Protoplasma最新文献

The endemic Mediterranean seagrass Posidonia oceanica is a valuable source of natural bioactive compounds that possess significant therapeutic potential. Here, we examined whether aqueous extracts of rhizomes (RE) and green leaves (GLE) of P. oceanica could exert a glucose-lowering effect on the HepG2 cell line, chosen as an in vitro model of liver cells. We assessed glucose uptake and storage, expression levels of GLUT-2 and -4 transporters and the exposure of the latter one at cell surface, as well as modulation of the expression, synthesis and/or activation of the GLUT2-transcription factor hepatocyte nuclear factor-1 alpha (HNF1α), and insulin receptor substrate-1 (IRS-1), AKT and protein kinase Cζ (PKCζ), which regulate GLUT-4 translocation. Glucose consumption/uptake and glycogen storage were increased with exposure to GLE alone. Furthermore, at the molecular level GLE-induced upregulation of (i) IRS-1, AKT, and PKCζ activation levels, (ii) GLUT-4 translation levels, and (iii) GLUT-4 exposure on the cell surface. Conversely, GLUT-2 protein was downregulated. Therefore, the application of the aqueous extract of green leaves of P. oceanica may be suitable for the development of new treatment agents or dietary supplements for diabetes mellitus acting through GLUT-4 mediated glucose import.

Protoplasts are single cells enclosed by the plasma membrane after cell wall removal. They are widely used in various biotechnological applications, including gene functional analysis, verification of genome editing reagents, and plant regeneration. Recent advances in genome editing have enabled the production of non-chimeric and transgene-free genome-edited plants using protoplasts. This process involves protoplast isolation, transformation, and regeneration, requiring advanced technical skills. Challenges in isolation and regeneration have limited their use in genome editing. In grapevines, however, very few studies have reported the use of protoplasts isolated from leaves. Efficient isolation and transformation protocols for Chardonnay remain lacking and require cultivar-specific optimization. In this study, we established a reliable and efficient protoplast isolation and transformation system by optimizing conditions for protoplast isolation and PEG-mediated transformation in Chardonnay cultivar. The yield of viable protoplasts was approximately 75 × 10⁶ per gram of leaf material, with a viability of 91%. A transformation efficiency of 87% was achieved under the optimized conditions. To evaluate the regeneration ability of mesophyll protoplast, transformed and untransformed protoplasts were cultured on solid and liquid MS media supplemented with 2 mg/L 2,4-D and 0.5 mg/L BA to facilitate microcalli formation. Microcalli formed on the feeder layer and developed into calli when transferred to liquid MS culture with 2 mg/L 2,4-D and 0.5 mg/L BA. However, the calli were unable to regenerate into roots or shoots. These findings provide a foundation for further optimization of protoplast-based regeneration systems in grapevines, with the potential to enhance genome editing applications in this species.

The genus Athenaea (Solanaceae) has been the target of recent pharmacological and taxonomic investigations, which point out promising species in metabolomic and biotechnological approaches. However, little is known about the chemical diversity of Athenaea species. Recent research has shown that some species could be good sources of steroidal lactones (withanolides) that can be used for different biological targets. These metabolites have anticholinestaric and antitumor activities, for example. Thus, we investigated the development, structure, and chemical nature of Athenaea leaves with the aim of identifying promising characters to corroborate the current systematics of the genus and, above all, the structures involved in the synthesis and accumulation of classes of chemical compounds. Secretory trichomes and idioblasts are the structures specialized in the accumulation of alkaloids, steroids, phenolics, and lipids in the leaves of Athenaea, and the morphotypes of the trichomes can help in distinguishing species. The differentiation and activity are precocious in such trichomes, being evident in the early stages of development. The secretory head of the trichome displays atypical development, with the presence of intercellular space, where secretion accumulates. Our results point out the site where biological activity compounds are stored in representative taxa of Athenaea, which may conduct biotechnological investigations in this genus.

The Malpighian tubules are well-known and studied as the principal excretory organs in most insects. They play a key role in the production of primary urine and osmoregulation. It works with the rectum while regulating the water and salt balance in the body. The distal ends of the tubules are found in contact with the wall of the rectum in insects that feed on dry substances or live in a nearly dry environment and therefore, need to retain water: that is an arrangement known as a cryptonephric system. In this study, Cassida palaestina Reiche, 1858 is a beetle species belonging to the order Coleoptera was used as material, and the morphological features of the Malpighian tubules of this species were examined using light microscopy and scanning electron microscopy. The four cryptonephric Malpighian tubules of C. palaestina are found at the junction of the midgut and hindgut. The apical surface of tubule cells is surrounded by numerous microvilli. The cytoplasm of tubule cells fills with granules of many different sizes. Here, we reported our observations on the cryptonephridial complex in C. palaestina, and this study is almost the first study to examine the structure of the excretory system of the genus Cassida. Insights into the structure of the cryptonephridial complex of this species are compared with the well-studied cryptonephridial complexes of Cucujiformia. The findings were found to be quite similar to those of other species studied in the literature (with the structure of the Malpighian tubules of insects within the same order and from different orders). These data are the basis for future morphological studies. At the same time, the presence or absence of the cryptonephridial complex among species in the Cucujiformia infraorder, which C. palaestina is a part of, helps to understand the phylogenetic relationship.

This special mini-review was planned as a synthesis of current understanding of the role of tapetum and orbicules, of the knowledge on pollenkitt, with addition of our own data on experimental orbicule simulation. The aim was to show the development of knowledge and ideas through time. Tapetum types are so changeable that the idea of norm becomes ghostly. The review is based on our own and other authors' results. Cyclic-invasive tapeta, surprising exine-like tapetal surface, direct connections of tapetum with microspores via filaments are probably not rare phenomena. Our in vitro experiments on microspore exine simulations, which have led also to appearance of orbicule-like structures, support the view of their by-product nature, based on self-assembly. Different types of orbicules and their development are examined. Tapetum and orbicule functions and especially pollenkitt production are reviewed, together with the data on sporopollenin. Some concise data on molecular and genetic studies are added.

Northeast India, a global biodiversity hotspot, harbors exceptional plant diversity within the Indo-Burma region. This study provides the first comprehensive integration of floristic, ecological, and genomic analyses of angiosperm diversity in North Guwahati, Assam, using the Indian Institute of Technology Guwahati campus as a model semi-natural landscape. Systematic year-long surveys recorded 434 angiosperm species belonging to 312 genera and 101 families, including 70 trees, 86 shrubs, and 244 herbs (with 31 climbers and a few aquatics). Poaceae was the most species-rich family (34 species), followed by Fabaceae (29) and Cyperaceae (26), reflecting typical tropical diversity. Spatial analysis revealed strong habitat-specific species distribution, with open plains supporting the highest diversity (206 species) and forest edges harboring rare taxa. Community structure across four ecological zones showed significant spatial heterogeneity, with Zone 1 having the highest Shannon-Wiener diversity (H' = 4.084) and Zone 4 the highest evenness (E = 0.905). Nuclear DNA content (2C values) was estimated via flow cytometry for 110 species, contributing 58 novel genome size records and revealing a 98-fold variation (0.43-42.5 pg). Monocots had significantly larger genomes than dicots (4.79 vs. 1.63 pg, p < 0.001), and ecological trends showed a progressive increase in genome size from herbaceous (1.93 pg) to woody forms (2.50 pg), supporting the large genome constraint hypothesis. GIS mapping integrated taxonomic, ecological, and genomic data, uncovering spatial patterns in diversity and genome evolution. region. This comprehensive framework provides a crucial foundation for assessing biodiversity and guiding conservation efforts in this ecologically important region.

The genus Senecio, which is a basal angiosperm group, holds significant importance for evolutionary and phylogenetic research. It is notable for possessing male meiotic characteristics that are rarely observed in most angiosperms. However, the current understanding about male meiosis in Senecio remains incomplete. Here, we traced the cell morphological characteristics of microsporogenesis, and male gametophyte development of Senecio cannabifolius was observed by transmission electron microscopy. The results showed that the microspore mother cells were surrounded by callose; the cytokinesis was simultaneous; the tetrad was tetrahedral; and the mature pollen was two-celled pollen with three germination pores. During the meiosis of microspore mother cells, there were abundant organelles in the cytoplasm at leptotene stage. Obvious and clear synaptonemal complex was found in pachytene stage. In the prophase I stage, the number of organelles in the cytoplasm decreased; the cristae of mitochondria decreased; and the electron density of plastids was low. It began to recover at the metaphase I and formed an obvious organelle band in the anaphase I, which separated the two daughter nuclei and contained abundant organelles. During this period, the organelles in the cytoplasm changed regularly, which was the phenomenon of cytoplasmic reorganization. The pollen wall was formed at the late uninucleate stage; the pollen wall was mature at the binucleate microspore stage; and the pollen has abortion phenomenon. These results for the first time revealed the ultrastructure of microspores and male gametophytes during the development of S. cannabifolius and enriched the understanding of the formation of pollen grains by microspores in Compositae plants.

Desmids are valuable bioindicators in peatland ecosystems due to their sensitivity to environmental changes. In temperate and boreal wetlands, seasonal desiccation of aquatic habitats, which is increasing in frequency and severity due to ongoing climate change, is currently considered a key factor structuring the distribution of individual taxa. In this study, the desiccation tolerance of Micrasterias thomasiana and Staurastrum hirsutum isolated from contrasting hydrological environments in the peatland habitats of the Ore Mountains, Czech Republic, is investigated. Using controlled experimental conditions, we subjected both young, actively growing and old, mature cultures to four different desiccation treatments and evaluated morphology and photosynthetic performance. Our results showed that young and old cultures of both species exhibited a very similar photophysiological response. Severe desiccation led to an irreversible decline in the effective quantum yield of photosystem II in both species, resulting in cell death. Mild drought stress allowed the cultures to recover, indicating that the stress severity determines the recovery potential. Finally, prolonged desiccation resulted in irreversible damage in older cultures of both species, emphasizing the limited desiccation resilience of desmids. We observed similarities in morphology with Zygnema "pre-akinetes," but in contrast to these resilient cells, the old cells of M. thomasiana and S. hirsutum did not survive the harsher desiccation conditions. Long-term mild desiccation revealed a higher resistance of S. hirsutum, probably due to the protective role of its dense mucilage. In nature, these two species usually inhabit localities with low desiccation risk or avoid and mitigate desiccation stress through localized survival strategies.

Eriococcid-induced galls exhibit many unusual features, such as sexual dimorphism and differences in life cycle duration, which are reflected in the morphology, anatomy, and metabolism of female- and male-induced galls. These sex-based distinctions between the galls result from differential developmental processes related to the time female and male insects remain inside the gall, their feeding activity, and the degree of stress imposed on the host plant cellular machinery. We assessed the immunocytochemical and Raman spectroscopy profiles of two host plant-gall inducer systems: Annona dolabripetala (Annonaceae)-Pseudotectococccus rolliniae Hodgson and Gonçalves, and Pseudobombax grandiflorum (Malvaceae)-Eriogallococcus isaias Hodgson and Magalhães. We expected differences in the dynamics of cell wall chemical components between male and female galls, with particular effects on gall structural and functional profiles, also regarding specific constraints in each system. The epitopes of xylogalacturonans and homogalacturonans, as well as their degree of methylesterification, are affected by the sex of the gall inducers, conferring a rigid structure to the cell walls of female-induced galls in comparison with those of the male-induced galls. Raman spectroscopy detected cellulose peaks in both female- and male-induced galls, with pronounced lignin bands in female-induced galls. The sex-based chemical distinctions between female- and male-induced galls imply in differences in terms of higher rigid cell walls in the female-induced galls, which was similar for both host plants.

The term "green synthesis" refers to the use of sustainable and environmentally friendly methods to produce materials, chemicals, or nanoparticles (NPs). This approach emphasizes the use of renewable resources, energy-efficient processes, and non-toxic chemicals to minimize environmental impact. In our study, we synthesized cerium oxide NPs (CeO₂ NPs) of varying crystal sizes using leaf extract from the Moringa oleifera plant and evaluated their effects on the photosynthetic and antioxidant properties of mustard (Brassica juncea L.). X-ray diffraction (XRD) analysis confirmed the successful synthesis of CeO₂ NPs, with average crystal sizes determined using the Debye-Scherrer equation as 4.5 nm, 8.5 nm, and 15.4 nm (designated as A, B, and C respectively). Fourier transform infrared spectroscopy (FTIR) analysis revealed stretching frequencies at 550 cm⁻¹, confirming the presence of Ce-O stretching bands and the use of natural compounds in the synthesis process. Scanning electron microscopy (SEM) analysis showed that the CeO₂ NPs were irregularly shaped and agglomerated, while transmission electron microscopy (TEM) analysis confirmed that the particles were spherical and polydisperse. Dynamic light scattering (DLS) and zeta potential analysis further confirmed the polydispersity and stability of synthesized NPs in solution. Following synthesis, the CeO₂ NPs were applied foliarly to mustard crops at concentrations of 50, 100, and 150 ppm. The results demonstrated that all concentrations of NPs enhanced growth, photosynthetic efficiency, and gaseous exchange parameters in mustard. Additionally, the NPs regulated balance between oxidation and reduction (redox) reactions in cell. It helps maintain cellular function by controlling reactive oxygen species (ROS) and antioxidants, preventing damage and ensuring normal metabolism. Notably, the 4.5 nm-sized NP (A) at a concentration of 100 ppm was the most effective in improving these parameters. CeO₂ NPs show promise as a sustainable alternative to traditional fertilizers and pesticides, contributing to more sustainable agricultural practices. This pioneering research highlights the potential of biogenically synthesized CeO₂ NPs in boosting crop performance, marking a significant advancement in agricultural nanotechnology.