Plant Pathology Journal最新文献

Fusarium oxysporum f. sp. lycopersici (Fol) is a soilborne pathogen that causes vascular wilt in tomatoes, severely affecting yield and quality. Grafting susceptible scions onto resistant rootstocks is a promising control strategy. This study evaluated four resistant tomato accessions (LE314, LE472, LE482, and LE501) for their ability to suppress Fol translocation and support scion performance. PCR analysis showed that all resistant accessions restricted Fol movement beyond the roots, with no detection in shoot tissues, indicating effective containment of the pathogen. Gene expression profiling revealed distinct temporal and accession-specific responses of LRR, WRKY41, and PR-1 genes. In field trials, heterografted tomatoes remained symptomless across planting years, while self-grafted plants exhibited severe wilt symptoms. All grafted combinations achieved 100% success without signs of incompatibility. Growth parameters (plant height, branch number, and canopy diameter), fruit size, and yield did not differ significantly between self- and heterografted plants. Importantly, fruit quality assessment indicated that specific traits, particularly total soluble solids and fruit firmness, were influenced by scion-rootstock interactions, while fruit pH and color attributes (L*, a*, b*) remained stable across grafted treatments. These results confirm that resistant rootstocks can prevent Fol infection and maintain agronomic performance, supporting intraspecific grafting as an effective and sustainable approach for managing Fusarium wilt in tomato production.

Plant pathogenic fungi modulate host immunity by secreting nuclear effectors that interact with host nucleic acids and proteins within the host nucleus. Nuclear effectors are widely known to possess a nuclear localization sequence (NLS) that allows them to enter the host nucleus through either the classical importin α-mediated or non-classical pathways. However, the conserved motif in NLS and the mechanism behind successful nuclear trafficking of fungal nuclear effectors remain largely unexplored. MoHTRs, the nuclear effectors of Magnaporthe oryzae, reprogram the transcription of host immunity-associated genes. Recent research has demonstrated that MoHTR1 requires a classical NLS for importin α-mediated entry into the host nucleus and towards the pathogenicity of M. oryzae. However, the NLS of other fungal nuclear effectors, such as MoHTR2, needs further investigation. In this study, we report that MoHTR2 does not interact with rice importin αs or βs. By performing serial truncation and site-directed mutagenesis, we identified 53HH54 as the core NLS motif essential for the nuclear localization of MoHTR2. We also found that the double histidine in MGG_13063, a nuclear effector candidate of M. oryzae, is involved in its nuclear localization. Deletion of the MoHTR2 core NLS reduced the invasive hyphal growth and lesion formation by M. oryzae. These findings enhance our understanding of the molecular mechanisms underlying the nuclear localization of fungal nuclear effectors and their roles in pathogenicity, contributing to a broader understanding of host-pathogen interactions.

Bacterial wilt caused by Ralstonia pseudosolanacearum is a destructive disease with a broad host range and global impact. To explore eco-friendly biocontrol strategies for bacterial wilt, we screened Pseudomonas strains that produce volatile organic compounds (VOCs) with antibacterial activity against R. pseudosolanacearum and potential biocontrol effects on tomato bacterial wilt. We evaluated antibacterial activity of VOCs produced by bacterial strains using on I-plate, and conducted plant assays against of bacterial wilt tomato plant. Two strains, KF32 and KF45, were identified as Pseudomonas koreensis, and P. fitomaticsae, respectively. Their VOCs significantly inhibited R. pseudosolanacearum growth in vitro and reduced disease incidence in tomato plants. Transcriptomic analysis was performed on R. pseudosolanacearum exposed to VOCs from strains KF32 and KF45. RNA sequencing revealed that VOCs from KF32 and KF45 downregulated genes related to cell motility and xenobiotic degradation of the pathogen. We analyzed VOCs produced by strains KF32 and KF45 using gas chromatography-mass spectrometry. Among the identified VOCs, 2-decanone which was produced by strain KF32 significantly inhibited the growth of R. pseudosolanacearum and reduced tomato bacterial wilt symptoms. This study highlights the potential of VOC-producing Pseudomonas strains KF32 and KF45 as biocontrol agents and contributing to the development of long-term strategies for managing bacterial wilt in tomato. Furthermore, understanding VOC-mediated interactions provides valuable insights for developing improved strategies to manage plant pathogenic bacteria.

Dimethyl sulfoxide (DMSO) is widely recognized for its versatile solvent properties, and for its role as a cryoprotectant in the preservation of cell and microorganism. Despite its extensive use across various fields, its impact on plant pathogens has received comparatively less attention in existing literature. This study focuses on investigating the effects of DMSO on Fusarium graminearum, a fungal pathogen that affects grains, through both bioinformatic and biological experiments. Our findings demonstrate that, although DMSO induces mycotoxin production in F. graminearum in vitro, it significantly reduces production and maturation of perithecia and pigmentation. Additionally, DMSO supplementation inhibits mycelial growth and conidial germination, potentially contributing to reduced pathogenicity on wheat coleoptiles. These results highlight DMSO's potential influence on plant pathogenic fungi beyond F. graminearum and may provide valuable insights for future research.

Phytopathogen caused loss of global crop production of 16% and up to 25% in developing countries. Among them, fungi accounted for the highest ratio value with 42%, which direct reduced crop yield and quality. Nanotechnology can be applied to crop protection to build sustainable agricultural production. Polymers (gum, mucilage, chitosan) are naturally derived, readily available, inexpensive, convertible, and biodegradable, which could be combined with nanotechnology to enhance their properties and benefit. In this review, ionic gelation is more popular than nanoprecipitation, emulsion, γ-rays irradiation, and chemical reduction methods in preparing nanocomposites-based polymers in the management of fungal diseases in crop production. The chitosan was often dominated among the polymers. Moreover, the chitosan can be applied as chitosan nanoparticles or combined with an active ingredient (saponin, copper, silver, zinc, titanium dioxide, ethanolic blueberry extract, methanol of nanche extract, Mentha longifolia extract, Cymbopogon martinii essential oil, Harpin, salicylic acid, Thiamine, hexaconazole, dazomet, hexaconazole-dazomet) to enhance their efficacy in managing plant fungal disease. The fungicide, mental, and plant extracts are often loaded into the chitosan matrix to enhance antifungal and/or physical barrier properties. While phytohormones, vitamins, and mental are often used to stimulate plant disease resistance. And chitosan can be used as an adjuvant in metal/oxide mixture. In recent years, other polymers including polyethylene glycol, nanoliposomes, and poly(L-lactide) have been shown remarkable capabilities including resisting water washing and acting as a membrane filter with antifungal properties. These results show that the nanocomposites based-polymer has the ability to effectively manage plant diseases.

Colletotrichum and Fusarium are globally important plant-pathogenic fungi that cause serious diseases in chili pepper and other crops, leading to substantial yield losses due to their broad host range, environmental persistence, and the limited effectiveness of chemical control, thereby highlighting the need for sustainable alternatives such as biological control. We investigate the biological control and plant growth-promoting potential of Burkholderia vietnamiensis FBCC-B8049, isolated from freshwater environments. The strain exhibited significant antifungal activity against Colletotrichum gloeosporioides, Colletotrichum acutatum, and Fusarium oxysporum in dual-culture assays, with stronger effects against Colletotrichum species. The inhibition was likely due to direct antagonism and volatile organic compounds (VOCs) produced by FBCC-B8049, which were particularly effective against Colletotrichum species. Additionally, FBCC-B8049 demonstrated plant growth-promoting activities including siderophore production for iron acqusition, phosphate solubilization for enhanced nutrient availability, and indole-3-acetic acid synthesis to promote root development. These combined activities enhance nutrient availability and promote seed germination and seedling growth in chili pepper. Ex vivo assays further revealed the effectiveness of FBCC-B8049 in suppressing anthracnose disease on pepper fruits through both direct application and bacterial VOCs emission. Phylogenetic analysis of 16S rRNA and recA gene sequences positioned FBCC-B8049 closely to Burkholderia vietnamiensis, a known plant growth-promoting rhizobacterium. These findings highlight FBCC-B8049 as a promising candidate for sustainable agricultural applications.

Fusarium head blight (FHB) is an important disease reducing yield and quality of wheat and barley. To study changes in fungicide efficacy over time, 161 FHB isolates (F. asiaticum and F. graminearum) were obtained from infected wheat and barley in the Jeolla provinces of the Republic of Korea from 2010-2013 and 2020-2023. Over 10 years, FHB fungi developed resistance to demethylation inhibitors (DMIs), methyl benzimidazole carbamates (MBCs), and phthalimides, with few exceptions. Also, no significant resistance against succinate dehydrogenase inhibitors (SDHI) and quinoneoutside inhibitors (QoI) was observed, but sensitivity to phenylpyrrole (PP) increased. Mycotoxin production by four representative isolates of both species indicated that higher doses of DMI, DMI + DMI, MBC, MBC + DMI, and PP controlled trichothecenes, whereas zearalenone was controlled only by SDHI. QoI, QoI + DMI, and phthalimide did not control mycotoxin production in either species. Despite resistance development, DMI, MBC, and PP can still be used to control FHB and mycotoxins in wheat and barley in Korea with close monitoring of resistance.

The rhizosphere microbiome of Panax ginseng plays a crucial role in promoting plant growth, enhancing stress resilience, and facilitating the biosynthesis of pharmacologically significant ginsenosides. However, continuous monocropping disrupts the microbial community balance, leading to soil degradation, the proliferation of soilborne pathogens, and decreased crop productivity. Advanced multi-omics technologies, such as metagenomics and metabolomics, have provided valuable insights into the structure and function of the ginseng rhizosphere microbiome. These studies highlight its potential for nutrient mobilization, disease suppression, and stress mitigation. Root exudates, including phenolic acids and ginsenosides, influence microbial composition; however, they may also exacerbate soil imbalances by promoting pathogenic fungi. Conversely, beneficial microbes, such as phosphate-solubilizing bacteria and siderophore-producing strains, enhance nutrient availability, mitigate heavy metal toxicity, and suppress pathogens through bioactive metabolites. This review emphasizes the functional roles of the ginseng rhizosphere microbiome and highlights knowledge gaps in leveraging microbial interactions for sustainable cultivation. A more comprehensive understanding of plant-microbe interactions, coupled with the integration of microbiome-driven strategies, can enhance ginseng productivity, boost bioactive compound yields, and support environmentally sustainable agricultural practices. These findings provide a foundation for advancing microbiome research and addressing challenges in ginseng cultivation.

Soil-borne pathogenic fungi cause substantial economic losses worldwide by infecting the underground parts of plants. In fruit trees, infections are especially damaging, as they often result in the death of the entire plant. Therefore, early detection is essential for effective disease management caused by soil-borne pathogens. In this study, we designed and validated real-time PCR primers targeting eight soil-borne and apple tree-associated phytopathogenic fungi. Each primer set successfully detected 20 ng of target genomic DNA (gDNA) within 25 cycles, while the same amount of non-target gDNA mixture was detected only after 35 cycles of amplification. Moreover, target DNA amplification remained unaffected in the presence of mixed non-target gDNA background, confirming the high specificity of the primers. Sensitivity test showed that 1 fg of plasmid DNA, corresponding to about 290 copies, was detectable around 30 cycles with all primer sets. These primers support accurate pathogen detection and early diagnosis in various environmental samples.

Disease dynamics are significantly influenced by insect vectors through their interactions with viruses and host plants. The objective of this study is to understand how increased temperatures affect virus transmission, providing insights critical for developing climate-resilient pest and disease management strategies. We investigated the effects of temperature on the survival and growth of Myzus persicae (Sulzer) (Hemiptera: Aphididae), a key vector of the cucumber mosaic virus (CMV). Experiments were conducted to assess aphid survival, reproduction, and intrinsic rate of increase on healthy and CMV-infected Nicotiana tabacum plants at 25℃ and 30℃. It was observed that higher temperatures did not negatively affect aphid survival. CMV transmission assay was performed by allowing aphids to acquire and inoculate the virus under varied temperature combinations, while the aphid feeding behavior was monitored at different temperatures. The transmission efficiency was markedly reduced at 30℃ compared to 25℃, regardless of variations in temperature during virus acquisition and inoculation. Analysis of probing behavior revealed that aphids' probing behavior differed at 30℃, likely contributing to reduced transmission efficiency at higher temperatures. These findings demonstrate the intricate interplay between temperature, vector behavior, and virus transmission. Together, this study emphasizes the importance of incorporating environmental temperature dynamics into the development of sustainable and climate-resilient strategies for managing vector-borne diseases in agriculture.