Phycological Research最新文献

{"title":"Edaphophycus epilithus gen. et sp. nov. (Oscillatoriales, cyanobacteria) with a description of the morphology and molecular phylogeny","authors":"Nam‐Ju Lee, Taehee Kim, Do‐Hyun Kim, Jang‐Seu Ki, Ok‐Min Lee","doi":"10.1111/pre.12499","DOIUrl":"https://doi.org/10.1111/pre.12499","url":null,"abstract":"Two strains of subaerial cyanobacteria were collected from two locations of the Republic of Korea, one in Seoul and the other in Gyeonggi‐do, both of which were studied using morphological and molecular traits. The genus Edaphophycus belonging to the family Coleofasciculaceae is morphologically very similar to the type genus Coleofasciculus and genus Kastovskya. However, in genera Coleofasciculus and Roseofilum thylakoids were reported as radial arrangements, whereas in genera Anagnostidinema, Geitlerinema, Kastovskya, and Wilmottia, belonging to family Coleofasciculaceae, thylakoids were reported as parietal arrangements, and in genus Edaphophycus in this study, thylakoids also appeared as parietal arrangements. Phylogenetic analysis of 16S rRNA showed that our two Edaphophycus epilithus strains clustered in the same clade, forming a sister relationship with genus Anagnostidinema. This suggested that our species belongs to the family Coleofasciculaceae. In addition, the ITS structure of E. epilithus showed different features when compared with genera Coleofasciculus and Anagnostidinema. These results demonstrated that E. epilithus sp. nov. is unique in morphology and molecular traits. Therefore, we propose this to be a novel species belonging to family Coleofasciculaceae and genus Edaphophycus gen. nov.","PeriodicalId":20544,"journal":{"name":"Phycological Research","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42661370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gene expression of a canopy‐forming kelp, Eisenia bicyclis (Laminariales, Phaeophyceae), under high temperature stress","authors":"Yoshino Hara, Yui Otake, Shingo Akita, T. Yamazaki, Fumio Takahashi, S. Yoshikawa, S. Shimada","doi":"10.1111/pre.12497","DOIUrl":"https://doi.org/10.1111/pre.12497","url":null,"abstract":"To understand the high temperature stress acclimation of a canopy‐forming kelp, RNA‐seq analysis was performed on cultured Eisenia bicyclis (Kjellman) Setchell (Laminariales, Phaeophyceae), a major component species of kelp forests along the coast of Japan. We established a culture strain from a population at the northernmost distribution limit of this species and measured photosystem II activity in young sporophytes. We found that photosystem II activity was lower at 25°C than at 5–15°C, thus, comparative RNA‐seq analysis was conducted between cultivated young thalli of E. bicyclis at 15°C and 25°C. Comparison with the expression genes revealed 277 up‐regulated genes and 327 down‐regulated genes at 25°C. The most up‐regulated gene was 3‐ketoacyl‐CoA thiolase, which is related to fatty acid degradation. This enzyme has been reported to positively regulate abscisic acid (ABA) signaling in Arabidopsis thaliana (Brassicaceae). In addition, heat shock proteins, ATP synthase, NADH‐dehydrogenase, and L‐ascorbate peroxidase were up‐regulated. The most down‐regulated gene was taurine catabolism dioxygenase TauD/TfdA. Genes related to fatty acid metabolism, photosynthesis, and synthesis of cell wall components were down‐regulated. These results suggest that E. bicyclis may counteract high temperature stress by up‐regulating genes involved in protein stabilization, energy production and antioxidant processes. Conversely, photosynthesis and other metabolic processes may be damaged due to the inability to withstand high temperature stress.","PeriodicalId":20544,"journal":{"name":"Phycological Research","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44038112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Asterocladon ednae sp. nov. (Asterocladales, Phaeophyceae) from the Philippines","authors":"Eriko Sasagawa, Wilfred John E. Santiañez, K. Kogame","doi":"10.1111/pre.12490","DOIUrl":"https://doi.org/10.1111/pre.12490","url":null,"abstract":"Members of the brown algal order Asterocladales are characterized by stellate arrangement of its chloroplasts, in which a stellate configuration has a protruding central pyrenoid complex. The order is represented by the genus Asterocladon, which consists of only three species so far. Similar to other small and filamentous seaweeds, studies on Asterocladon remain scant and their diversity poorly understood. To fill this gap, we conducted molecular‐assisted taxonomic studies on Asterocladon based on seven culture isolates collected from Okinawa Prefecture, Japan and Cebu, the Philippines. One culture isolate from the Philippines was revealed to be a new species of Asterocladon based on morpho‐anatomical and molecular analyses using rbcL and psaA genes and is described here as Asterocladon ednae. The other isolates were attributed to A. rhodochortonoides. A. ednae was most closely related to A. rhodochortonoides in morphology and molecular phylogeny but was distinguished from the latter by its elongately ellipsoid plurilocular sporangia. This is the first report of the genus and species A. ednae in the Philippines, further increasing the diversity of seaweeds in the country.","PeriodicalId":20544,"journal":{"name":"Phycological Research","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42710115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of DNA markers that distinguish male and female haploid germlings of the brown alga, Cladosiphon okamuranus","authors":"Koki Nishitsuji, Yoshie Nishitsuji, Yoshitaka Yonashiro, Nori Satoh","doi":"10.1111/pre.12489","DOIUrl":"https://doi.org/10.1111/pre.12489","url":null,"abstract":"Okinawa mozuku, Cladosiphon okamuranus, is one of many edible brown algae, yielding 22 Kton annually and contributing ¥5 billion to the Japanese economy. The life cycle of C. okamuranus is complicated, since the alga has self‐cloning life cycles in both haploid (N, male and female) and diploid (2N) conditions, but only diploid “seeds” (germlings) become edible sporophytes. Because haploid and diploid germlings are morphologically indistinguishable, haploid germlings are often mistakenly combined with diploid germlings for cultivation, which results in less efficient harvesting of mozuku. Sexual identification of haploid germlings is essential to develop better diploid strains by crossbreeding. With this aim, we performed RNA‐seq analysis of haploid germlings of C. okamuranus. Using its decoded diploid genome and transcriptomic information, we identified 269 genes that are expressed specifically in male or female haploids. BLAST analysis with Ectocarpus siliculosus gene models revealed that nine of 269 genes were putative sex determination‐related genes of C. okamuranus. A unique set of polymerase chain reaction primers for these nine genes was designed, and DNA amplification using primers enabled us to distinguish male and female haploid and diploid germlings. This tool will enable mozuku farmers to select diploid germlings free of haploid germlings. Using this DNA marker technique, the amount of mozuku cultivated in Okinawa is expected to increase.","PeriodicalId":20544,"journal":{"name":"Phycological Research","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42278954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effects of desiccation and salinity gradients on the PSII photochemical efficiency of an intertidal brown alga, Sargassum fusiforme from Kagoshima, Japan","authors":"Yukiko Yonemori, Shogo Kokubu, Gregory N. Nishihara, H. Endo, Ryuta Terada","doi":"10.1111/pre.12491","DOIUrl":"https://doi.org/10.1111/pre.12491","url":null,"abstract":"The responses of photochemical efficiency to desiccation and salinity gradients in an intertidal edible brown macroalga, Sargassum fusiforme (Harvey) Setchell (Sargassaceae, Fucales), were determined using a pulse amplitude modulation (PAM)‐chlorophyll fluorometer. The effective quantum yields (ΔF/Fm'; = ΦPSII) of photosystem II (PSII) dropped to zero after 360‐min aerial exposure under low irradiance (20 μmol photons m−2 s−1) and 120‐min exposure under high irradiance (700 μmol photons m−2 s−1) for this species at 20°C and 50% relative humidity. Under these conditions, ΔF/Fm' failed to recover to initial levels even after 1‐day rehydration in seawater. In general, ΔF/Fm' decreased as desiccation reduced the absolute water content (AWC, %). Nevertheless, when AWC was above ca. 20%, ΔF/Fm' was mostly restored to initial levels after 1‐day rehydration in seawater, suggesting strong tolerance to dehydration. Furthermore, S. fusiforme appeared to tolerate a broad range of salinity (i.e. 15–50 psu) during six days of culture; however, ΔF/Fm' declined when salinity was <10 and 60 psu. Strong tolerance to dehydration and salinity stress likely provides S. fusiforme an advantage that allows it to flourish in the intertidal habitat.","PeriodicalId":20544,"journal":{"name":"Phycological Research","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44269181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Selective utilization of phosphorus compounds by Chaetoceros tenuissimus (Bacillariophyceae): Approach using 31P nuclear magnetic resonance analysis","authors":"H. Yamaguchi, Masaki Zaima, Masao Adachi, Y. Tomaru, H. Asahara, N. Nishiwaki","doi":"10.1111/pre.12485","DOIUrl":"https://doi.org/10.1111/pre.12485","url":null,"abstract":"Several diatom species can utilize various forms of organic phosphorus via enzymatic hydrolysis. The present study identified which phosphorus compounds are preferentially utilized by planktonic diatom Chaetoceros tenuissimus cultures using a 31P nuclear magnetic resonance (NMR)‐based method. Our 31P NMR analysis, which involves a sample extraction procedure using DIAION™ CR11, detected and quantified phosphorus compounds present at concentrations of at least 7.5 μM in the seawater‐based media, including orthophosphate, phosphate monoester, phosphate diester, phosphonate, and other compounds. Based on this analysis, we examined the temporal variations of phosphorus compounds in C. tenuissimus cultures in which orthophosphate, phosphate monoester, phosphate diester, and phosphonate compounds were present simultaneously. Cells pre‐grown under phosphorus‐replete conditions utilized orthophosphate as the preferential phosphorus source and switched to phosphate monoester after exhausting orthophosphate. Enzymatic activity for phosphate monoester hydrolysis, namely phosphomonoesterase (synonym to alkaline phosphatase) activity, appeared when C. tenuissimus began to utilize phosphate monoester. In contrast, C. tenuissimus pre‐grown on phosphorus‐depleted media simultaneously hydrolyzed phosphate monoester and phosphate diester compounds, released orthophosphate from these compounds, and utilized the released orthophosphate and original orthophosphate without discrimination. Overall, we demonstrated that 31P NMR‐based method can comprehensively analyze the variations of dissolved phosphorus compounds in diatom cultures. Our results showed selective utilization of phosphorus compounds by C. tenuissimus and suggested that phosphate monoester and phosphate diester compounds were important phosphorus sources for this diatom in orthophosphate‐depleted coastal waters.","PeriodicalId":20544,"journal":{"name":"Phycological Research","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47771206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Galactolipid composition of Gertia stigmatica (Dinophyceae), an atypical member of the Kareniaceae with a peridinin‐containing, non‐haptophyte‐derived plastid","authors":"Jeffrey D. Leblond, Kyra Sabir, Jori E. Graeff","doi":"10.1111/pre.12488","DOIUrl":"https://doi.org/10.1111/pre.12488","url":null,"abstract":"Gertia stigmatica is an atypical member of the Kareniaceae that has a peridinin‐containing plastid rather than a tertiary, (acyloxy)fucoxanthin‐containing, haptophyte‐derived plastid, as is found in the canonical genera Karenia, Karlodinium, and Takayama. While the origin of G. stigmatica's plastid is uncertain per its original published description, with alternative hypotheses stating that it could have originated before or after the acquisition of a haptophyte‐derived plastid, the description of the species indicates that it does possess ultrastructural and genetic features that firmly place it within the Kareniaceae. As a photosynthetic, plastid‐containing organism, G. stigmatica, like other algae, possesses two galactolipids, mono‐ and digalactosyldiacylglycerol (MGDG and DGDG, respectively), that form the basis of its plastid‐associated photosynthetic membranes. MGDG and DGDG have been extensively characterized in peridinin‐containing dinoflagellates, where it has been observed that these dinoflagellates can be segregated into two clusters. One cluster is characterized by MGDG and DGDG possessing the polyunsaturated C18/C18 fatty acids (sn‐1/sn‐2 regiochemistry) octadecapentaenoic acid (18:5(n‐3)) and octadecatetraenoic acid (18:4(n‐3)), while the second cluster possesses eicosapentaenoic acid (20:5(n‐3)) in the sn‐1 position while retaining a polyunsaturated C18 fatty acid in the sn‐2 position. By contrast, Karenia brevis and Karenia mikimotoi have been observed to be enriched in species of MGDG and DGDG, such as 18:5(n‐3)/14:0 MGDG and DGDG, uncommon to peridinin‐containing dinoflagellates. Our objective was to characterize the galactolipids of G. stigmatica to compare it to both peridinin‐containing dinoflagellates and other members of the Kareniaceae to search for insight, such as (a) remnant 14:0 fatty acid‐containing galactolipid(s), into the evolution of its plastid. Our results show that G. stigmatica possesses 20:5(n‐3)/18:5(n‐3) MGDG and DGDG as the primary galactolipids, with little evidence of those galactolipid species enriched in K. brevis and K. mikimotoi. The implications of this for the evolution of the G. stigmatica plastid are discussed.","PeriodicalId":20544,"journal":{"name":"Phycological Research","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47595751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clymene sutherlandiae sp. nov.: A new species of Bangiales (Rhodophyta) from the southern hemisphere","authors":"W. Nelson","doi":"10.1111/pre.12487","DOIUrl":"https://doi.org/10.1111/pre.12487","url":null,"abstract":"A new species of the southern hemisphere genus Clymene, C. sutherlandiae, is described based on collections from the Otago coast, south east South Island of New Zealand, and from a site in western Tasmania. Found on mid‐upper intertidal rocks on open coasts, and frequently adjacent to sandy shores, this is a second species for the genus, previously known solely from the type species C. coleana found in the North Island, northern South Island and Chatham Islands of New Zealand.","PeriodicalId":20544,"journal":{"name":"Phycological Research","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43978143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal tolerance of Hypnea pseudomusciformis ecotypes (Cystocloniaceae, Rhodophyta) related to different floristic provinces along the Brazilian coast","authors":"Fábio Nauer, Mariana Cabral Oliveira, E. Plastino, Nair Sumie Yokoya, Mutue Toyota Fujii","doi":"10.1111/pre.12478","DOIUrl":"https://doi.org/10.1111/pre.12478","url":null,"abstract":"Studies on the effects of temperature on physiological processes are essential to model macroalgae biogeographic distribution. Tetrasporophytes of Hypnea pseudomusciformis were collected from three floristic provinces (tropical, transition and warm temperate) along the Brazilian coast (~3.000 km), representing three ecotypes. Specimens were cultured under 20°C, 24°C, 28°C and 32°C for 21 days, then physiological parameters (growth rates, photosynthesis and pigments content) were analyzed. H. pseudomusciformis specimens tolerated a temperature variation from 20°C to 32°C. However, all ecotypes displayed a significant decrease in physiological performance at 32°C in all parameters analyzed. We hypothesized that the H. pseudomusciformis ecotype from the tropical province is already living at its thermal physiological limit, reaching its maximum growth only in the winter months (June to September), whereas a warm temperate ecotype reaches maximum growth in the summer months (December to March). This wide thermal optimum may be the reason for the widespread distribution of this species along the Brazilian coast, allowing it to occupy different thermal environments.","PeriodicalId":20544,"journal":{"name":"Phycological Research","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48647701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Issue Information","authors":"","doi":"10.1111/pre.12476","DOIUrl":"https://doi.org/10.1111/pre.12476","url":null,"abstract":"Genus Neolyngbya (Cyanobacteria) is widely distributed along coastal region of Okinawa, including in Sunabe beach, Chatan, which is the type locality of Neolyngbya latusa sp. nov. (right). Neolyngbya can be found as macroscopic colony attached to rocks or other hard substrates in intertidal zones. Macroscopic colony images of N. intertidalis sp. nov. (top‐left) and N. latusa (middle‐left). Filament appearances of N. intertidalis (bottom‐left) and N. latusa (bottom‐middle) under a light microscope. Not drawn to scale.","PeriodicalId":20544,"journal":{"name":"Phycological Research","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47719749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}