Protoplasma最新文献

Sands are a harsh habitat with limited water and nutrients, and danger of burial or mechanical injury by moving particles. Sand entrapping plants (psammophytes) actively fix sand on their surfaces, which presumably offers adaptive benefits, such as mechanical protection and camouflage. This short article deals with the structural-functional aspects of sand-trapping in the annual psammophyte Ifloga spicata (Asteraceae). Ifloga spicata outer surfaces are entirely covered with a dense coating of particles, mainly sand and dust. The leaves are needle-shaped and curled with the adaxial surface hidden inside. The entire outer epidermis is secretory, comprised of large cells with thick pectinaceous cell walls and upper cell wall junctions with numerous wall creases. Ruthenium red staining of fresh hand sections of the leaf demonstrated that the outer epidermal cells produce a pectinaceous substance, which upon wetting ruptures outside the cell, resembling pectin "rays" in the Arabidopsis seed coat. TEM imaging showed vesicles arriving at the plasmalemma, fusing with it and the secretory product accumulated in periplasmic spaces inside the cell wall. Ifloga spicata and other sand entrapping plants live in nutrient poor habitats. Foliar particle capture could have an additional benefit of phosphorus accumulation from leaf deposited dust particles, as known in several Mediterranean origin plants.

MicroRNAs (miRNAs) are a class of non-coding RNAs (ncRNAs) that negatively regulate gene expression at the post-transcriptional level. Intramuscular fat (IMF) deposition in livestock is crucial for meat quality, affecting the meat's taste and tenderness. However, there has been little research on the miRNA transcriptome of yak in relation to intramuscular fat deposition in yak. In this study, RNA sequencing in the longissimus dorsi (LD) muscle samples was conducted to uncover the miRNAs expression profiles of yak at two ages: 3 months (calf) and 3 years (adult). A total of 1030 known miRNAs and 279 novel miRNAs were identified, of which 40 differentially expressed miRNAs (DE-miRNAs) were screened. We then obtained target genes of 40 DE-miRNAs and established enrichment analyses using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes Genomes (KEGG). We found target genes were involved in four significantly enriched pathways, and the MAPK signaling pathways were the key pathways. Moreover, we constructed a miRNA-mRNA regulatory network to visualize the functions of miRNAs related to IMF deposition in the yak. miR-122, miR-375, and miR-378 may play a key role in IMF deposition in the yak, and RORC, STAT3, ACACA, FTO, and FOXO1 were the core target genes. We randomly selected six miRNAs from DE-miRNAs to validate the sequencing results using RT-qPCR. This study revealed miRNAs expression profiles in yak IMF development between calf and adult and provided a miRNA database for further studies on the molecular mechanisms of IMF deposition in the yak.

Dengue virus (DENV) is a substantial global health threat with no specific antiviral treatment available. The development of effective vaccines is crucial to combat DENV infections. Plant-based expression systems, such as tobacco chloroplasts, have emerged as promising platforms for the production of DENV antigens. In this research article, we describe the construction of a tobacco chloroplast vector with novel insertion sites for DENV-1 protein III. Our present study successfully demonstrated the production of the envelope protein structural domain III (EDIII) dengue virus antigen in tobacco chloroplasts. We obtained transformed tobacco lines that show the expression of EDIII dengue antigen and were confirmed through Southern blotting analysis. Furthermore, the expression of EDIII antigen was further confirmed via immunoblotting and quantified. These findings suggest that tobacco chloroplast engineering holds promise as a method for future manufacture of an oral dengue boost vaccine that is safe, affordable, and effective, contributing to the global management and control of this particular dengue infection.

Plasmodesmata (PD) are nano-channels in plant cell walls that connect adjacent cells, facilitating the symplastic transport of micro- and macromolecules. In certain tissues, specialized transport requirements drive the formation of intercellular channels in diverse morphologies, compositions and functions, including sieve plate pores, plasmodesmo-pore units, lateral sieve area pore, and flexible gateways. These channels, derived from PD, are referred to as PD-derived intercellular gateways (PdIGs) in this review. Studies of PD and PdIGs are crucial for understanding how plants achieve cell-to-cell and long-distance transport of specific cargos under various physiological conditions. Multiple types of specialized microscopy are essential for studying these nano-channels, enabling elucidating their structures, compositions, distribution patterns, frequencies, and permeability. In particular, transmission electron microscopy (TEM), scanning electron microscopy (SEM), laser scanning confocal microscopy (LSCM), and structural illumination microscopy (SIM) offer advantages for such specialized analysis. With the aid of antibodies, fluorescent dyes, custom-built molecules, and image processing technologies, microscopy can also capture dynamic details of PD/PdIGs beyond morphology features. This review examines the application of these microscopy in studying specific aspects of PD/PdIGs, discusses the merits and limitations of these methods, and evaluate their suitability in PD studying the results obtained from these microscopy studies enhance our knowledge of PD/PdIGs and form the basis of the current paradigm of PD-based plant communication.

Salinity is one of the major abiotic constraints impairing barley production. Tunisian landraces constitute a valuable reservoir of useful traits for breeding programs. Therefore, exploring the molecular mechanisms underlying salinity tolerance is of great interest. Here, the proteome response to salt stress of the 4th leaf at the tillering stage was assessed in two barley accessions, Barrage Mellegue (BM, tolerant) and Saouef (S, sensitive). Results led to the selection of differentially abundant proteins (DAP), including 20 and 49 genotype specific salt responsive proteins, respectively, and 12 common ones. Moreover, 10 biological functions were associated to salinity response, including photosynthesis. Indeed, the RBCS protein was surabundant only in the tolerant genotype. Nevertheless, 8 proteins including PSB28, PPD3, TLP16.5, MgCh40, TLP17.4, Rubisco, OEE and PSBH were less abundant in the sensitive genotype, although invariable in the tolerant BM. Therefore, signaling, nucleic acid binding, protein synthesis, ROS scavenging and photosynthesis might be the main biological processes related to salinity tolerance in barley. In fact, based on hierarchical classification and protein-protein interactions, ES2A, Cp31 BHv, PRX II, Srpsus2, RBCS and RLP12 (RPS50) proteins were identified as key candidates. Our findings suggest that BM can mitigate the negative effect of salinity at the tillering stage by inducing signal transduction pathway elements, reducing nucleic acid binding process, regulating ROS scavenging system, decreasing protein synthesis and, maintaining the photosynthesis system. Our results would serve as a useful source for deciphering the mechanisms governing salt stress tolerance at all stages of development, which is essential for barley breeding programs.

The midgut of insects originates from the endoderm. It is located in the central part of the digestive tract and serves as the primary site for chemical digestion and nutrient absorption. The larvae of Cerambycidae are the most destructive life stage. However, the ultrastructure of the larval midgut has been reported in only a few cerambycid groups. This study employs light, scanning electron, and transmission electron microscopy to observe the midgut ultrastructure of the Rhytidodera bowringii White, 1853 larvae. From outside to inside, the midgut of R. bowringii consists of a muscle layer, a basal membrane, an epithelium, and a lumen. The external muscles of the midgut are arranged in an outer longitudinal muscle and inner circular muscle. The epithelial tissue mainly comprises two types of cells: digestive cells and regenerative cells. The arrangement of regenerative cells in the midgut forms nidi, where multiple cells cluster together. The nucleus occupies most of the cytoplasm, which contains only a small number of organelles. The basal plasma membrane of the midgut epithelial cells is conspicuously infolded in R. bowringii, and around the nucleus, with a large amount of rough endoplasmic reticulum. At the apical regions of these digestive cells, numerous tightly arranged microvilli and mitochondria can be observed and many vesicles are localized near the lumen. This indicates that the digestive cells in the midgut have a strong secretory activity of digestive enzymes and other proteins, which may facilitate the larvae of the cerambycid in digesting recalcitrant plant tissues. It is the first time that the ultrastructure of the midgut of the R. bowringii larvae has been studied. The results can provide foundational insights into the ultrastructural organization of the Cerambycidae larval digestive system and the toxic mechanisms underlying prevention strategies for this pest.

Type 2 diabetes mellitus (T2DM) is an extensive metabolic disorder that imposes significant health and economic problems worldwide. It is characterized by chronic hyperglycemia, insulin resistance, and systemic inflammation. T2DM is linked with an increased risk of terrible difficulties, including cardiovascular disease, neuropathy, and nephropathy. The developing proofs suggest that natural compounds such as Ashwagandha (Withania somnifera) may have therapeutic potential due to their anti-inflammatory, antioxidant, and glucose-regulating properties. Ashwagandha is a traditional medicinal herb that is rich in withanolides and has demonstrated efficacy in previous studies; however, its comprehensive role in mitigating T2DM-related complications is underexplored. The current study seeks to assess the anti-inflammatory and antidiabetic effects of Ashwagandha in a high-fat diet (HFD) and low-dose streptozotocin (STZ)-induced T2DM mouse model. We have selected male C57BL/6 mice, which were allocated into four experimental groups, i.e. controls, STZ-induced diabetic controls, diabetic mice treated with Ashwagandha (200 mg/kg), and diabetic mice treated with metformin. The mice were treated for 8 weeks and then we assisted histological changes in pancreatic and hepatic tissues, with analysis of molecular markers of inflammation and glucose metabolism, and biochemical parameters such as blood glucose, insulin levels, lipid profiles, and oxidative stress markers. We have found a significant reduction in systemic inflammation, enhanced glucose tolerance, improved insulin sensitivity, and restored function of pancreatic β-cell. Furthermore, Ashwagandha treatment is predicted to relieve hepatic steatosis and adipose tissue inflammation by altering key oxidative stress and inflammatory pathways.

Large interstitial telomeric regions are considered remnants and markers of chromosomal rearrangements or a result of several suggested molecular mechanisms of telomere repeats accumulation. More rare are cases when large interstitial repeats are found not close to, but at a distance from the centromere. However, synapsis, recombination, and effects on chromatin near these regions during meiotic prophase I have not been sufficiently studied. Using the model of three snake species of the genus Vipera: V. berus, V. nikolskii, V. renardi, we studied interstitial telomere sites (ITSs) in the pachytene nuclei of primary spermatocytes. We discovered an unusual composite chromosome in the species under study with two ITSs located far from the centromere. In V. berus, two very large adjacent ITS blocks were found on bivalent 5. In the other two species, V. nikolskii and V. renardi, two ITSs are also present on bivalent 5, but they are significantly smaller and barely distinguishable by FISH on pachytene bivalents. The possibility of forming crossing-over sites is shown between the two ITSs. Apparently, the three studied viper species received this complex structure of chromosome 5 from their common ancestor. However, the transformation of these telomeric repeat regions during evolution in the species under study occurred differently. Possible mechanisms of modifications of the telomeric regions are discussed.

Cauliflower Or gene governs massive accumulation of β-carotene in the edible 'curd' portion. However, homozygous dominant (OrOr) plants accumulate higher β-carotene than heterozygous (Oror) individuals, yet this phenomenon has not been thoroughly elucidated in relation to chromoplast morphology. A study was performed in a complete randomised block design with three replicates, in which curd samples of homozygous orange (OrOr; CF_Or-HM)_, heterozygous orange (Oror; CF_Or-HT) and white (oror; CF_WT) genotypes were analysed using transmission electron microscopy (TEM). The number of chromoplasts in a cell and their morphology (shape and size) exhibited significant variation in the genotypes. In CF_Or-HM genotypes, chromoplasts exhibited a membrane-like structure, but in CF_Or-HT, they were small granules. The number of chromoplasts was significantly higher in CF_Or-HM compared to CF_Or-HT. The CF_WT had leucoplasts instead of chromoplasts. The CF_Or-HM (15.1 ± 0.1 µg/g FW) had significantly higher β-carotene content than CF_Or-HT (5.6 ± 0.3 µg/g FW). Both CF_Or-HM and CF_Or-HT had 18 and 7 times higher β-carotene than the white counterpart CF_WT (0.8 ± 0.1 µg/g FW). The number and size of chromoplasts exhibit a strong correlation with the concentration of total carotenoids and β-carotene in the curd portion. This is the first systematic report on changes in chromoplast features associated with Or-gene zygosity in cauliflower.

Although sulfur (S) fertilizer is known to enhance flavor quality in S-rich pungent vegetables, its role in regulating non-S flavor compounds, such as capsaicinoids in peppers (Capsicum annuum L.), remains unclear. Here, field experiments were conducted using three treatments: S fertilizer (ammonium sulfate), nitrogen fertilizer (urea), and an unfertilized control (CK). Pepper yield, flavor compounds (capsaicinoids, soluble sugars, vitamin C, and volatiles), and rhizosphere microbiota were analyzed. The results showed that S fertilizer significantly increased the contents of soluble sugars, vitamin C, capsaicinoids, and 15 volatile compounds such as benzyl benzoate, (E,E)-2,4-nonadienal, and β-ionone, collectively achieving optimal pungent flavor. Moreover, S fertilizer reduced bacterial diversity and richness in the rhizosphere soil but exhibited minimal impact on fungal community structure. Notably, the bacterial genera unidentified_WD2101_oil_group and Rhizomicrobium were identified as potential key taxa enhancing capsaicinoid accumulation under S fertilizer. Additionally, Sphaerobacter (bacteria) and Pseudogymnoascus (fungi) emerged as critical microbial candidates driving the synthesis of volatile compounds in S-amended soils. This study provides new insights into the roles of rhizosphere microbiota under S fertilization, emphasizing their importance in improving pepper yield and quality.