Search Results (446)

The common bed bug, Cimex lectularius L., is a pervasive pest of humans throughout the world. Insecticide resistance, cryptic habits, and proclivity for harborage on human belongings have contributed to its global status as a difficult pest to control. Leaves from common bean plants, Phaseolus vulgaris L., which include numerous trichomes, have traditionally been used to capture wandering bed bugs in southeastern Europe. However, fresh leaves rapidly desiccate once removed from plants, losing their trapping ability. A leaf-derived trapping material was developed that does not desiccate as rapidly as fresh leaves and retains the potential to trap bed bugs. In this study, we tested the efficacy of the leaf-derived material in capturing bed bugs. We tested the leaf-derived material in both horizontal and vertical orientations, using fresh bean leaves as positive controls. When deployed horizontally, the leaf-derived material captured bed bugs of all life stages and both sexes (adults). Leaf-derived material was also found to capture bed bugs in a vertical orientation (only evaluated for adult male bed bugs). Because this experimental leaf-derived material was effective in both horizontal and vertical orientations and against all life stages, it may have great potential for development into bed bug monitoring or exclusion devices. Full article

Trichomes are specialized epidermal structures that protect plants from environmental stresses, regulated by transcription factors integrating hormonal and environmental cues. This study investigates the roles of two C2H2 zinc finger proteins, GIS2 and ZFP8, in regulating trichome patterning in Arabidopsis thaliana. Using dexamethasone-inducible overexpression lines, transcriptomic profiling, and chromatin immunoprecipitation, we identified 142 GIS2- and 138 ZFP8-associated candidate genes involved in sterol metabolism, senescence, and stress responses. GIS2 positively and directly regulated the expression of SQE5, linked to sterol biosynthesis and drought tolerance, and repressed SEN1, a senescence marker associated with abscisic acid and phosphate signaling. ZFP8 modulated stress-related target genes, including PR-4 and SPL15, with partial functional overlap between GIS family members. Spatially, GIS2 functions in inflorescence trichomes via integrating gibberellin-cytokinin pathways, while ZFP8 influences leaf trichomes through cytokinin and abscisic acid signal. Gibberellin treatment stabilized GIS2 protein and induced SQE5 expression, whereas SEN1 repression was gibberellin-independent. Chromatin immunoprecipitation and DEX-CHX experiment confirmed GIS2 binding to SQE5 and SEN1 promoters at conserved C2H2 motifs. These findings highlight hormone-mediated transcriptional regulation of trichome development by GIS2 and ZFP8, offering mechanistic insight into signal integration. The results provide a foundation for future crop improvement strategies targeting trichome-associated stress resilience. Full article

The parameters and plant habitat characteristics of glandular trichomes could allow for faster and cheaper identification and selection of more essential oil-rich wild aromatic plants for further cultivation. This study aimed to establish relationships between the parameters of peltate glandular trichomes and essential oil content in commercially potential Thymus pulegioides in relation to plant sex, chemotype, and habitat characteristics. In total, 124 T. pulegioides plants belonging to different chemotypes and sexes and collected from 23 natural habitats were analysed. Essential oils were extracted by hydrodistillation, and a light microscope was used to investigate parameters of peltate glandular trichomes in upper and lower leaf epidermises. For investigation of the dynamics of the parameters of peltate glandular trichomes, T. pulegioides were growing in open ground under the same environmental conditions. Results demonstrated that the essential oil percentage in phenolic chemotype plants was higher than in plants of a non-phenolic chemotype. Females and hermaphrodites did not significantly differ according to essential oil percentage. Cover abundance of T. pulegioides negatively affects the density and diameter of peltate glandular trichomes and the essential oil percentage in T. pulegioides. The parameters of peltate trichomes in the upper leaf epidermis could be anatomical markers, helping to select T. pulegioides with higher essential oil contents from natural habitats as promising candidates as new crops. Full article

Trichomes—microscopic appendages on the plant epidermis—play vital roles as both protective barriers and specialized biosynthetic factories. Acting as the first line of defense against environmental stressors, they also produce a wide range of pharmaceutically valuable secondary metabolites. This mini-review highlights recent advances in understanding the development, structure, and function of trichomes, with a focus on glandular secretory trichomes (GSTs) in key species such as Artemisia annua and Solanum lycopersicum. We explore how insights from these systems are driving innovation in plant synthetic biology, including modular genetic engineering and metabolic channeling strategies. These breakthroughs are paving the way for scalable, plant-based platforms to produce high-value compounds. By integrating molecular mechanisms with emerging technologies, this review outlines a forward-looking framework for leveraging trichomes in sustainable agriculture, natural product discovery, and next-generation biomanufacturing. Full article

Trichomes in cannabis (Cannabis sativa L.) are specialized structures responsible for cannabinoid and terpene biosynthesis, making their density a critical parameter for both research and industrial applications. However, consistent trichome density assessment remains challenging due to anatomical variability and the absence of standardized methodologies. This review critically examines the existing literature on trichome quantification across key floral structures—such as bracts, sugar leaves, calyxes, and the main cola—to identify the most reliable sites and practices for accurate evaluation. Evidence suggests that bracts represent the most consistent sampling unit, given their homogeneous trichome distribution and elevated cannabinoid concentration. Whilst sugar leaves and calyxes are also frequently analyzed, their morphological variability requires cautious interpretation. Furthermore, trichome shape, size, maturity, and vegetal surface expansion/shrinkage during stress must be considered when correlating density with secondary metabolite production. We also highlight the advantages of using more than only one floral structure and integrating microscopic imaging and software-assisted analysis to enhance reproducibility and accuracy. By synthesizing current methodologies and proposing pathways for standardization, this review aims to support more robust trichome assessment protocols, ultimately improving cannabinoid yield optimization, quality control, broader cannabis research frameworks, and an important aesthetic parameter for consumers. Future research efforts should focus on advancing imaging methodologies and optimizing sampling protocols to further improve the precision and reproducibility of trichome density and cannabinoid analyses. Full article

As high-CBD cannabis (Cannabis sativa L.) gains legal and commercial relevance in the United States, studies evaluating how external inputs impact critical traits remain limited. This study investigates the effects of methyl jasmonate (MeJA), ammonium bicarbonate (AB), and the genetic source (mother plant identity) on the growth and secondary metabolite traits of indoor cannabis. Plants were treated with 1 mM MeJA and/or AB under controlled conditions, and key traits, such as plant height, chlorophyll content, biomass, trichome density, and cannabinoid concentration, were measured. The MeJA treatment led to a significant 32% increase in trichome density. However, it did not significantly alter CBD or THC concentrations. The AB treatment enhanced vegetative growth, increasing chlorophyll content and plant height while reducing CBD concentrations, but the biomass gains could compensate for the lower cannabinoid in the total production. An interaction between MeJA and AB altered the CBD content, suggesting that MeJA may mitigate AB’s negative effect on cannabinoid synthesis. The genetic source significantly influenced most of the measured traits, highlighting the role of the genotype in trait expression and the importance of clonal consistency. These findings highlight the complex dynamics of external inputs and genetic factors in cannabis production, emphasizing the need for further research to optimize cultivation strategies. Future studies should refine input combinations and doses to improve both yield and cannabinoid profiles. Full article

The GLABROUS1 enhancer-binding protein (GeBP) gene family, a plant-specific class of transcriptional regulators, is involved in multiple biological processes, including the formation of trichomes, plant growth, and environmental adaptation. However, the functional characterization of SlGeBP genes in tomato remains poor, particularly regarding their roles in regulating developmental processes and stress response mechanisms. In this study, 11 SlGeBP family members were identified from the tomato genome and 97 GeBP proteins from six species were classified into three groups. A wide range of elements linked to phytohormone, stress, and plant development were presented on the promoter sequences. Gene expression profile analysis revealed a comprehensive expression during the vegetative and immature fruit development stages. Analysis of the expression level under nine hormones and seven stresses can help us to understand the responsiveness of SlGeBP genes associated with hormone induction and stress tolerance. Subcellular localization analysis exhibited that SlGeBP1 and SlGeBP5 were localized in the nucleus, and the yeast two-hybrid assay confirmed that SlGeBP1 could interact with SlGeBP5. This study will help us to understand the potential function of the SlGeBP family and may establish a basis for further research on phytohormone signaling and stress resistance. Full article

Thrips flavus (Thysanoptera: Thripidae) is a Eurasian pest that primarily attacks a variety of cash crops such as soybean. Currently, there is insufficient knowledge of thrips-resistance mechanisms in soybeans and a lack of effective thrips-resistant soybean varieties. The objective of this study was to identify the correlation between the pest thrips, T. flavus, resistance levels and morphological structures of soybean varieties. A total of 41 spring soybean varieties were planted in a field in Northeast China. Observations were made regarding the infestation intensity of T. flavus, the morphological structures (compound leaf shape, leaf length, leaf width, leaf surface humidity, trichome density, length, and color), leaf SPAD value, leaf nitrogen content, etc. Specifically, leaf trichome density (regardless of whether it was on the upper or lower surfaces of the upper, middle, or lower leaves), trichome color, and compound leaf shape all showed significant positive correlations with the amount of T. flavus. Additionally, principal component analysis (PCA) indicated that, during the peak flowering stage, leaf width, trichome length, trichome density, SPAD value, and nitrogen content were key factors for evaluating resistance; meanwhile, during the podding stage, leaf length, SPAD value, nitrogen content, and leaf surface humidity made the most significant contributions. Field resistance screening using the number of T. flavus per meter of double rows, the average number of T. flavus per plant, and hierarchical cluster analysis yielded consistent results. The soybean variety “podless-trichome” is a thrips-resistant variety (high resistance), and “Jinong 29” is a thrips-sensitive variety (high sensitivity). This study provides valuable insights into the occurrence of insect resistance to thrips in soybean varieties. Full article

Jasmonates have emerged as a prominent elicitor for enhancing trichome development and cannabinoid production in Cannabis sativa L. (cannabis). These glandular trichomes synthesize and store important cannabinoids, including tetrahydrocannabinol (THC) and cannabidiol (CBD), which determine the yield, potency, and quality of cannabis flowers. Methyl jasmonate (MeJA) acts through the COI1–JAZ–MYC signaling pathway to upregulate genes associated with trichome initiation and cannabinoid precursor formation. Evidence suggests that moderate MeJA concentrations (typically 50–100 µM) can effectively boost trichome density, elevate hexanoyl-CoA availability, and modestly enhance key biosynthetic enzyme activities, ultimately increasing THC and CBD content. However, higher methyl jasmonate doses can amplify these benefits, yet pose a risk of excessive vegetative stunting, highlighting the crucial trade-off between enhancing cannabinoid potency and maintaining overall biomass yield. Interaction with hormones like gibberellins, salicylic acid, and ethylene further shapes the plant’s stress responses and secondary metabolism. Application in controlled environments, such as greenhouses or vertical farms, shows promise for enhancing resin production while minimizing biomass loss. In outdoor conditions, the application may offer additional defense benefits against pests and pathogens. These responses can vary depending on the cultivar, underscoring the importance of cultivar-specific optimization. As demand for high-cannabinoid cannabis products continues to grow and agrochemical options remain limited, leveraging MeJA treatments offers a practical, non-genetically modified approach to optimize yield, quality, and resilience in cannabis cultivation. Full article

Cannabis sativa L. is a dioecious species known to produce over 1600 chemical constituents, including more than 180 cannabinoids classified into 11 structural groups. These bioactive compounds are predominantly synthesised in the glandular trichomes of female inflorescences. However, sex determination in C. sativa is influenced by both genetic and environmental factors, often leading to the development of male flowers on female plants. This unintended fertilisation reduces cannabinoid yield and increases genetic heterogeneity and challenges in medical cannabis production. Haploid and doubled haploid (DH) technologies offer a promising solution by rapidly generating homozygous lines from gametophytic (e.g., unpollinated ovaries and ovules) or sporophytic tissues (e.g., anthers and microspores) via in vitro culture or chromosome reduction during hybridisation. In land plants, the life cycle alternates between a diploid sporophyte and a haploid gametophyte generation, both capable of mitotic division to form multicellular bodies. A single genome regulates this phase transition and encodes the molecular, genetic, and epigenetic mechanisms that precisely control the developmental processes unique to each generation. While the application of haploid technology in C. sativa remains limited, through recent progress in haploid induction (HI) and CRISPR-based genome editing, the direct modification of haploid gametes or embryos enables the creation of null homozygous lines following chromosome doubling, improving genetic uniformity. Understanding the molecular mechanisms of spontaneous chromosome doubling may further facilitate the development of elite cannabis genotypes. Ultimately, enhancing the efficiency of DH production and optimising genome editing approaches could significantly increase the speed of genetic improvement and cultivar development in Cannabis sativa. Full article

Invertase (INV) irreversibly converts sucrose to glucose and fructose during processes such as differentiation and organ development in plants, especially during the development of trichomes. Systematic identification and analysis of INVs in Salicaceae remain limited. Here, INV genes in Populus deltoides and Salix suchowensis were investigated, and their chromosomal localization, collinearity, gene structures, cis-regulatory elements, and phylogenetic relationships were comprehensively analyzed. Twenty and seventeen INVs were found, respectively, in P. deltoides and S. suchowensis, most of which were derived from a common ancestor and exhibited similar chromosomal distribution and high collinearity. Orthologs between the two species showed conservation of gene structures and promoter regulatory elements. Multi-species phylogenetic analysis identified an evolutionary clade associated with seed fiber development in P. deltoides and S. suchowensis. Further evaluation of INV expression in female catkins at various stages of seed fiber formation verified the predominance of PdeVINV1, PdeVINV2, PdeVINV3, and PdeVINV4 in P. deltoides, as well as SsuVINV1 and SsuVINV2 in S. suchowensis, during critical phases of catkin fiber differentiation. These genes are likely to have significant regulatory roles in the initiation and development of catkin fiber cells. These findings provide a reference for future functional studies of INVs. Full article

Fresh produce, such as peaches and apples, are agricultural commodities, making them susceptible to contamination by foodborne pathogens such as Listeria monocytogenes and Salmonella enterica. Traditional methods, such as chlorine washes, have limitations related to antimicrobial efficacy, prompting interest in alternative techniques, such as power ultrasound. This study evaluated the use of power ultrasound, alone and combined with organic acids (citric, lactic, and malic), to reduce pathogen populations on whole apples and peaches. Pathogen cocktails of L. monocytogenes and S. enterica were spot-inoculated on fruit surfaces at an initial population level of 8–9 log CFU/fruit. The fruits were then submerged in water or citric, malic, or lactic acid at concentrations of 1%, 2%, or 5% alone or with power ultrasound treatment at 40 kHz for 2, 5, or 10 min. Results revealed that treatment conditions on apples exhibited significantly greater pathogen reduction than on peaches, likely due to the smoother surface topology on apples compared to the rougher, trichome-covered peach surfaces. Between the two pathogens, L. monocytogenes exhibited significantly greater resistance to treatments, resulting in maximum reductions of approximately 4 log CFU/fruit. In contrast, treatments were more effective against S. enterica, as lactic acid alone reduced S. enterica populations by >6 log CFU/fruit. Malic acid was the second-most effective organic acid against S. enterica, leading to >4 log CFU/fruit reduction. Synergistic antimicrobial effects were observed when organic acids were used in combination with power ultrasound. For instance, an additional reduction of 2–3 log CFU/fruit was achieved for S. enterica compared to the use of organic acid treatments alone. These findings support the use of organic acid and power ultrasound in hurdle as an effective strategy to mitigate foodborne pathogen risks on whole fruits such as apples and peaches. Further research would be helpful to optimize and validate such hurdle treatments for inactivating a broader spectrum of microbial pathogens on diverse produce surfaces. Full article

Flower-scented teas become increasingly popular to new generations, due to their infused floral essences of diverse volatile compounds and additional health functions. Flower-scented teas have significantly broadened the spectrum of aroma perception, intensity, and longevity. Here, Chimonanthus praecox flowers were used to scent tea dhools to create different Chimonanthus teas with strong and characteristic aromas. The dynamic absorption of aromas by three tea dhools, and aroma compatibility in three flower-scented teas, and the aroma retention in Chimonanthus teas during storage were investigated. At least twelve aroma compounds were selectively absorbed by three tea dhools, with seven compounds, pulegone, 3-phenylpropanol, (E)-cinnamaldehyde, cinnamyl alcohol, γ-phenylpropyl acetate, (E)-isoeugenol, and (E)-cinnamyl acetate, commonly absorbed to three Chimonanthus teas. The different absorption preferences to floral volatiles and absorption capacity of three tea dhools could be related to their surface structures and trichome conditions. Linalool, phenylmethyl acetate, and methyl salicylate as significant volatile components were substantially enhanced for both Chimonanthus flowers and tea dhools, thereby augmenting the floral bouquet of Chimonanthus tea. After 56 days of storage, alcohol volatiles emerged as the predominant volatile types, although esters are the major contributors to the aroma of freshly prepared Chimonanthus teas. Full article

Grewia tembensis and Grewia trichocarpa inhabit dry tropical zones and arid environments, adapting to extreme climatic conditions and limited moisture supplies. Overall, Grewia L. possesses a significant variety of bioactive chemical constituents of great therapeutic importance. Indeed, for these species, precise morphological analyses are poor, and their detailed characterization is almost non-existent. This research attempts to investigate and compare the micromorphological traits of G. tembensis and G. trichocarpa species through scanning electron microscopy (SEM). Micromorphological characteristics of the leaf and fructiferous structures turned out to be highly effective in separating the two species, G. tembensis and G. trichocarpa, especially regarding the type, density, and distribution of trichomes on the lower and upper surfaces of the leaves, along with the stomatal and trichome types on the surfaces of the fruits. Statistical analyses using principal component analysis, t-tests, and hierarchical clustering conducted on micromorphological data of the leaves, flowers, and fruits showed considerable variation within samples of G. tembensis and samples of G. trichocarpa. On the basis of their morphological assessment characteristics, the samples of both species were distinct and clustered into separate groups. This study emphasizes the necessity of performing detailed morphological studies of species by means of an electron microscope and proves that the leaf features are important for separating species. Such morphological traits of trichomes would offer an efficient tool to distinguish the species. Within the findings, this suggests that such diagnostics are likely to be highly useful for species identification in Grewia, especially in cases where there are no fruits available. Full article

Cymbidium are endangered and ornamental orchids, and the taxonomy and species identification of this genus have been debated due to some overlapping morphological features between taxa and limited data being available. The leaf morpho-anatomy of 12 Cymbidium species from China was investigated using light microscopy and paraffin sectioning. Based on a comparative analysis, some leaf morphological features that varied between species were selected and used for taxonomic differentiation as follows: (1) The shape and structure of leaves were varied and could be used for species delimitation. (2) Microscopic characteristics show that the leaves lacked trichomes and displayed polygonal to rectangular epidermal cells on both surfaces, with larger adaxial cells and more abaxial stigmata. Stomata were mostly distributed only on the abaxial side, but on both sides in Cymbidium mastersii, which exhibited a rare amphistomatic type. The stomatal complex was uniformly tetracytic in 11 species, while it was observed to be anomocytic in C. floribundum. (3) Anatomically, two distinct midrib configurations were identified, a shallow V-shape and V-shape. The mesophyll cells were homogeneous in 10 species, with the exception of a layer of parenchyma cells resembling palisade cells occurring in C. lancifolium and C. qiubeiense. The thickness of the cuticle varied between species, with the adaxial surface covered by a thicker cuticle than the abaxial surface and displaying either a smooth or corrugated surface. A fiber bundle was observed in six species, but absent in the other six. In the former group, the fiber bundle occurred adjacent to both epidermal cells in C. mastersii and C. hookerianum, while it was adjacent to the abaxial epidermis in four other species. The stegmata, with conical, spherical silica bodies, were associated with fiber bundles and mesophyll in seven species, but absent in the other five (C. kanran, C. defoliatum, C. floribundum, C. lancifolium, and C. serratum). Three kinds of crystals were identified, namely the terete bundle, the long tube bundle, and the raphide. (4) It was suggested that some of these variable features could be selected and used for the delimitation of the species and taxonomy of Cymbidium. In addition, a key to the 12 Cymbidium species based on their leaf morpho-anatomic features was proposed, which could lead to a better understanding of the taxonomy and conservation of Orchidaceae. Full article