Protoplasma最新文献

{"title":"Comparative genomic characterization and germination-associated expression of DET2 and CER10 related reductases in Chenopodium quinoa.","authors":"Kamal Hachani, Estefanía Contreras, Mohammed Yacine Tercha, Salim Azib, Ouiza Djerroudi Zidane, Raquel Iglesias-Fernández","doi":"10.1007/s00709-026-02280-0","DOIUrl":"https://doi.org/10.1007/s00709-026-02280-0","url":null,"abstract":"<p><p>Genome annotations frequently group DEETIOLATED2 (DET2), ECERIFERUM10 (CER10), and related proteins under broad steroid-reductase-like designations, despite experimentally characterized members participating in distinct metabolic pathways associated with plant development and environmental responses. Here, we comparatively characterized DET2 and CER10 related reductases in Arabidopsis thaliana, Amaranthus hypochondriacus, and the allotetraploid crop Chenopodium quinoa. Phylogenetic analysis resolved five groups and clearly separated DET2-like and CER10-like proteins. Conserved motifs, exon-intron organization, local microsynteny, and predicted membrane topology and protein structure further supported this distinction and the retention of paired quinoa loci following allopolyploidization. Public expression datasets revealed marked transcriptional differences among family members. Germination and expression analyses were subsequently performed in the quinoa accessions Giza1 and Puno (Q04), which showed contrasting responses to 250 mM NaCl. Q04 maintained rapid germination under salinity, whereas Giza1 displayed a pronounced delay and reduced final germination. Among four genes analysed by RT-qPCR, CqCER10.1 showed the clearest accession- and time-dependent expression pattern. Under 250 mM NaCl, CqCER10.1 transcript levels were significantly higher in Q04 than in Giza1 during early germination, coinciding with the markedly faster and more successful germination of Q04 under salinity. In Giza1, CqCER10.1 accumulation occurred later, broadly following its delayed germination progression. CqCER10.2 and CqDET2.2 remained weakly expressed, whereas CqDET2.1 accumulated mainly at later stages. Given the contrasting behaviour of the CER10-like copies (homoeologs), comparative analysis of their upstream regions in the QQ74 reference genome revealed substantial sequence divergence together with locally conserved regions and putative cis-regulatory elements. Overall, these results refine the classification of DET2- and CER10 related reductases in quinoa and reveal pronounced transcriptional asymmetry among retained gene copies. CqCER10.1 expression was associated with the contrasting germination behaviour of Giza1 and Q04, particularly under salinity. Whether this association reflects developmental progression, accession-specific regulation under salinity, or both remains to be determined.</p>","PeriodicalId":20731,"journal":{"name":"Protoplasma","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149207913","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":"Colleters in four species of Neotropical Lecythidaceae: distribution, structure, and exudate composition.","authors":"Diego Graciano, Sandra Maria Carmello-Guerreiro","doi":"10.1007/s00709-026-02279-7","DOIUrl":"https://doi.org/10.1007/s00709-026-02279-7","url":null,"abstract":"<p><p>Colleters are secretory emergences located near developing vegetative and reproductive meristems, traditionally associated with protecting young tissues against dehydration and microbial infection. The occurrence of colleters in eudicots is likely underestimated due to the scarcity of targeted anatomical studies. Here, we investigated the occurrence, distribution, structure, and histochemical composition of colleters in four Neotropical species of Lecythidaceae. Using light microscopy and scanning electron microscopy, we documented the distribution and anatomy of colleters at different developmental stages in Gustavia augusta L., Couroupita guianensis Aubl., Cariniana legalis (Mart.) Kuntze, and Lecythis pisonis Cambess. Colleters are conical and elongated, composed of a central parenchyma axis covered by a secretory epidermis with a well-developed cuticle. They occur in distinct positions in vegetative and reproductive organs: at the lateral extremities of the base of leaf primordia, corresponding to a stipular position, in an intrapetiolar position in G. augusta, and along the margins of developing leaves; in reproductive structures, they occur at the base of bracts and bracteoles in developing flowers of C. guianensis, C. legalis, and L. pisonis, and on the margins of the petals of C. guianensis. Histochemical analyses revealed a heterogeneous exudate composed mainly of mucilage associated with lipophilic, phenolic, proteinaceous, and terpenoid compounds. The occurrence of colleters near developing organs and the composition of their exudate are consistent with a potential protective function during organ development. These findings expand current knowledge about secretory structures in Lecythidaceae and provide a basis for further comparative studies of colleter diversity and secretion mechanisms in the family.</p>","PeriodicalId":20731,"journal":{"name":"Protoplasma","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149196193","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":"Large-scale tubular and tubular-lamellar intracellular membrane systems of fungi.","authors":"Igor S Mazheika, Oxana V Voronko, Olga V Kamzolkina","doi":"10.1007/s00709-026-02270-2","DOIUrl":"https://doi.org/10.1007/s00709-026-02270-2","url":null,"abstract":"<p><p>Filamentous fungi and oomycetes have four large intracellular membrane systems consisting of tubes, lamellae, or a combination thereof. Such elongated membrane structures can extend for tens of micrometers in hyphal cells, branching and connecting into bundles and networks. These systems are represented by tubular vacuoles, elongated mitochondria, endoplasmic reticulum, and macroinvaginations of the plasma membrane. They are most developed in xylotrophic and mycorrhiza-forming basidiomycetes. This review examines three membrane systems, excluding the macroinvaginations. Various morphotypes of these membrane systems, characteristic of certain taxonomic and ecological-trophic groups of fungi and oomycetes, are considered. Hypotheses explaining the role of large-scale membrane systems in the life processes of filamentous organisms are presented. These hypotheses are still relatively speculative because they rely more on morphology and topology than on the poorly studied physiology of these systems. The synthesizing hypothesis posits that, at least in the apical region of hyphae, tubular vacuoles, elongated mitochondria, and the endoplasmic reticulum interact closely and may facilitate intrahyphal solute transport, independent of mass flow and turgor gradients. Further studies of large-scale membrane systems are important for developing the structural physiology of filamentous fungi and other organisms.</p>","PeriodicalId":20731,"journal":{"name":"Protoplasma","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149184116","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":"Cloning and functional characterization of a cinnamate 4-hydroxylase (SmC4H) from the lycophyte Selaginella moellendorffii.","authors":"Wenchao Liu, Chunting Zhang, Hongyang Zhu, Yuhang Wu, Yifeng Wu","doi":"10.1007/s00709-026-02277-9","DOIUrl":"https://doi.org/10.1007/s00709-026-02277-9","url":null,"abstract":"<p><p>Cinnamate 4-hydroxylase (C4H) is a key cytochrome P450 enzyme in the phenylpropanoid pathway, providing essential precursors for lignin and flavonoid biosynthesis. While well characterized in seed plants, the functional and regulatory features of C4H in lycophytes remain less well understood. In this study, a C4H gene (SmC4H) from the lycophyte Selaginella moellendorffii was cloned and functionally characterized. Sequence and comparative analyses showed that SmC4H retains the characteristic CYP73 framework, including a non-canonical PSRF sequence, and falls within the supported land-plant C4H/CYP73 cluster in a maximum-likelihood phylogeny. SmC4H also displayed the complete 10-motif architecture observed in the sampled land-plant C4Hs and a 3-exon/2-intron organization shared by many of these genes. Heterologous expression in yeast confirmed its cinnamate 4-hydroxylase activity, and kinetic analysis showed that SmC4H exhibited its highest apparent catalytic efficiency toward trans-cinnamic acid. In addition, SmC4H was capable of accepting the bulky cinnamate analog 2-naphthoic acid as a substrate, indicating a degree of substrate permissiveness. Subcellular localization analysis demonstrated that SmC4H is localized to the endoplasmic reticulum. Expression profiling revealed that SmC4H transcripts were most abundant in stems, which also exhibited the highest mean relative lignin content among the tissues examined. In contrast, flavonoid content was highly enriched in leaves, suggesting distinct tissue-level accumulation patterns of phenylpropanoid metabolites. Finally, promoter activity assays demonstrated that the SmC4H promoter (pSmC4H) is capable of driving gene expression in both vascular (Nicotiana benthamiana) and non-vascular (Marchantia polymorpha) plants. These findings provide a comparative reference for plant C4H biochemistry and promoter activity.</p>","PeriodicalId":20731,"journal":{"name":"Protoplasma","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149184051","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":"Smooth muscle ultrastructure - still shrouded in mystery?","authors":"Elisabeth Ehler","doi":"10.1007/s00709-026-02278-8","DOIUrl":"https://doi.org/10.1007/s00709-026-02278-8","url":null,"abstract":"<p><p>Smooth muscle is fundamental to life, as its function underpins circulation, nutrition, and reproduction. However, in contrast to striated muscle, the arrangement of its contractile filaments, composed of myosin and actin, is not readily apparent by light microscopy and, even electron microscopy fails to reveal an obviously ordered structural organisation. The aim of this review is to bring together classic ultrastructural data with more recent immunofluorescent analyses to develop a model how the protoplasma of a smooth muscle cell might be organised.</p>","PeriodicalId":20731,"journal":{"name":"Protoplasma","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149184021","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":"3-dehydroquinate synthase contributes to anthocyanin accumulation and flower pigmentation in petunia.","authors":"Chenxi Wang, Jiahao Cao, Junwei Yuan, Yixun Yu","doi":"10.1007/s00709-026-02275-x","DOIUrl":"https://doi.org/10.1007/s00709-026-02275-x","url":null,"abstract":"<p><p>Anthocyanin biosynthesis in plants depends on the supply of aromatic amino acids. These amino acids are produced through the shikimate pathway. DHQS functions in an early reaction of the shikimate pathway and mediates the production of 3-dehydroquinate (DHQ) from 3-deoxy-D-arabino-heptulosonate 7-phosphate (DAHP). However, it is unclear whether DHQS contributes to the biosynthesis of flavonoids and anthocyanins. In this study, a single member of the DHQS family, PhDHQS, was identified in Petunia hybrida. GFP fusion protein analysis showed that PhDHQS is localized in chloroplasts. PhDHQS was highly expressed in the corolla, with the highest expression at the flower coloration stage, corresponding to flower buds of approximately 4 cm in length. Silencing of PhDHQS caused lighter flower coloration and significantly lower anthocyanin levels. Metabolomic analysis showed that six core anthocyanin compounds were significantly downregulated in PhDHQS-silenced corollas. These results suggest that PhDHQS contributes to anthocyanin accumulation by modulating the supply of phenylalanine-related precursors, providing new insights into the contribution of upstream shikimate pathway enzymes to flower color formation.</p>","PeriodicalId":20731,"journal":{"name":"Protoplasma","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149171721","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":"EMA-based chromosome preparation and fluorescent banding as an aid to detect adulteration in cultivated Lens culinaris.","authors":"Mihir Halder, Mrinmoy Midday, Timir Baran Jha","doi":"10.1007/s00709-026-02273-z","DOIUrl":"https://doi.org/10.1007/s00709-026-02273-z","url":null,"abstract":"<p><p>India, the world's largest consumer and importer of lentils, is concerned about intentional or unintentional adulteration of this high-protein staple, which compromises food security, local price stability, and efforts to boost per capita lentil production to reduce costly imports. In this study, cost-effective EMA-based chromosomal analysis using Giemsa and fluorescence staining confirms the presence of a mixed population of lentils growing in farmers' fields in West Bengal, raising quality concerns for lentil farmers in these areas. Moreover, the adulterant is identified as a very closely related germplasm of wild-type lentils, L. ervoides, by cluster analysis based on comparative chromosome analysis against the previously reported Lentil database. The karyomorphological features, such as the terminal secondary constrictions, 18-20 DAPI-positive signals in all chromosomes, and CMA-positive signals at nucleolar regions, along with seed and flower morphology and the presence of tendrils, effectively differentiate cultivated lentils from wild-type (adulterant) lentil germplasm. Cluster analysis also indicates that the adulterant is more closely related to wild-type lentil L. ervoides. This method provides an important tool for quality control and seed authentication in lentils and helps to enhance farmers' productivity, boost the economy, improve consumers' nutrition, and contribute to national productivity and GDP. Moreover, it emphasizes the need to create a national database of Indian lentil germplasm and develop region-specific certified germplasm programs to optimize per capita lentil production, considering the diverse agronomic conditions across India.</p>","PeriodicalId":20731,"journal":{"name":"Protoplasma","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149137967","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":"Methylated memories mechanism, evidence, and skepticism in plant transgenerational epigenetic inheritance.","authors":"Gurjant Singh","doi":"10.1007/s00709-026-02272-0","DOIUrl":"https://doi.org/10.1007/s00709-026-02272-0","url":null,"abstract":"<p><p>Plants are repeatedly offered as the strongest case that organisms can inherit acquired experience without a change in DNA sequence - a claim that brushes against more than a century of Weismannian orthodoxy. DNA methylation, small-RNA pathways, and chromatin marks can be reshaped by heat, drought, salinity, and pathogen attack, and in several plant systems these marks persist into unstressed offspring. Yet the field remains split. Well-controlled studies find epigenetic memory to be shallow, genotype-dependent, and easily confused with parental provisioning or incomplete resetting during gametogenesis, while a smaller set of striking systems - among them paramutation at the maize b1 locus and stress-induced methylation in clonal dandelions - show that heritable, sequence-independent memory is mechanistically real, at least in specific genomic contexts. This review focuses on DNA methylation, the best-characterized carrier of heritable epigenetic information in plants, and in particular on RNA-directed DNA methylation (RdDM), the de novo pathway most closely linked to stress, while placing it alongside the MET1 and chromomethylase pathways and chromatin-based memory. It uses maize paramutation and dandelion stress memory as two contrasting, illustrative case studies, situates them within the wider body of stress-methylation experiments in Arabidopsis, rice, and other species, lays out the skeptical counter-case, and considers why commercial interest in \"climate-smart\" epigenetically primed seed is forcing the field to resolve these questions faster than the data currently allow.</p>","PeriodicalId":20731,"journal":{"name":"Protoplasma","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149114378","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":"Harnessing Sargassum myriocystum as a sustainable source of cellulose nanocrystals: structural, thermal, and colloidal insights.","authors":"Neha P Nair, Radhika Rajasree S R","doi":"10.1007/s00709-026-02271-1","DOIUrl":"https://doi.org/10.1007/s00709-026-02271-1","url":null,"abstract":"<p><p>The environmental drawbacks of non-biodegradable plastics have sparked the demand for eco-friendly alternatives. This study focuses on the isolation and characterization of cellulose nanocrystals (CNCs) from the brown seaweed Sargassum myriocystum, a promising nanofiller. Cellulose was isolated from seaweed using alkali-bleaching treatments, then hydrolyzed using different concentrations of sulfuric acid to selectively remove amorphous regions, yielding CNCs. The cellulose yield was 33.78%, while the CNC yields ranged from 13.96- 14.41%. Characterization methods like FTIR, X-ray Diffraction(XRD), Thermogravimetric Analysis(TGA), and morphological studies through Scanning Electron Microscopy (SEM)and Transmission Electron Microscopy(TEM) identified the physical as well as chemical characteristics of the isolated products. The results highlighted that the CNCs exhibited high crystallinity, with crystallinity index increasing from 46.5% for cellulose to 78% for CNCs, indicating successful removal of amorphous regions and enrichment of crystalline domains. Thermal stability analysis revealed improved thermal properties after bleaching and hydrolysis of CNCs. The CNCs had a nano-sized, needle-like shape with an average length of 200-630 nm and width of 10-20 nm; forming stable suspension with zeta potential value of -37.5 mV,-21.6 mV,which are suitable for use as nanofillers in the development of materials and composites; enhancing mechanical and barrier properties. This work advances circular valorization of marine biomass.</p>","PeriodicalId":20731,"journal":{"name":"Protoplasma","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149114408","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":"Glutamine synthetase GLN1;5 and ACT domain repeat ACR1 functionally interact at the seed level in Arabidopsis thaliana.","authors":"Emanuel Moreira, Cláudia Pereira, Sílvia Coimbra, Paula Melo","doi":"10.1007/s00709-026-02265-z","DOIUrl":"https://doi.org/10.1007/s00709-026-02265-z","url":null,"abstract":"<p><p>GLN1;5 is one of the five Arabidopsis thaliana glutamine synthetase (GS) cytosolic isoenzymes, almost exclusively expressed in seeds, where it plays a critical role in nitrogen reassimilation during seed maturation and germination. ACT Domain Repeat (ACR) proteins are believed to act as nutrient sensors, although their precise functions in plants remain unclear. The eFP browser expression analysis shown that one ACR isogene, AtACR1, entirely overlaps with AtGLN1;5 expression, suggesting a possible interaction between these proteins. This study aimed to elucidate the functional relationship between the two proteins, using an integrated approach combining phenotypic, biochemical, and molecular analyses. The similarity in phenotypes of the two mutants, acr1 and gln1;5 highlights the crucial role of both proteins in nutrient utilization during germination and supports their potential interaction. Furthermore, in acr1 seeds, GS activity was reduced despite increased protein levels and gene expression, especially of the GLN1;5. Pull-down assays using recombinant proteins and seed extracts from wild-type, acr1, and gln1;5 mutants confirmed a specific interaction between ACR1 and GLN1;5. In addition, recombinant ACR1 protein enhances GS activity in wild-type but not in gln1;5 mutant seed extracts, indicating a regulatory role of ACR1 in GLN1;5 activation. Hormonal treatment of wild-type seed revealed antagonistic regulation of ACR1 and GLN1;5 genes by abscisic and gibberellic acid during germination, further supporting a role for ACR1 in modulating GS activity during this process. By using complementary and alternative approaches, our findings establish ACR1 as a key regulator of glutamine synthetase in seeds, with implications for normal seedling development.</p>","PeriodicalId":20731,"journal":{"name":"Protoplasma","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149040014","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}