Protoplasma最新文献

Salt stress is one of the major threats affecting crop yield. We assessed the behaviour of three barley genotypes, Ardhaoui, Manel, and Testour under 200 mM NaCl with the aim of evaluating the physiological and molecular mechanisms involved in barley salinity tolerance. Results revealed that salinity stress significantly decreases plant growth and water-holding capacity, particularly in the salt-sensitive genotype Testour. Tissue ionic content assessment demonstrated significantly distinct salinity-induced responses. The salt-tolerant genotype Ardhaoui accumulated more K⁺ and less Na⁺ content in both leaves and roots compared with the two other genotypes, leading to an increased K⁺/Na⁺ ratio. Furthermore, the genotype Ardhaoui exhibited a stronger selectivity transport capacity of K⁺ over Na⁺ from root to leaf compared to both Manel and Testour. This effect was due to enhanced K⁺ retention and Na⁺ exclusion, regulated by HvHKT expression. Indeed, higher HvHKT2;1 gene transcript abundance was detected in both leaves and roots of the Ardhaoui genotype, as well as an upregulation of HvHKT1;1 and HvHKT1, mainly in Ardhaoui roots. In view of the severe impact of salinity on plant development, these findings could be applied to the genetic improvement of plant salinity tolerance.

Curdlan, an exopolysaccharide, has gained sufficient attention in recent years due to its potential health benefits. Its unique physico-chemical and rheological properties create an appropriate substitute for diverse applications in agriculture, food, and pharmaceutical industries. This review begins with an overview of bioactive properties, structural characteristics, curdlan biosynthesis, and its production technologies. Curdlan is useful in the modulation of immune responses and as an effective agent against diseases like malaria, cancer, dengue, and COVID-19. This review also expounds on the potential role of curdlan in the food industry as a thickener, texture modifier, stabilizer, and emulsifier. This biomolecule holds promise for functional food development due to its prebiotic properties. Research on curdlan has proved its potential role in the biomedical sector, and it acts positively in drug delivery and tissue engineering practices. Thus, curdlan offers a potential remedy in response to growing environmental concerns and the urgent demand for environment-friendly substitutes for synthetic polymers.

We reported the histological and anatomical analyses of Legnotus limbosus's alimentary and excretory system using stereomicroscope, light and electron microscopy. As a result of the obtained data, the digestive tract of L. limbosus has three main parts: fore, mid, and hindgut. The salivary gland and gastric caeca are structures that assist digestion. The salivary gland is a pair consisting of the principal and accessory salivary glands. The foregut has the pharynx and esophagus. The pharynx structure is located immediately after the mouth and continues with the esophagus as a thin, long canal. The esophagus connects to the ventriculus 1 (V1). The midgut consists of three parts: V1, V2, and V3. The V1 and V2 have a single layer of cylindrical epithelium. However, the proximal and distal parts of V3 have cylindrical epithelium, while the lateral part exhibits a cuboidal form. The ileum and rectum make up the hindgut. The first has a cylindrical epithelium; the second has a squamous epithelium. The two pairs of Malpighian tubules, which are attached to the midgut-hindgut junction, are responsible for excretion and osmoregulation. Crystals with a deltoid shape are seen in the lumen of the Malpighian tubule and the rectum. This study is the first on the digestive and excretory system morphology of the Cydnidae family and will make significant contributions to studies on this subject in the Heteroptera, including this family.

Calyx nectaries are common secretory structures in Clerodendrum (Lamiaceae) that play an important role in plant indirect defence. These structures possess intricate morphological and anatomical features that are associated with the secretion physiology. This study intended to elucidate the structurally homologous calyx nectary glands of two Clerodendrum species that undergo morphological and anatomical changes facilitating nectar secretion. The morpho-anatomical, histochemical and ultrastructural features of the calyx nectary glands in two Clerodendrum species, viz., C. chinense and C. infortunatum, were studied throughout floral maturation stages using light and electron microscopy. The flower calyx possesses distinct disc-shaped patelliform nectary glands with different morphologies in both species. Histological analyses revealed distinct tissue regions in the nectary glands in both species. The nectary glands showed well-defined palisade-like secretory epidermis bounded by cuticular covering, lipid-rich intermediate layer, nectary parenchyma with prominent vascular bundles and photosynthetically active sub-nectary parenchyma tissue. Ultrastructural analysis revealed the presence of dense cytoplasm with a large number of mitochondria and chloroplasts in the nectariferous region in both species. Starch granules were found to be present within the chloroplasts and leucoplasts, and their depletion was noted in both the species, more prominently in C. infortunatum, suggesting their possible role in nectar biosynthesis. Anatomically, the calyx nectaries in both species were shown to be homologous and conserved which showed differential changes in both cell and tissue levels throughout floral maturation. Synthesis of nectar components in the nectary parenchyma supplemented with vascular supply and their regulation by hydrophobic barrier could shed light on the nectar biosynthesis and secretion process. Also understanding these nectary structures in taxonomic groups can provide valuable insights into phylogenetic relationships within the genus.

Heliotropium L. genus belongs to the Boraginaceae family and is represented by approximately 250 species found in the temperate warm regions of the world, and there are 15 species of these species recorded in Türkiye. Heliotropium hirsutissimum Grauer grows in Bulgaria, Greece, N. Africa, Syria, and Türkiye. There is no record showing that H. hirsutissimum is a heat-tolerant plant. However, in our field studies, it was observed that H. hirsutissimum, which is also distributed in Hisaralan Thermal Springs of Sındırgı-Balıkesir, Türkiye, grows in the thermal area with extremely high soil temperature (57.6 °C (~ 60 °C)). It was thought that it would be useful to investigate the tolerance mechanism of the H. hirsutissimum plant to extremely high temperatures. For this purpose, the plant seeds were obtained from a geothermal area in the thermal spring. Growing plants were exposed to 20, 40, 60, and 80 ± 5 °C soil temperature gradually for 15 days under laboratory conditions. We measured the effect of high soil temperature on some morphological changes, relative water content, thiobarbituric acid reactive substances, cell membrane stability, and hydrogen peroxide analysis to determine stress levels on leaves and roots. Changes in osmolyte compounds, some antioxidant enzyme activities, ascorbate content, and chlorophyll fluorescence and photosynthetic gas exchange parameters were also determined. As a result of the study carried out to determine the stress level, it was observed that there was not much change and it was understood that the plant was tolerant to high soil temperature. In addition, there was a general increase in osmolytes accumulation, antioxidant enzyme activities, and ascorbate level. There was no significant difference in photosynthetic gas exchange and chlorophyll fluorescence parameters of plants grown at different soil temperatures. The high temperature did not negatively impact the photosynthetic yield of H. hirsutissimum because this plant was found to enhance its antioxidant capacity. The increase in antioxidant activity helped reduce oxidative damage and protect the photosynthetic mechanism under high temperature conditions, while the significant increase in the osmolyte level helped maintain the water status and cell membrane integrity of plants, thus enabling them to effectively withstand high soil temperatures.

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.