Pathogenic mechanisms of maize sheath blight: Integrative advances and perspectives

Stemphylium vesicarium: a rising threat to European horticulture

Stemphylium vesicarium is an emerging multi-host fungal pathogen that increasingly threatens European and global horticulture. Initially recognized as the causal agent of brown spot of pear and Stemphylium leaf blight of onion, the pathogen is now associated with diseases of other economically important crops, including spinach. Its broad host range, host-specialized pathotypes, host-specific toxins, and widespread fungicide resistance make disease management particularly challenging, often resulting in severe yield losses. The epidemiology of S. vesicarium is shaped by its polycyclic nature and dual reproductive strategy, with sexual ascospores colonizing alternative hosts in early spring and asexual conidia acting as the primary source of inoculum. The pathogen overwinters associated to crop residues, woody tissues, and alternative weed hosts, and can also spread through infected seeds, transplants, and thrips. Multilocus phylogenetics and whole-genome sequencing have clarified taxonomic ambiguities within Stemphylium , revealing substantial genetic diversity and complex population structures. In Europe, favourable climatic conditions, limited chemical control, fungicide-insensitive populations, and the lack of resistant cultivars in many crops underscore the urgent need for integrated disease management strategies. This review aims to give a valuable insight into the current knowledge on taxonomy, epidemiology, genetic diversity, toxin-mediated pathogenicity, and management of S. vesicarium , and identifies key research gaps to support sustainable disease control in European horticulture.

Environmentally safe in vitro biocontrol strategies for the sustainable management of Curvularia lunata leaf spot of rice: current advances and future perspectives

Rice (Oryza sativa L.), a cornerstone of global food security and trade, is increasingly threatened by the emerging fungal pathogen Curvularia lunata, which causes brown leaf spot, grain discoloration, kernel rot, and substantial yield and grain quality losses. This review synthesizes current knowledge on the biology, epidemiology, pathogenicity, diagnosis, and integrated management of C. lunata, with particular emphasis on its increasing importance under changing climatic conditions. The pathogen survives in infected seed, crop residues, and alternate grass hosts, while warm temperatures, prolonged leaf wetness, and high relative humidity favor rapid disease development and repeated secondary infection cycles. Advances in molecular diagnostics, including internal transcribed spacer (ITS) sequencing, multilocus sequence typing, and loop-mediated isothermal amplification (LAMP), have substantially improved the rapid and accurate identification of C. lunata. The review further highlights the extensive pathogenic and genetic variability of the pathogen, which complicates disease surveillance and resistance breeding. Sustainable management requires an integrated disease management approach combining certified disease-free seed, field sanitation, residue and weed management, balanced nutrient and silicon application, optimized planting practices, biological control using Trichoderma spp., Bacillus spp., Pseudomonas fluorescens, and antagonistic yeasts, botanical extracts, and the judicious use of fungicides through seed treatment and timely foliar applications. Climate change is expected to further expand the geographical distribution and epidemic potential of C. lunata, emphasizing the need for climate-resilient disease management strategies. Future research should prioritize pathogen population genomics, host resistance, rapid diagnostics, biological control optimization, and precision disease forecasting to safeguard rice productivity, grain quality, and global food security.

Genotypic variation in morphophysiological and yield-related responses of maize to maize bushy stunt phytoplasma infection

Characterizing the Seedborne Nature of Pantoea ananatis in Rice: Pathogenicity and Evidence of Vertical Transmission.

Pantoea ananatis is an emerging bacterial pathogen in rice with increasing reports across global rice-growing regions. While previous studies have suggested its presence in the seed, direct evidence for seed-to-plant transmission in rice remains limited. In this study, we characterized P. ananatis isolates recovered from naturally contaminated rice seeds and evaluated their potential for vertical transmission through two successive plant generations. Nine isolates from three rice varieties were assessed for their impact on germination, seedling health, and symptom development. Disease progression was tracked across generations, and host genotype effects were also explored. Isolates from the highly susceptible variety JiBoYa exhibited elevated virulence in rice, suggesting genotype-dependent pathogenicity. Disease onset in second-generation plants occurred approximately 30 days earlier than in the first, accompanied by significantly increased disease severity and compromised seed production. These results provide compelling evidence that P. ananatis can be vertically transmitted in rice and may accumulate across generations, leading to enhanced virulence expression. We propose further molecular and epidemiological investigations to elucidate the mechanisms underlying seedborne persistence, virulence diversity, and the broader implications for pathogen management.

Pathogenicity and virulence of Ralstonia solanacearum species complex: Understanding its virulence mechanisms for proper management

ABSTRACT The soil-borne Gram-negative beta-proteobacterium Ralstonia solanacearum species complex (RSSC) causes bacterial wilt, a devastating plant disease that threatens crop production and food security worldwide. In this review, we first summarize current knowledge of RSSC pathogenicity and virulence, focusing on the factors that determine its ability to infect and cause disease, including advances in resistance breeding and the genetic basis of host resistance to bacterial wilt. Next, we highlight the questions provided from the previous studies and describe our recent studies, which revealed that the phc QS network is a highly complex regulatory system that dominates global gene expression and finely tunes RSSC virulence throughout the infection process, from root epidermis invasion to colonization of xylem vessels. Finally, we identify key knowledge gaps and discuss future research directions and practical strategies for the effective management of bacterial wilt.

Fire blight research: 2026 and beyond

Fire blight disease, caused by the highly virulent bacterial pathogen Erwinia amylovora , is a devastating disease that continues to spread to new regions worldwide. High-density planting systems for apple combined with large plantings of consumer-preferred but highly susceptible cultivars have fueled disease outbreaks that can result in significant numbers of tree losses. These cultivation trends, together with the aggressive nature of the pathogen, make fire blight management extremely challenging. The fire blight research community recently met at the Fourth International Symposium on Fire Blight of Rosaceous Plants in Richland, Washington USA in June, 2025. This meeting offered an opportunity for interaction among scientists with expertise in plant pathology, microbial genetics, horticulture, and plant breeding and genetics. Here, we discuss key ideas arising from discussions at the meeting and highlight advances in fire blight research including topics such as host-pathogen interactions, particularly work on the type III secretion system and biofilm formation, E. amylovora infection biology, host resistance and breeding strategies for fire blight resistance in apple and pear, fire blight disease management from global to farm scale, biocontrols, and the linkage of horticultural management with fire blight management. Finally, we provide guidance for future research as we look for both incremental and transformational gains in understanding the E. amylovora -fire blight pathosystem that can lead to significant advances moving towards successful, sustainable disease management.