Protoplasma最新文献

{"title":"Floral morphoanatomy in Gymnocalycium (Cactaceae): Phylogenetic insights from structural analysis.","authors":"Celeste B Pérez, Stella M Solís, Valeria V González","doi":"10.1007/s00709-026-02268-w","DOIUrl":"https://doi.org/10.1007/s00709-026-02268-w","url":null,"abstract":"<p><p>The genus Gymnocalycium represents a distinct lineage within the tribe Cereeae (Cactaceae), recently assigned to the monogeneric subtribe Gymnocalyciinae. Although molecular phylogenetic studies consistently supports the monophyly of the genus, detailed floral morphoanatomical information remains scarce. This study investigates the floral morphoanatomy of four species representing four subgenera (Gymnocalycium saglionis, G. schickendantzii, G. schroederianum, and G. spegazzinii) using light and scanning electron microscopy. Our findings revealed conserved floral morphoanatomical features among the species examined, including nectar chambers with nectarostomata, nectariferous epidermis composed of trichomes or papillae, and rounded-oblate orbicules distributed along the inner anther walls. To our knowledge, this study provides the first report of orbicules in the subfamily Cactoideae. Pollen grains are consistently isopolar, radiosymmetric, and trizonocolpate, with a tectate-punctate exine, whereas interspecific differences occur mainly in exine ornamentation and pollen morphometric variables. Gymnocalycium schroederianum is distinguished by branched stigmatic lobes and nanospinulate pollen ornamentation, while the other species exhibit nanospinulate to microspinulate pollen ornamentation. Branched multicellular trichomes were also observed in the nectar chambers of G. sagionis, G. schickendantzii and G. spegazzinii, a character previously unreported in the family. Overall, the results expand the comparative knowledge of floral morphoanatomy in Gymnocalycium and reveal both conserved and variable characters among the species examined, providing a basis for future studies integrating floral morphology, reproductive biology, palynology, and phylogenetic data.</p>","PeriodicalId":20731,"journal":{"name":"Protoplasma","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149040009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beyond parallel pathways: molecular integration and functional crosstalk between autophagy and endocytosis in plants.","authors":"Md Arif Sakil","doi":"10.1007/s00709-026-02269-9","DOIUrl":"https://doi.org/10.1007/s00709-026-02269-9","url":null,"abstract":"<p><p>Autophagy and endocytosis represent two fundamental membrane trafficking pathways that are essential for cellular homeostasis, stress responses, and development in plants. While traditionally studied as independent processes, mounting evidence reveals extensive crosstalk between these pathways at multiple levels, including shared molecular machinery, convergent trafficking routes, and coordinated regulation. This review examines the molecular mechanisms underlying the interplay between autophagy and endocytosis in plants, highlighting recent discoveries of shared protein complexes, membrane contact sites, and regulatory networks. Additionally, this review discusses how these pathways cooperate during stress responses, nutrient recycling, and protein quality control while also exploring their distinct roles in plant immunity and development. Understanding the intricate relationship between autophagy and endocytosis provides crucial insights into plant cell biology and offers potential strategies for improving stress tolerance and crop productivity.</p>","PeriodicalId":20731,"journal":{"name":"Protoplasma","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149025975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ejectosome biogenesis and assembly in the raphidophycean alga Gonyostomum semen.","authors":"Peter Heywood","doi":"10.1007/s00709-026-02264-0","DOIUrl":"https://doi.org/10.1007/s00709-026-02264-0","url":null,"abstract":"<p><p>The raphidophycean flagellate Gonyostomum semen (Ehrenberg) Diesing is a stramenopile protist whose ejectosomes - rod-like organelles at the cell periphery - are discharged as mucilaginous threads, which kill some zooplankton grazers. Ejectosomes are formed from fibrils, which are first distinguishable in the Golgi, where they can reach 650 nm in length, have a diameter of 21-27 nm, and possess a narrow electron-transparent lumen. Fusion of Golgi vesicles forms a post-Golgi structure containing many fibrils, which gives rise to an immature ejectosome in which some fibrils crisscross at an angle of approximately 45 degrees to the longitudinal axis of the ejectosome and other fibrils are approximately parallel to the longitudinal axis of the ejectosome. The arrangement of fibrils is not discernible in the mature ejectosome, where they form a densely stained core; between the core and the ejectosome membrane lies a less-stained layer. The anterior end of the core terminates in a domed structure that is in contact with the ejectosome membrane. Mature ejectosomes, which are approximately 1.8 to 3.1 μm long by 0.5-0.6 μm in diameter, migrate to the cell periphery and discharge in response to chemical or physical stimuli. This paper describes the assembly of ejectosomes in G. semen and presents a structure somewhat different from that previously reported.</p>","PeriodicalId":20731,"journal":{"name":"Protoplasma","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149025885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cytorrhysis under drought, osmotic and freezing stress.","authors":"Matthias Stegner, Karin Fehringer, Alexander Flörl, Anna-Lena Strasser, Jasmin Lindner, Sandra Plangger, Tanja Schäfernolte, Viktoria Thoma, Gilbert Neuner, Ingeborg Lang","doi":"10.1007/s00709-026-02263-1","DOIUrl":"https://doi.org/10.1007/s00709-026-02263-1","url":null,"abstract":"<p><p>Cytorrhysis describes the shrinkage of plant cells caused by water loss, during which the protoplast and cell wall contract while remaining connected. Cytorrhysis can occur naturally during drought and freezing and can be experimentally induced by exposure to osmotic substances. Although traditionally studied separately, the cytorrhysis process itself shares the same underlying mechanisms: water efflux along chemical potential gradients and the mechanical response of the cell wall-plasma membrane continuum. Cytorrhysis has been documented across diverse taxa - including algae, bryophytes, ferns and seed plants - indicating that it represents a fundamental response of walled cells to dehydration. Besides osmotic effects, the extent of cytorrhysis is also strongly affected by biomechanical cell structure. Cell size, wall thickness, elasticity and tissue architecture influence the likelihood of cellular collapse. Small, thick-walled cells withstand larger pressure differences and develop negative turgor pressure whereas large, thin-walled cells collapse more readily. During freezing, extracellular ice imposes temperature-dependent dehydration forces, and biomechanical constraints may generate negative turgor pressure. Recent advances, including cryo-microscopy, differential scanning calorimetry and psychrometric water-potential measurements, allow more precise quantification of freeze dehydration and structural responses. Functionally, cytorrhysis can be protective or damaging. Moderate, reversible cytorrhysis helps maintain membrane integrity e.g. in desiccation-tolerant species. In freezing environments, cells undergoing cytorrhysis survive temperatures far below those tolerated by supercooling cells. However, excessive dehydration may cause cell death. Integrating classical observations with modern biophysical approaches provides a renewed perspective on cytorrhysis and highlights structural traits that could be exploited to enhance plant resilience to drought and freezing stress in a changing climate.</p>","PeriodicalId":20731,"journal":{"name":"Protoplasma","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149002375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metabolic acclimation of rice cultivars via cold stress-induced carbohydrate accumulation.","authors":"Arezoo Tarikhpasand-Modabber, Reza Maali-Amiri, Salehe Naderi","doi":"10.1007/s00709-026-02262-2","DOIUrl":"https://doi.org/10.1007/s00709-026-02262-2","url":null,"abstract":"<p><p>This study was conducted to comparatively investigate the accumulation of carbohydrates and transcript levels of genes encoding relevant enzymes in two rice (Oryza sativa L.) cultivars 'Hashemi' (cold-sensitive) and 'Kouhsar' (cold-tolerant) at 1, 3 and 6 days after cold stress (DAS) (4℃). The sinusoidal pattern of H₂O₂ and MDA in Hashemi under cold, compared with the steadily decreasing levels in Kouhsar indicates differing oxidative damage, reflected in 2.28- and 2.39-fold higher contents, respectively, at 6 DAS. Kouhsar had higher sucrose than Hashemi on all stress days, with a peak increase of 24% at 6 DAS. Glucose and fructose values increased more in Hashemi but changes ratio in fructose were more prominent and was accompanied by higher expression of sucrose transporters and invertase genes. In both cultivars, raffinose and trehalose values reached their highest levels at 6 DAS with no significant difference between them. During stress, higher expression of galactinol synthase, trehalose-6-phosphate phosphatase and phosphoenol pyruvate carboxylase genes was observed in Kouhsar, with the most increases of 23%, 35% and 30%, respectively, at 6 DAS. Despite chlorophyll deceasing and carotenoids increasing under cold, Kouhsar exceeded Hashemi by 69% in chlorophyll and 31% in carotenoids at 6 DAS. The results suggest that cold tolerance is more effectively conferred by the maintenance of sucrose level at the beginning of stress and its continued increase along with Raf and Treh accumulation throughout the stress period. Enhancing these features may pave the way for breeding programs to increase production sustainability in cold regions.</p>","PeriodicalId":20731,"journal":{"name":"Protoplasma","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148983156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of the Δ12-acyl-lipid desaturase gene insert and expression under the control of the CBF1 promoter on resistance tobacco to the cold stress.","authors":"Tetiana Kyrpa, Maksym Kharkhota, Mykola Kuchuk","doi":"10.1007/s00709-026-02267-x","DOIUrl":"https://doi.org/10.1007/s00709-026-02267-x","url":null,"abstract":"<p><p>The mechanisms of plant resistance and adaptation to low temperature and frost stress remain a very important topic for research, as they can directly and indirectly affect the productivity of the agricultural sector. Evolved plant defence systems are currently one of the main methods recommended for use in biotechnology. One of them is to increase the proportion of unsaturated fatty acids in membrane phospholipids. Desaturases are enzymes that promote the formation of double bonds in fatty acids and thereby convert them from saturated to unsaturated. However, the insertion and expression of transferred genes can have both positive and negative effects, so we used the cold-inducible promoter of CBF1 to regulate the expression of the Δ12-acyl-lipid desaturase gene from the cyanobacterium Synechocystis sp. PCC 6803 in the model plant Nicotiana tabacum. We found an altered spectrum of unsaturated fatty acids in transgenic plants and better adaptive parameters under conditions of in vitro plant cultivation based on the results of the study of superoxide dismutase activity, the level of malondialdehyde accumulation and electrolyte loss compared to control plants.</p>","PeriodicalId":20731,"journal":{"name":"Protoplasma","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148983185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated transcriptomic and metabolomic analyses reveal sodium selenite-induced molecular responses and metabolic remodeling in Stemona tuberosa roots.","authors":"Lianghua Yin, Tianrun Zhu, Jianhua Wang, Wenyu Cao, Qiuduo Lai, Zunquan Wu, Juntao Gan, Qiang Xiao","doi":"10.1007/s00709-026-02266-y","DOIUrl":"https://doi.org/10.1007/s00709-026-02266-y","url":null,"abstract":"<p><p>Selenium (Se) is a bioactive trace element that influences plant growth, development, and metabolic processes. However, the molecular and metabolic responses of medicinal plants to exogenous sodium selenite remain poorly understood. In this study, Stemona tuberosa Lour. roots were treated with 20 mg/L sodium selenite (Na₂SeO₃) for 40 days, and integrated transcriptomic and metabolomic analyses were performed to characterize Se-responsive changes. The results revealed substantial transcriptional and metabolic changes in response to Na₂SeO₃ treatment. Metabolomic analysis identified 669 differentially accumulated metabolites (DAMs), predominantly involving amino acids and derivatives, organic acids, carbohydrates, lipids, and secondary metabolism-related compounds. KEGG enrichment analysis showed that DAMs were mainly associated with metabolic pathways, amino acid biosynthesis, nucleotide metabolism, inositol phosphate metabolism, and secondary metabolite biosynthesis. Transcriptomic analysis identified 16,577 differentially expressed genes (DEGs), including 9,134 upregulated and 7,443 downregulated genes. These DEGs were mainly enriched in metabolic processes, stimulus responses, plant hormone signal transduction, phenylpropanoid biosynthesis, flavonoid biosynthesis, and starch and sucrose metabolism. Transcription factor analysis indicated that AP2/ERF, MYB, WRKY, bHLH, and NAC families were prominently represented among Se-responsive transcription factors. Integrated analyses identified coordinated associations among genes, transcription factors, and metabolites, suggesting that these coordinated molecular patterns may be associated with the response of S. tuberosa roots to Na₂SeO₃. Overall, this study provides insights into the molecular and metabolic changes associated with Na₂SeO₃ exposure in medicinal plants.</p>","PeriodicalId":20731,"journal":{"name":"Protoplasma","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148983148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Loop-mediated isothermal amplification (LAMP) for quality control of Coscinium fenestratum: a colorimetric platform for detecting Anamirta cocculus adulteration.","authors":"Anju P B, Smita Nair","doi":"10.1007/s00709-026-02261-3","DOIUrl":"https://doi.org/10.1007/s00709-026-02261-3","url":null,"abstract":"<p><p>Coscinium fenestratum (Gaertn.) Colebr., commonly known as tree turmeric, is a critically endangered medicinal plant extensively used in Ayurveda and Siddha systems for treating metabolic disorders and various infectious diseases. Due to overexploitation and habitat loss, Coscinium fenestratum faces severe conservation threats, resulting in a scarcity of authentic raw material and frequent adulteration with morphologically similar species such as Anamirta cocculus. The present study reports the development and validation of an internal transcribed spacer (ITS) based loop-mediated isothermal amplification (LAMP) assay for rapid authentication of C. fenestratum and sensitive detection of A. cocculus adulteration. Species specific LAMP primers were designed targeting the variable regions of ITS sequence, and assay optimization identified 7 mM MgSO₄ and 1 M betaine as the optimal reagent concentrations. Colorimetric detection using hydroxy naphthol blue (HNB) dye enabled closed-tube visual detection with a violet to sky blue color transition upon amplification. The assay demonstrated 100 per cent specificity with no cross-reactivity between species and achieved a limit of detection of 0.05 per cent adulterant DNA. Analysis of ten market samples including bark and powdered bark specimens revealed 30 per cent adulteration in the tested samples. The developed LAMP assay requires minimal equipment, uses crude DNA extracts, and delivers results within 60 min, making it suitable for resource-limited laboratory settings. This rapid, sensitive, and user-friendly molecular tool enables reliable authentication and quality control of Ayurvedic medicinal raw materials.</p>","PeriodicalId":20731,"journal":{"name":"Protoplasma","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148956391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Precocious programmed cell death and tapetal dysfunction cause pollen abortion in Lycium barbarum male-sterile line ningqi-5.","authors":"Zhou Ting, Yang Xiao Hui, Li Yu, Liang Wen Yu, Zhang Hong, Guan Cui Ping, Yang Shu Juan","doi":"10.1007/s00709-026-02260-4","DOIUrl":"https://doi.org/10.1007/s00709-026-02260-4","url":null,"abstract":"<p><p>Male sterility is a valuable trait in plant breeding that enables efficient hybrid seed production by eliminating the need for manual emasculation. In Lycium barbarum, the male sterile line Ningqi-5 exhibits complete pollen abortion, but the underlying cytological mechanisms remain unclear. In this study, we systematically compared anther development between the fertile line Ningqi-1 and the male sterile line Ningqi-5 using light microscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and TUNEL assays to elucidate the cellular basis of male sterility. Our results revealed that microspore abortion in Ningqi-5 occurs at the tetrad stage, characterized by delayed callose wall degradation, failure of microspore release, and progressive degeneration of tetrads. TEM and SEM analyses showed abnormal tapetal ultrastructure in Ningqi-5, including thickened cell walls, absence of Ubisch bodies, aggregated and adherent secretions, and disrupted sporopollenin transport. Furthermore, TUNEL assays demonstrated premature initiation of programmed cell death (PCD) in the tapetum of Ningqi-5 during the tetrad stage. These defects collectively disrupt nutrient supply, exine formation, and microspore maturation. We conclude that male sterility in L. barbarum Ningqi-5 results from a synergistic interplay of three key factors, include failure to degrade the callose wall, impaired tapetal secretion function, and precocious tapetal PCD. This study provides a comprehensive cytological framework for understanding pollen abortion in L. barbarum.</p>","PeriodicalId":20731,"journal":{"name":"Protoplasma","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148956317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seed shattering habit in millets and the secrets of the abscission layer - a comprehensive review.","authors":"Majiga Revanth Kumar, Koppula Nithya Sree, Pegada Venkata Maruthi Sai Teja, Shweta, Sandeep Nalla, Sreedevi Menon, Shiva Kumar Reddy Mudedla, Yenda Damodhara Rao, Vaidurya Pratap Sahi","doi":"10.1007/s00709-026-02259-x","DOIUrl":"https://doi.org/10.1007/s00709-026-02259-x","url":null,"abstract":"<p><p>Though seed shattering continues to be a significant barrier affecting yield stability and harvesting efficiency in millets and other grasses, millets are increasingly acknowledged as climate-resilient, nutrient-rich 2007cereal crops with the potential to strengthen global nutritional and food security under the combined pressures of climate change, population growth, and limited natural resources. Since strong artificial selection favoured non-shattering phenotypes during domestication, seed shattering, an adaptive trait in wild species that promotes seed dispersal through the formation and activation of specialised abscission layers, became a distinguishing feature of cultivated cereals. With a focus on the morphological, physiological, hormonal, and genetic modulation of the abscission zone, this article summarizes the state of the art regarding seed shattering in millets. Abscission layer morphology, location, and lignification vary greatly among grasses, from well-defined lignified zones in rice and sorghum to non-lignified and anatomically subtle zones in Setaria and Panicum species. Cell wall-modifying enzymes like polygalacturonases, cellulases, expansins, and pectin methylesterases that mediate middle lamella degradation are modulated by coordinated hormonal signalling involving auxin, ethylene, and abscisic acid, which controls the timing and progression of cell separation at the physiological level. Domestication-related genes, including SH1, qSH1, SH4, and LES1, demonstrate convergent evolutionary mechanisms controlling abscission layer development in a variety of grass lineages at the molecular level. Understanding these regulatory networks has been greatly enhanced by recent developments in transcriptomics, functional genomics, and genome sequencing in both model species and underused millets. The role of millets as climate-smart cereals for sustainable future agriculture is reinforced by the integration of anatomical, physiological, and genetic insights, which offer a solid basis for targeted breeding and genome-editing strategies intended to improve seed retention, enhance yield stability, and increase harvest efficiency.</p>","PeriodicalId":20731,"journal":{"name":"Protoplasma","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148930899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}