Protoplasma最新文献

A large set of tRNAs is imported into the plant mitochondria from the cytosol. Besides tRNA import, the mitochondria are capable of uptaking DNA from the cytosol. These two processes may partially overlap, but little is known about which membrane proteins act as carriers for both DNA and RNA. In our work, we studied the role of tRNA carriers in the outer mitochondrial membrane in DNA transfer into the Arabidopsis mitochondria. The outer membrane translocase receptor subunit Tom20-2 and tRNA import-engaged Tric1/Tric2 proteins are involved in the import of short (265 bp), but not long (2.7 kb), DNA fragments. The presence of one of the Tric subunits is sufficient for the normal functioning of the DNA transport channel formed by these proteins. Based on treatment of mitochondria isolated from tric1/tric2 knockout line with antibodies, we suggest that Tric1/2 plays a central role in the import of not only tRNA but also short-length DNA fragments, sharing channel with VDAC1 and Tom40. Thus, our results suggest that Tric1/2 proteins and TOM complex subunits take part in both tRNA and DNA translocation, revealing a new layer of multifunctionality of outer membrane carrier proteins.

Throughout the life of a plant, generations of different forms of reactive oxygen (ROS) and nitrogen species (RNS) are derived as a by-product of metabolic events. The quantum of ROS and RNS becomes higher once a plant encounters a perturbed situation either through biotic or abiotic factor. As each of reactive species is harmful to the cells beyond certain optimal level, it requires a mechanism to detoxify RONS induced cellular toxicity. For the purpose cell has instituted highly organized multi-layered defense mechanisms. In the first layer of defense, cell produces different antioxidant enzymes and non-enzyme molecules. Once generated, ROS and RNS become beyond the detoxification capacity of cellular antioxidant pool, another strategy comes into the operation wherein a few targeted cells undergo self-autolysis progression known as programmed cell death (PCD). The process of PCD has been partially dissected in plants emphasizing either under amplified ROS or RNS condition. However, there are evidences for reaction between species of ROS and RNS. It is unequivocally evident that superoxide has tendency to react with nitric oxide giving rise to a very potential oxidant called peroxynitrite that has ability to nitrosylate several biomolecules thus, altering cellular fate. This suggests that cellular damage caused by reactive species of nitrogen and oxygen is not only an outcome of accumulation of individual species of ROS and RNS, but a combinatorial product of ROS and RNS may have a key role to play. In this review, we intend to advocate role of cellular nitro-oxidative condition in PCD in plants.

Mucilage cells have critical ecological and functional importance, including water storage, transport, and seed protection. These cells can exhibit diverse morphologies, often accompanied by structural changes in the cell wall, which are key to their functionality. In Myrsine umbellata, epidermal mucilage cells exhibit dual secretion: phenolic compounds and mucilage. These contents are separated by a "cell wall"; however, the formation and composition of this wall after cell differentiation remain unclear. Although some studies suggest the presence of an inner cell wall, its development and chemical makeup have not been thoroughly investigated. Using immunocytochemistry and transmission electron microscopy, we found that the new wall forms continuously with the innermost layer of the outer periclinal wall. This new layer resembles primary walls in composition, containing high levels of homogalacturonans (HGs) with a high degree of methyl-esterification, and rhamnogalacturonan I (RG-I) with arabinan side chains. It also includes low concentrations of de-esterified HGs bound to calcium ions and RG-I with galactan side chains. In the mature stage, the new wall also contains higher concentrations of arabinogalactan proteins (AGPs) and cellulose. This newly formed wall compartmentalizes the mucilage cell, isolating the protoplast from the mucilaginous compartment, thus preserving the protoplast and preventing cell death in this idioblast.

Solanum villosum Mill. is an underutilized traditional medicinal plant of the Solanaceae family. Solasodine is a steroidal glycoalkaloid chemical compound; it is an important secondary metabolite in this species and is widely utilized in various pharmaceutical industries due to its bioactive properties. The study aims to establish a hairy root culture and investigate the effects of biotic and abiotic elicitors on enhancing the production of the bioactive compound solasodine from the elite hairy root line. The results indicated that various strains of Agrobacterium rhizogenes (A4, LBA9402, ATCC 15834, and MTCC 532) exhibited differing potentials in inducing hairy roots on leaf explants. The integration of different genes (rolA, rolB, rolC, rolD, aux1, ags, and virD1) of Ri plasmid in hairy root culture was confirmed by PCR-based analysis. The maximum transformation efficiency (84.39 ± 1.57%) was observed in the A4 strain. The HPLC analysis was performed and out of the various established hairy root lines, the SVTR-19 (Solanum villosum Transformed Root-Line-19) hairy root line induced by the A4 strain accumulated the highest amount of solasodine content (0.691 ± 0.046 mg g^‒1 DW). The optimum accumulation of solasodine (15.325 ± 0.024 mg g^‒1 DW) was observed in the hairy roots elicited with 7.5 mg l^‒1 methyl jasmonate after 6 days of treatment. The results suggest that elicitation could effectively enhance solasodine production in S. villosum hairy root cultures.

The intestinal barrier is a critical defense against external pathogens and plays a central role in immune regulation and nutrient absorption. Oxidative stress and chronic inflammation in high-altitude environments can exacerbate the damage to the intestinal barrier in Baimei ternary pigs. Anthocyanin extract of Lycium ruthenicum Murray (AEL), has garnered widespread attention due to its rich anthocyanin flavonoid content, which exhibits antioxidant and anti-inflammatory properties. These properties help alleviate inflammation and oxidative stress, thereby enhancing gut function in animals. Based on this, the study employed Bamei ternary pigs and supplemented their basic diet with varying concentrations of AEL to investigate its impact on gut barrier function. The results demonstrated that AEL inhibited key factors of the intestinal Toll-like receptor pathway, including Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), tumor necrosis factor receptor-associated protein 6 (TRAF6), and nuclear factor kappa B (NF-κB), affecting gene transcription and protein expression levels. This led to a reduction in pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), an increase in anti-inflammatory IL-10 production, and improved antioxidant capacity by enhancing total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activity, while decreasing malondialdehyde (MDA) production. Additionally, AEL improved intestinal morphology and facilitated the transcription and expression of tight junction proteins, including zonula occludens-1 (ZO-1), claudin-1 (CLDN-1), and occludin (OCLN). AEL also elevated the transcription levels of mucin 1 (MUC1) and mucin 2 (MUC2), as well as the secretion levels of polymeric immunoglobulin receptor (pIgR) and secretory immunoglobulin A (SIgA), while increased the number of intestinal goblet cells. Furthermore, dietary supplementation with AEL altered the structure of the intestinal microbiota, enhancing the abundance of beneficial bacterial genera such as Verrucomicrobiaceae, Rikenellaceae, Butyricicoccaceae, UCG-005、Rikenellaceae_RC9_gut_group、norank_f_Ruminococcaceae、Eubacterium_oxidoreducens_group, thereby promoting the production of intestinal short-chain fatty acids (SCFAs). In conclusion, AEL inhibits the Toll-like receptor pathway, reduces the production of inflammatory factors, enhances antioxidant levels, improves intestinal morphology and microbiota structure,, thereby reinforcing intestinal barrier function.

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.