, bacteria, fungi, and weeds. However, their extensive use raises significant environmental concerns. The paper reviews and describes the reported adverse effects of pesticides on terrestrial and marine life to raise awareness of the ecological impact of pesticide use across life niches. The adverse effects on soil microorganisms, arthropods, reptiles, and amphibians highlight the extensive ecological disruption caused by these chemicals. Understanding the mechanisms of pesticide toxicity and their impact on various organisms is crucial for developing effective bioremediation techniques and on-field management practices. By implementing these strategies and enhancing environmental biomonitoring, countries can mitigate the harmful effects of pesticides, ultimately protecting biodiversity and ensuring the health of their ecosystems.

Forest decline is a complex phenomenon; however, there is often a tendency to oversimplify by attributing it to a single cause, neglecting the interaction of multiple factors. Ever since the detection of the pinewood nematode (PWN), Bursaphelenchus xylophilus , in Portugal (and in Europe) over two decades ago, pine wilt cases in the country have been primarily attributed to this pathogen, leading authorities to enforce strict containment and control measures. Other contributing factors are generally overlooked, with the system being easily overwhelmed by disturbances such as droughts and fires. In this study, a physiographic approach was used to assess multiple factors potentially affecting tree wilting, including environmental parameters in the landscape, alongside other biological agents, and infestation by the PWN. The study area is a highly managed production forest where control measures have been implemented since the detection of PWN in the 1990´s. Pine decline was found to be aggregated in the landscape, with topographic parameters associated with water availability playing a significant role. Wilting trees were affected by multiple biological agents, even though the density of PWN was positively correlated with the decline. However, B. xylophilus was also found to be present in asymptomatic hosts, suggesting an ability to persist for some time in healthy trees within the forest. This research illustrates the multifaceted nature of pine forest decline and the limitations of managing it as originating from a single cause. A critical overview of current PWN management measures is provided, along with proposals for a more heuristic and holistic approach.

Legumes are among the most important crops globally, serving as a major food source for protein and oil. In tropical regions, the cultivation of legumes has expanded significantly due to the increasing demand for food, plant-based products, and sustainable agriculture practices. However, tropical environments pose unique challenges, including high temperatures, erratic rainfall, soil infertility, and a high incidence of pests and diseases. Indeed, legumes are vulnerable to infections caused by bacteria, fungi, oomycetes, viruses, and nematodes. This review highlights the importance of legumes in tropical farming and discusses major diseases affecting productivity and their impact on the economy, environment, and lives of smallholder legume farmers. We emphasize the use of legume genetic resources and breeding, and biotechnology innovations to foster resistance and address the challenges posed by pathogens in legumes. However, an integrated approach that includes other cultivation techniques (e.g., crop rotation, rational fertilization, deep plowing) remains important for the prevention and control of diseases in legume crops. Finally, we highlight the contributions of plant genetic resources to smallholder resilience and food security.

Among the most concerning threats impacting global forest ecosystems is the pinewood nematode (Bursaphelenchus xylophilus (Steiner and Buhrer, 1934) Nickle, 1970), the causal agent of pine wilt disease. In Europe, effective management of this pest requires comprehensive regulatory and monitoring strategies, including the annual collection of thousands of wood samples from symptomatic trees and their surroundings, inspection of wood packaging materials like pallets, and the trapping of the insect vector, Monochamus spp., through national networks. Insects and wood samples are sent to official laboratories, where the latter are sometimes incubated at 25 °C for 15 days, aiming to maximize the probability of the detection of the nematode. This study expected to elucidate the effect of the wood incubation process on the detection of B. xylophilus by analyzing wood samples from pallets and green wood obtained from pine stands, both harbouring nematodes in adult and juvenile stages. Additionally, the investigation sought to assess how the presence of fungi, which serve as a food source for the nematodes, enables B. xylophilus to persist in treated pallet wood that is colonized by these fungi. The results indicated that the incubation period is unnecessary for detecting B. xylophilus in pallets, except when the wood is heavily colonized by fungi providing suitable nutrition for the nematodes, although such occurrences are expected to be rare. Furthermore, this study found no significant differences in population growth between the two stages of the nematode’s life cycle. This suggests that second-stage juveniles present in wood samples, despite not undergoing sexual differentiation, do not hinder the reproductive capacity of B. xylophilus. The risk of a potential infestation in treated pallet wood is unlikely if the treatment has been performed correctly, and the incubation does not contribute to increasing the probability of detecting the PWN. Conversely, for samples obtained from trees, the incubation period significantly enhances nematode detection.