Search Results (633)

The plant microbiome plays a role in pathogen defense, but its role in different resistant varieties and ecological niches remains unclear. This study used 16S rRNA and ITS sequencing to investigate microbial communities and interactions in disease-resistant (PT) and susceptible (Bourbon) coffee varieties of five ecological niches: leaves, fruits, roots, rhizosphere soil, and non-rhizosphere soil. We found that the microbial communities differed significantly between the two varieties. The resistant variety was enriched in beneficial bacteria from the Actinobacteriota phylum and a stable, modular microbial network dominated by saprotrophic fungi. In contrast, the susceptible variety had a higher abundance of opportunistic pathogens and stress-indicator fungi, including Neurospora spp., which were more prominent in the rhizosphere and non-rhizosphere soils. These networks were fragile and dominated by pathotrophic fungi, reflecting ecological imbalance. Our findings show that plant disease resistance is influenced not only by host genetics but also by co-evolutionary interactions with the microbiome. These insights provide a foundation for developing targeted biocontrol strategies to manage plant-associated microbial communities. Full article

Strawberry (Fragaria x ananassa) production has increased around the world, but crop quality and yield are threatened by fungal pathogens. Botrytis cinerea is a filamentous fungus that infects over 1400 species of crops, causing gray mold disease with devastating losses to horticulture worldwide, including strawberry. The heavy reliance on synthetic fungicides in the strawberry industry has led to the emergence of fungicide resistance in B. cinerea. Therefore, understanding the fundamental biology of B. cinerea is an important step in the search for novel antifungals. Although B. cinerea is one of the most serious pathogens of strawberry, this pathosystem is understudied compared to other plant hosts. Consequently, further evidence is needed on pathogen penetration and early disease development in strawberry tissues. Here, we adapted and advanced assays using detached strawberry leaves, fruits, and petals to study B. cinerea infection. These assays allow the comparison of the treatment effect on the same fruit, avoiding confounding from differential ripening, and facilitate the screening of fungicides or biocontrol agents. Through chlorophyll fluorescence analysis and scanning electron and confocal microscopy, we quantified lesions caused by B. cinerea in the early stages of infection in fruit and petals, and demonstrated that B. cinerea penetrates through the stomata of strawberry achenes, revealing a previously unrecognized infection route in this host. These data provide a deeper understanding of the B. cinerea–strawberry interaction and will serve as a foundation for future studies seeking novel antifungal treatments against B. cinerea. Full article

This study characterizes Phoradendron nervosum, a hemiparasitic mistletoe species prevalent in Ecuador, using morphological, molecular, and ecological modeling approaches. Morphological analysis revealed that P. nervosum possesses green-yellowish cylindrical stems, lanceolate leaves with entire margins, and berry-like fruits with mucilaginous pulp. DNA sequencing of the internal transcribed spacer (ITS) region confirmed a 99.43% identity with P. nervosum (GenBank: AH009776.2), supporting the taxonomic classification. A maximum entropy (MaxEnt version 3.4.4) model was developed using 36 occurrence points and 19 bioclimatic variables to assess potential distribution across the Tumbaco region in Ecuador. Key environmental factors influencing the species’ distribution were precipitation during the warmest quarter (BIO_18), temperature seasonality (BIO_4), and mean diurnal temperature range (BIO_2). The model showed good predictive performance (AUC = 0.736), identifying areas with high suitability for P. nervosum, particularly in habitats with adequate water availability and thermal stability. Findings suggest that this mistletoe parasitizes both native and exotic tree species, potentially impacting biodiversity and forest health. This research provides a baseline for monitoring mistletoe spread under climate change scenarios and emphasizes the need for management strategies in agroforestry systems where host trees are vulnerable. Full article

Cucumber mosaic virus (CMV) is a destructive viral pathogen of vegetables, fruits, grains, and ornamentals across the globe. This study investigated the comparative antiviral efficacy of chitosan–salicylic acid nanocomposite (Ch/SA NC) and salicylic acid (SA) against CMV in cucumber plants. Transmission electron microscopy (TEM) analyses revealed that Ch/SA NCs can aggregate on the viral coat protein surface, suggesting direct nanoparticle–virus interaction. Greenhouse trials showed that Ch/SA NC, particularly at 90 ppm applied 24 h before CMV inoculation, was the most effective treatment in reducing disease severity and viral load. SA at the same concentration also conferred significant protection when used prophylactically. An RT-PCR analysis confirmed suppression or complete silencing of CMV coat protein gene expression, especially Ch/SA NC-treated plants. Both treatments significantly enhanced the physiological condition of infected plants, including restoration of chlorophyll a, chlorophyll b, and carotenoids, and elevated levels of total phenolics, flavonoids carbohydrates, and proteins. In addition, they boosted the key antioxidant enzymes activities (POX, PPO, SOD) and improved vegetative growth indicators such as plant height, fruit fresh weight, and number of fruits per plant. These results indicate that Ch/SA NC and SA not only inhibit CMV replication but also stimulate host defense responses, improving overall plant health. The strong antiviral effect is likely due to the dual action of Ch/SA NC: direct virus binding and induction of systemic acquired resistance (SAR). Given their efficacy and eco-friendly nature, especially the Ch/SA NC, these treatments offer a promising strategy for integrated viral disease management. Future studies should investigate long-term environmental safety, molecular mechanisms, and field-level applicability. Full article

Urban wildlife conservation is emerging as a critical component of sustainable city ecosystems. Rather than simply increasing tree abundance or species richness, conservation management should focus on key species. In this research, Xishan Forest Park in Beijing was chosen as a case study. Our aim was to identify keystone taxa critical for avian foraging and nesting during the breeding season. We performed a network analysis linking bird species, their diets, and nest plants. Dietary components were detected using DNA metabarcoding conducted with avian fecal samples. Nest plants were identified via transect surveys. Two indices of the network, degree and weighted mean degree, were calculated to evaluate the importance of the dietary and nest plant species. We identified 13 bird host species from 107 fecal samples and 14 bird species from 107 nest observations. Based on the degree indices, fruit trees Morus and Prunus were detected as key food sources, exhibiting both the highest degree (degree = 9, 9) and weighted mean degree (lnwMD = 5.21, 4.63). Robinia pseudoacacia provided predominant nesting sites, with a predominant degree of 7. A few taxa, such as Styphnolobium japonicum and Rhamnus parvifolia, served dual ecological significance as both essential food sources and nesting substrates. Scrublands, as a unique habitat type, provided nesting sites and food for small-bodied birds. Therefore, targeted management interventions are recommended to sustain or enhance these keystone resource species and to maintain the multi-layered vertical vegetation structure to preserve the diverse habitats of birds. Full article

Penicillium expansum is an acidogenic fungal species that belongs to the phylum Ascomycota. During the infection and colonization of host fruits, P. expansum can efficiently express glucose oxidase (GOX) and oxidize β-D-glucose to generate gluconic acid (GLA). In this study, the bioinformatics analysis method was employed to predict and analyze the function of the GOX protein. In addition, a comprehensive assessment was conducted on the P. expansum GOX coding gene GOX2, and the expression response rules of GOX2 under different external stress environments were explored. The results show that GOX is an unstable hydrophilic protein. It is either an integrated membrane protein (such as a receptor or channel) that is directly anchored to the membrane through a transmembrane structure or a non-classical secreted protein that is secreted extracellularly. RNA-seq data analysis shows that the GOX2 gene is regulated by multiple environmental factors, including pH, temperature, carbon base, and chemical fungicides. The expression level of GOX2 reaches its maximum value under alkaline conditions (pH 8–10) and at approximately 10 °C. Using starch as the carbon source and adding sodium propionate or potassium sorbate has the effect of inhibiting the expression of the GOX2 gene. The analysis of the function of the GOX protein and the characteristics of the GOX2 gene in P. expansum provides new insights into the glucose oxidase-encoding gene GOX2. The research results provide significant value for the subsequent development of new disease resistance strategies by targeting the GOX2 gene and reducing post-harvest disease losses in fruits. Full article

Tomato (Solanum lycopersicum L.) is one of the most preferred hosts of polyphagous stink bugs (Hemiptera: Pentatomidae) and leaf-footed bugs (Hemiptera: Coreidae). These hemipterans can infest tomato fruits at all stages of fruit ripening. However, it is unclear whether there is any feeding preference for these true bugs among different ripening stages of tomato (green, breaker, pink, and red stages). Feeding and behavioral assays were performed to determine the feeding preference and damage potential of two common stink bugs—the brown marmorated stink bug (Halyomorpha halys (Stål)) and the southern green stink bug (Nezara viridula L.)—and a leaf-footed bug (Leptoglossus zonatus (Dallas)) among the various ripening stages of tomato. The results indicated that green is the most preferred ripening stage for N. viridula and L. zonatus, while pink tomatoes were found to be a more preferred feeding site for H. halys. Fully ripe red tomatoes were found to be the least preferred feeding site for all three insects. The findings of this study will be useful for developing fruit damage symptom-based monitoring programs and establishing economic threshold levels for these pests in tomatoes, as well as informing harvesting regimes. Full article

The analysis of soil nematode communities provides information on their impact on soil quality and the health of different agricultural cropping systems and soil management practices, which is necessary to evaluate their sustainability. Here, we evaluated the status of nematode communities and trophic groups’ abundance in fifteen fields hosting different cropping systems and managed according to organic or conventional practices. The nematode population densities differed significantly across cropping systems and management types covering various European climatic zones (spanning 121 to 799 individuals per sample). Population density was affected by the duration of the cropping system, with the lowest value in the vegetable cropping system (on average about 300 individuals) and the highest in the long-term fruiting system (on average more than 500 individuals). The occurrence and abundance of the different trophic groups was partly dependent on the cropping system or the management method, particularly for the bacteria, fungal and plant feeders. The taxonomical classification of a subset of samples allowed us to identify 22 genera and one family (Dorylaimidae) within the five trophic groups. Few taxa were observed in all fields and samples (i.e., Rhabditis and Cephalobus), while Aphelenchoides or Pratylenchus were present in the majority of samples. Phosphorus content was the only soil chemical parameter showing a positive correlation with total nematode population and bacterial feeders’ absolute abundance. Based on the nematological ecological indices, all three cropping systems were characterized by disturbed soil conditions, conductive and dominated by bacterivorous nematodes. This knowledge could lead to a choice of soil management practices that sustain a transition toward healthy soils. Full article

Apples (Malus domestica), one of Iran’s oldest cultivated fruit crops, hold considerable economic importance. In this study, 170 apple leaf samples representing various commercial cultivars were collected across the country. RT-PCR screening targeted five common apple-infecting viruses and two viroids: apple chlorotic leaf spot virus (ACLSV), apple stem pitting virus (ASPV), apple stem grooving virus (ASGV), apple green crinkle-associated virus (AGCaV), apple mosaic virus (ApMV), apple scar skin viroid (ASSVd), and hop stunt viroid (HSVd). To identify additional or novel agents, 40 RT-PCR-negative samples were pooled into two composite groups and analyzed using next-generation sequencing (NGS). NGS was also performed on individual samples with mixed infections to retrieve full genomes. RT-PCR confirmed the presence of ACLSV, ASPV, ASGV, AGCaV, ApMV, and HSVd. NGS further revealed three additional pathogens: citrus concave gum-associated virus (CCGaV), apple hammerhead viroid (AHVd), and apricot vein clearing-associated virus (AVCaV), which were subsequently detected across the collection by RT-PCR. AGCaV was most prevalent (47.6%), followed by ACLSV (45.8%), HSVd (27.6%), AVCaV (20.5%), ASGV (17%), AHVd (15.2%), ASPV (14.1%), CCGaV (4.7%), and ApMV (3.5%). Mixed infections occurred in 67% of samples. Phylogenetic analysis based on CP genes (ACLSV, ASGV, AGCaV) and full genomes (AVCaV, AHVd) clustered Iranian isolates together, suggesting a common origin. This is the first report in Iran of AGCaV, CCGaV, ApMV, and AVCaV in apple, and notably, the first global report of AVCaV in a non-Prunus host. The findings provide the first comprehensive assessment of the sanitary status of apple trees in Iran. Full article

The spotted wing drosophila, Drosophila suzukii is an injurious polyphagous pest threatening worldwide soft fruit production. Its high adaptability to new colonized environments, short life cycle, and wide host range are supporting its rapid spread. The most common techniques to reduce its significant economic damage are based on multiple insecticides applications per season, even prior to the harvest, which reduces agroecosystem biodiversity and affects human and animal health. Environmental concerns and regulatory restrictions on insecticide use are driving the need for studies on alternative biological control strategies. This study aimed to assess the effect of T. drosphilae in controlling D. suzukii infestations and its interaction with P. vindemiae, a secondary parasitoid naturally present in Apulia (South Italy). Field experiments were carried out in organic cherry orchards in Gioia del Colle (Bari, Italy) to test the efficacy and adaptability of T. drosphilae following weekly releases of artificially reared individuals. Additionally, the interaction between P. vindemiae and T. drosphilae was studied under laboratory conditions. Results from field experiments showed that D. suzukii populations were significantly lower when both parasitoids were present. However, T. drosophilae was less prone to adaptation, so its presence and parasitism were limited to the post-release period. Laboratory experiments, instead, confirmed the high reduction of D. suzukii populations when both parasitoids are present. However, the co-existence of the two parasitoids resulted in a reduced parasitism rate and offspring production, notably for T. drosophilae. This competitive disadvantage may explain its poor establishment in field conditions. These findings suggest that the field release of the two natural enemies should be carried out with reference to their natural population abundance to not generate competition effects. Full article

Zeugodacus cucuribitae (Coquillett) (Z. cucuribitae) is a global extremely invasive quarantine pest which has a wide host range of fruits and vegetables. At present, there are a few control measures for Z. cucuribitae, and deltamethrin and avermectin are commonly used. Among the hosts of Z. cucuribitae, Luffa acutangular, Luffa cylindrica, Sechium edule, Brassica oleracea var. botrytis, Musa nana, and Fragaria × ananassa are non-favored hosts. However, it is still not clear why these hosts are non-favored and whether there are any repellent components of Z. cucuribitae in these hosts. In this study, the components of these six hosts were collected from the literature, and the genes of odor and chemical sensation were determined from the genome of Z. cucuribitae. After the potential relationships between these components and genes were determined by molecular docking methods, the KEGG and GO enrichment analysis of these genes was conducted, and a complex network of genes vs. components vs. Kegg pathway vs. GO terms was constructed and used to select the key components for experiments. The results show that oleanolic acid (1 mg/mL, 0.1 mg/mL, and 0.01 mg/mL), rotenone (1 mg/mL, 0.1 mg/mL, and 0.01 mg/mL), and beta-caryophyllene oxide (1 mg/mL, 0.1 mg/mL, and 0.01 mg/mL) had a significant repellent effect on Z. cucuribitae, and three components, rotenone (1 mg/mL and 0.1 mg/mL), echinocystic acid (1 mg/mL, 0.1 mg/mL, and 0.01 mg/mL), and beta-caryophyllene oxide (1 mg/mL, and 0.1 mg/mL) had significant stomach toxicity in Z. cucuribitae. Furthermore, a complex signaling pathway was built and used to predict the effect of these components on Z. cucuribitae. These components probably play roles in the neuroactive ligand–receptor interaction (ko04080) and calcium signaling (ko04020) pathways. This study provides a reference for the prevention and control of Z. cucuribitae and a scientific reference for the rapid screening and development of new pest control drugs. Full article

Colletotrichum fructicola is a member of the gloeosporioides complex and can act as a pathogen, causing anthracnose in various plants and as an endophyte residing in healthy plants. As a plant pathogen, C. fructicola has been frequently reported to cause anthracnose in chili fruit and tea plants, bitter rot in apples and pears, crown rot in strawberries, and Glomerella leaf spot in apples, which are the most common diseases associated with this pathogen. Over the years, C. fructicola has been reported to infect a wide range of plants in tropical, subtropical, and temperate regions, including various types of fruit crops, ornamental and medicinal plants, tree nuts, peanuts, and weeds. Several reports have also been made regarding endophytic C. fructicola recovered from different plant parts. Endophytic C. fructicola has the ability to switch to a pathogenic state, which may contribute to the infection of host and other susceptible plants. Due to the economic importance of C. fructicola infections, the present review highlighted C. fructicola as a plant pathogen and endophyte, providing a summary of its infections in various plants and endophytic ability to inhabit plant tissues. Several control measures for managing C. fructicola infections have also been provided. Full article

Blueberry is a high-value fruit crop in the United States, with Georgia and Florida serving as important early-season production regions. In these areas, several thrips species (Thysanoptera: Thripidae), including Frankliniella tritici (Fitch), Frankliniella bispinosa (Morgan), and Scirtothrips dorsalis (Hood), have emerged as economically significant pests. While F. tritici and F. bispinosa primarily damage floral tissues, S. dorsalis targets young foliage. Their rapid reproduction, high mobility, and broad host range contribute to rapid population buildup and complicate the management programs. Species identification is often difficult due to overlapping morphological features and requires the use of molecular diagnostic tools for accurate identification. Although action thresholds, such as 2–6 F. tritici per flower cluster, are used to guide management decisions, robust economic thresholds based on yield loss remain undeveloped. Integrated pest management (IPM) practices include regular monitoring, cultural control (e.g., pruning, reflective mulch), biological control using Orius insidiosus (Say) and predatory mites, and chemical control. Reduced-risk insecticides like spinetoram and spinosad offer effective suppression while minimizing harm to pollinators and beneficial insects. However, the brief flowering period limits the establishment of biological control agents. Developing species-specific economic thresholds and phenology-based IPM strategies is critical for effective and sustainable thrips management in blueberry cropping systems. Full article

Huanglongbing (HLB), caused mainly by Candidatus Liberibacter asiaticus (CLas), is a devastating disease threatening citrus production worldwide, leading to leaf mottling, fruit deformation, and significant yield losses. This study generated a comprehensive co-expression network analysis using RNA-seq data from 17 public datasets. Weighted gene co-expression network analysis (WGCNA) was applied to identify gene modules associated with citrus species, tissue types, and days post-infection (DPIs). These modules revealed significant enrichment in biological pathways related to stress responses, metabolic reprograming, ribosomal protein synthesis, chloroplast and plastid function, cellular architecture, and intracellular transport. The results offer a molecular framework for understanding HLB pathogenesis and host response. By elucidating module-specific functions and their correlation with species- and tissue-specific responses, this study provides a robust foundation for identifying key genetic targets. These insights facilitate breeding programs focused on developing HLB-tolerant citrus cultivars, contributing to the long-term sustainability and resilience of global citrus production. Full article

Lemon, widely used in food, medicine, cosmetics, and other industries, has considerable value as a commodity and horticultural product. Previous research has shown that the fungus Diaporthe citri infects several citrus species, including mandarin, lemon, sweet orange, pomelo, and grapefruit, in China. Although D. citri has been reported to cause melanose disease in lemons in China, key pathological evidence, such as Koch’s postulates fulfillment on lemon fruits and detailed morphological characterization, is still lacking. In May 2018, fruits, leaves, and twigs were observed to be infected with melanose disease in lemon orchards in Chongqing municipality in China. The symptoms appeared as small black discrete spots on the surface of fruits, leaves, and twigs without obvious prominent and convex pustules. D. citri was isolated consistently from symptomatic organs and identified provisionally based on the morphological characteristics. The identification was confirmed using sequencing and multigene phylogenetic analysis of ITS, TUB, TEF, HIS, and CAL regions. Pathogenicity tests were performed using a conidium suspension, and melanose symptoms similar to those observed in the field were reproduced. To our knowledge, this study provides the first comprehensive evidence for D. citri as a causal agent of melanose disease in lemons in China, including morphological characterization and pathogenicity assays on lemon fruits. This report broadens the spectrum of hosts of D. citri in China and provides useful information for the management of melanose in lemons. Full article