Search Results (569)

Powdery mildew in wheat, caused by the biotrophic fungus Blumeria graminis f. sp. tritici (Bgt), is a major threat to global wheat production, yet the molecular mechanisms underlying differential cultivar resistance remain largely unresolved. In this study, tandem mass tag (TMT)-based quantitative proteomics was employed to investigate protein dynamics in resistant (Yannong37) and susceptible (Yannong1766) wheat cultivars at 0 and 24 h following Bgt inoculation. A total of 276 proteins exhibited significant changes in abundance after infection, with enrichment in cell wall and plasmodesmata-associated proteins. Comparative analysis further identified 456 differentially expressed proteins between the two cultivars at 24 h post-inoculation. Protein–protein interaction network analysis indicated that proteins involved in secondary metabolism and immune responses form coordinated regulatory networks contributing to disease resistance. RT–qPCR validation supported the reliability of the proteomic data. Notably, TaCAD-A1 displayed higher transcript abundance in the resistant cultivar and was associated with reduced fungal biomass accumulation. Silencing of TaCAD-A1 resulted in decreased expression of multiple defense-related genes. Collectively, these findings suggest that TaCAD-A1 may positively contribute to wheat resistance against Bgt infection and may be associated with defense responses and monolignol biosynthesis-related processes. Full article

The NAC transcription factor superfamily is one of the most prominent plant-specific regulatory gene families, extensively participating in multiple metabolic processes that govern plant growth, tissue development and stress adaptation. Masson pine (Pinus massoniana Lamb.) is a native dominant conifer widely cultivated across South China, whose timber resources possess great exploitation potential in pulp manufacturing and the paper industry. In this study, a total of 98 non-redundant NAC family members were mined at the genome-wide level. Functional validation revealed that PmNAC82, a member belonging to the VND evolutionary subgroup, acts as a core regulatory factor controlling wood formation. Subcellular localization tests confirmed PmNAC82 exclusively resides in the cell nucleus. Heterologous genetic transformation in poplar demonstrated that this gene positively regulates the accumulation of lignin and cellulose. Furthermore, through RT-qPCR, yeast one-hybrid assays, and EMSA, we confirmed that PmNAC82 can bind to the promoters of PtrMYB3, PtrMYB21 and PmCesA7. These findings provide a solid foundation for further investigation into the molecular functions of NAC genes in Masson pine as well as their potential application towards molecular breeding strategies aimed at improving wood quality. Full article

Mycotoxins are one of the biggest threats to global food safety, public health, and economic stability. More than 400 mycotoxins have been found to be secondary metabolites of toxigenic fungi, mostly from the genera Aspergillus, Fusarium, Penicillium, and Alternaria. Aflatoxins (AFs), ochratoxin A (OTA), deoxynivalenol (DON), zearalenone (ZEA), fumonisins (FBs), patulin (PAT), and T-2/HT-2 toxins are the most dangerous to the health of people and animals. Conventional physical and chemical decontamination methods are only partially effective and can reduce food quality, leave toxic residues, or be too expensive for smallholder food systems. Recent studies have shown that the application of lactic acid bacteria (LAB) as a biological detoxification method is a safe, cost-effective, and environmentally friendly option, and has a long history of safe use in fermented foods. Selected strains or taxonomic units have been granted GRAS status by the FDA or QPS (Qualified Presumption of Safety) status by EFSA. However, their use for mycotoxin detoxification still requires strain-level safety assessment and efficacy validation in the intended food matrix. There are several mechanisms by which LAB employ to reduce the bioavailability of mycotoxins in food systems: (i) physical adsorption via cell wall components such as peptidoglycan, teichoic acids, and exopolysaccharides; (ii) enzymatic biotransformation that may produce non-toxic or less-toxic metabolites, though the safety of degradation products requires case-by-case toxicological assessment; (iii) antifungal metabolite production that inhibits fungal growth and mycotoxin biosynthesis; and (iv) competitive exclusion of toxigenic fungi during fermentation. This comprehensive review examines the existing evidence on the detoxification of major food mycotoxins by LAB, with an emphasis on mechanisms, strain-specific efficacy, food-matrix applications, and factors that affect detoxification efficacy. Discussion has also been made of translating in vitro findings to in vivo settings and food-scale applications, alongside regulatory frameworks, current challenges, and future research directions. The review also suggests ways to combine LAB with new technologies, such as encapsulation, genetic engineering, and fermentation optimization, to make food systems safer by synergistically controlling mycotoxins. Full article

Fruit endocarp and seed coat are essential protective structures that influence key agronomic and mechanical traits in species with lignified protective tissues, yet their regulatory mechanisms remain incompletely understood. Here, we conducted a comprehensive genome-wide analysis of the MADS-box gene family in four angiosperm species: Juglans sigillata, Carya illinoinensis, Macadamia integrifolia, and Ricinus communis. A total of 58, 55, 57, and 57 MADS-box genes were identified, respectively, and systematically characterized through phylogenetic, structural, and evolutionary analyses. Comparative results revealed that MIKCc-type genes are highly conserved and primarily expanded via segmental duplication under strong purifying selection. Co-expression network analysis identified MADS-box genes as high-connectivity hub candidates that are strongly associated with genes involved in tissue specification, hormone signaling, and secondary cell wall biosynthesis. Promoters analysis indicated that these genes contain diverse cis-regulatory elements; however, these results are based on sequence prediction and do not demonstrate functional regulatory interactions. Across species, MADS-box genes exhibited analogous temporal expression dynamics during lignified endocarp and seed coat development, consistent with a potentially conserved transcriptional framework. Collectively, this study provides new insights into the evolutionary diversification and putative functions of MADS-box genes, and proposes a putative hierarchical regulatory framework for lignified endocarp and seed coat development. These findings supply valuable candidate target genes for future molecular breeding aimed at improving shell thickness, hardness, and related agronomic traits in woody nut and oilseed species. Full article

This study presents a high-quality chromosome-level genome assembly of Morchella sextelata (54.64 Mb, 26 pseudochromosomes) and systematically characterizes its genomic and evolutionary features. Phylogenetic analysis indicates that M. sextelata diverged early within the Morchella genus (~14.2 million years ago) and underwent substantial genomic remodeling, with 1124 expanded and 1961 contracted gene families. Enrichment analysis of rapidly expanded gene families highlights two prominent functional themes: genes associated with small molecule/ion binding and secondary metabolite biosynthesis, and genes linked to the Fanconi anemia pathway and DNA repair/recombination. Notably, 56.96% of the COG-annotated M. sextelata-specific genes encode retrotransposon-related proteins, and this enrichment coincides with the expansion of DNA repair systems—a pattern reminiscent of the “transposon domestication” model. Functional genomic analyses further reveal that the glycoside hydrolase system is dominated by GH5, GH43, and GH3 families, suggesting a predicted capacity for plant cell wall polysaccharide degradation, while 12 biosynthetic gene clusters indicate genetic potential for terpenoid and non-ribosomal peptide biosynthesis. These findings provide a valuable genomic resource for M. sextelata and offer new insights into the role of transposable element mediated remodeling in fungal genome evolution. Full article

Tracheoid idioblasts in Nepenthes are anatomically specialized cells that differ distinctly from surrounding tissues in morphology, wall structure, and staining properties. Their presence has been documented in both vegetative organs, such as roots and stems, and in highly modified carnivorous leaves that form pitchers. We tested the hypothesis that if tracheoid idioblasts function to reinforce the mechanical strength of Nepenthes pitchers or to protect them from animal damage, they exhibit a secondary cell wall composition comparable to that of sclerenchyma or xylem cells, particularly with respect to its lignin and hemicellulose components. We assessed the localization of cell wall components in gland cell walls using histochemical tests, immunolabeling, and confocal microscopy. Light and scanning electron microscopy were used to reveal the tracheoid idioblast structure. Two species were examined: Nepenthes albomarginata T.Lobb ex Lindl. and Nepenthes bicalcarata Hook. f. In both species, giant tracheoid idioblasts with helical bands of secondary wall material were found throughout the pitchers. Negative phloroglucinol, fuchsin, and safranin staining test results demonstrated the absence of lignins in the tracheoid idioblast secondary cell walls. A histochemical test showed that the wall thickenings of the tracheoid idioblasts contained polysaccharides and cellulose and were rich in unsubstituted or low-substituted xylans, resembling the secondary cell walls of sclerenchyma and xylem cells. Our results suggest that tracheoid idioblasts with a helical secondary wall that is rich in xylans but not lignified most likely function as elastic reinforcing elements that increase the mechanical integrity of the organ while maintaining its flexibility and ability to undergo reversible deformation. Furthermore, tracheoid idioblasts may provide defense against herbivory. Full article

Ramie (Boehmeria nivea) is renowned for its superior fiber strength, length, and unique properties, yet its genetic improvement has lagged behind other fiber crops. This review synthesizes recent advances in ramie fiber development at the genetic, genomic, and molecular levels. Population genomic analyses have uncovered distinct domestication, improvement, and feralization signatures, identifying numerous fiber-related genes under selection. Parallel genetic and molecular studies have mapped scores of loci and genes governing fiber formation, laying the foundation for molecular breeding. However, despite the availability of genetic transformation systems, the need for methodological improvements remains a major challenge for engineering fiber traits via transgenic approaches. Overall, a solid research foundation has been established. Future progress in establishing marker-assisted and genomic selection breeding systems, optimizing transformation protocols, and developing efficient gene-editing methods holds promise for realizing molecular breeding to enhance fiber quality and yield in ramie. Full article

Ormosia macrocalyx grows in tropical forests and is endangered in Mexico. The species has ecological and economic importance. To evaluate the relationship between fruit length and seed number, Pearson correlation and principal component analysis were used. A linear mixed-effects model was also applied. Pearson correlation, principal components analysis (PCA) and a Linear Mixed-Effects Model (LMM) were performed on an exploratory basis. In addition, seed coat and cotyledon anatomy were examined, and histochemical tests for secondary metabolites were carried out. Two high correlations and two components were obtained from the PCA, and the LMM showed that fruit length influenced the number of seeds per fruit. In the seed coats, differentiated layers of macrosclereids and osteosclereids were identified, where the hilar region presented macrosclereids and a pyriform bar of tracheids, the reserved cotyledons showed double-walled cells and simple plasmodesmata, the histochemical analyses demonstrated the presence of cellulose, condensed tannins, lipids, alkaloids, and proteins, and no starch was present. This study provides the first description of seed coat and cotyledon anatomy in O. macrocalyx, as well as the first report of secondary metabolites in storage cotyledons. These results could be useful for further studies of this species. Full article

The co-culture between Trametes sp. D and Aspergillus niger L14 resulted in a distinct orange-brown antagonistic band at their interface. Direct hyphal contact was associated with markedly enhanced production of numerous secondary metabolites (SMs), some of which were absent or decreased in monocultures. T. sp. D induced indolic compounds and cyclic dipeptides, such as Indole-3-acetamide and Cyclo-(Pro-Phe), whereas A. niger L14 overproduced polyketide-derived pigments and organic acids, such as Fonsecin and Kojic acid. These SMs did not inhibit their producer but suppressed the opponent’s growth, indicating reciprocal chemical antagonism. Transcriptomic analysis revealed upregulation of stress-related and metabolic genes, consistent with each fungus activating defense pathways. Biochemical assays showed that the confrontation zone had the highest oxidative stress markers, cell wall-degrading enzyme activity, and acidification (notably by A. niger L14), reflecting intense interfungal antagonism. The stress-response mitogen-activated protein kinase (MAPK) pathway was also activated in both fungi. Our findings supported a mechanistic model of fungal competition involving direct contact, chemical exchange, enzymatic attack, and stress signaling, highlighting that physical interactions likely contributed to triggering cryptic secondary metabolism and robust defense responses. Full article

The toxicity of copper (Cu) severely affects the growth and physiological metabolism of plants. 2-(3,4-Dichlorophenoxy) triethylamine (DCPTA) is a plant growth regulator known to enhance plant tolerance to various abiotic stresses; however, its specific role in mitigating Cu toxicity via cell wall modulation and nitrogen metabolism remains unclear. “Zhongnong 26” (Cucumis sativus L.) seedlings were subjected to a randomized block design with four treatments: control (CK), 0.25 mg/L DCPTA, 50 μM Cu, and 50 μM Cu + 0.25 mg/L DCPTA, with three biological replicates per treatment. The results indicated that DCPTA application significantly alleviated Cu-induced growth inhibition. Specifically, DCPTA improved root system architecture by markedly increasing total root length (68.8%), surface area (68.7%), and the number and length of secondary lateral roots (69.6%, 173.2%). Furthermore, DCPTA enhanced the biosynthesis of cell wall polysaccharides—including pectin (24.3%), hemicellulose 1 (22.4%), hemicellulose 2 (23.7%) and cellulose (33.1%) in roots. Fourier Transform Infrared (FTIR) spectroscopy analysis revealed that DCPTA modified functional groups (e.g., –OH, –COOH) within the cell wall, enhancing their metal-chelating capacity. Consequently, DCPTA promoted the immobilization of Cu in the root cell wall fractions (particularly pectin and HC2) and shifted Cu into less toxic, pectate- and protein-bound forms, thereby reducing its translocation to leaves. Additionally, DCPTA restored the activities of key nitrogen metabolism enzymes in leaves and roots. Compared with Cu treatment alone, nitrate reductase (NR) activity increased by 77.7% and 90.6%, while glutamine synthetase (GS) activity remained stable, and glutamate synthase (GOGAT) activity increased by 10.3% and 71.3% in leaves and roots, respectively. In conclusion, DCPTA enhances copper sequestration in roots by coordinating the regulation of root structure and cell wall strengthening (with an increase in pectin and hemicellulose content). This is crucial for protecting the nitrogen metabolism within the cells (including the enzymes that drive the nitrate–ammonium reduction pathway) to maintain metabolic balance under Cu stress. Full article

GDSL esterase/lipase (GELP) proteins constitute an evolutionarily conserved yet functionally diversified hydrolase family in land plants. They participate in cuticle and secondary cell wall biosynthesis, seed lipid remobilization, reproductive development, and hormone-mediated responses to biotic and abiotic stresses. Despite extensive genome-wide and comparative genomic studies that have categorized large GELPs across numerous crops and model species, only a fraction of members have been functionally characterized in plants, and their catalytic mechanisms and regulatory architectures remain poorly understood. Recent population genomics and cross-species orthogroup analyses in 46 angiosperms have uncovered substantial natural variation within GELP coding sequences and regulatory regions, providing a powerful framework to link allelic diversity to evolutionary trajectories and physiological functions. This review synthesizes current knowledge on GELP evolution, biochemical properties, and roles in development and stress adaptation, and critically evaluates how these insights can be translated into biotechnology and molecular breeding strategies. It highlights emerging resources and concepts from orthogroup-based classification and multi-species datasets that enable systematic discovery of GELP alleles affecting agronomic traits. It further outlines research exploiting GELPs in crop improvement, emphasizing the integration of reverse and forward genetics with multi-omics profiling, biochemical and structural characterization, and gene regulatory network reconstruction. Systematic assessment of the phenotypic impacts of single and combinatorial GELP perturbations on yield, quality, and stress resilience is proposed as a key step toward translating basic insights into breeding and engineering strategies. Full article

Baicalin, a natural plant-derived compound, holds promise in addressing clinical bacterial resistance when combined with antibiotics. This study evaluated the antibacterial activity of the combination of baicalin and cefotaxime and explored its mechanism of action on the cell wall and biofilm of multidrug-resistant Pseudomonas aeruginosa (MRPA). The results showed that the combination of baicalin and cefotaxime exerted a synergistic inhibitory effect on the growth of MRPA, with a fractional inhibitory concentration index (FICI) of 0.28. Mechanistically, compared with cefotaxime alone, the combination of baicalin and cefotaxime enhanced the permeability of the cell membrane and cell wall of MRPA, thereby increasing cell damage. It also exhibited stronger antibiofilm activity by inhibiting numerous virulence factors (pyocyanin, elastase, lectin), reducing cellular metabolic activity, and downregulating the expression of biofilm genes (pslA, pelA, algD) and quorum-sensing genes (lasl, lasR, rhll, rhlR, pqsA, pqsR). The molecular docking results revealed that baicalin could stably bind to wbpE, LasR, and RhlR. Therefore, this interaction may indirectly influence the processes related to antibiotic resistance and biofilm formation in bacterial cells. Metabolomic analysis revealed that the combination of baicalin and cefotaxime upregulated 863 metabolites and downregulated 587 metabolites. These metabolites mainly included amino acids, lipids, nucleotides, carbohydrates, and secondary metabolites. The combination primarily enriched key pathways such as amino acid metabolism, lipid metabolism (sphingolipid metabolism) and secondary metabolite biosynthesis. Through these pathways, it triggers significant metabolic reprogramming, thereby interfering with the supply of cell wall synthesis precursors, membrane structural stability, and the generation of biomembrane matrix. Ultimately, it synergistically enhances the effects of cell wall damage and biomembrane inhibition. In conclusion, this study confirms that the combination of baicalin and cefotaxime exerts significant synergistic antibacterial activity against MRPA. It also reveals the mechanism of action of the combination on the cell wall and biofilm of MRPA at the metabolic level, providing theoretical support for the development of novel strategies to combat MRPA. Full article

With the continuous expansion of Pleurotus ostreatus cultivation, substantial quantities of post-harvest spent mushroom substrate (SMS) are generated. Improper disposal of this organic waste poses potential threats to soil health, including contamination and ecological imbalance. Consequently, a rigorous safety assessment is indispensable to support the sustainable and agronomically viable utilization of SMS as a soil amendment. In this study, P. ostreatus SMS was subjected to sterilized and non-sterilized treatments, and a controlled co-culture system integrating P. ostreatus mycelium with wheat was established. This system facilitated a comprehensive evaluation of residual mycelium impacts on wheat growth and development at phenotypic, cytological, and non-targeted metabolomics (LC-MS) levels. Results demonstrated that direct field application of non-sterilized SMS severely compromised wheat performance, inducing root necrosis and significantly reducing grain set. Comparative experiments confirmed that non-sterilized SMS—not its sterilized counterpart—exerted pronounced phytotoxic effects, markedly inhibiting seedling growth and triggering wilting symptoms. To elucidate the temporal dynamics of mycelial interaction, wheat seedlings were inoculated with viable P. ostreatus mycelium and co-cultured for seven days. Under these conditions, the mean root length of the control group (10.82 cm) was approximately threefold that of the treatment group. Histopathological analysis revealed a progressive infection pattern initiating at the root apex and extending basipetally; prolonged exposure ultimately caused complete root system collapse. Scanning electron microscopy further showed extensive mycelial colonization on infected root surfaces, accompanied by characteristic cellular damage—including severe cell wall wrinkling and widespread cell death. LC-MS profiling identified 1867 annotated compounds. Comparative analysis revealed significant dysregulation of secondary metabolism, with 495 metabolites upregulated and 419 metabolites downregulated in the treatment group. Collectively, these findings provide robust evidence that unprocessed P. ostreatus SMS poses tangible agronomic risks upon direct soil application. This study establishes a critical scientific foundation for developing safe, evidence-based protocols for the valorization and integrated management of SMS. Full article

Pasteurella multocida (P. multocida) is not only the core pathogen of bovine respiratory disease (BRDC) but also a significant zoonotic agent, posing a dual threat to global animal husbandry and public health. This study utilized untargeted metabolomics to systematically dissect the metabolic regulatory network of P. multocida in response to tylosin within a One Health framework. The results revealed significant “defense–growth” metabolic reprogramming: activation of amino sugar and nucleotide sugar pathways (e.g., CDP-glucose) indicated cell wall remodeling, while directional shifts in the phenylalanine–tyrosine network directed flux toward defensive secondary metabolites. Concurrently, amino acid disorders and the overactivation of the ABC transporter system exacerbated an internal energy crisis, characterized by a shift from respiration to glycolysis, ATP depletion, and ROS accumulation. SEM observations confirmed membrane integrity disruption and cytoplasmic leakage. Crucially, this metabolic stress and the transition into a “persister-like” dormant state are closely linked to the adaptive expression of antimicrobial resistance (AMR) genes. Under the selective pressure of tylosin, these metabolic perturbations may facilitate the emergence and horizontal transfer of resistance determinants, which can circulate through the animal–human–environment interface. By revealing the metabolic physiological basis of tylosin’s action and its role in inducing bacterial tolerance, this study provides critical theoretical insights for antimicrobial stewardship, aiming to mitigate the risk of AMR transmission and preserve the efficacy of macrolides for both veterinary and human medicine. Full article

Secondary cell wall (SCW) formation and lignin biosynthesis are critical biological processes that determine wood properties. Masson pine (Pinus massoniana Lamb) is a fast-growing conifer species with significant economic value for the pulp and paper industry. While R2R3-MYB transcription factors are known as master regulators of SCW biosynthesis, the specific R2R3-MYB members regulating lignin formation in Masson pine remain largely uncharacterized. In this study, we identified 317 R2R3-MYB genes in the Masson pine genome. Phylogenetic analysis revealed that PmMYB289, a member of the P20 subgroup, is highly homologous to the Arabidopsis SCW regulators AtMYB52 and AtMYB54. Expression profiling demonstrated that PmMYB289 is predominantly expressed in highly lignified old stems. Transcriptional activation assays confirmed that PmMYB289 lacks autoactivation activity. Subcellular localization analysis revealed that PmMYB289 was localized to the nucleus. Ectopic overexpression of PmMYB289 in tobacco (Nicotiana benthamiana) resulted in dwarfed plant growth, reduced stem diameter, and curled leaves. Molecular analysis of these transgenic lines showed a significant downregulation of most key SCW biosynthetic genes, with the exception of NbPAL1. These findings indicate that PmMYB289 acts as a crucial transcriptional repressor in SCW biosynthesis, providing valuable genetic resources for the molecular breeding of superior Masson pine varieties. Full article