Journal of Phycology最新文献

{"title":"Two new species of Dulcicalothrix (Nostocales, Cyanobacteria) from India and erection of Brunnivagina gen. nov., with observations on the problem of using multiple ribosomal operons in cyanobacterial taxonomy","authors":"Aniket Saraf,&nbsp;Prashant Singh,&nbsp;Naresh Kumar,&nbsp;Sagarika Pal,&nbsp;Jeffrey R. Johansen","doi":"10.1111/jpy.13488","DOIUrl":"10.1111/jpy.13488","url":null,"abstract":"<p>Two new species of <i>Dulcicalothrix, D. adhikaryi</i> sp. nov. and <i>D. iyengarii</i> sp. nov., were discovered in India and are characterized and described in accordance with the rules of the International Code of Nomenclature for algae, fungi, and plants (ICN). As a result of phylogenetic analysis, <i>Calothrix elsteri</i> is reassigned to <i>Brunnivagina</i> gen. nov. During comparison with all <i>Dulcicalothrix</i> for which sequence data were available, we observed that the genus has six ribosomal operons in three orthologous types. Each of the three orthologs could be identified based upon indels occurring in the D1–D1′ helix sequence in the ITS rRNA region between the 16S and 23S rRNA genes, and in these three types, there were operons containing ITS rRNA regions with and without tRNA genes. Examination of complete genomes in <i>Dulcicalothrix</i> revealed that, at least in the three strains for which complete genomes are available, there are five ribosomal operons, two with tRNA genes and three with no tRNA genes in the ITS rRNA region. Internal transcribed spacer rRNA regions have been consistently used to differentiate species, both on the basis of secondary structure and percent dissimilarity. Our findings call into question the use of ITS rRNA regions to differentiate species in the absence of efforts to obtain multiple operons of the ITS rRNA region through cloning or targeted PCR amplicons. The ITS rRNA region data for <i>Dulcicalothrix</i> is woefully incomplete, but we provide herein a means for dealing with incomplete data using the polyphasic approach to analyze diverse molecular character sets. Caution is urged in using ITS rRNA data, but a way forward through the complexity is also proposed.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"60 5","pages":"1139-1160"},"PeriodicalIF":2.8,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jpy.13488","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141902036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel high-throughput oxygen saturation measurements for quantifying the physiological performance of macroalgal early life stages","authors":"R. J. Veenhof,&nbsp;M. A. Coleman,&nbsp;C. Champion,&nbsp;S. A. Dworjanyn,&nbsp;R. Venhuizen,&nbsp;L. Kearns,&nbsp;E. M. Marzinelli,&nbsp;A. K. Pettersen","doi":"10.1111/jpy.13489","DOIUrl":"10.1111/jpy.13489","url":null,"abstract":"<p>Understanding how macroalgal forests will respond to environmental change is critical for predicting future impacts on coastal ecosystems. Although measures of adult macroalgae physiological responses to environmental stress are advancing, measures of early life-stage physiology are rare, in part due to the methodological difficulties associated with their small size. Here we tested a novel, high-throughput method (rate of oxygen consumption and production; <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mover>\u0000 <mi>V</mi>\u0000 <mo>̇</mo>\u0000 </mover>\u0000 <msub>\u0000 <mi>O</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ dot{V}{mathrm{O}}_2 $$</annotation>\u0000 </semantics></math>) via a sensor dish reader microplate system to rapidly measure physiological rates of the early life stages of three habitat-forming macroalgae, the kelp <i>Ecklonia radiata</i> and the fucoids <i>Hormosira banksii</i> and <i>Phyllospora comosa</i>. We measured the rate of O₂ consumption (respiration) and O₂ production (net primary production) to then calculate gross primary production (GPP) under temperatures representing their natural thermal range. The <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mover>\u0000 <mi>V</mi>\u0000 <mo>̇</mo>\u0000 </mover>\u0000 <msub>\u0000 <mi>O</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ dot{V}{mathrm{O}}_2 $$</annotation>\u0000 </semantics></math> microplate system was suitable for rapidly measuring physiological rates over a temperature gradient to establish thermal performance curves for all species. The <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mover>\u0000 <mi>V</mi>\u0000 <mo>̇</mo>\u0000 </mover>\u0000 <msub>\u0000 <mi>O</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ dot{V}{mathrm{O}}_2 $$</annotation>\u0000 </semantics></math> microplate system proved efficient for measures of early life stages of macroalgae ranging in size from approximately 50 μm up to 150 mm. This method has the potential for measuring responses of early life stages across a range of environmental factors, species, populations, and developmental stages, vastly increasing the speed, precision, and efficacy of macroalgal physiological measures under future ocean change scenarios.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"60 5","pages":"1161-1172"},"PeriodicalIF":2.8,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jpy.13489","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141893698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Freezing stress tolerance of benthic freshwater diatoms from the genus Pinnularia: Comparison of strains from polar, alpine, and temperate habitats","authors":"Eva Hejduková,&nbsp;Jan Kollár,&nbsp;Linda Nedbalová","doi":"10.1111/jpy.13486","DOIUrl":"10.1111/jpy.13486","url":null,"abstract":"<p>Diatoms are among the most important primary producers in alpine and polar freshwaters. Although temperate diatoms are sensitive to freezing, polar diatoms often exhibit more resistance. This is particularly true for members of the (predominantly terrestrial) <i>Pinnularia borealis</i> species complex. However, it remains unclear to what extent this resistance applies to other representatives of the genus. Here, we compare the freezing-stress tolerance of 11 freshwater, benthic strains representing different species of <i>Pinnularia</i> (including <i>Caloneis</i>) from polar, alpine, and temperate habitats. As vegetative cells, strains were exposed to freezing temperatures of −4, −10, −20, −40, −80, and −196°C. Survival was assessed by light microscopy and photosynthetic measurements. We observed vegetative cells to be sensitive to low freezing temperatures; only “mild” freezing was survived by all tested strains, and most tested strains did not survive treatments ≤−10°C. However, individual strain sensitivities appeared related to their original habitats. For example, polar and alpine strains better withstood “mild” and “moderate” freezing (−4 and −10°C, respectively); although temperate strains were significantly affected by the “mild” freezing treatment, polar and alpine strains were not. The −10°C treatment was survived exclusively by polar strains, and only <i>P. catenaborealis</i> survived all treatments. Interestingly, this species exhibited the lowest survival in the −10°C treatment, potentially implying some metabolic activity even at freezing temperatures. Thus, despite more extensive sampling throughout the genus and finer temperature scaling compared to previous studies, the remarkable freezing-stress tolerance of the <i>P. borealis</i> species complex remains unique within the genus.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"60 5","pages":"1105-1120"},"PeriodicalIF":2.8,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jpy.13486","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141788381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The ecology of giant kelp colonization and its implications for kelp forest restoration","authors":"Daniel C. Reed,&nbsp;Stephen C. Schroeter,&nbsp;David Huang,&nbsp;Denise Weisman,&nbsp;Kathryn M. Beheshti,&nbsp;Rachel S. Smith","doi":"10.1111/jpy.13487","DOIUrl":"10.1111/jpy.13487","url":null,"abstract":"<p>The success and cost-effectiveness of kelp forest restoration hinges on understanding the colonization ecology of kelps, particularly with respect to dispersal potential, recruitment success, and subsequent establishment. To gain needed insight into these processes we examined spatial patterns and temporal trajectories of the colonization of a large artificial reef by the giant kelp <i>Macrocystis pyrifera</i>. The 151 ha artificial reef complex was constructed in three phases over 21 years, enabling dispersal, recruitment, and subsequent establishment to be examined for a wide range of environmental conditions, dispersal distances, and source population sizes. Natural colonization of all phases of the artificial reef by giant kelp was rapid (within 1 year) and extended across the entire 7-km-long reef complex. Colonization density declined with distance from the nearest source population, but only during the first phase when the distance from the nearest source population was ≤3.5 km. Despite this decline, recruitment on artificial reef modules farthest from the source population was sufficient to produce dense stands of kelp within a couple of years. Experimental outplanting of the artificial reef with laboratory-reared kelp embryos was largely successful but proved unnecessary, as the standing biomass of kelp resulting from natural recruitment exceeded that observed on nearby natural reefs within 2–3 years of artificial reef construction for all three phases. Such high potential for natural colonization following disturbance has important implications for kelp forest restoration efforts that employ costly and logistically difficult methods to mimic this process by active seeding and transplanting.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"60 5","pages":"1121-1138"},"PeriodicalIF":2.8,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jpy.13487","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141777287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seaweeds as holobionts: Current state, challenges, and potential applications","authors":"Ezequiel M. Marzinelli,&nbsp;Torsten Thomas,&nbsp;Sebastian Vadillo Gonzalez,&nbsp;Suhelen Egan,&nbsp;Peter D. Steinberg","doi":"10.1111/jpy.13485","DOIUrl":"10.1111/jpy.13485","url":null,"abstract":"<p>Seaweeds play a strong ecological and economical role along the world's coastlines, where they support industries (e.g., aquaculture, bioproducts) and essential ecosystem services (e.g., biodiversity, fisheries, carbon capture). Evidence from wild and cultured seaweeds suggests that microorganisms play crucial roles in their health and functioning, prompting the need for considering seaweeds and their microbiome as a coherent entity or “holobiont.” Here we show that the number of studies investigating seaweed hosts and their microbiome have increased in the last two decades. This likely reflects the increase in the appreciation of the importance of microbiomes for eukaryotic hosts, improved molecular approaches used to characterize their interactions, and increasing interest in commercial use of seaweeds. However, although increasing, most studies of seaweed holobionts have focused on (i) a few seaweed species of ecological or commercial significance, (ii) interactions involving only bacteria, and (iii) descriptive rather than experimental approaches. The relatively few experimental studies have mostly focused on manipulating abiotic factors to examine responses of seaweeds and their microbiome. Of the few studies that directly manipulated microorganisms to investigate their effects on seaweeds, most were done in laboratory or aquaria. We emphasize the need to move beyond the descriptions of patterns to experimental approaches for understanding causation and mechanisms. We argue that such experimental approaches are necessary for a better understanding of seaweed holobionts, for management actions for wild and cultivated seaweeds, and to better integrate studies of seaweed holobionts with the broader fields of seaweed ecology and biology, which are strongly experimental.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"60 4","pages":"785-796"},"PeriodicalIF":2.8,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jpy.13485","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141759353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kelp dissolved organic carbon release is seasonal and annually enhanced during senescence","authors":"Andrew Kalani Carlson,&nbsp;Takeshi Yoshimura,&nbsp;Isao Kudo","doi":"10.1111/jpy.13483","DOIUrl":"10.1111/jpy.13483","url":null,"abstract":"<p>Macroalgae influence local and global biogeochemical cycles through their production of dissolved organic carbon (DOC). Yet, data remain scarce and annualized estimates are typically based on high growth periods without considering seasonal variability. Although the mechanisms of active exudation and passive leakage need clarifying, ecophysiological stress is known to enhance DOC release. Therefore, DOC leakage from seasonally senescent macroalgae may be overlooked. This study focuses on the annual kelp <i>Saccharina japonica</i> var. <i>religiosa</i> (class Phaeophyceae) from Oshoro Bay, Hokkaido, Japan. Three years (2020–2022) of seasonal data were collected and analyzed, with least squares mean DOC release rates established for kelp (<i>n</i> = 88) across 16 incubation experiments (<i>t</i> ≥ 4 d, DOC samples ≥1 · d⁻¹) under different photosynthetically active radiation (PAR) treatments (200, 400, 1200, or 1500 μmol photons · m⁻² · s⁻¹). Differences in PAR, dry weight biomass (g DW), sea surface temperature, or salinity could not explain DOC release-rate variability, which was high between individual kelp. Instead, there were significant intra-annual differences, with mean DOC release rates (mg C · g⁻¹ DW · d⁻¹ ± standard error between <i>n</i> kelp) higher during the autumn “late decay” period (0.71 ± 0.10, <i>n</i> = 27) compared to the winter “early growth” period (0.14 ± 0.025, <i>n</i> = 10) and summer “early decay” period (0.25 ± 0.050, <i>n</i> = 24). This relationship between seasonal senescence and macroalgal DOC release is further evidence that long-term, place-based studies of DOC dynamics are essential and that global extrapolations are premature.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"60 4","pages":"980-1000"},"PeriodicalIF":2.8,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141731226","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":"The photosynthetic performance and photoprotective role of carotenoids response to light stress in intertidal red algae Neoporphyra haitanensis","authors":"Yongbo Huang,&nbsp;Ziyu Weng,&nbsp;Shuang Li,&nbsp;Shuyu Zhang,&nbsp;Haimin Chen,&nbsp;Qijun Luo,&nbsp;Rui Yang,&nbsp;Tao Liu,&nbsp;Tiegan Wang,&nbsp;Peng Zhang,&nbsp;Juanjuan Chen","doi":"10.1111/jpy.13480","DOIUrl":"10.1111/jpy.13480","url":null,"abstract":"<p><i>Neoporphyra haitanensis</i>, a red alga harvested for food, thrives in the intertidal zone amid dynamic and harsh environments. High irradiance represents a major stressor in this habitat, posing a threat to the alga's photosynthetic apparatus. Interestingly, <i>N. haitanensis</i> has adapted to excessive light despite the absence of a crucial xanthophyll cycle-dependent photoprotection pathway. Thus, it is valuable to investigate the mechanisms by which <i>N. haitanensis</i> copes with excessive light and to understand the photoprotective roles of carotenoids. Under high light intensities and prolonged irradiation time, <i>N. haitanensis</i> displayed reduction in photosynthetic efficiency and phycobiliproteins levels, as well as different responses in carotenoids. The decreased carotene contents suggested their involvement in the synthesis of xanthophylls, as evidenced by the up-regulation of lycopene-β-cyclase (<i>lcyb</i>) and zeaxanthin epoxidase (<i>zep</i>) genes. Downstream xanthophylls such as lutein, zeaxanthin, and antheraxanthin increased proportionally to light stress, potentially participating in scavenging reactive oxygen species (ROS). When accompanied by the enhanced activity of ascorbate peroxidase (APX), these factors resulted in a reduction in ROS production. The responses of intermediates α-cryptoxanthin and β-cryptoxanthin were felt somewhere between carotenes and zeaxanthin/lutein. Furthermore, these changes were ameliorated when the organism was placed in darkness. In summary, down-regulation of the organism's photosynthetic capacity, coupled with heightened xanthophylls and APX activity, activates photoinhibition quenching (qI) and antioxidant activity, helping <i>N. haitanensis</i> to protect the organism from the damaging effects of excessive light exposure. These findings provide insights into how red algae adapt to intertidal lifestyles.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"60 4","pages":"942-955"},"PeriodicalIF":2.8,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141626955","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":"Influence of multi-stressor combinations of pCO2, temperature, and salinity on the toxicity of Heterosigma akashiwo (Raphidophyceae), a fish-killing flagellate","authors":"Malihe Mehdizadeh Allaf,&nbsp;Charles G. Trick","doi":"10.1111/jpy.13481","DOIUrl":"10.1111/jpy.13481","url":null,"abstract":"<p>Climate change and global warming have led to more frequent harmful algal blooms in the last decade. Among these blooms, <i>Heterosigma akashiwo</i>, a golden-brown phytoflagellate, is one of the 40 species with a high potential to form harmful blooms, leading to significant fish mortality. Climate change leads to rising atmospheric and ocean temperatures. These changes, along with altered rainfall patterns and meltwater input, can cause fluctuations in ocean salinity. Elevated atmospheric carbon dioxide (CO₂) levels increase water acidity as oceans absorb CO₂. This study investigated the effects of temperature, salinity, and CO₂ levels on lipid production, hemolytic activity, and toxicity of <i>H. akashiwo</i> using the design of experiment approach, which can be used to investigate the effect of two or more factors on the same response simultaneously in a precise manner with fewer experiments and materials but in a larger region of the factor space. The lipid content was measured using a high-throughput Nile Red method, and the highest level of lipid content was detected at 25°C, a salinity of 30, and a CO₂ concentration of 400 ppm. Hemolytic activity was assessed using rabbit blood erythrocytes in a 96-well plate, and the optimal conditions for achieving the highest hemolytic activity were determined at 15°C, a salinity of 10, and a CO₂ concentration of 400 ppm. As the chemical structure of the toxin is not known, we used the toxicity against the cell line RTgill-W1 as the cell toxicity proxy. The maximum toxicity was identified at 15°C, a salinity of 10, and a CO₂ level of 700 ppm.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"60 4","pages":"1001-1020"},"PeriodicalIF":2.8,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jpy.13481","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141590586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Breakthrough innovation will be essential for scaling up marine macrophyte restoration and achieving targets","authors":"M. A. Coleman,&nbsp;T. M. Glasby","doi":"10.1111/jpy.13484","DOIUrl":"10.1111/jpy.13484","url":null,"abstract":"","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"60 4","pages":"781-784"},"PeriodicalIF":2.8,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141580044","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":"Comparative plastome and mitogenome analyses indicate that the marine prasinophyte green algae Pycnococcus provasolii and Pseudoscourfieldia marina (Pseudoscourfieldiophyceae class nov., Chlorophyta) represent morphotypes of the same species","authors":"Olivier Crépeault,&nbsp;Christian Otis,&nbsp;Jean-François Pombert,&nbsp;Monique Turmel,&nbsp;Claude Lemieux","doi":"10.1111/jpy.13482","DOIUrl":"10.1111/jpy.13482","url":null,"abstract":"<p>The marine prasinophyte green algae <i>Pycnococcus provasolii</i> and <i>Pseudoscourfieldia marina</i> represent the only extant genera and known species of the Pycnococcaceae. However, their taxonomic status needs to be reassessed, owing to the very close relationship inferred from previous sequence comparisons of individual genes. Although <i>Py. provasolii</i> and <i>Ps. marina</i> are morphologically different, their plastid <i>rbc</i>L and nuclear small subunit rRNA genes were observed to be nearly or entirely identical in sequence, thus leading to the hypothesis that they represent distinct growth forms or alternate life-cycle stages of the same organism. To evaluate this hypothesis, we used organelle genomes as molecular markers. The plastome and mitogenome of <i>Ps. marina</i> UIO 007 were sequenced and compared with those available for two isolates of <i>Py. provasolii</i> (CCMP 1203 and CCAP 190/2). The <i>Ps. marina</i> organelle genomes proved to be almost identical in size and had the same gene content and gene order as their <i>Py. provasolii</i> counterparts. Single nucleotide substitutions and insertions/deletions were localized using genome-scale sequence alignments. Over 99.70% sequence identities were observed in all pairwise comparisons of plastomes and mitogenomes. Alignments of both organelle genomes revealed that <i>Ps. marina</i> UIO 007 is closer to <i>Py. provasolii</i> CCAP 190/2 than are the two <i>Py. provasolii</i> strains to one another. Therefore, our results are not consistent with the placement of <i>Ps. marina</i> and <i>Py. provasolii</i> strains into distinct genera. We propose a taxonomic revision of the Pycnococcaceae and the erection of a new class of Chlorophyta, the Pseudoscourfieldiophyceae.</p>","PeriodicalId":16831,"journal":{"name":"Journal of Phycology","volume":"60 4","pages":"1021-1027"},"PeriodicalIF":2.8,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jpy.13482","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141580045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}