Protoplasma最新文献

Floral nectaries are generally linked to an exchange that facilitates pollen transport, and consequently, pollination. We have characterized the ontogenesis, histochemistry, and ultrastructure of the floral nectary of Pseudobombax longiflorum (Mart.) A. Robyns (Bombacoideae, Malvaceae) from a developmental perspective and related with secretion dynamics. Light and electron microscopies were used. The floral nectary is on the proximal and median portions of the adaxial face of the calyx. Protoderm, fundamental meristem, and procambial strands form the nectary. At maturity, it is composed of glandular claviform trichomes and nectariferous and subnectariferous parenchyma vascularized predominantly by phloem. Phenolic compounds, oils, and proteins were observed in the trichome and parenchyma cells. Druse crystals occurred in the parenchyma. Starch grains decreased in the parenchyma in pre-anthesis buds, and with the nectar exudation began. Mitochondria, ribosomes, endoplasmic reticulum, Golgi bodies, and plastids containing starch grains characterize the cytoplasm of secretory cells and the apparatus compatible with nectar production. Plamodesmata occurred between parenchyma cells, parenchyma cell and basal trichome cell, and trichome cells, indicating a symplastic pathway of the pre-nectar. The downward flow of nectar through the apoplast could be prevented by the impregnation of lipids into the anticlinal walls of the stalk cell. In trichome apical cell, nectar accumulation occurred in periplasmic and subcuticular spaces. Nectar appeared to be externalized through the cell wall and cuticle. Insights into trichome development have enhanced our understanding of the formation of functional floral nectary components and nectar secretion in Malvaceae, marking the first ontogenetic and ultrastructural study in Bombacoideae.

The integrity of herbal products is frequently undermined by both intentional and unintentional adulteration, leading to substantial health risks and economic losses. Loop-mediated isothermal amplification (LAMP), a DNA-based molecular technique, has emerged as a formidable solution due to its simplicity, specificity, sensitivity, and ability to operate under isothermal conditions. The review critically evaluates the application of LAMP in authenticating herbal materials, showcasing its enhanced efficiency and user-friendliness compared to conventional techniques. The LAMP technique employs four to six primers that target six to eight distinct regions of the target DNA, ensuring unparalleled specificity. The amplification at a constant temperature negates the need for thermal cyclers, thus rendering it highly suitable for point-of-care applications and field-based authentication. The article presents case studies that illustrate LAMP's efficacy in detecting adulteration across traditional medicines, dietary supplements, and crude drug materials. Visualization methods in LAMP, such as turbidity, colorimetry, and fluorescence, greatly enhance its accessibility and ease of use, making it well-suited for both laboratory and field applications. Although there are limitations, such as primer design complexity and contamination risks, recent innovations, including the use of lyophilized reagents, multiplexing capabilities, and integration with mobile detection platforms, are significantly advancing the practicality of LAMP assays. This review underscores the potential of LAMP in both regulatory and commercial contexts, promoting the authenticity, safety, and quality of herbal products, thereby making a vital contribution to consumer protection and the sustainability of the herbal medicine trade.

H₂S is a lipophilic gaseous molecule with the characteristic pungent "rotten egg" odour. Studies have shown that H₂S at lower concentrations acts as a gasotransmitter, providing evidence for its crucial role in plant growth, development and stress responses. The present work underlies the effects of moderate and high concentrations of NaCl stress and two concentrations of NaHS (H₂S donor) on certain metabolic signatures of tomato seedlings. In this study, tomato seedlings were grown under different NaCl concentrations (0 mM, 40 mM, 80 mM and 120 mM) and three concentrations of H₂S, i.e. T0 (0 µM), T1 (25 µM) and T2 (100 µM) were applied exogenously. The results showed a reduction in MDA content, electrolytic leakage, Na⁺/K⁺ ratio, and proline content in tomato seedlings with exogenous application of H₂S under NaCl stress. On the contrary, exogenous H₂S application at T2 concentration increased chlorophyll content, RWC, endogenous H₂S content, L-DES activity and ascorbate content under 80 mM NaCl stress. Concomitantly, exogenous H₂S treatment, particularly at T2 concentration, upregulated the antioxidative enzyme activity like glutathione reductase (GR), catalase (CAT), ascorbate peroxidase (APOD), peroxidase (POD) and superoxide dismutase (SOD) in NaCl-treated tomato seedlings. These results indicate that exogenous H₂S application, especially at T2 concentration, imparts a higher amount of alleviation in salt-stressed tomato seedlings grown under 80 mM NaCl. Thus, a concentration-dependent interaction of NaCl stress and H₂S signaling appears to be mediated through long-distance signaling in tomato seedlings.

The genus Rhododendron, comprising approximately 1200 species, is the largest within its family and possesses significant ornamental value. However, functional genomics studies in this genus are hampered by an inefficient Agrobacterium-mediated stable transformation system. To facilitate rapid gene function verification, we developed a protoplast-based transient expression system using petal tissues. We optimized the enzymatic hydrolysis conditions (2.0% cellulase, 1.00% macerozyme, 0.6 mol/L mannitol, 8-h digestion) and established a two-step purification protocol involving centrifugal precipitation followed by flotation. For polyethylene glycol (PEG)-mediated transformation, the optimal parameters were 40% PEG4000, 0.10 mol/L CaCl₂, 35 °C, 25 μg of plasmid, and a 20-min incubation. The system's feasibility for subcellular localization was confirmed by expressing HSFC1a-eGFP and RCI2B-eGFP fusion proteins in R. pulchrum protoplasts. Furthermore, qRT-PCR analysis showed that the transcript levels of HSFC1a and RCI2B peaked at 12 h post-transformation, demonstrating time-dependent expression dynamics.

The rice leaffolder, Cnaphalocrocis medinalis, is a major pest threatening rice production, causing significant yield losses. Developing resistant cultivars offers a sustainable and eco-friendly approach to its management. This study aimed to identify leaffolder-resistant rice genotypes and explore associated genomic regions using SSR markers for future marker-assisted breeding. A total of 96 rice landraces were evaluated under both net house and field conditions across two cropping seasons. Based on consistent phenotypic performance, 20 genotypes were classified as resistant, 28 as moderately resistant, and 28 as susceptible. Genetic screening using reported SSR markers for leaffolder resistance revealed high polymorphism, with an average PIC of 0.75 and gene diversity ranging from 0.612 to 0.834. Cluster and structure analysis grouped the genotypes into three major clusters, with most resistant genotypes forming a distinct group. PCA further validated this genetic grouping, effectively separating resistant, moderately resistant, and susceptible genotypes. Additionally, heat map of kinship matrix supported the population differentiation. AMOVA indicated that 86% of total genetic variation was attributed to differences within populations, while 14% was observed among populations. Association analysis using simple linear regression identified three markers viz: RM72, RM48, and RM162, on chromosomes 8, 2 and 6, respectively, linked to leaffolder resistance. Notably, these markers are located near genes, that are involved in rice defense responses against leaffolder as well as other biotic stresses. Overall, the integration of phenotypic and molecular data in this study provides a foundation for marker-assisted selection and provides valuable genomic resources for developing durable leaffolder-resistant rice cultivars.

Gliomas are the most frequent tumors of the central nervous system, with an extremely low efficiency of treatment. Primary glioma cell cultures may provide an in vitro model for studying these tumors and the development of therapeutic approaches. In this review, we assess different factors that may contribute to glioma malignancy, such as the presence of glioma stem cells, cellular heterogeneity, and selection for specific genotypes. We discuss approaches for primary glioma cell culture establishment and the role of particular components of the cultivation media: culture in monolayer, neurospheres, and glioblastoma organoids; the influence of serum, growth factors, and surface coating; and the presence of glioma stem cells. Different cell culture protocols have various drawbacks - loss of the parental tumor cellular composition, loss of glioma stem cells, or loss of the glioma microenvironment. We argue that to produce primary glioma cell culture, researchers shall use a combination of standardized protocols: serum-free neurosphere culture, serum-based monolayer culture, and glioblastoma organoids.

This study provides a detailed embryological and histochemical analysis of seed development in Miconia crenata, an autonomous apomict, and its sexual congener M. tococa (Melastomataceae). Both species exhibit a nuclear endosperm that is only partially cellularized and is rapidly consumed by the developing embryo. For the first time in Melastomataceae, partial endosperm cellularization was confirmed. Histochemical tests revealed that nucellar cells accumulate polysaccharides, which are gradually mobilized during embryogenesis, indicating that the nucellus contributes nutritionally to embryo growth. In M. crenata, additional embryos can arise adventitiously from cells near the hypostasis. Our findings highlight that the reduced nutritional contribution of the endosperm, combined with the compensatory role of the nucellus, may facilitate the maintenance and evolution of autonomous apomixis in the family, a pattern also seen in Asteraceae. These results expand our understanding of reproductive strategies in angiosperms and the structural basis for autonomous seed development.

Sideroxylon obtusifolium (Humb. ex Roem. & Schult.) T.D. Penn. is a tree species belonging to the Sapotaceae family, whose black berries can be consumed fresh or as jam. It is widely distributed in Mexico, Belize, Costa Rica, Venezuela, Bolivia, Brazil, Paraguay, Argentina, and Uruguay. While previous studies have focused on describing its floral biology, the development of the ovule and pollen has not been studied from an anatomical point of view. To provide further insights into the sexuality of this fruit tree, we conducted a study of the processes of sporogenesis and gametogenesis using conventional plant anatomical techniques. Flowers of different sizes were fixed in FAA, embedded in paraffin, sectioned, and stained with Safranin-Astra Blue for light microscopy. The processes of sporogenesis and gametogenesis result, on the one hand, in the anatropous, unitegmic, and tenuinucellate ovule, with a Polygonum embryo sac. On the other hand, it gives pollen grains that are released as monads in a tricellular state. This study provides anatomical data not previously described for this species and is part of the embryological studies that are currently being carried out in different species of fruit trees in South America. These findings enhance the embryological understanding of Sapotaceae and offer a foundation for future research in systematics, phylogeny, and conservation biology of Sapotaceae.

Diabetes mellitus and Alzheimer's disease are interconnected, with type 2 diabetes raising dementia risk. Decoctions and infusions of Tripleurospermum monticolum (Asteraceae) are traditionally used to treat cough, stomachaches, and fever, while its flowers are commonly brewed into tea to alleviate stomach discomfort. The study examined the inhibitory effects of methanol and aqueous extracts from T. monticolum (capitulum, root, and aerial parts) on key enzymes (acetylcholinesterase, butyrylcholinesterase, α-amylase, and α-glucosidase) and assessed antioxidant activity, as well as the total phenolics, flavonoids, and tannins. Essential oils were analyzed via GC-MS/MS, and morphological, anatomical, and metabolite tests were also performed. In the essential oil of the capitulum, (2Z,8Z)-matricaria ester (64.1%) is the dominant compound, while the aerial part is rich in pentacosane (22.2%) and caryophyllene oxide (13.5%). The root, on the other hand, contains high levels of geranyl isovalerate (30.7%). The aerial part methanol extract showed the highest phenolic (74.686 µg GAE/mg), flavonoid (259.083 µg RE/mg), and tannin (83.000 µg TAE/mg) contents. Root methanol extract had the strongest 2,2-Diphenyl-1-picrylhydrazyl radical (DPPH^•) activity (20.855%), while capitulum methanol extract was most effective in 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS^•⁺) scavenging (9.362%). T. monticolum extracts exhibited antibacterial activity with MIC values ranging from 1250 to 2500 µg/mL, and notable anticandidal effects (MIC = 625-2500 µg/mL), particularly against Candida tropicalis. Additionally, the essential oils from the root and flower demonstrated antifungal efficacy, with MIC values of 625 µg/mL and 1250-2500 µg/mL, respectively. The qualitative analysis revealed alkaloids, flavonoids, and tannins in all samples, while lipids were selectively detected in CM, APM, and RM, showing metabolic variability. T. monticolum exhibited promising antioxidant, enzyme inhibitory, antimicrobial, and phytochemical properties, highlighting its potential as a multifunctional medicinal plant, particularly in the context of diabetes and neurodegenerative disease management.