Jana Cechova

This study investigated the composition and temporal dynamics of wood-inhabiting fungal communities in four aging tree species in Lednice Castle Park (Czech Republic), located within the Lednice–Valtice Cultural Landscape, a UNESCO World Heritage Site. Forty wood cores were collected from 20 trees at two time points (2023 and 2024). The hosts included horse chestnut (Aesculus hippocastanum L.), copper beech (Fagus sylvatica ‘Atropunicea’ L.), oak (Quercus robur L.), and poplar (Populus alba L.), each exhibiting visual signs of decline. Fungal assemblages were profiled using ITS2 high-throughput amplicon sequencing. Ascomycota dominated across all hosts (72–89% of reads), while Basidiomycota contributed 8–24%, largely represented by Agaricomycetes in F. sylvatica. Alpha diversity varied significantly among hosts (Shannon: F_3,36 = 10.61, p = 0.001 in 2023; F_3,36 = 10.00, p = 0.001 in 2024). Temporal shifts were host-dependent: F. sylvatica exhibited the strongest year-to-year decline in richness (Chao1: −83%, p = 0.007) and increased beta dispersion, while A. hippocastanum and P. alba showed significant increases in diversity (+65% and +42%, respectively). Community composition was shaped by host species (PERMANOVA Bray–Curtis: p = 0.001) and shifted over time (Jaccard: p = 0.001), with F. sylvatica showing the highest temporal turnover. Functional guild analysis revealed consistent dominance of saprotrophs (29–41%) and mixed pathotroph–saprotroph guilds (23–36%) across hosts, indicating active degradation processes inside functional xylem. These results indicate that, within the studied system, the wood mycobiome of aging trees is host-dependent and temporally dynamic rather than static or functionally neutral. Short-term temporal turnover observed between sampling years may contribute to shifts in fungal community composition and succession within wood, with potential implications for tree decline processes in managed historical park landscapes.

The genus Tilia (Malvaceae) comprises long-lived broadleaf trees of considerable ecological, cultural, and historical importance in temperate Europe and Asia. Among these, Tilia × europaea L. (common European linden) is a key native species in Central and Northern Europe, with individuals documented to live for several centuries. While the phyllosphere and soil-associated microbiomes of linden have been studied, the internal fungal communities inhabiting ancient trees remain poorly understood. In this study, the complete mycobiome of linden tree wood was analyzed. Wood-inhabiting fungi (the wood mycobiome) include endophytes, saprotrophs, and potential pathogens that can strongly influence host vitality and ecosystem processes. Advances in high-throughput amplicon sequencing (HTAS) now provide unprecedented opportunities to characterize these hidden communities. In this study, we investigated the trunk wood mycobiome of an ancient T. × europaea L. individual using a culture-independent HTAS approach. The results reveal a diverse fungal assemblage, including taxa like Arthinium or Phialemonium not previously reported from living linden wood, and highlight potential implications for tree health and longevity. This work provides a first baseline characterization of the internal mycobiome of the ancient Tilia tree and contributes to broader efforts to conserve its biological and cultural value.

This study investigated the composition and temporal dynamics of wood-inhabiting fungal communities in four aging tree species in Lednice Castle Park (Czech Republic), located within the Lednice–Valtice Cultural Landscape, a UNESCO World Heritage Site. Forty wood cores were collected from 20 trees at two time points (2023 and 2024). The hosts included horse chestnut (Aesculus hippocastanum L.), Copper beech (Fagus sylvatica ʻAtropuniceaʼ L.), oak (Quercus robur L.), and poplar (Populus alba L.), each exhibiting visual signs of decline. Fungal assemblages were profiled using ITS2 high-throughput amplicon sequencing. Ascomycota dominated across all hosts (72 – 89 % of reads), while Basidiomycota contributed 8 – 24 %, largely represented by Agaricomycetes in F. sylvatica. Alpha diversity varied significantly among hosts (Shannon: F₃,₃₆ = 10.61, p = 0.001 in 2023; F₃,₃₆ = 10.00, p = 0.001 in 2024). Temporal shifts were host dependent: F. sylvatica exhibited the strongest year-to-year decline in richness (Chao1: - 83 %, p = 0.007) and increased beta dispersion, while A. hippocastanum and P. alba showed significant increases in diversity (+ 65 % and + 42 %, respectively). Community composition was shaped by host species (PERMANOVA Bray–Curtis: p = 0.001) and shifted over time (Jaccard: p = 0.001), with F. sylvatica showing the highest temporal turnover. FUNGuild analysis revealed consistent dominance of saprotrophs (29 – 41 %) and mixed pathotroph–saprotroph guilds (23 – 36 %) across hosts, indicating active degradation processes inside functional xylem. These results demonstrate that the wood mycobiome of aging trees is neither static nor functionally neutral, but host-dependent and temporally dynamic. Short-term environmental variation may accelerate fungal succession inside wood, potentially influencing tree decline trajectories in managed historical park landscapes.

The genus Tilia (Malvaceae) comprises long-lived broadleaf trees of considerable ecological, cultural, and historical importance in temperate Europe and Asia. Among these, Tilia × europaea L. is a key native species in Central and Northern Europe, with individuals documented to live for several centuries. While the external and soil-associated microbiomes of linden have been studied, the internal fungal communities inhabiting ancient trees remain poorly understood. Wood-inhabiting fungi (the wood mycobiome) include endophytes, saprotrophs, and potential pathogens that can strongly influence host vitality and ecosystem processes. Advances in high-throughput amplicon sequencing (HTAS) now provide unprecedented opportunities to characterize these hidden communities. In this study, we investigated the trunk wood mycobiome of an ancient Tilia × europaea L. individual using a culture-independent HTAS approach. The results reveal a diverse fungal assemblage, including taxa like Arthinium or Phialemonium not previously reported from living linden wood, and highlight potential implications for tree health and longevity. This work provides a first baseline characterization of the internal mycobiome of ancient Tilia trees and contributes to broader efforts to conserve their biological and cultural value.

There exists a wide range of plant pathogens that are commonly referred to as seed-borne pathogens due to their dominant mode of spread. Treating seeds to eliminate such pathogens is therefore very important in contemporary seed production. In the present study, eight types of nanoparticles were evaluated for their effectiveness against Xanthomonas hortorum pv. carotae, a seed-borne pathogen that affects plants of the Apiaceae family. Initially, parameters considering the inhibitory and bactericidal activity of individual nanoparticles were evaluated under in vitro conditions. In this way, three nanoparticles based on copper, silver, and silver/selenium composite were identified as being the most effective. Subsequently, their ability to eliminate Xanthomonas hortorum pv. carotae from artificially infected carrot seeds was tested. This was achieved through the qPCR quantification of the pathogen in 14-day-old plantlets developed from seeds inoculated with Xhc. Based on the obtained results, copper-based nanoparticles were the most effective, resulting in an approximately 10-fold decrease in the occurrence of Xhc in plantlets compared to the untreated control. Taking into account the fact that X. hortorum pathovars also attack other important horticultural crops, the presented results may have a much wider scope than just carrot seeds.

Neofusicoccum parvum (Pennycook & Samuels) Crous, Slippers & A.J.L. Phillips is a cosmopolitan pathogen causing dieback of multiple diverse woody hosts including highbush blueberry (Vaccinium corym...

Tomato is the most consumed vegetable in the world. The tomato brown rugose fruit virus (ToBRFV) is an important destructive virus that damages tomatoes and peppers with significant economic impact. The detection and characterization of this important viral pathogen were evaluated at the molecular and morphological level. The viral isolate was purified and inoculated on tomato and pepper plants. Small RNAs were sequenced in both plants and the profiles were compared. The complete genome of the isolate was obtained, and microRNA (miRNA) profiles were unveiled by small RNA sequencing. Symptoms caused by the isolate were also described and the morphology of the isolate was observed by transmission electron microscopy. Our results contribute to further understanding of the role of miRNAs in ToBRFV pathogenesis, which may be crucial for understanding disease symptom development in tomatoes and peppers.

Nanotechnologies have received tremendous attention since their discovery. The current studies show a high application potential of nanoparticles for plant treatments, where the general properties of nanoparticles such as their lower concentrations for an appropriate effects, the gradual release of nanoparticle-based nutrients or their antimicrobial effect are especially useful. The presented review, after the general introduction, analyzes the mechanisms that are described so far in the uptake and movement of nanoparticles in plants. The following part evaluates the available literature on the application of nanoparticles in the selective growth stage, namely, it compares the observed effect that they have when they are applied to seeds (nanopriming), to seedlings or adult plants. Based on the research that has been carried out, it is evident that the most common beneficial effects of nanopriming are the improved parameters for seed germination, the reduced contamination by plant pathogens and the higher stress tolerance that they generate. In the case of plant treatments, the most common applications are for the purpose of generating protection against plant pathogens, but better growth and better tolerance to stresses are also frequently observed. Hypotheses explaining these observed effects were also mapped, where, e.g., the influence that they have on photosynthesis parameters is described as a frequent growth-improving factor. From the consortium of the used nanoparticles, those that were most frequently applied included the principal components that were derived from zinc, iron, copper and silver. This observation implies that the beneficial effect that nanoparticles have is not necessarily based on the nutritional supply that comes from the used metal ions, as they can induce these beneficial physiological changes in the treated cells by other means. Finally, a critical evaluation of the strengths and weaknesses of the wider use of nanoparticles in practice is presented.

Symbiotic interaction between plants and microorganisms in the rhizosphere is an important factor affecting plant growth and fitness. Arbuscular mycorrhiza fungi symbiosis increases resistance of the plants to stress factors, including pathogens. Tomato brown rugose fruit virus (ToBRFV) is an important destructive virus damaging tomatoes and peppers with losses that can reach 100%. It is listed on the list of current quarantine organisms in the Czech Republic. The aim of this study was to evaluate influence of root colonization with Funneliformis mosseae or/and Azospirillum brasilense on ToBRFV symptoms and viral titre reduction. Plants treated with arbuscular mycorhizal fungi (AMF) had lower symptom emergence after 14 dpi, however there was no difference in symptoms emergence after 21 dpi within all treatments. The highest colonization intensity by Funneliformis mosseae was detected in ToBRFV negative plants treated with both AMF and Azospirillum (AZO) and the lowest in ToBRFV positive plants with the same treatment (AMF + AZO). Colonization intensity of Azospirillum brasilense in all treated variants went from 20% to 41%. Results suggest that the combination of those two beneficial microorganisms in ToBRFV-infected plants negatively affected AMF colonization.

The use of high-throughput small RNA sequencing is well established as a technique to unveil the miRNAs in various tissues. The miRNA profiles are different between infected and non-infected tissues. We compare the SARS-CoV-2 positive and SARS-CoV-2 negative RNA samples extracted from human nasopharynx tissue samples to show different miRNA profiles. We explored differentially expressed miRNAs in response to SARS-CoV-2 in the RNA extracted from nasopharynx tissues of 10 SARS-CoV-2-positive and 10 SARS-CoV-2-negative patients. miRNAs were identified by small RNA sequencing, and the expression levels of selected miRNAs were validated by real-time RT-PCR. We identified 943 conserved miRNAs, likely generated through posttranscriptional modifications. The identified miRNAs were expressed in both RNA groups, NegS and PosS: miR-148a, miR-21, miR-34c, miR-34b, and miR-342. The most differentially expressed miRNA was miR-21, which is likely closely linked to the presence of SARS-CoV-2 in nasopharynx tissues. Our results contribute to further understanding the role of miRNAs in SARS-CoV-2 pathogenesis, which may be crucial for understanding disease symptom development in humans.