The filamentous fungus Elsinoë arachidis is a major foliar pathogen responsible for peanut scab, which is a significant disease affecting commercial peanut cultivation. Elsinochrome (ESC), produced by numerous phytopathogenic Elsinoë species, is a non-host-selective polyketide phytotoxin with strong photosensitive activity and plays a crucial role in pathogenesis on host plants. In E. arachidis, a dual-domain enzyme encoded by the gene ESCB3, containing both O-methyltransferase and a FAD-dependent monooxygenase domain, has been identified. To elucidate the role of ESCB3, the biological function, expression pattern of the ESC biosynthesis gene cluster, and associated metabolomics analyses were investigated in the present study. An ESCB3 deletion mutant (ΔESCB3) was created by targeted gene disruption. Notably, ESC production was completely blocked in the ΔESCB3 mutant, and the expression of ESC biosynthetic genes, except for the polyketide synthase gene ESCB1, was significantly downregulated. Additionally, the ΔESCB3 exhibited heightened sensitivity to multiple stress tolerance compared with the wild type, especially oxidative stress/H2O2, highlighting the crucial role of ESCB3 in growth, development, and ESC biosynthesis in E. arachidis. Pathogenicity assays revealed a significant reduction in the pathogenicity of the ΔESCB3 mutant, suggesting a possible correlation with the suppressed biosynthesis of ESC. Metabolomic analyses further confirmed that ESCB3 is indispensable for the ESC biosynthetic process and acts as a key regulatory factor. Collectively, the results of this study provide significant insights into the molecular mechanisms governing ESCB3-mediated virulence and ESC production in E. arachidis, offering potential targets for disease control strategies in peanut scab. [Formula: see text] Copyright © 2026 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Schisandra chinensis (Turcz.) Baill is a traditional Chinese herbal medicine with extremely high medicinal value. However, the leaf blight caused by Alternaria tenuissima severely affects the yield and quality of S. chinensis, making it one of the most significant diseases in its cultivation. Biological control is regarded as a highly efficient, ecologically safe and sustainable strategy. In this study, a biocontrol isolate Bac302 with significant inhibitory effect on A. tenuissima was screened in the rhizosphere soil of S. chinensis, and its inhibitory rate reached 81.78%. The screened biocontrol isolate Bac302 was identified as Bacillus velezensis by morphological observation and joint phylogenetic analysis based on 16S rRNA and gyrB gene sequences. The detached leaf protection test and field experiments showed that the isolate Bac302 had a control effect with 92.4% and 71.6% respectively in the control of leaf blight on S. chinensis, demonstrating great potential for field application. Additionally, B. velezensis Bac302 exhibits both a direct and indirect biocontrol mechanisms. The direct mechanism included isolate Bac302 significantly impacted the normal development of the hyphal and spores of A. tenuissima. Meanwhile, Bac302 was found to significantly inhibit the growth and pathogenicity of A. tenuissima by destroying the integrity of its cell membranes. The indirect mechanism involved inducing systemic disease resistance in the plants, significantly enhancing the activities of defense-related enzymes. The results showed that B. velezensis Bac302 could be an effective biocontrol agent for managing leaf blight on S. chinensis, which has a broad application prospect.

Peanut scab, caused by Elsinoe arachidis, is a major disease in peanut-growing regions of China. To clarify the phenotypic characteristics and toxigenic divergence of the pathogen, 70 strains from major peanut-growing regions were subjected to morphological characterization, phylogenetic analysis, elsinochrome (ESC) quantification, and phytotoxicity assessment. Based on colony color, the strains were divided into five morphological groups (Group A-E), with the dark red pigmented Group D being dominant (50%). Growth rates varied among strains, with the coefficient of variation within each morphological group ranging from 10% to 25%, but no distinct pattern was observed across groups. All isolates were identified as E. arachidis and resolved within a species-level clade based on ITS and TEF1-alpha phylogenetic analyses. ESC quantification revealed a significant correlation between colony color and toxin accumulation, with coral red and dark red strains (Groups A and D) accumulating higher ESC levels. Phytotoxicity assays demonstrated a significant positive correlation between lesion area and ESC accumulation (r = 0.921, P < 0.01). This study systematically characterized the intraspecific phenotypic differentiation of E. arachidis in China for the first time, establishing a correlation between pathogenic intensity, colony color, and ESC synthesis capacity. Furthermore, colony color was proposed as a visual phenotypic indicator for the rapid identification of highly virulent strains, and ESC accumulation was identified as the key metabolic process underlying phytotoxicity differentiation. These findings enhanced the understanding of population differentiation in E. arachidis and provide a theoretical basis for elucidating disease outbreak mechanisms and developing targeted control strategies.

Mycocentrospora acerina is responsible for inducing severe leaf blight on Asarum heterotropoides. However, its poor sporulation under standard culture conditions significantly limits research on pathogenicity and disease management. This study aimed to develop an efficient high-yield and reproducible sporulation protocol by optimizing cultural conditions and nutritional factors. The results indicate that near-ultraviolet (near-UV) light serves as a critical inducer of sporulation for M. acerina. In contrast to the standard culture on potato dextrose agar medium at 20°C, where the pathogen fails to produce conidia, exposure to near-UV light effectively stimulated sporulation, yielding a relatively robust production of 1.37 × 103 conidia/ml after 21 days. Furthermore, V8 medium provided the optimal substrate conditions, yielding 4.56 × 103 conidia/ml under the same cultural conditions after 14 days, a value significantly higher than those on other tested media. The optimized protocol (near-UV light, V8 medium, 20°C, pH 7.0, 1 g/liter of glucose, and 1 g/liter of potassium nitrate) achieved a conidial yield of 1.0 × 105 conidia/ml after 14 days. The conidia produced using the optimized sporulation protocol were morphologically identical to wild-type conidia and exhibited similar germination and pathogenicity. This established sporulation protocol provides vital materials for further studies, including infection, pathogenicity mechanism, and host-pathogen interaction dynamics, and lays a theoretical basis for developing targeted strategies to control Asarum leaf blight.

Leaf blight on Schisandra chinensis caused by Alternaria tenuissima severely impacts its yield and quality. Plant-derived bioactive compounds serve as a key component of biological control systems, offering promising solutions for environmentally friendly disease management through their natural and sustainable properties. This study systematically investigated the antifungal activity of magnolol, a key bioactive compound from Magnoliae Officinalis Cortex (“Houpo” in Chinese), against A. tenuissima and elucidated its underlying mechanisms. In vitro assays demonstrated that magnolol dose-dependently inhibited mycelial growth, achieving a 93.4

Panax ginseng C. A. Meyer is a high-value medicinal crop increasingly cultivated in understory systems for sustainable production. However, its yield and economic return are severely constrained by ginseng rust rot, caused by Ilyonectria robusta. To address this constraint, we elucidated how canopy tree species regulate disease incidence via distinct allelopathic compounds released from decomposing needle litter. Using UHPLC-Orbitrap-HRMS-based untargeted metabolomics, we identified vanillic acid as the phenolic acid displaying the most significant differential abundance between decomposing red pine (RP) and Japanese larch (JL) needles. Targeted quantification confirmed its presence in RP forest soil at an ecologically relevant concentration of 0.18 μmol·L⁻¹ . Bioassays revealed a concentration-dependent biphasic effect of vanillic acid on Ilyonectria robusta. Specifically, a low concentration (0.1 μmol·L⁻¹) stimulated mycelial growth and increased spore germination rate to 92.5%. In contrast, concentrations ≥ 1.0 μmol·L⁻¹ were inhibitory, with mycelial growth suppressed by 34.7% at 5.0 μmol·L⁻¹. Concurrently, vanillic acid at 0.1 μmol·L⁻¹ suppressed radicle elongation of ginseng. These findings elucidate a biochemical mechanism for the elevated disease incidence under RP canopies and provide a direct scientific rationale for selecting JL over RP as canopy trees in understory ginseng systems. This supports the development of ecology-based management strategies to enhance sustainable production.

Nanocarrier-mediated delivery of double-stranded RNA (dsRNA) is a promising strategy for plant disease control. Our previous study has shown that the self-assembled ε-poly-l-lysine/carboxymethyl chitosan (ε-PL@CMCS) nanocarrier significantly improves the efficiency of RNA interference (RNAi) against Rhizoctonia solani AG3 TB. However, the molecular mechanisms underlying this enhancement and the potential ecological impacts on phyllosphere microbial communities remain unclear. In this study, we confirmed that dsRsGH1@ε-PL@CMCS had no adverse effects on the growth and development of plants. Transcriptome analysis revealed that DEGs were significantly enriched in ‘SNARE interactions in vesicular transport’ pathway. Among them, dsRsGH1@ε-PL@CMCS specifically upregulate the vesicle transport protein SEC22 in Nicotiana tabacum. Surface plasmon resonance (SPR) assay demonstrated that the dsRsGH1@ε-PL@CMCS binds to SEC22 protein with 7.6-fold higher affinity than that of the naked dsRsGH1. Silencing SEC22 in the dsRsGH1@ε-PL@CMCS treatment reduced the silencing efficiency of RsGH1 from 53.3% to 39%, confirming its essential role. Concurrently, high-throughput sequencing revealed that SIGS treatments did not disrupt bacterial community structure but increased fungal diversity and suppressed the pathogen, while enriching beneficial fungi such as Tulasnella. Our findings elucidate a molecular link between nano-bioprotectant dsRsGH1@ε-PL@CMCS-enhanced RNAi and host vesicle transport, while confirming the biocompatible and microbiome-modulating potential. This provides a dual perspective for developing efficient and sustainable RNAi-based strategies for protecting plants.

Rhizoctonia solani Kühn is an important fungal pathogen that causes serious crop yield losses worldwide. The application of nanoscale strategies based on RNA interference (RNAi) represents an environmentally friendly and efficient approach for plant disease control. In this study, R. solani glycosyl hydrolase family 1 (RsGH1), which functions as a cell wall degrading enzyme (CWDE), and was screened as a prospective RNAi target gene for managing R. solani AG3 TB. Additionally, a novel nanosystem for loading and stabilization of double-stranded RNA (dsRNA) was developed. When the mass ratio of ε-poly-L-lysine (ε-PL) to carboxymethyl chitosan (CMCS) is 1:1, ε-PL can spontaneously conjugate with CMCS to form nanoscale spherical particles by electrostatic interaction, hydrogen bonding and Van der Waals forces. Compared with ε-PL alone, the introduction of CMCS resulted in more regular and uniform nanoparticles. dsRsGH1 spontaneously binds with ε-PL@CMCS, which is referred to as dsRsGH1@ε-PL@CMCS. ε-PL@CMCS protected dsRNA from RNase A degradation effectively. The combination of dsRsGH1 with ε-PL@CMCS remarkably improved the deposition and adhesion of dsRsGH1 droplets on Nicotiana tabacum (N. tabacum) leaves. The application of ε-PL@CMCS improved the RNAi efficiency of dsRsGH1 and prolonged its protective duration on crops. dsRsGH1 derived from R. solani AG3 TB also exhibited broad-spectrum activity against R. solani AG1-IA in rice and maize plants. In this study, a self-assembled multi-component nano-fungicide was designed based on dsRNA and nanocarriers. This work proposes an eco-friendly strategy to manage R. solani.

Tobacco wildfire disease, caused by Pseudomonas syringae pv. tabaci, severely reduces tobacco yield and quality, yet the host response remains poorly understood. Here, a comprehensive transcriptomic analysis of Nicotiana tabacum infected with P. syringae pv. tabaci YH3 was performed at four developmental stages. Among the top 12 KEGG pathway enrichment analysis, the differentially expressed genes (DEGs) involved in the MAPK signaling pathway-plant, carbon fixation in photosynthetic organisms, plant hormone signal transduction, ribosome, plant-pathogen interaction, and RNA degradation were significantly enriched at three time points. Notably, among the identified DEGs, leucine-rich repeat receptor-like protein kinase (LRR-RLK), indole-3-acetic acid (IAA), and cysteine synthase (CS) emerged as potential key regulatory genes involved in the tobacco response to P. syringae pv. tabaci YH3 infection. These findings provide a molecular framework for understanding the transcriptomic response of N. tabacum to P. syringae pv. tabaci infection and offer promising candidate genes for investigations into the interaction mechanisms between this pathogen and its host plants.

Aconitum kusnezoffii is a perennial herbaceous medicinal plant of the family Ranunculaceae, with unique medicinal value. Damping off is one of the most important seedling diseases affecting A. kusnezoffii, occurring widely and often causing large-scale seedling death in the field. To clarify the species of the pathogen causing damping off in A. kusnezoffii and to formulate an effective control strategy, this study conducted pathogen identification, research on biological characteristics, and evaluation of fungicide inhibitory activity. Through morphological characteristics, cultural traits, and phylogenetic tree analysis, the pathogen causing damping off in A. kusnezoffii was identified as Rhizoctonia solani, belonging to the AG5 anastomosis group. The optimal temperature for mycelial growth of the pathogen was 25-30 ℃, with OA medium as the most suitable medium, pH 8 as the optimal pH, and sucrose and yeast as the best carbon and nitrogen sources, respectively. The effect of light on mycelial growth was not significant. In evaluating the inhibitory activity of 45 chemical fungicides, including 30% hymexazol, and 4 biogenic fungicides, including 0.3% eugenol, it was found that 30% thifluzamide and 50% fludioxonil had significantly better inhibitory effects on R. solani than other tested agents, with EC_(50) values of 0.129 6,0.220 6 μg·mL~(-1), respectively. Among the biogenic fungicides, 0.3% eugenol also showed an ideal inhibitory effect on the pathogen, with an EC_(50) of 1.668 9 μg·mL~(-1). To prevent the development of resistance in the pathogen and to reduce the use of chemical fungicides, it is recommended that the three fungicides above be used in rotation during production. These findings provide a theoretical basis for the accurate diagnosis and effective control strategy for R. solani causing damping off in A. kusnezoffii.

Botrytis cinerea can cause gray mold in more than 200 kinds of fruits and vegetables. Its rapidly developed resistance to pyrimethanil has become a key problem that restrict the application of pyrimethanil. At present, the research on the resistance mechanism of pyrimethanil remains insufficiently explored. In this study, we compared the mutation and expression level of the CGS, the target gene of pyrimethanil suggested by Fungicide Resistance Action Committee (FRAC), and the mitochondrial gene mutation related to pyrimethanil resistance. The results showed that the pyrimethanil resistance has nothing to do with the mutation and expression of the CGS gene of B. cinerea, but it is related to the E407K point mutation of mitochondrial gene Bcmdl1. Combined transcriptome analysis and exogenous amino acid reversal tests revealed that pyrimethanil resistance is associated with non-target enzyme genes, including 8 key genes involved in methionine synthesis (from serine/homoserine to S-adenosylmethionine) and 21 candidates linked to metabolic resistance. Significant changes in expression of several genes were observed in sensitive strains. Through the measurement of enzyme activities, the following enzymes were preliminarily associated with pyrimethanil resistance in B.cinerea: O-acetylserine hydrogenolysis synthase (OAS), methionine synthase (MS) (involved in methionine biosynthesis), and metabolic detoxification enzymes P450s and GSTs. The research outcomes are intended to clarify the multi-level resistance mechanisms of B. cinerea to pyrimethanil. This will offer a theoretical basis for effectively preventing or delaying fungicide resistance and implementing resistance management strategies.

Rainfall, particularly in continental climates with a monsoonal tendency, impacts the microbial niches during the growth of mountain cultivated ginseng. With shifts in the microbial community, diseases in ginseng cultivated and protected under rain shelter conditions may ultimately be altered. Such cultivation may influence microflora dynamics through variations in meteorological parameters; however, this is not yet clear. The present study found that rain shelter cultivation affected the distribution of fungal communities within mountain cultivated ginseng. This led to an improved community structure in the ginseng rhizosphere, characterized by the proliferation of antagonistic fungi and a reduction in pathogenic fungi. A correlation analysis of meteorological factors found that soil temperature and humidity were the primary meteorological factors affecting mountain cultivated ginseng. It is evident that rain shelter cultivation regulated the microecological environment of the mountain cultivated ginseng’s rhizosphere and resulted in positive outcomes. A disease investigation supported this finding. The incidence of ginseng root diseases, such as rust and root rot, was reduced by 5–6%. The incidence of ginseng leaf diseases, including gray mold and black spot, was reduced by 5–10%. This research provides evidence to address the dynamics of microbial ecology under rain shelter cultivation and its benefits for sustainable mountain cultivated ginseng management.

Light regulation is critical in fungal growth, development, morphogenesis, secondary metabolism, and the biological clock. The fungus Elsinoë arachidis is known to produce the mycotoxin Elsinochrome (ESC), a key factor contributing to its pathogenicity, under light conditions. Although previous studies have predominantly focused on the light-induced production of ESC and its biosynthetic pathways, the detailed mechanisms underlying this process remain largely unexplored. This study explores the influence of light on ESC production and gene expression in E. arachidis. Under white light exposure for 28 days, the ESC yield was observed to reach 33.22 nmol/plug. Through transcriptome analysis, 5925 genes were identified as differentially expressed between dark and white light conditions, highlighting the significant impact of light on gene expression. Bioinformatics identified specific light-regulated genes, including eight photoreceptor genes, five global regulatory factors, and a cluster of 12 genes directly involved in the ESC biosynthesis, with expression trends confirmed by RT-qPCR. In conclusion, the study reveals the substantial alteration in gene expression associated with ESC biosynthesis under white light and identifies potential candidates for in-depth functional analysis. These findings advance understanding of ESC biosynthesis regulation and suggest new strategies for fungal pathogenicity control.

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Accurate larval identification is a prerequisite for integrated pest management, but remains a long-term difficulty in insect taxonomy. Previous descriptions are mainly focused on the most disruptive final instar larvae. However, earlier instars especially cross-instar larval morphological comparisons were rarely delivered hitherto. Polyphylla laticollis and Maladera orientalis are pests that damage peanut crops at various developmental stages. The first instar larvae of P. laticollis and the mature larvae of M. orientalis attack peanuts simultaneously and cause different types of damage. In this study, we compared the life histories and larval morphologies through field investigations and scanning electron microscopy (SEM) observations. These cross-instar white grubs are similar in sizes, but exhibit morphological differences on their mouthparts, thoracic legs, anal slits, and rasters. This study presents a novel approach to larval identification, with a goal of generating new insights into integrated pest control practices on white grubs.

BACKGROUND:Peanut (Arachis hypogaea), a vital oil and food crop globally, is susceptible to web blotch which is a significant foliar disease caused by Phoma arachidicola Marasas Pauer&Boerema leading to substantial yield losses in peanut production. Calcium treatment has been found to enhance plant resistance against pathogens.RESULTS:This study investigates the impact of exogenous calcium on peanut resistance to web blotch and explores its mechanisms. Greenhouse experiments revealed that exogenous calcium treatment effectively enhanced resistance to peanut web blotch. Specifically, amino acid calcium and sugar alcohol calcium solutions demonstrated the best induced resistance effects, achieving reduction rates of 61.54% and 60% in Baisha1016, and 53.94% and 50% in Luhua11, respectively. All exogenous calcium treatments reduced malondialdehyde (MDA) and relative electrical conductivity (REC) levels in peanut leaves, mitigating pathogen-induced cell membrane damage. Exogenous calcium supplementation led to elevated hydrogen peroxide (H2O2) content and superoxide anion (O2∙-) production in peanut leaves, facilitating the accumulation of reactive oxygen species (ROS) crucial for plant defense responses. Amino acid calcium and sugar alcohol calcium treatments significantly boosted activities of peroxidase (POD), superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) in peanut leaves. Activation of these antioxidant enzymes effectively scavenged excess ROS, maintaining ROS balance and mitigating cellular damage.CONCLUSIONS:In summary, exogenous calcium treatment triggered ROS production, which was subsequently eliminated by the activation of antioxidant enzymes, thereby reducing cell membrane damage and inducing defense responses against peanut web blotch.

新农科建设对高等农林院校人才培养提出了新要求.沈阳农业大学植物保护实验教学中心自成立以来,在实验室建设与管理方面不断探索与创新,在新型人才培养中发挥了重要作用.该文以沈阳农业大学植物保护实验教学中心为例,阐述了在新农科背景下,中心在管理机制、责任体系、制度建设、实验室建设、人员队伍建设、运行体系等方面的理论基础和实践经验,以及新的工作思路和方法,对同类实验室建设与管理工作具有借鉴意义.

为提高药用植物病理学实验课程教学水平、创新教育教学方法、实现实验教学信息化,沈阳农业大学植物保护实验教学中心将数码显微互动系统引入实验教学过程中,不断探索与实践药用植物病理学实验教学新模式.本文介绍了药用植物病理学实验课程的基本情况,分析了传统实验教学现状与不足,探讨了数码显微互动系统的优势及其应用于该课程的模式构建,并分享了取得的教学效果,以期为数码显微互动与农林院校实验教学融合的教育教学方法研究提供参考借鉴.

光是真菌感知和适应环境的重要信息载体,调控多种生理生化过程.痂囊腔菌素(Elsinochromes,ESC)是花生疮痂病菌重要的毒力因子,蓝光对其具有正调控作用,为了进一步揭示光调控ESC机制,开展了花生疮痂病菌蓝光受体基因EaWC 1克隆、生物信息学分析和表达模式研究.结果表明,蓝光受体基因EaWC 1全长为3261bp,具有一个完整的开放阅读框,编码长度为1086个氨基酸的蛋白质,相对分子质量11.95 kD,理论等电点为8.81,具有核定位信号,为稳定亲水性蛋白.qPCR定量分析表明,EaWC 1基因表达受到蓝光诱导,其表达模式与ESC毒素含量呈显著正相关.研究结果对于阐明花生疮痂病菌蓝光受体生物功能,揭示ESC毒素生物合成光调控机制和调控网络奠定了理论基础.

Panax ginseng C. A. Meyer is one of the most important medicinal herbs in China. It is known for its high medicinal value and economic value. The ginseng root rust rot (RRR) has always been one of the important diseases troubling the ginseng industry. The yield reduction rate of RRR is ~30%. To understand why the Cylindrocarpon species bring about the ginseng RRR in Northeastern China, this study isolates 45 strains from samples collected in Liaoning, Jilin, and Heilongjiang provinces. The rDNA-internal transcribed spacer (ITS) sequence was analyzed to identify the pathogenic species. The morphological characteristics of colonies and conidia of each strain on potato dextrose agar (PDA) medium were observed, and the pathogenicity difference between different pathogenic species was analyzed by pricking method and determining the cell wall degrading enzyme activity. The BLAST alignment analysis shows that the homology of rDNA-ITS between 45 strains and Cylindrocarpon is more than 99%, among which 28 are identified as Cylindrocarpon destructans, three are identified as C. destructans var. destructans, and 14 are identified as Ilyonectria robusta. The colony diameters of all 45 isolated range from 4.21 ± 0.16a to 7.78 ± 0.25c cm after several days of incubation. Among all the species, I. robusta has the fastest growth rate, and C. destructans var. destructans has the slowest growth rate. Pathogenicity test results show that the pathogenicity of C. destructans var. destructans is the strongest, followed by C. destructans. I. robusta has relatively weak pathogenicity.