Search Results (1,361)

In resource-poor sandy habitats, alien plant co-invasion often triggers intense belowground competition mediated by rhizosphere microorganisms. However, the mechanisms by which these plants overcome nutrient limitations remain unclear. Here, we conducted an eight-month in situ monitoring of single- and co-invasion plots of Solanum rostratum and Cenchrus pauciflorus Benth. in the Horqin Sandy Land. By integrating soil enzyme assays with 16S rRNA and internal transcribed spacer (ITS) amplicon sequencing, we characterized their rhizosphere microbial community assembly. Co-invasion exposed both species to convergent biotic stress, characterized by the significant enrichment of the pathogenic fungi Didymella and Pseudogymnoascus (linear discriminant analysis (LDA) > 4.0). To mitigate these pressures, the dominant competitor, S. rostratum, specifically recruited a cross-kingdom phosphate-solubilizing consortium comprising Bacillus and Penicillium (LDA > 4.0). This targeted recruitment significantly enhanced rhizosphere activities, increasing phosphatase and sucrase to 86.10 U/g and 2.17 U/g, respectively, thereby maintaining available phosphorus at a high level (35.55 mg/kg). Conversely, the subordinate competitor, C. pauciflorus, lost key native stress-resistant bacteria such as Rubrobacter (relative abundance dropping from 5.39% to 3.27%) and failed to recruit effective microbes, leading to the rapid depletion of available phosphorus (dropping to 21.38 mg/kg). Ultimately, under dual nutrient and pathogenic stress, the precise recruitment and functional integration of cross-kingdom phosphate-solubilizing microbes are strongly linked to the divergent belowground competitive outcomes between these co-invading plants. Full article

This study portrays macroalgal assemblage structure in the transitional water system Mar Piccolo of Taranto (eLTER site) from 2012 to 2023, assessing the impact of the establishment of non-indigenous species (NIS). Seasonal sampling at three sites evaluated diversity and biomass variation through PERMANOVA, PCoA, PERMDISP and Indicator Value (IndVal) analyses. Results reveal significant spatio-temporal heterogeneity: Site 1 remains dominated by native species (>70% biomass) and summer peaks of NIS (>70% biomass) were recorded at Site 3, whereas Site 4 experienced a substantial NIS expansion, reaching 97% of the total biomass by 2021. Statistical clustering identified distinct indicator species for each inlet of the basin, such as Amphiroa beauvoisii (IndVal = 100) in the First Inlet and the NIS Hypnea corona (IndVal = 65.6) in the Second. Water temperature emerged as a primary driver of community shifts. Most species, including both native (Chondracanthus acicularis; r_s = 0.50, p ≤ 0.05) and several NIS (Polysiphonia morrowii r_s = 0.65, p ≤ 0.5; Osmundea oederi r_s = 0.70, p ≤ 0.5), exhibited negative correlations with mean thermal values, while Ulva laetevirens (r_s = −0.50, p ≤ 0.05) showed greater tolerance. These findings highlight the importance of LTER monitoring in demonstrating that the Mar Piccolo’s resistance to NIS pressure is non-uniform across the basin. Under a global warming scenario, thermal forcing is actively reshaping macroalgal assemblages. Full article

INDETERMINATE DOMAIN (IDD) transcription factors are plant-specific regulators essential for plant development and stress adaptation. As a globally important staple crop, common wheat (Triticum aestivum L.) is frequently threatened by fungal diseases such as powdery mildew and stripe rust. To date, however, the IDD gene family in wheat has not been systematically characterized, and its roles in biotic stress responses remain unclear. In this study, we performed genome-wide identification and a comprehensive analysis of the TaIDD gene family. A total of 41 TaIDD genes were identified, which were unevenly distributed across 15 chromosomes and divided into four phylogenetic groups. Synteny and selective pressure analyses demonstrated that segmental duplication was the main driver of family expansion and that TaIDD genes underwent strong purifying selection during evolution. Cis-acting element analysis revealed abundant hormone- and stress-related elements in their promoter regions. Transcriptome and RT-qPCR analyses indicated that TaIDD genes exhibited distinct expression patterns under abiotic and biotic stress. Notably, TaIDD13, TaIDD19, TaIDD27, TaIDD37, TaIDD39, and TaIDD41 were significantly induced by multiple fungal pathogens, suggesting their potential involvement in stress-responsive pathways that may be related to disease resistance. Subcellular localization analysis further confirmed that TaIDD39 was exclusively localized in the nucleus, consistent with its function as a transcriptional regulator. Our findings provide insights into the evolutionary characteristics and stress-response mechanisms of TaIDD genes and highlight TaIDD39 and other potential candidates that may serve as valuable resources for wheat molecular breeding to enhance broad-spectrum disease resistance and stress tolerance. Full article

Silicon (Si) amendment can enhance plant resistance to biotic stress, yet its role in tri-trophic interactions under multiple herbivore attack remains unclear. This study examined how Si influences herbivore-induced plant volatiles (HIPVs) and the foraging behavior of the predatory mirid Cyrtorhinus lividipennis that preys on eggs of the white-backed planthopper (WBPH; Sogatella furcifera). A 2 × 2 factorial design was employed to test the effects of Si amendment (+Si vs. −Si) and the striped stem borer (SSB; Chilo suppressalis) infestation (+SSB vs. −SSB) on plant volatile emissions and predator behaviors, with WBPH infestation present in all treatments. Cage and Y-tube experiments showed higher predator attraction and increased WBPH egg predation in +Si+SSB treatment relative to −Si+SSB treatment. HS-SPME-GC/MS analysis revealed that, regardless of Si amendment, SSB infestation massively altered the overall volatile profile, while Si amendment reduced emission of many volatiles in SSB infested plants. Single compound bioassays further identified that, regardless of Si amendment, SSB infestation significantly up-regulated four repellents for C. lividipennis. Compared with the −Si+SSB treatment, the +Si+SSB treatment down-regulated one repellent volatile and up-regulated three attractant volatiles. These findings indicate that Si amendment potentially enhances biocontrol of the subsequent herbivore under dual herbivory through altering HIPV emissions induced by the prior herbivory. Full article

Wood strength, renewability and appearance make it one of the most preferred and widely used natural materials in structural and cultural applications. The gradual degradation of wood from abiotic and biotic factors has an adverse impact on its structural durability and service life. This study investigates the effect of surface treatment of wood of the invasive tree species of tree-of-heaven, through short-term immersion in an acrylic polymer (Paraloid-B72) containing silica dioxide (SiO₂) nanoparticles at low concentrations (0–4% w/v) to impart hydrophobic behavior and weathering resistance. FTIR analysis confirmed the successful incorporation of the acrylic polymer and silica nanoparticles within the wood structure without altering the chemical integrity of the substrate. For both treated and untreated wood specimens, the physical properties (density, equilibrium moisture content, surface roughness, color-parameters), hygroscopic properties (swelling/absorption, contact angle) and weathering resistance tests were conducted using xenon-arc combined with wetting–drying cycles. The findings revealed that treated wood has significantly improved hydrophobic performance and dimensional stability, reducing moisture uptake. Treatment significantly increased the samples’ resistance to artificial weathering, with the effectiveness dependent on nanoparticle concentration. Although moderate surface color changes were observed in treated samples (compared to untreated ones), during their exposure to weathering, reduced lightness and slight increases in red and yellow chromatic coordinates were observed, with treated specimens exhibiting higher color stability during aging. Nevertheless, surface roughness increased significantly by the treatment, slightly restricting the method when a highly smooth surface touch is required. The proposed modification method appears promising to prolong the wooden structures’ service-life, meanwhile inspiring modern strategies for conserving historical timber structures that cannot be moved and should be protected by applying less invasive protective methods. Full article

Wild maize (teosinte) has been reported to be less susceptible to biotic and abiotic stresses than its modern relative, corn. The composition of the teosinte root microbiome may be linked to traits such as drought tolerance and pest resistance. Trichoderma spp. are ubiquitous saprotrophic fungi found in the plant rhizosphere, enhancing host plant growth and crop productivity while alleviating biotic and abiotic stresses. The present study identified ten Trichoderma fungal isolates associated with the rhizosphere microbiome of teosinte (Zea mays spp. mexicana) and performed in vitro screening to assess both their multi-trait plant growth-promoting activities and their biological control potential against the phytopathogens Aspergillus flavus and Fusarium verticillioides. Additionally, interaction tests were conducted to evaluate the phytostimulant effect of Trichoderma spp. on maize (Zea mays) seed germination. Taxonomic and phylogenetic analysis identified five different Trichoderma species: T. rifaii (TA and TH); T. azevedoi (TB and TI); T. afroharzianum (TE); T. hamatum (TF and TG); and Trichoderma sp. (aff. bannaense) (TC, TD, and TJ). Partial least squares discriminant analysis revealed the isolates TF, TG, and TJ to have the highest potential for use as biocontrol and biostimulant agents. The present study is the first to examine Trichoderma species associated with the teosinte microbiome, and the results suggest that Trichoderma isolates are a potential sustainable alternative for improving maize cultivation. Full article

Modern agriculture, heavily influenced by the Green Revolution, has increased productivity through the intensive use of external inputs and agrochemicals, but at the cost of growing environmental degradation, loss of biodiversity, pest resistance, and risks to human health. This production model has proven to be environmentally unsustainable in the face of current challenges, such as climate change, the increase in the world’s population, and the depletion of natural resources. In this context, agroecology emerges as an integrative scientific approach that promotes the transition from conventional agricultural systems to diversified, resilient, and functionally balanced agroecosystems, based on ecological principles and the progressive reduction of synthetic inputs. This review addresses the role of fungal microorganisms, with an emphasis on entomopathogenic fungi and fungi associated with the plant microbiome, as key tools in the sustainable management of biotic agricultural challenges. This paper addresses the biology and multifunctionality of entomopathogenic fungi, not only as biological control agents but also as crop growth promoters and phytopathogen suppressors. Taken together, the background information presented reinforces the potential of entomopathogenic fungi as strategic components in agroecological transition processes, contributing to productive sustainability, reduced agrochemical use, and the restoration of the ecological functionality of agroecosystems. Full article

Domain of unknown function (DUF) proteins play important roles in plant responses to biotic and abiotic stresses. DUF4228 proteins, as members of the DUF superfamily, are widely present in plants and exert significant functions under various stress conditions. Sugarcane is an important economic and energy crop in China. However, the role of DUF4228 family members in sugarcane has not been reported. In this study, 126 ScDUF4228 genes were identified for the first time in the genome of the modern cultivar XTT22 and systematically named based on their chromosomal locations (ScDUF4228-1 to ScDUF4228-126). These genes are located on 7 chromosomes of the XTT22 genome, exhibiting an overall uneven distribution. Phylogenetic analysis revealed that the 126 ScDUF4228 proteins can be divided into 9 groups (I–IX). Gene structure analysis indicated that most ScDUF4228 family members lack introns or contain only 1–2 introns, and all members possess a complete DUF4228 domain. Ka/Ks analysis demonstrated that the family as a whole has undergone purifying selection (Ka/Ks < 1), indicating high functional conservation during evolution. Cross-species collinearity analysis showed significant species-specific expansion of the DUF4228 gene family in the Poaceae (particularly in sugarcane and its close relatives), a phenomenon not prominently observed in dicotyledons. Analysis of tissue expression patterns, developmental stages, and diurnal rhythms revealed that the spatiotemporal expression profiles of the 126 ScDUF4228 family members vary, suggesting they may function individually or synergistically during different developmental periods in sugarcane. Yeast medium assay depicted that three members of the ScDUF4228 (ScDUF4228-7, ScDUF4228-18, ScDUF4228-23) family had significant resistance potential under drought stresses. Furthermore, transcriptome analysis after drought treatment showed that ScDUF4228-23 exhibited the most significant upregulation, suggesting it may be a key gene in sugarcane’s response to drought. These results suggest that the DUF4228 gene family has undergone dramatic expansion in sugarcane and may play a crucial regulatory role in drought stress responses. This study provides the necessary molecular foundation for further exploring the functions of ScDUF4228 family members. Full article

The ADP-glucose pyrophosphorylase (AGPase) gene family plays an essential role in starch metabolism and stress adaptation. However, its function in antiviral defense remains largely uncharacterized. Cucumber (Cucumis sativus L.), a globally important vegetable crop, frequently experiences severe yield losses due to viral infections. In this study, we systematically identified five AGPase genes in cucumber, categorizing them into large and small subunits. Analysis of conserved motifs revealed ten conserved sequences, with the NTP (Nucleoside Triphosphate) transferase domain representing a signature feature of the AGPase family. Promoter regions contained multiple cis-regulatory elements associated with stress responses and hormone signaling. Transcriptomic profiling revealed tissue-specific expression patterns of CsAGP genes, with pronounced enrichment in leaves. Notably, CsAGP2, CsAGP4, and CsAGP5 were strongly induced under biotic and abiotic stresses. Of these, CsAGP4 exhibited rapid, transient induction specifically in the virus-resistant line ‘228’, but not in the susceptible line ‘65G’. Hormonal treatments showed that abscisic acid (ABA) rapidly activated most CsAGP genes and acted synergistically with viral infection to amplify CsAGP4 expression. Functional analysis via CRISPR/Cas9-mediated knockout of CsAGP4 revealed that the mutation disrupted starch granule formation and significantly altered resistance to watermelon mosaic virus (WMV) in ‘Poinsett 97’. Our work provides a systematic characterization of the AGPase gene family in cucumber and establishes its role in defense responses. Importantly, we identify CsAGP4 as a positive regulator of antiviral immunity, highlighting its potential as a target for breeding virus-resistant cucumber varieties. Full article

Medicinal plants grown outside their native forest habitat may produce phytochemical profiles that differ from wild-harvested material, yet the ecological mechanisms underlying these differences remain poorly synthesized across disciplines. This review proposes that the forest understory functions as a multi-signal elicitation system in which canopy light filtering, arbuscular mycorrhizal fungi (AMF), and above-ground biotic interactions collectively shape secondary metabolite profiles. AMF-mediated induced systemic resistance and above-ground biotic interactions operate through confirmed jasmonate-mediated pathways. Sunfleck-driven reactive oxygen species signaling is hypothesized but untested, and the red-to-far-red ratio modulated phytochrome B pathway characterized in Arabidopsis remains unconfirmed in shade-tolerant species. Using three saponin-rich medicinal plants (Panax vietnamensis, Panex quinquefolius, and Paris polyphylla) as case studies, we formalize this as a testable chemical terroir hypothesis with three falsifiable predictions. We also translate it into an ecological co-cultivation design principle with three production levels and a two-step operational framework, and identify priority experiments, analytical methods, and implementation challenges needed for validation. These contributions bridge forest ecology and medicinal plant science while identifying critical evidence gaps requiring resolution before field implementation. Full article

Verticillium wilt (VW), caused by the soil-borne fungus Verticillium dahliae, is a major disease that markedly compromises both the yield and fiber quality of cotton. In this study, we explored the function and underlying mechanism of the cotton expansin gene GhEXLB2 in response to VW infection. Expression profiling revealed that members of the GhEXL family exhibit distinct patterns across tissues and under various biotic and abiotic stresses. Notably, GhEXLB2, which encodes an extracellular protein, showed the strongest induction following V. dahliae challenge. Ectopic expression of GhEXLB2 in Arabidopsis thaliana promoted root elongation and root hair formation, and was associated with improved resistance to the pathogen. In contrast, silencing GhEXLB2 in cotton via virus-induced gene silencing (VIGS) led to pronounced vascular browning, increased pathogen recovery, and a lower level of disease resistance. In addition, RNA-seq profiling of GhEXLB2-silenced (VIGS) cotton plants revealed that most differentially expressed genes were enriched in pathways related to phytohormone signaling and plant–pathogen interactions, with salicylic acid (SA) signaling and WRKY transcription factors emerging as central regulatory components. Analysis of the GhEXLB2 promoter further identified multiple cis-acting elements associated with stress and hormone responsiveness. When integrated with protein–protein interaction (PPI) prediction data, these results suggest that GhEXLB2 may be modulated by a network of transcription factors and signaling pathways. Collectively, the evidence supports a positive association between GhEXLB2 and VW resistance. This study provides a framework for understanding expansin functions in cotton defense against VW. Full article

Rice (Oryza sativa L.) is a staple food crop, feeding more than 3.5 billion people. With the increasing demand for food in the 21st century, weed infestation poses the most significant biotic threat to global food security, and herbicides remain the most effective and economic way to manage it in field. However, weeds can rapidly adapt under herbicide selection pressure due to their high competitiveness, rapid growth, and reproductive capacity. Hence, we collected Echinochloa crus-galli populations from Heilongjiang and Hebei provinces in China and investigated their resistance mechanisms to pyrazosulfuron-ethyl (PSE), a sulfonylurea herbicide that inhibits acetolactate synthase (ALS). Dose–response experiments confirm that the resistant (R) population exhibits 52.9-fold resistance to PSE compared with the susceptible (S) population. Inhibitor bioassays with malathion and NBD-Cl, together with ALS activity assays, ALS gene sequencing, and molecular docking, collectively suggest that resistance is strongly associated with the ALS Trp-574-Leu target-site substitution, with a possible additional contribution from enhanced herbicide metabolism. However, because the S and R populations originate from geographically distinct locations, some of the observed physiological and molecular differences may also reflect inherent population variation. Specifically, the ALS W574L substitution is predicted to reduce key interactions between ALS and PSE. This study provides valuable evidence for the risk of PSE resistance evolution in E. crus-galli and elucidates the molecular mechanism conferring resistance to ALS inhibitors. Full article

Peanut (Arachis hypogaea L.) production faces persistent threats from various infectious diseases. Planting healthy varieties with robust botanical defense networks is critical for minimizing future costs. Non-expressor of pathogenesis-related (NPR) regulators are involved in immune activation and act as key targets for deeper stress adaptation, and are thus promising targets for genetic enhancement. In this study, we characterized the peanut NPR4B protein and demonstrated its local subcellular binding to the nucleus. Ectopic overexpression of AhNPR4B in Arabidopsis thaliana significantly enhanced resistance to the necrotrophic pathogen Botrytis cinerea and enhanced cold tolerance, as supported by quantitative and statistical analyses (p < 0.05). As regards underlying molecular events, Y2H (Yeast 2-Hybrid) analysis revealed a binding in vitro physical relation of AhPR2-like to AhNPR4B. This binding was demonstrated in vivo through BiFC (Bimolecular Fluorescence Complementation). These results suggest that the AhNPR4B-AhPR2-like complex may act as a key regulatory module associated with biotic and abiotic stress signaling, potentially contributing to broad-spectrum stress resistance. These findings provide foundational insights into the functional roles of AhNPR4B and its interaction with AhPR2-like in regulating stress resistance and support its potential as a candidate target for future genetic improvements to enhance stress resilience in peanuts. Full article

Tomato is widely produced in Burkina Faso for its culinary, nutritional, and economic value. Tens of thousands of farmers are involved in its production throughout the country. However, they face significant biotic constraints that limit yields and income. In particular, tomato yellow leaf curl virus (TYLCV), a begomovirus transmitted by whiteflies (Bemisia tabaci), severely affects tomato production. This study evaluated the response of 13 tomato genotypes to tomato yellow leaf curl disease (TYLCD), including eight lines with different Ty resistance gene combinations; three local improved varieties, and two commercial varieties in western and central Burkina Faso. All genotypes developed TYLCD symptoms with considerable variability in genotypic responses. Four genotypes carrying a single gene, namely CLN4279O (Ty2), CLN4270I (Ty1/Ty3), CLN4270F (Ty1/Ty3), and CLN4018G (Ty2), exhibited the best field tolerance, with lower disease incidence and severity across sites. In contrast, genotype CLN4078A carrying two resistance genes (Ty1/Ty3 + Ty2), and the checks PETOMECH and ROMA VF were highly susceptible. Hierarchical clustering grouped the genotypes into four classes based on tolerance level and yield. These findings highlight the variability in resistance expression under field conditions and suggest possible interactions between host genotype, environmental factors, and virus populations. Broader multi-site evaluations, supported by molecular diagnostics to identify endemic TYLCV strains, are needed to refine the selection process. Full article

Candida albicans is the causal agent of invasive candidiasis, which might be lethal in immunocompromised patients. Biofilm formation is considered a key virulence factor of C. albicans and is associated with its elevated resistance to antifungals. C. albicans and bacteria like E. coli are frequently found to form mixed biofilms on biotic or abiotic surfaces, rendering them more refractory to existing antifungals. To investigate how E. coli endogenous indole interplaying with exogenous IAA exerts modulatory effects on dual-species biofilm with C. albicans, an E. coli strain deficient in the indole biosynthetic gene tnaA was constructed, and the enzyme TnaA inhibitor was administered to block the indole production in E. coli monoculture and/or E. coli–C. albicans dual culture. Phenotypic assay revealed that indole deficiency attenuated E. coli mono-species biofilm by 12% (tnaA∆ versus WT E. coli), and the lack of indole in the E. coli cell-free culture filtrate abolished the ability to promote C. albicans biofilms, evidenced by the fact that the treatment with WT E. coli culture supernatants exhibited a 1.7-fold promotive effect, while treatment with tnaA∆ displayed no significant difference from the broth control towards C. albicans biofilms. Furthermore, impaired E. coli indole production might disrupt E. coli–C. albicans biofilm, as examined by confocal laser scanning microscopy (CLSM). Moreover, indole-3-acetic acid (IAA) was found to exhibit more potent biofilm-modulatory activity than indole by CLSM imaging with dual biofilms of WT E. coli–C. albicans, in contrast to those of E. coli tnaA∆–C. albicans post-supplemented with exogenous IAA. This study provides evidence for indole as a signaling molecule mediating bacterial–fungal communication during mixed-biofilm formation. Indole and its derivatives, particularly in combination with existing antifungals, have potential in the development of anti-biofilm strategies to eradicate refractory fungal infections. Full article