Search Results (484)

Pruning residues from medicinal and aromatic plant cultivations represent an under-exploited biomass rich in bioactive metabolites. In this study, pruning by-products from Lavandula angustifolia Mill. ‘Essence Purple’ and Helichrysum italicum (Roth) G.Don were investigated as sources of essential oils (EOs) within a circular economy perspective. Micromorphological analyses confirmed the presence of secretory glandular trichomes in the residual biomass. EOs were obtained by steam distillation (0.33% and 0.15% yield for lavender and helichrysum, respectively) and chemically characterized by GC-FID and GC-MS. A total of 51 and 55 compounds were identified, accounting for 99.68% and 99.57% of the total composition. The main constituents were τ-cadinol (23.09%) and linalyl acetate (14.07%) in lavender EO and γ-curcumene (15.47%) and eudesm-4(14)-en-11-ol (10.71%) in helichrysum EO. Pruning-derived EOs showed a higher sesquiterpene content than those from conventional plant organs, indicating a compositional shift. Phytotoxic assays on Hordeum vulgare, Raphanus sativus, Lolium multiflorum, and Sinapis alba revealed concentration-dependent effects, with a stronger inhibition of radicle elongation than seed germination. These concentrations should be interpreted as indicative of intrinsic phytotoxic potential under controlled conditions. Ecotoxicological tests showed no significant reduction in viability in Artemia salina, whereas concentration- and time-dependent immobilization was observed in Daphnia magna, highlighting species-specific sensitivity, likely related to differences in the uptake and membrane interactions of lipophilic compounds. These findings highlight pruning residues as a promising biomass for the recovery of bioactive phytocomplexes with potential applications in sustainable weed management, although further studies under agronomically relevant conditions and comprehensive environmental assessments are required to validate their practical applicability. Full article

The effects of progressive drought stress were examined in four economically important plant species belonging to the Lamiaceae family: catnip (Nepeta cataria L.), lavender (Lavandula angustifolia Mill.), holy basil (Ocimum tenuiflorum L.), and perilla mint (Perilla frutescens (L.) Britton). Plants were grown in a controlled pot experiment under three soil water capacity levels: 70% (control), 50% (moderate stress), and 30% (severe stress), and the drought stress lasted for 30 days. The study evaluated a comprehensive set of leaf micromorphological parameters, including the density and diameter of glandular trichomes, stomatal density and size, and the thickness of the lamina, mesophyll, epidermis, cuticle, and parenchymal layers. In addition, essential oil (EO) content, total flavonoid content (TFC), and elemental composition were analyzed. Drought responses were strongly species-specific. O. tenuiflorum, P. frutescens, and N. cataria showed high sensitivity characterized by reduced biomass and thinning of leaf tissues. These changes were accompanied by typical xeromorphic adaptations, such as increased stomatal and glandular trichome density, and reduced stomatal size. L. angustifolia exhibited pronounced cuticle thickening, suggesting an effective structural mechanism to minimize water loss. Secondary metabolism also responded differently among species. In some cases, drought shifted metabolic allocation toward flavonoid accumulation at the expense of essential oils, whereas in others, moderate stress promoted the co-accumulation of both compounds. These patterns indicate distinct adaptive strategies linking anatomical plasticity with metabolic regulation. Overall, moderate drought supported adaptive responses, while severe water limitation impaired growth and metabolic production. From a practical perspective, maintaining moderate soil water availability appears critical to optimize both plant performance and the accumulation of valuable secondary metabolites in Lamiaceae species. Full article

During a study of cyanobacterial colonization on coal ash dumps at the Apatity Thermal Power Plant (Murmansk Region, NW Russia), two strains of Nostoc-like morphotypes were collected, cultivated, and examined using a polyphasic approach. Both strains KPABG–133801 and KPABG–133804 exhibited high similarity in the 16S rRNA gene (99.93%) and identical 16S–23S ITS regions. Phylogenetically, they provided robustly supported affinity to the genus Pseudoaliinostoc, which currently comprises eight species predominantly distributed in Southeast Asia. The similarity of the 16S rRNA gene (95.74–97.25%), the divergence in the 16S–23S ITS rRNA region (18.56–26.28%), and the unique hypothetical secondary structures of conserved helices (D1–D1′, Box–B, V3) strongly suggest that these Arctic strains represent a new species, Pseudoaliinostoc murmanicum, which is described and illustrated in this study. The species forms bright blue-green colonies that gradually turn olive-green with age and is characterized by elongated cells in young trichomes, vegetative cell width of less than 3.2 µm, and the presence of akinetes wider than 3.5 µm. Full article

Forage grasses are an important component of livestock systems due to their contribution to animal feed, soil conservation, and carbon sequestration. In the face of climate change, analyzing stomatal characteristics allows us to understand the mechanisms of adaptation and tolerance to environmental stress. Therefore, the objective of this study was to determine the stomatal characteristics and trichome density of ten forage grasses present in a pine-oak dominated ecosystem. Sampling was carried out in October and November 2022 on a 1938 ha area. Mature, healthy leaves were selected, and epidermal impressions were obtained from the adaxial and abaxial surfaces using the cyanoacrylate method. Observations were made with an optical microscope at 400× magnification, quantifying stomatal density, trichome density, number of epidermal cells, and stomatal index per mm². The results indicated that nine species were amphistomatic, while Schizachyrium scoparium exhibited an epistomatic pattern. Muhlenbergia arizonica showed the highest stomatal density, and Setaria parviflora the lowest. It is concluded that there is high stomatal variability among species, highlighting its importance for the management and improvement of pastures. Full article

Glandular trichomes (GTs) are epidermal outgrowths that function as “natural cell factories” for the synthesis of specialized metabolites. Beyond their traditional understanding, GTs on cucumber fruits can form an undesirable trait known as bloom, which negatively affects market value. However, the secretory process, metabolite profiles, and genetic regulation underlying GT development in cucumber remain largely unclear. In this study, we employed scanning electron microscopy (SEM), transmission electron microscopy (TEM), histochemical staining, multi-omics analyses, and liquid chromatography–mass spectrometry (LC-MS) to systematically investigate GT development. The secretory process was classified into four distinct stages via SEM observations: morphogenesis, active metabolism, head sunken, and metabolite release. TEM revealed progressive ultrastructural changes, including increased organelle abundance and expansion of the periplasmic space, which facilitate metabolite transport and release. This process occurs through an autonomous mechanism involving osmiophilic substances and eventual cell rupture. LC-MS analysis identified 744 metabolites belonging to 11 classes, with phenylpropanoids/polyketides—particularly flavonoids—being the most abundant. While metabolite classes are conserved between European greenhouse and North China ecotypes, specific metabolite contents vary significantly. Multi-transcriptome analysis identified 60 candidate genes associated with GT development. Among these, CsaV4_3G003418 was functionally validated through virus-induced gene silencing (VIGS) to be involved in early GT development. Collectively, this work elucidates the secretory mechanism and metabolic characteristics of cucumber GTs, providing a foundation for future functional studies and biotechnological applications of secondary metabolites. Full article

Bayberry (Morella rubra Lour.; syn. Myrica rubra (Lour.) Siebold & Zucc.) leaves are rich in bioactive compounds but remain underutilized. This study investigated the optimal harvest stage and processing methods to develop high-quality functional powder. We first compared three growth stages: red buds (RB), new leaves (NL), and old leaves (OL). RB exhibited the highest antioxidant capacity and unique volatile profile; however, NL was selected for processing optimization due to the balance between quality and biomass availability. Subsequently, NL was subjected to freeze-drying (FD), mechanical drying (MD), steaming followed by MD (S-MD), and shade drying (SD). Results showed that FD preserved the vibrant green color, glandular trichome structure, ascorbic acid, and fresh volatiles (monoterpenes). Conversely, thermal drying (MD and S-MD) disrupted cellular barriers, which facilitated the extraction of minerals and robust polyphenols like myricitrin, yielding the highest extraction of flavonoids and corresponding antioxidant activity, measured by hydrophilic oxygen radical absorbance capacity (H-ORAC), in hot water extracts than FD. SD significantly degraded quality due to prolonged enzymatic oxidation. While FD is ideal for preserving aesthetics and heat-sensitive nutrients, low-cost MD and S-MD are recommended for producing antioxidant-rich powders for functional food applications where extraction efficiency is prioritized. Full article

Fruit trichomes and pericarp architecture are pivotal for biological defense and postharvest resilience in the genus Actinidia. However, the evolutionary diversity of these structures and the molecular mechanisms governing their development—particularly under the influence of polyploidization—remain poorly understood. We performed a systematic evaluation of 21 Actinidia species and 14 cultivars using scanning electron microscopy (SEM) and histological analysis. To determine the effects of genome doubling, an autotetraploid line was induced from diploid A. chinensis cv. ‘Donghong’, followed by comparative transcriptomic and temporal expression profiling. Morphological characterization identified three distinct evolutionary groups based on fruit surface traits: glabrous, caducous-spotted, and persistent-pubescent. All observed trichomes featured a unique bipartite multicellular architecture. Kiwifruit pericarp thickness (59.8–534.6 μm) was locally reinforced at trichome insertion sites. Among kiwifruit cultivars, polyploidization significantly increased both trichome length and total amount. Transcriptomic analysis revealed 235 differentially expressed genes (DEGs) enriched in hormonal signaling and flavonoid pathways. Two key candidate genes, Achv4p15g023764.t1 and Achv4p01g000003.t1, were identified as candidate genes for stage-specific regulators governing early morphogenesis and late maturation. By characterizing the morphological diversity and genetic underpinnings of Actinidia trichome and epidermal variation, this study establishes a potential scientific framework for the targeted kiwifruit breeding of novel kiwifruit cultivars with optimized fruit surface characteristics. Full article

The white-backed planthopper, Sogatella furcifera, and the brown planthopper, Nilaparvata lugens, severely impact rice production, necessitating effective selection methods for resistant cultivars. S. furcifera poses a significant threat to rice cultivation, particularly in Asia. Through this study, we aimed to establish an effective approach to identifying resistant rice varieties based on feeding behavior, physiological and chemical responses, and genetic analysis. Three key activities were involved: (1) evaluation of planthopper feeding behavior utilizing the honeydew drop method, the electrical penetration graph technique, and growth rate analysis; (2) investigation into the physiological and chemical traits of rice; and (3) analysis of resistance-related gene expression. The results indicated larger honeydew drop areas, fewer and shorter probing events, and structural defenses such as increased trichome density in resistant rice genotypes, likely hindering insect attachment and feeding. We confirmed the suitability of the growth rate method for resistance screening. Gene expression analysis identified PR10a upregulation in resistant rice, suggesting a molecular basis for resistance. This study enables the selection of rice varieties resistant to planthoppers, supporting sustainable pest management and breeding programs. The findings support sustainable pest management by enabling the targeted selection of resistant varieties, ultimately aiding in the development of rice genotypes with enhanced resistance across growth stages. Full article

Vicia villosa Roth var. glabrescens (smooth vetch) is an economically important legume cover crop valued for its nitrogen-fixing capacity, high biomass yield, and adaptability across diverse agroecosystems. Here, we present a chromosome-scale, high-quality genome assembly of V. villosa var. glabrescens, constructed using PacBio HiFi sequencing combined with Hi-C scaffolding. The assembly spans 3.70 Gb with a scaffold N50 of 4.69 Mb and exhibits lower heterozygosity (0.9%) compared to V. villosa Roth (3.1%). Genome analysis revealed significant expansion of long terminal repeat retrotransposons (LTR-RTs), as well as lineage-specific proliferation of miniature inverted-repeat transposable elements (MITEs) in V. villosa var. glabrescens. Comparative genomics with V. villosa Roth highlighted gene family expansions associated with trichome development, providing insights into the genetic basis of morphological and adaptive differences within the Vicia species. This reference genome provides a foundational resource for accelerating the breeding of V. villosa varieties with enhanced agronomic traits and contributes to a broader understanding of legume genomics and plant genome evolution. Full article

Research into the effects of environmental stressors associated with global climate change (GCC) on cyanobacteria and microalgae is scarce, with bloom-forming planktonic cyanobacteria being the exception. This study aimed to address the issue by assessing morphological and biochemical changes in cyanobacterial and microalgal cells exposed to an increased temperature (T), ultraviolet radiation (UVR) and carbon dioxide (CO₂) concentration. The strains selected were Calothrix sp. SLM0211 and Coelastrella sp. SLM0503, which were isolated from a coastal environment in the central Mediterranean island of Malta. Elevated UVR had a pronounced effect on Calothrix sp. filaments, which produced screening compounds and resorted to trichome coiling to enhance self-shading. Enhanced growth was observed in cultures of Calothrix sp. grown at an increased CO₂ concentration, which produced significantly high amounts of biomass, chlorophylls and carotenoids. An increased T resulted in stunted growth and low biomass accumulation in both strains. Each strain exhibited a unique response to T and UVR stressors, which stimulated the production of exopolymeric substances (EPS) and mycosporine-like amino acids (MAAs) in cultures of Calothrix sp. and lipid production in Coelastrella sp. cells. Our findings indicate that the effects of stressors related to GCC on cyanobacterial and microalgal cells are strain-specific, making changes at community and ecosystem levels difficult to predict. Full article

The maturity of cannabis flowers at harvest critically influences cannabinoid yield and product quality. However, conventional assessment methods rely on subjective visual inspection of trichomes and stigmas, making them inherently inconsistent. This research presents an automated framework integrating computer vision and deep learning to objectively evaluate cannabis flower maturity. High-resolution macro images were acquired using low-cost smartphone-based systems under greenhouse and laboratory conditions. A two-stage pipeline was implemented: a fine-tuned Faster R-CNN model detected trichomes (Precision: 0.815; Recall: 0.802), while a YOLOv8 classifier categorized them into clear, milky, or amber classes (Accuracy: 98.6%). In parallel, a YOLOv8 segmentation model delineated stigmas (AP50: 52.2%) to compute color ratios as maturity indicators. Features were aggregated at the flower level and correlated with HPLC-measured cannabinoid concentrations. A dataset of over 14,000 images was collected across multiple imaging sessions to support training, evaluation, and correlation experiments. Results demonstrated that stigma coloration—detectable with low-end devices—provides a robust visual indicator of peak chemical maturity, with the green-to-orange transition aligning with maximum cannabinoid concentration. This work offers a scalable, cost-effective solution for real-time maturity assessment in cannabis cultivation, contributing to improved harvest timing and quality control. Full article

Dew formation occurs frequently and in substantial amounts, serving as an important water source with significant ecological implications for plant growth. Although previous studies have demonstrated that dew can supplement leaf water, quantitative evidence of leaf dew absorption under different dew intensities remains limited. In this study, a stable isotope tracer experiment was conducted to quantify dew absorption under varying dew amounts and to analyze absorption rates and influencing factors across different plant species. Results showed that all four species were capable of absorbing dew, mainly due to specialized leaf surface morphology and microstructures. At a dew intensity of 0.1 mm, Tillandsia ionantha, whose leaves are densely covered with shield-like trichomes, exhibited an extremely high dew absorption rate of 92%. In contrast, the leaf surface of purple shamrock (Oxalis triangularis ‘Purpurea’) is covered with abundant hydrophobic trichomes that strongly restrict dew entry, resulting in a very low absorption rate of only 1.43%. Dew absorption varied markedly among species under different dew amounts. Under dew intensities of 0.1, 0.2, and 0.3 mm, T. ionantha showed consistently high absorption rates of 92%, 89.60%, and 71.74%, respectively, whereas Epipremnum aureum exhibited much lower rates of 3.72%, 6.15%, and 2.45%. Moreover, under a dew intensity of 0.2 mm, dew absorbed by E. aureum leaves could be transported to the roots, indicating internal redistribution of foliar-absorbed water. Overall, dew represents an important supplementary water source for plants, and interspecific differences in leaf surface morphology and microstructures lead to substantial variation in dew absorption capacity. These findings provide experimental evidence for understanding species-specific strategies of dew utilization and have implications for the efficient use of dew as a water resource. Full article

Cyanobacteria of the genus Tychonema are common inhabitants of freshwater bodies in a temperate zones. In Lake Baikal, Tychonema sp. was first reported in 2014. It grows excessively on the bottom on almost all substrates types, forming epiphytic and epizoic biofilms, and its role in the mass mortality events affecting of endemic Baikal sponges is discussed. The cyanobacterial strain BBK16 (=IPPAS B-2063^T), isolated from a biofilm on a log pier in the Bolshiye Koty settlement in 2016, was used for further taxonomic characterization. Key morphological features of strain BBK16 include its growth as a creeping mat, highly motile trichomes that are sometimes narrowed and hooked at the ends, and the presence of rounded-conical apical cells with a calyptra. Strain ultrastructure (fascicular parietal thylakoids and type D cell division) differs from Tychonema species with radial thylakoids but aligns with other genera in the Microcoleaceae family. A comprehensive analysis, including 16S rRNA gene phylogeny, conserved protein phylogeny, and whole-genome comparisons, confirmed its placement within the genus Tychonema. The average nucleotide identity, average amino acid identity and digital DNA–DNA hybridization values between strain BBK16 and T. bourrellyi FEM GT703 were 90.7%, 91.1% and 43.3%, respectively, indicating values below the standard thresholds for species delineation. Based on combined morphological, genomic, and ecological evidence, we propose the name Tychonema litorale sp. nov. for strain BBK16, a novel species described in accordance with the International Code of Nomenclature for Algae, Fungi, and Plants. Full article

Accurate genotyping of small insertions and deletions (InDels; <5 bp) remains technically challenging in routine molecular breeding, largely due to the limited resolution of agarose gel electrophoresis and the labor-intensive nature of polyacrylamide-based assays. Here, we present the Tri-Primer Amplification Refractory Mutation System (TP-ARMS), a simple and cost-effective PCR-based strategy that enables high-resolution genotyping of small InDels using standard agarose gels. The TP-ARMS employs a universal reverse primer in combination with two allele-specific forward primers targeting insertion and deletion alleles, respectively. This design allows clear discrimination of homozygous and heterozygous genotypes using a two-tube PCR workflow. The method showed complete concordance with Sanger sequencing in detecting 1–5 bp InDels across multiple crop species, including rice (Oryza sativa) and quinoa (Chenopodium quinoa). In addition, using a TP-ARMS reduced experimental time by approximately 90% compared with PAGE-based approaches and avoided the high equipment and DNA quality requirements of fluorescence-based assays. The practical applicability of the TP-ARMS was demonstrated in breeding populations, including efficient genotyping of a 3-bp InDel in OsNRAMP5 associated with cadmium accumulation and a 6-bp promoter InDel in OsSPL10 underlying natural variation in rice trichome density across 370 accessions. Collectively, the TP-ARMS provides a robust, scalable, and low-cost solution for precise small InDel genotyping, with broad applicability in marker-assisted breeding and functional genetic studies. Full article

Background: Artificial inoculation of Epichloë endophytes into elite forage germplasm aims to establish beneficial symbioses for developing high-yield, high-quality, and stress-tolerant cultivars, but host specificity of the fungi often causes compatibility issues in non-natural hosts. Methods: The E. bromicola isolated from native wild barley was inoculated into cultivated wild barley (Hordeum brevisubulatum) and cultivated barley (Hordeum valgare), forming Hb+Eb and Hv+Eb. The NHb+Eb (native wild barley naturally infected with E. bromicola) served as a control. We analyzed fungal colonization patterns and symbiotic gene regulation to clarify the compatibility between E. bromicola and non-natural hosts. Results: Compared with NHb+Eb and Hb+Eb, E. bromicola in Hv+Eb showed obvious hyphal vacuolization. E. bromicola colonization altered host trichome morphology and induced stomatal closure. Correspondingly, expression of the siderophore biosynthesis gene sidN and the NADPH oxidase complex genes (NoxA, NoxB, NoxR, RacA) was significantly lower (p < 0.05) in Hv+Eb than in Hb+Eb and NHb+Eb. Conclusions: This study reveals that the incompatibility between cultivated barley and E. bromicola is characterized by altered hyphal morphology, which is linked to the downregulation of sidN and Nox. These findings provide a critical theoretical foundation for developing highly compatible cereal-Epichloë germplasms. Full article