Protoplasma最新文献

Rupestrian fields are high-altitude environments with nutrient-poor soils, posing challenges for dioecious species like Baccharis platypoda DC. This study assessed leaf anatomy and chemical composition to explore variations related to environmental conditions and sex differences. Leaves from male and female individuals were collected in Serra do Cipó, Minas Gerais, Brazil. Anatomical and chemical analyses, including histochemical tests and chromatographic techniques, were performed to evaluate structural traits and compound profiles. Both sexes exhibited a uniseriate epidermis, dorsiventral mesophyll, and hypostomatic profile, with capitate glandular trichomes distributed on both surfaces, with abundant secretion observed predominantly on the abaxial side. Significant differences were observed between sexes in the thickness of the adaxial cuticle and epidermis, as well as in the proportions of palisade and spongy parenchyma. Histochemical tests detected various compounds in trichomes and secretions. Flavonoid content ranged from 5.95 to 7.50% relative to the dry weight of the crude extract, with higher values observed in female leaves. Chromatographic analyses annotated phenolic compounds, terpenes, and other less common classes. The findings highlight traits that may contribute to ecological success in nutrient-poor environments and reveal subtle sex-based anatomical and chemical differences. This study advances the understanding of the responses of dioecious species to challenging habitats and provides a basis for future ecological and biochemical research.

Adult males of Podisus nigrispinus Dallas (Heteroptera: Pentatomidae) produce pheromones in their dorsal-abdominal glands, which are located internally between abdominal tergites III and IV. These pheromones attract adult individuals making them useful for biological control and as bait for capture. This article presents a morphological description of the dorsal-abdominal glands in male P. nigrispinus using light microscopy, as well as scanning and transmission electron microscopy. The glands consist of a pair of coiled tubular secretory structures, each opening in an enlarged reservoir. The glandular epithelium is composed of three cell layers: a basal layer of flattened cells, a middle layer of both columnar secretory cells and narrowed interstitial cells, and an apical layer of duct cells. The duct cells enclose a glandular reservoir lined with a cuticle, into which the secretory cells release their products through a sinuous intracellular duct. Each glandular reservoir opens outward through a pair of ostioles in the dorsal tergite, controlled by a tegumental valve. Cytoplasmic characteristics suggest that the secretory product is likely synthesized through fatty acid metabolism, similar to the sex pheromones produced by other insects.

The generalized response of the cyanobacterium Nostoc sp. PCC 7120 to and its recovery from phosphorus (P) starvation stress differ drastically under diazotrophic and non-diazotrophic growth modes. In nitrogen (N) -replete medium, Nostoc sp. PCC 7120 cells were resilient even to prolonged P starvation when its growth was supported by mobilization of cellular reserves of P (polyphosphate) and glycogen on the background of accumulation of nitrogen and carbon reserves (mainly cyanophycin). The P-starving cells quickly recovered upon re-feeding with inorganic phosphate (P_i). Under diazotrophic conditions, P starvation essentially diminished the fixation of dinitrogen. As a result, most of the vegetative cells comprising the trichomes of the cyanobacterium died and decomposed while other cells retained their structural integrity but did not divide. In turn, the latter fell into two categories: some of them showed signs of nutrient starvation; while the other became dormant but did not display the signs of starvation. They resembled neither akinete nor chlorotic cells but were similar to arthrospores lacking a thickened sheath. Re-feeding with P_i triggered a quick resuscitation of the dormant vegetative cells manifested by mobilization of their internal reserves, resumption of the cell growth and division. These processes took place faster than the formation of heterocytes with well-developed envelope (thus, nitrogenase activity recovered by the 7th day after re-feeding of the cells with P_i). The results provide a deeper insight into the mechanisms of stress tolerance in Nostoc sp. PCC 7120 and modulation of the cyanobacterial productivity in natural ecosystems and artificial cultivation facilities by nitrogen and P availability.

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.

Water is essential for all forms of life, and its loss triggers a series of protective responses in both prokaryotic and eukaryotic organisms. This review summarizes the fundamental mechanisms that underlie desiccation tolerance, focusing on the phenomenon of anhydrobiosis. Key strategies include osmoprotection, accumulation of compatible solutes such as trehalose and sucrose, protein anti-aggregation, and enhanced antioxidant activity. Osmoadaptation enables cells to regulate osmotic pressure and maintain membrane integrity during water loss. Intrinsically disordered proteins, particularly late embryogenesis abundant (LEA) proteins, contribute to protein stabilization by forming molecular shields under desiccation stress. Furthermore, the upregulation of antioxidant enzymes, such as superoxide dismutase (SOD) and catalase (CAT), mitigates oxidative damage to nucleic acids and proteins. Together, these mechanisms preserve cellular integrity and functionality, facilitating recovery upon rehydration.

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.

Onopordum acanthium L. (Asteraceae), a traditionally used medicinal plant, was investigated for its morphological, phytochemical, and biological properties in this comprehensive study. Methanolic and aqueous extracts were prepared from different parts of the plant (root, stem, leaf, flower, and fruit) and analyzed for their phenolic composition, antioxidant, antidiabetic, anticholinesterase, antimicrobial, and genotoxic activities. LC-MS/MS analysis revealed that chlorogenic acid was most abundant in the flower (3045.38 ng/mL) and root (728.53 ng/mL) aqueous extracts, while quinic acid reached 856.27 ng/mL in the root. Quercetin, apigenin, and luteolin were also detected at significant levels. The fruit methanol extract showed the highest total phenolic (100.78 ± 0.0015 µg GAE/mg), flavonoid (603.67 ± 0.0015 µg RE/mg), and tannin (186.22 ± 0.0015 µg TAE/mg) contents. Antioxidant assays demonstrated notable ABTS^•⁺ (38.38 ± 0.0042%) and DPPH^• (28.43 ± 0.0252%) scavenging capacities in the same extract. Regarding enzyme inhibition, the flower aqueous extract showed the strongest α-glucosidase inhibition (45.58%), while the fruit aqueous extract exhibited moderate α-amylase inhibition (26.33%). The stem methanol extract displayed the highest acetylcholinesterase inhibition (19.02%), whereas the root aqueous extract showed the highest butyrylcholinesterase inhibition (10.76%). Antimicrobial assays revealed moderate antifungal activity, particularly against Candida tropicalis (MIC = 312.5 µg/mL), with the flower and fruit methanol extracts being the most effective. Genotoxicity assessment using Ames and Allium tests confirmed biosafety up to 5 mg/plate and 250 mg/L, respectively, except for flower extracts, which showed slight cytogenotoxicity. Overall, this study highlights O. acanthium as a promising natural source of phenolic compounds with therapeutic potential, particularly in managing oxidative stress, diabetes, and neurodegenerative disorders.

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.

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.

Plants during their evolution have acquired a highly efficient apparatus comprising several photoreceptor systems, the most effective in the transition from scoto- to photomorphogenesis being the blue-light-absorbing cryptochromes (crys) and the red - far-red-absorbing phytochromes (phys). Within the phytochrome family, the major ones are phyA and phyB, the former one comprising two photochemically and functionally distinct types - light-labile and soluble phyA' and relatively light-stable and amphiphilic phyA″. Cryptochromes are represented by cry1 and cry2. phyB and phyA were shown to interact with cry1, the substrate of their phosphorylation activity, modifying its photoregulatory responses. In this work, with the use of phytochrome fluorescence spectroscopy in vivo, we investigated the possible effects of phyA-cry1 interactions on the state of phyA and its native types, phyA' and phyA″ in etiolated Arabidopsis (Columbia) plants. In cry1 mutant (cry1) and cry1 overexpressor (CRY1OX), the spectroscopic properties and total content of phyA remained practically unchanged as compared to the wild type (WT), whereas the [phyA']/[phyA″] ratio was raised from approximately 0.8-1.0 in the WT and CRY1OX to 1.6 in cry1. This shift in the phyA pools' balance towards phyA' suggests that cry1 hampers the formation of phyA' from phyA″, possibly interfering with the phosphorylation of the latter. cry1 and phyA″ localized in the cytoplasm are likely to be responsible for the induction of the fast membrane depolarization effects (Folta and Spalding 2001), whereas the slow end-point photoregulation reactions may be connected with the nuclear fraction of cry1 interacting with phyA' and/or phyA″.