Author: slquinlan

Mol Microbiol. 2026 Nov 6. doi: 10.1111/mmi.70130. Online ahead of print.

ABSTRACT

Vascular streak dieback (VSD) has emerged as a major threat to woody ornamental production in the United States (U.S.), currently affecting at least 50 tree and shrub species across 25 botanical genera in at least twelve U.S. states. The putative causal agent, here termed the VSD-associated Ceratobasidiaceae lineage (Csp), presents diagnostic challenges due to its fastidious growth requirements and vascular colonization pattern. Here, we integrate genomics-guided marker discovery with multi-platform genome-anchored tools (SSR, TaqMan qPCR, and LAMP that target unique genomic regions identified through comparative genomics) to deliver a field-deployable, genome-anchored toolkit for detection and genotyping of Csp across nurseries and landscapes. We evaluated the performance of these tools using 103 samples representing DNA isolated from 64 VSD-symptomatic plants or their fungal isolates and 39 non-target Ceratobasidiaceae outgroups. Genome assembly of Illumina reads yielded ten informative microsatellite markers with an overall amplification success rate of 95.8% (91.7%-100.0% across Csp samples). These markers demonstrated strong performance in distinguishing the Csp samples from the outgroups. Among the three TaqMan probes developed, VSD048 exhibited superior performance with 100% detection across Csp samples, characterized by cycle threshold (C_T) values of 26.8 ± 4.2, and no cross-reactivity with C. theobromae or other Ceratobasidiaceae species. A multi-laboratory ring trial confirmed the reproducibility of the VSD048 TaqMan assay across various testing platforms. The loop-mediated isothermal amplification (LAMP) assay targeting the Csp-unique region achieved a sensitivity of 0.82 [95% CI 0.68-0.968] and specificity of 1.00 [95% CI 1.00-1.00], with a practical detection threshold of approximately 25 copies of the target region. Our molecular survey of the disease revealed a surprisingly broad host range beyond Cercis canadensis (Eastern redbud), encompassing eight additional genera, and confirmed its geographical distribution across the eastern and midwestern U.S. These validated molecular tools provide rapid, sensitive, and specific detection methods for Csp surveillance and management. The field-applicable LAMP assay and laboratory-based TaqMan/SSR protocols offer complementary approaches for different diagnostic scenarios, thereby enabling early detection and supporting efforts to limit the spread of this emerging pathogen in nursery and landscape settings.

PMID:42992528 | DOI:10.1111/mmi.70130

Front Plant Sci. 2026 Oct 21;17:1975585. doi: 10.3389/fpls.2026.1975585. eCollection 2026.

ABSTRACT

INTRODUCTION: Parsley (Petroselinum crispum) is a productive natural source of apigenin, a medicinally valuable secondary metabolite. This study evaluated the effects of light intensity and ultraviolet (UV) exposure on free apigenin (aglycone) accumulation in the Giant of Italy parsley cultivar grown under controlled environment conditions.

METHODS: Plants were grown under light-emitting diodes (LED) with a 16-h photoperiod and daily light integrals (DLI) of 19.0, 23.8, or 28.5 mol m^-2 d^-1. After eight weeks, mature leaves from control plants were harvested for analysis. The remaining plants received supplemental UV light at 475 μ cm^-2 to serve as a stressor for inducing free apigenin biosynthesis throughout the 16-h photoperiod for 1, 2, 4, or 8 days. Free apigenin was quantified in lyophilized leaf samples with high-performance liquid chromatography-ultraviolet (HPLC-UV) detection.

RESULTS: LED light intensity did not affect free apigenin accumulation, whereas UV exposure significantly increased it. The 8-d UV treatment produced the highest free apigenin content, at 10.44 ± 1.91 mg kg^-1, compared with 1.08 ± 0.31 mg kg^-1 in the untreated control, representing an 867% increase.

DISCUSSION: These findings suggest that supplemental UV exposure may be an effective strategy for increasing free apigenin accumulation in parsley grown under controlled environmental conditions. Among the exposure durations tested, the greatest accumulation occurred after eight days of UV treatment.

PMID:42984520 | PMC:PMC13730883 | DOI:10.3389/fpls.2026.1975585

J Endocrinol. 2026 Nov 5:JOE-26-0341. doi: 10.1530/JOE-26-0341. Online ahead of print.

ABSTRACT

Plant-parasitic nematodes cause extensive crop losses that threaten global food security and create substantial economic hardship, yet strategies for their control remain limited. Although plant-parasitic nematodes have life cycles that mirror those of their free-living and animal-parasitic relatives, comparatively little is known about the signals that drive life-cycle progression. Dafachronic acids (DAs) are steroid hormones that control life cycle by activating DAF-12 nuclear receptors in Caenorhabditis elegans and animal-parasitic nematodes. To define whether an analogous pathway exists in plant-parasitic nematodes, we investigated the responsiveness of DAF-12 orthologs from six plant-parasitic nematode species to Δ7-DA, an endogenous DAF-12 ligand in C. elegans and several animal-parasitic nematodes. We find that whereas some plant-parasitic nematode receptors are activated by Δ7-DA, others are not. Structural modeling of all six ligand-binding domains, together with docking of Δ7-DA into each model, indicates that responsiveness is governed by a combinatorial ligand-recognition network surrounding the ligand carboxylate rather than by any single contact residue. We further demonstrate that egg and second-stage juvenile extracts from the soybean cyst nematode, Heterodera glycines, lack detectable DA but contain distinct lipophilic fractions that activate its DAF-12 ortholog. Together, these findings suggest that some plant-parasitic nematodes may utilize endogenous DAF-12 ligands that are structurally distinct from DA. Uncovering modulators of this pathway could lead to new strategies to combat nematode-driven crop loss.

PMID:42985882 | DOI:10.1530/JOE-26-0341

Microbiol Mol Biol Rev. 2026 Nov 4:e0016024. doi: 10.1128/mmbr.00160-24. Online ahead of print.

ABSTRACT

SUMMARYMany Sordariomycete fungi produce flask-shaped perithecia that encapsulate meiotic cells and facilitate dispersion of sexual spores. Perithecial development represents a striking example of complex multicellularity in fungi, requiring coordinated gene regulation through transcriptional, chromatin-based, and post-transcriptional mechanisms. This review summarizes recent work to dissect sexual development in several well-studied fungi: Neurospora crassa, Sordaria macrospora, Podospora anserina, and Fusarium graminearum. Studies with these fungi have uncovered interconnected regulatory mechanisms that coordinate fruiting body development. Transcription factor networks control differentiation of perithecial tissues and cell types. Chromatin regulators, such as histone chaperones, ATP-dependent chromatin remodelers, acetyltransferases, and Polycomb Repressive Complex 2, impact major developmental transitions. In addition, post-transcriptional mechanisms that operate during sexual development play critical regulatory roles. Recoding of the transcriptome by A-to-I mRNA editing is specific to perithecia and is essential for sexual development of N. crassa and F. graminearum. Finally, sex-specific genome defense pathways protect genome integrity and are essential for the completion of meiosis in some species. We summarize recent advances and highlight the remarkable regulatory complexity underlying fruiting body development in Sordariomycete fungi. In addition, we identify key open questions for future research.

PMID:42980367 | DOI:10.1128/mmbr.00160-24

Microbiol Mol Biol Rev. 2026 Nov 3:e0002726. doi: 10.1128/mmbr.00027-26. Online ahead of print.

ABSTRACT

SUMMARYFungal pathogens represent a significant threat to public health. Aspergillus fumigatus, Candida albicans, Cryptococcus neoformans, and Rhizopus delemar are the primary causative agents for aspergillosis, candidiasis, cryptococcosis, and mucormycosis. They and their closest relatives are responsible for more than 94% of fungal disease-related deaths. All four fungal diseases may lead to meningitis, with mortality rates approaching 99%. They are among the WHO-designated priority fungal pathogens needing new and more effective treatments. In response to this therapeutic gap, we developed DectiSomes-drug-loaded liposomes targeted to fungal cells by host-pathogen receptors. Host-pathogen receptors have many advantages over antibodies as liposome-targeting proteins, including a lack of immunogenicity. Of the pathogen receptors we tested, Dectin-1 and Dectin-2 are the most effective targeting proteins against the fungal pathogens tested. Liposomes loaded with amphotericin B and coated with one of these pathogen receptors bind specifically and strongly to the four pathogens and kill them, reducing the effective dose of amphotericin B by more than an order of magnitude over the untargeted control. DectiSomes are also more effective in murine models of fungal infection. Furthermore, we developed small, malleable versions of DectiSomes with improved drug delivery to the brain and are more effective against cryptococcal meningitis, holding promise for treating all forms of fungal meningitis. Herein, we review our progress and discuss the potential of DectiSomes as a new and effective targeted delivery system for antifungal drugs. In addition, we discuss the challenges associated with fungal diseases and the roadblocks to antifungal drug development and medical mycology research.

PMID:42975093 | DOI:10.1128/mmbr.00027-26

Hortic Res. 2026 Jun 11;13(11):uhag223. doi: 10.1093/hr/uhag223. eCollection 2026 Nov.

ABSTRACT

Whether plant life form influences the long-term persistence of polyploid lineages remains an important unresolved question in plant evolution. Previous studies have suggested that perennial herbaceous plants harbor higher proportions of neo-polyploids, yet comprehensive phylogenetic validation across paleopolyploid lineages using genomic data remains limited. The rapid accumulation of plant genome sequences, particularly from horticultural and agricultural species, provides an unprecedented opportunity to investigate the evolutionary relationships among polyploidization, plant growth form, and plant stature across seed plants. Here, we analyzed 351 seed plant genomes, including major cereals, vegetables, fruits, and their wild relatives, to investigate the long-term evolutionary associations between paleopolyploidization and plant phenotypic diversity. Phylogenetically informed comparative analyses showed that lineages experiencing more paleopolyploidization events were significantly more likely to exhibit herbaceous rather than woody growth forms. We further found that paleopolyploidization frequency was negatively associated with plant height across seed plants after accounting for phylogenetic relatedness. In addition, evolutionary rates, estimated using synonymous substitution rates (Ks), were associated with paleopolyploidization, plant growth form, and species richness. Herbaceous species exhibited higher Ks values than woody and vine species, and plant families with higher evolutionary rates tended to contain more species. Together, these findings provide a phylogenetically informed evidence that paleopolyploidization is closely associated with plant growth form, plant stature, and evolutionary rate, offering new insights into the long-term evolutionary consequences of genome duplication in seed plants.

PMID:42967069 | PMC:PMC13722872 | DOI:10.1093/hr/uhag223

Ecol Evol. 2026 Oct 30;16(11):e74574. doi: 10.1002/ece3.74574. eCollection 2026 Nov.

ABSTRACT

Understanding the spatial dynamics of genetic ancestry is essential for elucidating historical and contemporary patterns of gene flow among populations. Honey bees in the United States have a 400-year history of importation, management, and adaptation to diverse environments. Genetic diversity is a key factor for colony health and resilience. Notably, the most genetically diverse populations in the country originate from the invasive A-lineage (Africanized or ‘Killer’ honey bees). In this study, we leveraged a nationwide community-science platform to assemble an extensive genomic dataset of U.S. honey bee populations and used it to ask how this invasive lineage is spreading across the country and how its spread has impacted honey bee genetic diversity nationwide. Using RFMix, we assigned local ancestry across the genome to capture fine-scale ancestry patterns and applied TreeMix to genome-wide allele frequency data to infer directional gene flow among U.S. populations. Our analyses revealed patterns consistent with a strong northward migration, with major source populations in southern states such as Texas (TX), Arizona (AZ), and Florida (FL), and primary targets in northern states including Michigan (MI), New York (NY), and Vermont (VT). Covariance estimates indicated strong genetic connectivity, particularly from TX and AZ. Spatial visualization of migration edges highlighted key routes of A-lineage expansion. Together, these results provide the first genome-wide evidence for a nationwide spread of A-lineage ancestry in the U.S., offering insights to guide breeding strategies and predict the future dynamics of honey bee genetic diversity.

PMID:42967103 | PMC:PMC13722957 | DOI:10.1002/ece3.74574

Plant Dis. 2026 Oct 30. doi: 10.1094/PDIS-04-26-0745-RE. Online ahead of print.

ABSTRACT

Early leaf spot (ELS), caused by Passalora arachidicola, remains one of the most economically important foliar diseases of peanut (Arachis hypogaea), and resistance within the cultivated germplasm is limited. Fungicide applications are commonly used to manage this disease, but this practice increases production costs, the risk of fungicide resistance, and environmental concerns. Wild Arachis species harbor diverse resistance alleles, but their direct use in breeding is constrained by ploidy barriers. In this study, eight induced allotetraploids derived from nine wild Arachis species were produced. Along with their diploid parents, they were evaluated for ELS resistance using in vitro detached leaf bioassays. Disease resistance was quantified using multiple components, including incubation period, lesion number, sporulation, and diseased leaf area. Several allotetraploids-particularly MagDio1, MagKuhl1, MagHoeh1, and ValMicro1-exhibited significantly reduced lesion development, limited sporulation, and slower disease progression compared with cultivated controls. In all cases, induced allotetraploids displayed resistance levels equal to or greater than those of both diploid parents, indicating enhanced resistance following allotetraploidization. Notably, Arachis hoehnei and its derived allotetraploid consistently exhibited strong resistance across disease components, identifying this phylogenetically distinct species as a novel resistance source. These results demonstrate that induced allotetraploids represent peanut-compatible reservoirs of diverse ELS resistance alleles and provide practical resources for breeding programs aimed at developing cultivars with more durable and diversified resistance to early leaf spot.

PMID:42963873 | DOI:10.1094/PDIS-04-26-0745-RE

Plant Physiol. 2026 Oct 30:kiag803. doi: 10.1093/plphys/kiag803. Online ahead of print.

ABSTRACT

Soil boron deficiency is a global abiotic stress, negatively impacting on crop yield. In the dicot model species Arabidopsis thaliana, inhibition of root elongation is one of the earliest symptoms of boron deficiency. In the monocot model maize (Zea mays L.), boron deficiency-induced root defects are widely unexplored. In this study, we assessed boron deficiency-induced defects in the primary root system of maize and tested the suitability of phenylboronic acid (PBA) as boron deficiency mimic by performing phenotypic, histological, molecular, and biochemical analyses. Our analyses showed that boron deficiency and PBA resulted in similar defects in primary root elongation and lateral root density. The PBA-induced defects, however, were much stronger than those induced by boron deficiency, particularly regarding lateral root development. We provide evidence that the PBA-induced defects were caused by the boric acid moiety and show that both boron deficiency and PBA altered the levels of auxin and reactive oxygen species. Strikingly, PBA did not affect rhamnogalacturonan-II (RG-II) dimerization. Interference of boron-mediated RG-II crosslinking, however, was previously proposed to be the mode of action of PBA in planta. Our study shows that PBA is particularly suited for the molecular dissection of lateral root development in maize and suggests that PBA does not mimic known molecular boron deficiency responses.

PMID:42960663 | DOI:10.1093/plphys/kiag803

Plant Physiol Biochem. 2026 Oct 26;240:111896. doi: 10.1016/j.plaphy.2026.111896. Online ahead of print.

ABSTRACT

The soybean gene Glyma.20G085100 (Gm20P), contributing to the cqSeed protein-003 QTL, and its paralog Glyma.10G134400 (Gm10P), were edited using the CRISPR/Cas9-based genome editing reagents. Two mutants, a gm20p single mutant and a gm10p gm20p double mutant devoid of editing reagents, were identified. Additional gm10p and gm20p single mutants were isolated from F2 population of the cross between the gm10p gm20p double mutant and the wild-type Thorne. The above mutants were characterized in different growing conditions. Seed protein content of the gm10p single and the gm10p gm20p double mutant were significantly reduced relative to the gm20p single mutant and Thorne, with a concomitant increase in oil and starch content. A delayed maturity phenotype was observed in the gm20p single, the gm10p single, and gm10p gm20p double mutants under field conditions across multiple environments. Under controlled conditions in a growth chamber, prominent delayed maturity was only observed under short-day conditions, while long-day conditions induced phenotypic changes in growth in the gm10p gm20p double mutant, but slight delay in maturity. Transcriptomic analysis revealed that the gm10p gm20p double mutant exhibited repression of genes involved in light signaling, enhanced expression of JAZs in JA signaling, suppression of ABA-responsive and senescence-related genes, and elevation of genes that inhibit IAA signaling. Furthermore, the gm10p gm20p double mutant displayed higher sensitivity to salt and ABA during germination. Collectively, these results suggest that both Gm10P and Gm20P modulate light signaling and impact soybean development, maturity and seed reserve content.

PMID:42945731 | DOI:10.1016/j.plaphy.2026.111896