Journal of Phycology最新文献

{"title":"Exploring cyanobacteria from the Andaman mangroves of Thailand: Descriptions of new species of Desertifilum, Roseofilum, Tigrinifilum, and Persinema using a polyphasic approach.","authors":"Billy Lim Chun Ginn, Jantana Praiboon, Faradina Merican, Sinchai Maneekat, Cong Zeng, Giuseppe C Zuccarello, Narongrit Muangmai","doi":"10.1111/jpy.70074","DOIUrl":"https://doi.org/10.1111/jpy.70074","url":null,"abstract":"<p><p>Non-heterocytous filamentous cyanobacteria are increasingly recognized as abundant and diverse microbial components of tropical and subtropical mangrove ecosystems. However, taxonomic studies of cyanobacteria in Thailand have largely focused on freshwater and artificial hypersaline environments, leaving mangrove-associated cyanobacterial communities understudied. In this polyphasic study, cyanobacterial mats were isolated and characterized from mangrove environments along the Andaman coastlines of Ranong and Phang-Nga provinces. Comparative analysis of morphology, salinity tolerance, habitat preference, 16S rRNA gene phylogeny and genetic similarity, 16S-23S ITS rRNA region phylogeny, secondary structure and percent dissimilarity supported the descriptions of Desertifilum andamanense sp. nov., Tigrinifilum phangngense sp. nov., Roseofilum epilithicum sp. nov., and Persinema corticola sp. nov., while justifying the continued recognition of D. fontinale and D. tharense. Two divergent ITS rRNA region operons in T. floridanum with different leader motifs, D1-D1', and D2 regions proved to be useful diagnostic markers of the ITS rRNA region for species and strain differentiation within Tigrinifilum. Our results underscore the importance of a polyphasic approach that also considers intragenomic ITS rRNA region variation to ensure robust and accurate taxonomic assessments of cyanobacteria. This study also provides records of the genera Desertifilum, Roseofilum, Tigrinifilum, and Persinema in Thailand, contributing to a more comprehensive understanding of the nation's diversity and biogeography of cyanobacteria.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144958421","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":"Palmelloid-like structure formation mechanism in Chlorella sorokiniana under ethanol stress.","authors":"Rediat Abate, Changzi Liu, Yonghong Bi, Wujuan Mi, Gaofei Song, Yuheng Zhang, Demeke Kifle, Gao Yahui","doi":"10.1111/jpy.70077","DOIUrl":"https://doi.org/10.1111/jpy.70077","url":null,"abstract":"<p><p>Although the formation of \"palmelloid-like\" cells as a response to environmental stress has been sporadically reported in Chlorella sp., the association between morphological and molecular indices has been poorly understood. Hence, this study investigated the morphological and molecular effects of ethanol stress on C. sorokiniana by providing 0.0%, 0.025%, and 0.1% (v/v) ethanol. The results showed that cell growth, chlorophyll a, and photosynthetic efficiency were promoted under 0.025% ethanol. In contrast, the cells under 0.1% ethanol treatment were highly stressed; cell growth and physiological activities were inhibited, the content of cellular lipid, carbohydrate, reactive oxygen species, and the cell volume increased, and palmelloid-like structures with copious cell envelopes and higher cell wall carbohydrate contents were observed. The transcriptomic gene set enrichment analysis showed that chitin binding and organelle organization were upregulated while the developmental process was downregulated. Genes for actin-related-2, auxin-biding 1, phosphatidylinositol 4-kinase alpha1, phosphatidylinositol 4-phosphate 5-kinase 2 isoform A, and cytokinesis dedicator 4 were downregulated, whereas polysaccharide export, putative polygalacturonase, carbohydrate deacetylase, chitin, cellulose biosynthesis, and unsaturation of fatty acids were upregulated, implying polysaccharide was incorporated into the cell wall, and the rigidity of the cell membrane was promoted. These results suggest the suppression of the developmental process and cytokinesis and the overexpression of microtubules and cell-envelope genes could be the driving force for palmelloid-like structure formation, which could enhance the survival of cells under stress conditions by reducing cell surface area, promoting the production of protective cover and settleability, and adjusting cell rigidity.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144958459","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":"Flow cytometry and holotomography illuminated the relationship between iron availability and the growth and cellular development of Symbiodinium sp.","authors":"Haifeng Gu","doi":"10.1111/jpy.70047","DOIUrl":"https://doi.org/10.1111/jpy.70047","url":null,"abstract":"","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"61 4","pages":"752-754"},"PeriodicalIF":3.4,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144832989","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":"Implications of the finding of a new member of brown algae in freshwaters for biodiversity and the transition from marine to freshwater environment","authors":"Orlando Necchi Jr","doi":"10.1111/jpy.70061","DOIUrl":"https://doi.org/10.1111/jpy.70061","url":null,"abstract":"","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"61 4","pages":"755-756"},"PeriodicalIF":3.4,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144832990","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":"Molecular and cytomorphological characterization of Pseudanabaena vesniana sp. nov. and Pseudanabaena suomiensis var. macedonica var. nov. (Pseudanabaenales, Cyanobacteriota) with evidence of microcystin-producing Pseudanabaena taxa.","authors":"Boris Aleksovski, Aniket Saraf, Evgenija Stefanoska, Sanja Kiprijanovska, Ana Vuchurević, Kiril Pakovski, Aleksandar Dimovski, Muriel Gugger, Svetislav Krstić","doi":"10.1111/jpy.70064","DOIUrl":"https://doi.org/10.1111/jpy.70064","url":null,"abstract":"<p><p>Detailed molecular and cytomorphological characterization of two toxic Pseudanabaena strains (NMCCC 011 and NMCCC 012), isolated from highly polluted shallow areas of Monospitovo Marsh (North Macedonia), was performed using a \"polyphasic\" approach. This involved morphological and ultrastructural characterization, phylogenetic assessment of the 16S rRNA gene, analyses of the 16S-23S internal transcribed spacer (ITS) rRNA region, and investigations of the mcyB gene. The 16S rRNA gene phylogenetic analysis and the ITS rRNA region analyses confirmed that strain NMCCC 011 was a novel species for which we have proposed the name Pseudanabaena vesniana sp. nov., whereas NMCCC 012 represented a novel variety of Pseudanabaena suomiensis, here designated as P. suomiensis var. macedonica. The overall 16S rRNA gene phylogenetic analysis grouped Pseudanabaena into four large clades. Two of them comprised the primary lineages of diversification, hosting most Pseudanabaena sensu stricto infrageneric units. Most of these units formed distinctly recognizable subclades corresponding to different Pseudanabaena species (Cyanobacteriota); however, some strains were misidentified, leading to several scattered species through different subclades within the genus. Additionally, the genus Pseudanabaena was determined to be polyphyletic, with some strains clustering within the genera Tumidithrix and Thalassoporum (Cyanobacteriota). The 16S rRNA gene sequence identity within Pseudanabaena sensu stricto ranged from 95.7% to 99.9%, while the identity with Tumidithrix, Thalassoporum, and Thermostichus (Cyanobacteriota) ranged from 87.6% to 92.0%. Furthermore, both strains NMCCC 011 and NMCCC 012 produced microcystins and 2-methylisoborneol. The production of microcystins was confirmed by genetic and enzyme-linked immunosorbent assay (ELISA) analyses. Through this study, we report the presence of the mcyB gene in Pseudanabaena.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144855617","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":"A genetic transformation system for the heterotrophic diatom Nitzschia putrida (Bacillariophyceae).","authors":"Longji Deng, Yixuan Li, Yasuhiro Tanizawa, Yasukazu Nakamura, Ryoma Kamikawa, Amanda Hopes, Thomas Mock","doi":"10.1111/jpy.70070","DOIUrl":"https://doi.org/10.1111/jpy.70070","url":null,"abstract":"<p><p>Diatoms are important primary producers in aquatic ecosystems. Most of them are photoautotrophs and have evolved to thrive under diverse environmental conditions from the poles to the tropics. However, some diatom species such as Nitzschia putrida have lost photosynthesis and have therefore become free-living secondary heterotrophs. Thus, these diatoms provide unique opportunities to study the evolutionary processes required to thrive without photosynthesis and independent of a resource-providing host. They may also provide a chassis for reverse engineering photosynthesis in eukaryotic organisms. Here, we have developed a genetic transformation system for N. putrida using a biolistic approach. By leveraging genome and transcriptome data, we identified the nicotinamide adenine dinucleotide hydride (NADH)-ubiquinone reductase complex 1 promoter as a robust candidate for driving transgene expression. Through Golden Gate Cloning, we engineered plasmids, including the selectable marker nourseothricin and the reporter eGFP. An evaluation of transformation efficiency confirmed the successful integration and expression of the transgenes. Fluorescence microscopy demonstrated the expression of eGFP in the transformed cell lines, which retained a growth phenotype similar to that of the wild type cells. Thus, our work in combination with the available genome and transcriptome of N. putrida enables reverse genetics with a free-living secondary heterotroph.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144855616","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":"Biochemical characterization of phosphoenolpyruvate carboxykinases from multiple species of brown algae.","authors":"Jian-Qiang Jin, Yuusuke Yokooji, Toshiyuki Shibata, Haruyuki Atomi","doi":"10.1111/jpy.70069","DOIUrl":"https://doi.org/10.1111/jpy.70069","url":null,"abstract":"<p><p>Phosphoenolpyruvate carboxykinase (PEPCK) is involved in the conversion of phosphoenolpyruvate (PEP) to oxaloacetate (OAA). In addition to playing a role in gluconeogenesis in various organisms, PEPCK also functions in the C₄ cycle to concentrate CO₂ for photosynthesis in some C₄ plants. Brown algae harbor genes related to the C₄ cycle, including the PEPCK gene, and are proposed to employ a C₄ cycle-like pathway. However, little is known about the CO₂-concentrating mechanisms and the properties of the enzymes involved in brown algae. Here, we obtained soluble recombinant PEPCKs of five brown algae and carried out biochemical analyses. The five PEPCKs were ATP-dependent and displayed similar or higher specific activities compared with their counterparts from other organisms. Phosphoenolpyruvate carboxykinase from Ishige okamurae (Io-PEPCK) exhibited the highest specific activity in both carboxylation and decarboxylation directions, with values of 48.4 and 63.3 μmol · min^-1 · mg^-1, respectively. Additionally, Io-PEPCK displayed a k_cat/K_mHCO3 value of 9.2 × 10³ · M^-1 · s^-1, much higher than those of previously characterized PEPCKs. The response of PEPCK activity to various metabolites showed that citrate and malate inhibited the carboxylation but promoted the decarboxylation activity of Io-PEPCK. Various ATP concentrations resulted in different degrees of inhibition on the carboxylation activity of PEPCK, suggesting that ATP concentration potentially regulates PEPCK activity in brown algae. The analysis of cell extracts from I. okamurae suggested that PEPCK rather than PEPC dominates the carboxylation in this brown alga. Based on previous knowledge and the results presented here, a model for a C₄ cycle-like pathway in brown algae has been proposed.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144835464","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":"Assessment of rhodolith-forming species diversity in British Columbia uncovers novel cryptic diversity in the genera Boreolithothamnion and Rhodolithia gen. nov. (Florideophyceae, Rhodophyta) and the occurrence of hybrid rhodoliths.","authors":"Keelie E Taylor, Gary W Saunders","doi":"10.1111/jpy.70066","DOIUrl":"https://doi.org/10.1111/jpy.70066","url":null,"abstract":"<p><p>Rhodolith collections in British Columbia have historically been limited, and published regional species diversity data are poor. The acquisition of recent collections, notably from rhodolith beds in Haida Gwaii, provided an opportunity to assess diversity in these waters. The DNA barcode markers COI-5P, rbcL-3P, and psbA were used to identify unique genetic groups, which were then placed into a phylogenetic context with other coralline algae and subsequently observed anatomically. These analyses uncovered six rhodolith-forming species: two known, viz. Boreolithothamnion phymatodeum and Boreolithothamnion soriferum; a species provisionally called Boreolithothamnion sp. 1heterocladum; and three novel species described here, viz. Boreolithothamion astragaloi sp. nov., Boreolithothamnion tanuense sp. nov., and Rhodolithia gracilis gen. et. sp. nov., which comprises three varieties. Of particular interest, sequences of the ITS rDNA region showed the variety Rhodolithia gracilis var. gracilis × ramosa var. nov. to be a hybrid of the other two varieties: Rhodolithia gracilis var. gracilis var. nov. and Rhodolithia gracilis var. ramosa var. nov. Although understanding the full extent of BC rhodolith beds will require additional sampling, these findings indicate that rhodoliths are widespread and diverse in British Columbia.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144835463","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":"De novo transcriptome of the red alga Gracilariopsis tenuifrons (Gracilariales, Rhodophyta) in response to prolonged temperature stress.","authors":"André V F Faria, Olivier Godfroy, J Mark Cock, Estela M Plastino","doi":"10.1111/jpy.70067","DOIUrl":"https://doi.org/10.1111/jpy.70067","url":null,"abstract":"<p><p>Transcriptomic information is still scarce for seaweeds, especially for species from tropical regions. Laboratory-based physiological studies of some red algae have shown that they can tolerate temperatures that exceed those observed in their natural conditions. To understand the molecular mechanisms related to this tolerance, we chose as a model the agarophyte red alga Gracilariopsis tenuifrons and analyzed transcriptomic profiles at two different temperatures: 25°C (control temperature) and 33°C (stress temperature). Under the stress temperature conditions, only a relatively small percentage of genes were differentially expressed compared to the control temperature (5.75% were down-regulated and 5.25% were up-regulated at 33°C). Analysis of the predicted functions of the differentially regulated genes indicated enrichment in DNA-associated processes for the up-regulated genes and enrichment in gene ontogeny categories related to photosynthesis and membrane-associated processes for the down-regulated genes. The de novo transcriptome data provided in this study is a valuable scientific resource for future comparative research on red algae at stress conditions.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144817021","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":"Expanding our knowledge of Synurales (Chrysophyceae) in Florida, United States: Proposing three novel Mallomonas taxa.","authors":"Petr Knotek, Martin Pusztai, Iva Jadrná, Pavel Škaloud","doi":"10.1111/jpy.70062","DOIUrl":"https://doi.org/10.1111/jpy.70062","url":null,"abstract":"<p><p>We conducted a survey of Synurales diversity in Florida (United States), focusing on two established hotspots-Ocala National Forest and Myakka River State Park-and two previously unexplored sites-Manatee Lake and Lake Lee. Using transmission electron microscopy (TEM), we identified 69 species, increasing the total number recorded from Florida to 90. Among these, three species-Mallomonas cornea sp. nov., M. laureana sp. nov., and M. joergenii sp. nov.-have been newly described based on detailed morphological and molecular analyses. We have also proposed a new combination, M. poseidonii comb. et stat. nov., and established a new section, Corneae sect. nov., based on molecular phylogenetics. Our findings revealed an independent emergence of ribbed scale shield ornamentation in M. joergenii sp. nov. and suggested that internal scale reticulation in M. laureana sp. nov. may be an adaptation to high UV irradiance in tropical environments. This study underscores the value of DNA sequence data in resolving taxonomic ambiguities, elucidating evolutionary patterns, and enhancing species recovery from type localities.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144731924","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}