Plant Tissues Research Articles

Root nutrient uptake, photosynthetic transients, growth and leaf anatomy of Citharexylum myrianthum suggest tolerance to soil cadmium toxicity

ABSTRACT The increase in water and soil contamination by potentially toxic elements (PTEs) constitutes a major environmental concern. Amongst these elements, cadmium (Cd) stands out due to its high mobility in both soil and plant vascular tissue. Consequently, effective strategies for PTE removal are urgently needed. This study aimed to examine the growth, anatomical and cellular traits, chlorophyll fluorescence, macro- and micronutrients content of Pau-Viola (Citharexylum myrianthum Cham.) seedlings exposed to different Cd concentrations 0.25, 0.5, or 0.75 μmol/kg in soil. C. myrianthum seedlings exposed to Cd exhibited minimal alterations in morphophysiological attributes. Cadmium was predominantly retained in the root system with limited translocation to the shoots, thereby preserving growth and nutritional balance. The lower Cd accumulation in the leaves helped maintain the integrity of the photosynthetic electron transport chain and the chlorophyll index, resulting in only minor changes in chlorophyll a fluorescence transients. The observed tolerance of C. myrianthum to Cd-initiated toxicity suggests metallic potential use in reforestation programs for Cd-contaminated areas, as the species demonstrated resilience and physiological stability under such conditions.

Highly Sensitive and Selective Turn-On Fluorescent Carbon Dots for Real-Time Ethylene Sensing and Imaging in Plant Tissues

Highly Sensitive and Selective Turn-On Fluorescent Carbon Dots for Real-Time Ethylene Sensing and Imaging in Plant Tissues

In vitro Assessment of the Antifungal Effects of Papaya Seed Extracts on Selected Fungal Pathogens Associated with Garden Egg Plants

Garden egg (Solanum aethiopicum) is a nutritionally important vegetable widely cultivated in Africa, yet its production is significantly hampered by fungal pathogens that infect wounds and other plant tissues. This study evaluated the in vitro antifungal efficacy of Carica papaya (papaya) seed extracts against fungal species commonly associated with garden egg infections, including Fusarium spp., Aspergillus niger, and Rhizopus stolonifer. Methanolic and ethanolic extracts of papaya seeds were prepared and tested using agar diffusion and biomass inhibition methods. Fungal isolates were obtained from infected garden egg samples in Kogi State, Nigeria, and identified morphologically. The methanol extract showed superior inhibitory effects on fungal radial growth compared to the ethanol extract, with minimum inhibitory concentrations (MIC₅₀) of 35% for Fusarium spp. and 40% for A. niger, while Rhizopus sp. was less sensitive. Both extracts significantly suppressed fungal growth, though commercial fungicide Benlate exhibited complete inhibition. The study highlights the potential of papaya seed extracts as affordable, eco-friendly, and safe alternatives to synthetic fungicides for managing fungal diseases in garden egg cultivation, promoting sustainable agriculture and reducing reliance on chemical pesticides

Bioinformatics Analysis and Functional Verification of Phytoene Synthase Gene PjPSY1 of Panax japonicus C. A. Meyer

Phytoene synthase (PSY) is a multimeric enzyme that serves as the first enzyme in carotenoid synthesis within plant tissues and plays a crucial role in the production of carotenoids in plants. To understand the function of the PSY gene in Panax japonicus C. A. Meyer. fruit, the gene’s transcript was obtained by analyzing the transcriptome sequencing data of Panax japonicus fruit. The CDS sequence of the gene was cloned from Panax japonicus fruit using the RT-PCR cloning technique and named PjPSY1, which was then subjected to biosynthetic analysis and functional verification. The results showed that the open reading frame of the gene was 1269 bp, encoding 423 amino acids, with a protein molecular mass of 47,654.67 KDa and an isoelectric point (pI) of 8.63; the protein encoded by these amino acids was hydrophilic and localized in chloroplasts, and its three-dimensional structure was predicted by combining the pymol software to annotate the N site of action and active centre of the protein. Phylogenetic analysis demonstrated that PjPSY1 had the closest affinity to DcPSY from Daucus carota. Overexpression of PjPSY1 led to a significant increase in the content of carotenoid-related monomers in Arabidopsis thaliana, with Violaxanthin being synthesized in transgenic Arabidopsis thaliana but not in wild-type Arabidopsis thaliana. The PjPSY1 clone obtained in this study was able to promote carotenoid synthesis in the fruits of Panax japonicus, revealing that the mode of action of PjPSY1 in the carotenoid biosynthesis pathway of Panax japonicus fruits has a positive regulatory effect.

Diversity of organ-specific plant transcriptomes

Plant transcriptomes comprise nuclear and organellar (mitochondrial and plastid) transcripts expressed by nuclear and organellar genomes, respectively. They are spatiotemporally shaped during development. The aim of this review was to summarize the most relevant transcriptomic responses in various plant organs and tissues in the developmental context. The dynamicity of organ- or tissue-specific transcriptomic responses was discussed based on the complexity and diversity of the recently characterized plant genomes and transcriptomes. Data were taken from high-throughput studies on numerous species, including model, crop and medicinal plant species. Vascular element transcriptomes as well as the root, leaf, flower and seed transcriptomes were exhaustively characterized. Transcriptomic alterations within various tissue and organ-specific transcriptomes employed various gene classes depending on the species, a given organ/tissue and the developmental stage. The specificity of organ-specific transcriptomes related to the over-representation of certain gene families and a plethora of transcription factors was focused. In addition, transcriptomes of medicinal plant species were characterized. The perspectives of medicinal plant species to synthesize valuable secondary metabolites (including quinones, carotenoids, phytoestrogens, terpenoids, steroids, flavonoids, phenolic derivatives, polysaccharides, glycosides, anthocyanins and macrocyclic peptides) were described based on organ transcriptomic patterns. Future research should be broadened by investigation of transcriptomes from field grown plants. Also, the potential of biomedical plants should be better revealed by genetic engineering and genome editing in further biotechnological applications.

Trans-organ analysis of gene co-expression networks reveals a mobile long-distance regulator that balances shoot and root development in Arabidopsis.

Long-distance regulation between individual organs is a fundamental process for the optimized adaptation of the plant body to diverse environments. However, systematic methods for identifying key genes for long-distance regulation are currently unavailable. Here we present a new approach, trans-organ analysis of gene co-expression networks, which offers a unique way of identifying candidates for such genes. This approach revealed that TGA7 functions as a shoot-to-root mobile bZIP transcription factor in Arabidopsis to activate photosynthetic genes directly in shoots and nitrate-uptake-related genes, both directly and via a transcriptional cascade, in roots. Analysis of grafted chimeras showed that nitrogen-deficiency-induced enhanced TGA7 expression in shoot vascular tissue promotes TGA7 protein accumulation in roots, boosting root growth and nitrate uptake. Furthermore, the loss of TGA7-mediated long-distance regulation perturbed the balance between shoot and root development under nitrogen deficiency. These findings underscore the utility of our approach for uncovering long-distance regulation in plants.

Genomics and Transcriptomics of Candidatus Phytoplasma Asteris Induced Sesame Phyllody Modulating Hormonal and Defense Alterations.

Sesame phyllody, a destructive disease caused by phytoplasma infection, induces severe morphological abnormalities, including floral virescence, phyllody, witches' broom, leaf deformation, and stunted growth. This study aimed to characterize phytoplasma isolates from diverse regions of India, identifying them as Candidatus Phytoplasma asteris (16Sr-I), Candidatus Phytoplasma citri (16Sr-II), and Candidatus Phytoplasma australasia (16Sr-II). Whole-genome sequencing of Candidatus Phytoplasma asteris isolate SPGN revealed a genome size of 563,754 bp, encoding 542 proteins, including several genes associated with antibiotic resistance. Effector prediction analysis identified key virulence-associated proteins, such as SAP50-like, SAP34-like, TENGU-su inducer, and immunodominant membrane proteins, which manipulate host development and immune responses. Transcriptomic analysis of infected sesame plants revealed significant gene expression alterations, with upregulated genes linked to floral malformation, vascular tissue modifications, and stress responses, while the downregulated genes were associated with flavonoid metabolism and immune signaling. Phytoplasma infection disrupted hormonal pathways, leading to increased expression of auxin, cytokinin, and gibberellin-related genes, suggesting hormonal dysregulation as a key factor in symptom development. Furthermore, immune suppression was evident through the downregulation of key defense-related genes, including those involved in MAPK signaling and pathogenesis-related protein families. These findings enhance our understanding of phytoplasma pathogenesis in sesame and provide potential targets for developing effective disease management strategies.

Optimizing spirotetramat applications for effective onion thrips control in bulb and green onions.

Onion thrips, Thrips tabaci Lindeman, (Thysanoptera: Thripidae) is the most significant pest of Alliums (Amaryllidaceae) and is primarily managed with insecticides. Spirotetramat, a systemic insecticide, is currently recommended for early season use in bulb onion production, but its residual effects based on application timing, frequency, and plant age are poorly understood. From 2016 to 2023, we conducted a series of trials assessing the impact of these factors on thrips control. We compared 2 application timings and frequencies on onion thrips management in bulb onions. Finally, we conducted a separate green onion experiment, altering plant age and application frequency to determine the effect on onion thrips populations and spirotetramat uptake by the plant. Our results showed that 2 sequential applications of spirotetramat reduced onion thrips densities by 50%, but application timing had no impact on thrips densities in both bulb and green onions. Green onions that received 2 applications of spirotetramat had significantly higher spirotetramat levels in the leaf tissue than those treated once. In green onions, more spirotetramat was detected in young plants compared with older ones, and there was a negative correlation between spirotetramat levels in leaf tissue and onion thrips densities on plants. Overall, our results indicated that 2 applications of spirotetramat are necessary for effective onion thrips control on bulb onion and green onion, likely due to increased insecticide levels in plant tissue.

Critical Levels of Copper, Zinc, and Manganese Toxicity in Soil and Tissues of Plants That Cohabit Vineyards in the Pampa Biome

Old vineyards in production in the Pampa biome have high levels of metals, such as copper (Cu), zinc (Zn), and manganese (Mn). The high metal contents in the soil can damage the growth and development of the cover plant species that cohabit the vineyards. However, it is possible to define the critical toxicity level (CTL) of metals in soil and tissue in order to monitor and define possible strategies for reducing metal inputs and selecting more tolerant species. This study aimed to define the CTL of Cu, Zn, and Mn in the soil and plant tissue of plants present between the rows of vineyards with different cultivation histories in the Pampa biome in South America. For this purpose, soil and plant tissue samples were collected in a native field area (NF), without agricultural cultivation and in two vineyards, vineyard 1 (V1) and vineyard 2 (V2), both with a history of fungicide application. To define the CTL, the foliar concentrations and soil contents of Cu, Zn, and Mn were correlated with the dry mass production of the shoot. The CTLs for Cu, Zn, and Mn in the soil were set at 15, 3.0, and 35 mg kg−1, respectively. In the tissue, CTLs for Cu, Zn, and Mn were estimated at 75, 77, and 380 mg kg−1, respectively. The contents of Cu, Mn, and Zn in the soil of the vineyards are above the CTL. The concentrations of the metals in the tissue varied, with samples above the CTL for Cu and Zn in the vineyards. The values of Cu, Zn, and Mn in NF are below the CTL in soil and tissue. The high contents of Cu, Zn, and Mn in the soil and tissue limited the dry mass production of the plants between the rows of vineyards.

Transcriptome and 2-DE proteome analyses reveal defense-associated development in the leaf galls induced by psyllids on Machilus japonica var. kusanoi.

Galls are abnormal plant tissues that result from the interaction between the defense responses of plants and the activities of galling herbivores. During infection, secondary metabolites are synthesized to mitigate the oxidative stress whereas growth and cellular processes in infected tissues are reprogrammed. Although the regulatory networks of growth-related phytohormones are recognized as the main component in gall formation, other factors like oxidative stress might also being critical in gall development. In this study, we focused on the spherical psyllid galls found in the leaves of Machilus japonica var. kusanoi to analyze the differences in transcript, protein content, and several metabolites between galls and leaves. Early gall tissues were enriched in cell cycle regulation and organization genes, suggesting processes, such as mitosis, meiosis, and microtubule-based movement. Proteins such as CAM7, LSH6, and eIF2β, associated with seed development, were highly expressed in early gall tissues. We demonstrated a significant role for ROS-related stress responses in early gall development. Higher amount of polyphenols, which are well-known antioxidants, was found in gall tissue as well. This study provides valuable insights into the mechanisms underlying gall development and enhances our understanding of this complex process. Future research should explore the impact of ROS modulation on gall tissue development and assess phytohormone content at various psyllid larval and gall stages to elucidate the regulatory network involved in gall morphogenesis.

Expression of a multigene mushroom luciferin biosynthesis pathway as a pseudo-polycistron in plants.

Mushroom bioluminescence is based on a luciferin/luciferase cycle that includes four catalytic enzymes and a post-translational modifier phosphopantetheinyl-transferase (NpgA). The luciferin cycle includes conversion of the plant cell wall precursor caffeic acid to the mushroom luciferin (3-hydroxyhispidin) substrate-suggesting a logical system for development of in vivo luciferin production rather than addition of exogenous luciferin substrate. In planta luciferin biosynthesis is demonstrated from a polycistronic concatenation of the luciferin pathway genes with intervening self-cleaving intein-F2A peptides. Bioluminescence was greater with NpgA transiently expressed separately from the luciferin biosynthesis (LBS) polycistron in N. benthamiana but was not detectable in tomato even with all genes on separate promoters. Separation of the bioluminescence reporter and luciferin substrate pathway facilitated studies of mushroom luciferase that reveal instability for the luciferin substrate. Agrobacterium expressing the luciferase is shown to be an effective quantitative biosensor for both the presence of luciferin as well as plant tissue quenching of bioluminescence during tissue disruption. Large plant species-dependent differences in bioluminescence assay quenching are observed, with tomato displaying instantaneous suppression comparable to wild-type negative controls. Although bioluminescence is observed using transient luciferin/luciferase co-expression in tobacco (N. benthamiana), luciferin could not be isolated for use in exogenous assay. The challenge of using the mushroom luciferin biosynthesis pathway in transgenic plants as a complementation reporter is discussed in the context of our inability to detect luciferin in tomato transgenic lines after homozygous segregation using digital PCR. The utilization of in vivo mushroom luciferin biosynthesis is anticipated to be increasingly effective in the future based on ongoing gene improvements in pathway biosynthesis subject to the constraint of substrate instability.

Quince seed mucilage as an alternative for agar in plant tissue culture

In order to reduce the expenses of plant tissue culture for plant industry, cheaper materials and/or equipment would be welcome especially in developing countries. In the present study, we tested mucilage extracted from seeds of quince (Cydonia oblonga) as alternative for agar in tissue culture. The seeds are currently disposed of as waste products of fruit industry. Tomato and tobacco lateral buds and stems were used as explants, and callus formation and the number of shoots, roots, and leaves were measured after thirty days of in vitro culture. The performance of quince mucilage based medium (QM) in comparison to agar was studied, varying the amounts of hormones, salts and sucrose in the medium. Statistical analyses, based on negative binomial regression, show that QM improved the production of callus, shoots, roots and leaves from tobacco explants. In tomato, results from QM and agar were similar to each other except with root production in which QM excelled. The results suggest that QM has potential for use as a gelling agent in plant tissue culture.

Genome-wide identification, evolution, and expression analysis of StNRT (nitrate and peptide transporter) gene family in potato (Solanum tuberosum L.)

BackgroundNitrate and peptide transporters play crucial roles in the uptake, and allocation of nitrate in plant cells and tissues. They are essential in the utilization of nitrogen, as well as in plant development, crop production and yield formation. The NRT family (Nitrate Transporter/Peptide Transporter familiy, NRT/NPF) is one of the largest transporter families in the plant kingdom. Some family members have been extensively studied in thale cress (Arabidopsis thaliana) and rice (Oryza sativa). Although it has been reported in potatoes, it has not been comprehensively and systematically analysed yet. The purposes of this research were to comprehensively identify the NRT genes in the potato genome, to systematically analyze the gene structure, chromosomal distribution, and cis-elements in promoter regions, to identify protein conserved domains and motifs, and to study the expression profile of the StNRT gene in different tissues and under nitrogen stress.ResultsBioinformatics and transcriptome analyses of the StNRT gene family were conducted to dissect the structure, evolution, and expression of the StNRTs in Solanum tuberosum L. In total, 81 StNRT genes were identified and classified into 4 clades. Chromosomal localization analysis revealed that the 81 StNRT genes were located on 12 chromosomes of potato. Among these genes, 2 pairs of genes (StNRT53/56 and StNRT61/62) were predicted to be tandemly duplicated genes, and 8 pairs of genes were segmentally duplicated genes. The collinearity analysis revealed that the StNRTs in potato were closely related to the SlNRTs in tomato. The expression profiles of the StNRTs in different tissues and under different nitrogen conditions revealed distinct spatial expression patterns of these genes and their potential roles in response to various nitrogen conditions. Multiple StNRT genes exhibited differential expression in the roots, stems, and leaves of Qingshu 9 and Xiazhai 65 potato seedlings, indicating their potential key roles in regulating nitrate uptake in potato.ConclusionsThis study systematically characterizes the gene structure, conserved protein domains and motifs, evolutionary relationships, and expression profiles of the StNRT gene family in S. tuberosum. These findings provide critical insights into the functional mechanisms of StNRTs, and identify candidate genes for improving the nitrogen use efficiency (NUE) in potato cultivation.

An updated sulfate transporter phylogeny uncovers a perennial-specific subgroup associated with lignification.

Sulfate-proton co-transporters (SULTRs) mediate sulfate uptake, transport, storage, and assimilation in plants. The SULTR family has historically been classified into four groups (SULTR1-SULTR4), with well-characterized roles for SULTR groups 1, 2, and 4. However, the functions of the large and diverse SULTR3 group remain poorly understood. Here, we present an updated phylogenetic analysis of SULTRs across angiosperms, including multiple early-divergent lineages. Our results suggest that the enigmatic SULTR3 group comprises four distinct subfamilies that predate the emergence of angiosperms, providing a basis for reclassifying the SULTR family into seven subfamilies. This expanded classification is supported by subfamily-specific gene structures and amino acid substitutions in the substrate-binding pocket. Structural modeling identified three serine residues uniquely lining the substrate-binding pocket of SULTR3.4, enabling three hydrogen bonds with the phosphate ion. The data support the proposed neofunctionalization of this subfamily for phosphate allocation within vascular tissues. Transcriptome analysis of Populus tremula × alba revealed divergent tissue expression preferences among SULTR subfamilies and between genome duplicates. We observed partitioned expression in vascular tissues among the four SULTR3 subfamilies, with PtaSULTR3.4a and PtaSULTR3.2a preferentially expressed in primary and secondary xylem, respectively. Gene coexpression analysis revealed coordinated expression of PtaSULTR3.4a with genes involved in phosphate starvation responses and nutrient transport, consistent with a potential role in phosphate homeostasis. In contrast, PtaSULTR3.2a was strongly coexpressed with lignification and one-carbon metabolism genes and their upstream transcription regulators. PtaSULTR3.2a belongs to a eudicot-specific branch of the SULTR3.1 subfamily found only in perennial species, suggesting a specialized role in lignifying tissues. Together, our findings provide a refined phylogenetic framework for the SULTR family and suggest that the expanded SULTR3 subfamilies have undergone neofunctionalization during the evolution of vascular and perennial plants.

The role of plant host genetics in shaping the composition and functionality of rhizosphere microbiomes.

The plant microbiome comprises a wide range of microorganisms associated with different plant tissues. Over the past decades, significant research efforts have focused on understanding and harnessing the plant rhizosphere microbiome for optimal plant growth and health. However, while environmental factors are often the primary focus of these studies, the influence of plant genotype remains comparatively underexplored. In fact, the plant genotype influences a multitude of factors including root morphology and exudate composition, which play an integral role in shaping the rhizosphere niche. In this review, we discuss how alterations in plant host genetics could lead to differences in the assembly and diversity of the rhizosphere microbiome. Furthermore, we summarize current approaches to decipher complex plant traits and their ecological implications in host-microbiome systems and interactions.

Genotypic variations of Tamarix aphylla (L.) H.Karst. population for heavy metal phytoremediation: a case study in Markazi province, Iran

BackgroundIn recent years, there has been a growing focus on utilizing suitable plant species for the extraction of heavy metals from contaminated soils. Trees offer a more economically viable option for remediating heavy metal-contaminated soils as their extensive root systems, substantial biomass, lower requirements, and management contribute to reduced operational costs. This study seeks to enhance the understanding of metal accumulation in Tamarix aphylla (L.) H.Karst. and to investigate the variation among different genotypes from the Markazi province in Iran. The genotypes were selected from 11 distinct locations within central Markazi province. One-year-old cuttings were planted in contaminated soil from the effluent outlet of an industrial area in mid-April. The morpho-physiological characteristics and levels of heavy metals in the plant tissues were assessed after a duration of three months.ResultsThe results revealed that the roots of the Ahmad-Abad genotype exhibited the highest levels of copper, iron, manganese, and zinc absorption, whereas its branches demonstrated the greatest sodium uptake. Notably, the Ahmad-Abad genotype also showed the highest potassium absorption. Collectively, these findings suggest that the Ahmad-Abad genotype is particularly suitable for phytoremediation efforts in contaminated environments due to its capacity to accumulate elevated levels of heavy metals.ConclusionsThe research study provides valuable insights into genetic variation, ecotype diversity, and the potential for genetic engineering to enhance phytoremediation processes in T. aphylla.

Combined application of biochar and PGPR alleviates Cd stress in wheat by improving antioxidant defense mechanism and crop physiology

Soil heavy metals toxicity is an emerging threat for ecosystem and environment; therefore a greenhouse pot experiment was conducted to investigate the impact of corn stalk (CSBC) and farmyard manure biochar (FYMBC) coupled with the seed inoculation of Bacillus cereus (PGPR1) and Pseudomonas frederiksbergensis (PGPR2) strains under Cd stress on wheat production, antioxidants, osmoprotectants and soil biochemical characteristics. Overall, results of the study revealed that Cd pollution significantly (p < 0.05) reduced the plant growth by accumulating in plant tissues. However, the combined application of FYMBC+PGPR2 notably improved plant physiology and yield attributes. Moreover, wheat chlorophyll a (15.27%), b (16.39), total chlorophyll (15.96), photosynthetic rate (22.29), stomatal conductance (13.52) and transpiration rate (12.21) significantly increased under FYMBC+PGPR2 treatment. Similarly, a significant improvement was also observed in plant osmoprotectants and antioxidants activity, whilst Cd uptake in roots and shoots decreased up to 39.37 and 55.32% under respectively FYMBC+PGPR2 amendment. Additionally, soil nutrients including total N (565.61), available P (42.15) and K (19.78) along with PLFA (49.78) and bacterial CUE (63%) also showed efficiency under the integrated application of FYMBC+PGPR2. Inclusively, these findings provide a sustainable solution for the bioremediation of Cd in agricultural soil by improving soil and plant health.

Structural elucidation of the haptoglobin-hemoglobin clearance mechanism by macrophage scavenger receptor CD163.

Intravascular hemolysis releases hemoglobin into the bloodstream, which can damage vascular and renal tissues due to its oxidative nature. Circulating haptoglobin acts as a primary defense by binding to free hemoglobin, forming a haptoglobin-hemoglobin (HpHb) complex that is then recognized and cleared by the CD163 scavenger receptor on macrophages. While the function and structure of HpHb complex are mostly well-defined, the molecular mechanism underlying its interaction with CD163 remains unclear. Here we report the cryo-electron microscopy structures of human CD163 in its unliganded state and in its complex with HpHb. These structures reveal that CD163 functions as a trimer, forming a composite binding site at its center for one protomer of the dimeric HpHb, resulting in a 3:1 binding stoichiometry. In the unliganded state, CD163 can also form a trimer, but in an autoinhibitory configuration that occludes the ligand binding site. Widespread electrostatic interactions mediated by calcium ions are pivotal in both pre-ligand and ligand-bound receptor assemblies. This calcium-dependent mechanism enables CD163/HpHb complexes to assemble and, once internalized, disassemble into individual components upon reaching the endosome, where low calcium and lower pH conditions prevail. Collectively, this study elucidates the molecular mechanism by which CD163-mediated endocytosis efficiently clears different isoforms of HpHb.

Identification and characterization of the pathogens causing Fusarium dry rot of potatoes

Based on the results obtained in this study, the taxonomic status of 11 fungal strains belonging to the Fusarium oxysporum species complex isolated from potato tubers with symptoms of Fusarium dry rot collected in three federal districts of the Russian Federation was clarified. The pathogenicity of strains to tubers of three potato cultivars and their sensitivity to fungicides recommended for the protection of this crop were characterized. The phylogenetic analysis of fragments of translation elongation factor (tef) and large subunit of RNA polymerase II (rpb2) genes allowed to identify the analyzed Fusarium strains as representatives of two species – F. oxysporum s. str. (4) and F. nirenbergiae (7). The F. nirenbergiae strains turned out more aggressive to tubers of potato cultivars ‘Gala’, ‘Impala’ and ‘Red Scarlett’ and caused on average 1.3–1.9 times more extensive damage of plant tissue (19.0–41.6 mm) compared to F. oxysporum strains (3.2–34.6 mm), which demonstrated high intraspecific variability in pathogenicity. Characterization of strain’ sensitivity to four fungicides containing active substances from different chemical classes revealed both interspecific and intraspecific differences of fungi. The strains of both species were the most sensitive to the benomyl-containing fungicide, which effectively inhibited fungal growth (EC50 = 0.0003 % on average for each species). The lowest sensitivity of the strains, especially F. oxysporum, was found in relation to the fludioxonil-containing fungicide (EC50 &gt; 1 %).

Diversity and functional roles of endophytic and rhizospheric microorganisms in Ophioglossum vulgatum L.: implications for bioactive compound synthesis

BackgroundOphioglossum vulgatum L. is a widely utilized medicinal plant, with the entire plant being used for medicinal purposes. This study systematically characterized the endophytic and rhizospheric community structure, taxonomic diversity, and symbiotic networks within distinct compartments of O. vulgatum, while evaluating their potential associations with the accumulation of pharmacologically active metabolites.MethodsEndophytic and rhizospheric community profiling was conducted via Illumina sequencing, while bioactive compounds were identified using UPLC-ESI-MS/MS.ResultsRoots and leaves harbored beneficial bacteria (e.g., Methylobacterium, Streptomyces, Sphingomonas, and Flavobacterium). Dominant fungi included Archaeorhizomyces (rhizosphere soil) and Homophron (roots/leaves). Dark septate endophytes (DSEs; e.g., Cladosporium, Cladophialophora, and Chaetomium) were abundant across rhizosphere soil, roots, and leaves. Alpha/beta diversity analyses showed higher microbial richness in rhizosphere soil than in plant tissues. Functional predictions (PICRUSt2/FUNGuild) linked endophytic and rhizospheric bacteria to metabolism, human diseases, and biological systems. Network analysis highlighted Basidiomycota as keystone taxa, with modular community structure. Functional predictions revealed that endophytic and rhizospheric microorganisms were associated with critical metabolic pathways, particularly in the biosynthesis of flavonoids and alkaloids (primary bioactive compounds). LEFSe analyses highlighted compartment-specific biomarkers: Acidobacteria, Basidiomycota, and Ascomycota were enriched in distinct zones (rhizosphere, roots, and leaves), with Actinobacteria exhibiting highly significant correlations (P &amp;lt; 0.01) with flavonoids, lipids, and quinones, while Acidobacteria, Basidiomycota, and Ascomycota were strongly linked to steroids and tannins (P &amp;lt; 0.05).ConclusionThe diversity and abundance of microbial communities in O. vulgatum exhibited tissue-specific and rhizosphere-dependent variations, with distinct patterns strongly correlating to bioactive compound accumulation. Notably, biomarker taxa including Actinobacteria, Acidobacteria, Basidiomycota, and Ascomycota demonstrated robust microbe–metabolite interactions, suggesting their critical regulatory role in biosynthesis pathways. These findings establish endophytic-rhizospheric microbiota as key biosynthetic modulators, proposing innovative approaches for enhancing phytochemical production through targeted microbial community manipulation.