Harmful Algae最新文献

筛选
英文 中文
An early-warning forecast model for red tide (Karenia brevis) blooms on the southwest coast of Florida 佛罗里达西南海岸赤潮(Karenia brevis)绽放预警预报模型
IF 5.5 1区 生物学
Harmful Algae Pub Date : 2024-09-24 DOI: 10.1016/j.hal.2024.102729
{"title":"An early-warning forecast model for red tide (Karenia brevis) blooms on the southwest coast of Florida","authors":"","doi":"10.1016/j.hal.2024.102729","DOIUrl":"10.1016/j.hal.2024.102729","url":null,"abstract":"<div><div><em>Karenia brevis</em> blooms occur nearly annually along the southwest coast of Florida, and effective mitigation of ecological, public health, and economic impacts requires reliable real-time forecasting. We present two boosted random forest models that predict the weekly maximum <em>K. brevis</em> abundance category across the Greater Charlotte Harbor estuaries over one-week and four-week forecast horizons. The feature set was restricted to data available in near-real time, consistent with adoption of the models as decision-support tools. Features include current and lagged <em>K. brevis</em> abundance statistics, Loop Current position, sea surface temperature, sea level, and riverine discharges and nitrogen concentrations. During cross-validation, the one-week and four-week forecasts exhibited 73 % and 84 % accuracy, respectively, during the 2010–2023 study period. In addition, we assessed the models’ reliability in forecasting the onset of 10 bloom events on time or in advance; the one-week and four-week models anticipated the onset eight times and five times, respectively.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Explainable machine learning for predicting diarrhetic shellfish poisoning events in the Adriatic Sea using long-term monitoring data 利用长期监测数据预测亚得里亚海腹泻性贝类中毒事件的可解释机器学习
IF 5.5 1区 生物学
Harmful Algae Pub Date : 2024-09-23 DOI: 10.1016/j.hal.2024.102728
{"title":"Explainable machine learning for predicting diarrhetic shellfish poisoning events in the Adriatic Sea using long-term monitoring data","authors":"","doi":"10.1016/j.hal.2024.102728","DOIUrl":"10.1016/j.hal.2024.102728","url":null,"abstract":"<div><div>In this study, explainable machine learning techniques are applied to predict the toxicity of mussels in the Gulf of Trieste (Adriatic Sea) caused by harmful algal blooms. By analysing a newly created 28-year dataset containing records of toxic phytoplankton in mussel farming areas and diarrhetic shellfish toxins in mussels (<em>Mytilus galloprovincialis</em>), we train and evaluate the performance of machine learning (ML) models to accurately predict diarrhetic shellfish poisoning (DSP) events. Based on the F1 score, the random forest model provided the best prediction of toxicity results at which the harvesting of mussels is stopped according to EU regulations. Explainability methods such as permutation importance and Shapley Additive Explanations (SHAP) identified key species (<em>Dinophysis fortii</em> and <em>D. caudata</em>) and environmental factors (salinity, river discharge and precipitation) as the best predictors of DSP toxins above regulatory limits. These findings are important for improving early warning systems, which until now were based solely on empirically defined alert abundances of DSP species. They provide experts, aquaculture practitioners, and authorities with additional information to make informed risk management decisions.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Prevalence and distribution of dissolved paralytic shellfish toxins in seawater in the Yellow Sea and the Bohai Sea, China 中国黄海和渤海海水中溶解性麻痹性贝类毒素的流行和分布情况
IF 5.5 1区 生物学
Harmful Algae Pub Date : 2024-09-22 DOI: 10.1016/j.hal.2024.102730
{"title":"Prevalence and distribution of dissolved paralytic shellfish toxins in seawater in the Yellow Sea and the Bohai Sea, China","authors":"","doi":"10.1016/j.hal.2024.102730","DOIUrl":"10.1016/j.hal.2024.102730","url":null,"abstract":"<div><div>Paralytic shellfish toxins (PSTs) could be secreted by PSTs-producing microalgae or released by ruptured cells in seawater. In this study, the distribution of dissolved PSTs in the Yellow Sea and the Bohai Sea, China, was investigated by two cruises in April and July 2023. Seawater samples were collected from the surface, middle and bottom layers, and the profiles of PSTs were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the spatial distribution characteristics of dissolved PSTs and their correlation with environmental factors were explored. Results showed that C1/2, GTX1/4, GTX2/3 and dcGTX2/3, were detected in seawater samples in both spring and summer, with the detection rates 100 % and 97.6 %, respectively. The total PST (ΣPSTs) concentrations ranged in 12 ∼ 590 pmol L<sup>−1</sup>, 9.3 ∼ 546 pmol L<sup>−1</sup>, 12 ∼ 2,452 pmol L<sup>−1</sup>, and not detected (nd) ∼ 188 pmol L<sup>−1</sup> in seawater samples collected from the surface, middle and bottom layers in spring, and the surface layer in summer, respectively. Concentrations of PSTs markedly varied in the vertical water column in different sea regions. Generally, concentrations of ΣPSTs in the bottom seawater were higher than those in the surface and middle layers in the Bohai Sea and the North Yellow Sea, but no significant difference in the different water layers in the South Yellow Sea. In addition, concentrations of ΣPSTs in surface waters were much lower in summer than those in spring. In both spring and summer, dissolved PSTs in surface seawater were mainly distributed in the South Yellow Sea. These results indicate that PSTs were prevalent in the Yellow Sea and the Bohai Sea, of which the potential hazard to marine organisms should be highly concerned.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142316289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Potential siderophore-dependent mutualism in the harmful dinoflagellate Alexandrium pacificum (Group IV) and bacterium Photobacterium sp. TY1-4 under iron-limited conditions 有害甲藻亚历山大藻(第 IV 组)与光杆菌 TY1-4 在铁限制条件下可能存在的依赖苷元的互生关系
IF 5.5 1区 生物学
Harmful Algae Pub Date : 2024-09-20 DOI: 10.1016/j.hal.2024.102726
{"title":"Potential siderophore-dependent mutualism in the harmful dinoflagellate Alexandrium pacificum (Group IV) and bacterium Photobacterium sp. TY1-4 under iron-limited conditions","authors":"","doi":"10.1016/j.hal.2024.102726","DOIUrl":"10.1016/j.hal.2024.102726","url":null,"abstract":"<div><div>Specific bacterial species induce algal blooms by producing growth-promoting substances, such as siderophores, under iron-limited conditions. However, the molecular mechanisms underlying these effects remain poorly understood. This study investigates the interactions between the harmful dinoflagellate <em>Alexandrium pacificum</em> (Group IV) and siderophore-producing bacteria, with a focus on iron acquisition facilitated by bacterial siderophores. During algal bloom seasons in the South Sea of Korea, <em>Photobacterium</em> sp. TY1-4 was isolated, which enhances <em>A. pacificum</em> cell density under iron-deficient conditions, TY1-4 can use the sterile exudates from <em>A. pacificum</em> as the sole source of carbon<em>,</em> suggesting a mutualistic relationship. Transcriptomic and genomic analyses revealed siderophore-mediated redox-based signaling and non-reductive pathways enhancing iron bioavailability. <em>Photobacterium</em> sp. TY1-4 initiates siderophore production through quorum sensing, whereas <em>A. pacificum</em> utilizes specific receptors and transporters for hydroxamate-type siderophores (<em>ApFHUA</em> and <em>ApFHUC</em>) to uptake iron. Three redox key iron-uptake genes were also identified in <em>A. pacificum</em>: membrane-bound ferroxidase <em>ApFET3</em>, high-affinity iron permease <em>ApFTR1</em>, and ferric-chelate reductases/oxidoreductases <em>ApFRE1</em>, with transcription levels inversely related to bioavailable iron. Increased iron bioavailability mediated by siderophores alleviates iron stress in <em>A. pacificum</em>, supporting its growth in iron-scarce environments. Additionally, <em>A. pacificum</em> co-cultured with <em>Photobacterium</em> sp. TY1-4 synthesized high-toxicity STXs, including GTX4, GTX2, and STX. These findings highlight the critical role of bacterial siderophores in iron binding and their potential impact on harmful algal bloom dynamics.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1568988324001598/pdfft?md5=193af3676fa67a46f3e3f7035ea047ab&pid=1-s2.0-S1568988324001598-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142316093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Response to the CO2 concentrating mechanisms and transcriptional time series analysis of Ulva prolifera under inorganic carbon limitation 无机碳限制下莼菜对二氧化碳浓缩机制的响应及转录时间序列分析
IF 5.5 1区 生物学
Harmful Algae Pub Date : 2024-09-19 DOI: 10.1016/j.hal.2024.102727
{"title":"Response to the CO2 concentrating mechanisms and transcriptional time series analysis of Ulva prolifera under inorganic carbon limitation","authors":"","doi":"10.1016/j.hal.2024.102727","DOIUrl":"10.1016/j.hal.2024.102727","url":null,"abstract":"<div><div><em>Ulva prolifera</em> is a dominant species in green tides and has been affecting marine ecosystem for many years. Due to the low availability of CO<sub>2</sub> in the environment, <em>U. prolifera</em> utilizes the CO<sub>2</sub> concentrating mechanisms (CCMs) to increase intracellular inorganic carbon concentration. However, the transcriptional response mechanism and temporal changes of <em>U. prolifera</em> CCMs based on transcriptomics have not been thoroughly described. Therefore, we induced <em>U. prolifera</em> CCMs in a low CO<sub>2</sub> environment to explore the dynamic regulation of CCMs expression under inadequate inorganic carbon supply. The results showed that inorganic carbon limitation increased the inorganic carbon affinity of <em>U. prolifera</em>, upregulating CCMs. The first 24 h of inorganic carbon environmental changes were the most active period for <em>U. prolifera</em>'s expression regulation. <em>U. prolifera</em> gradually achieved a new steady state by regulating metabolic processes such as nucleic acids, energy, and ethylene-activated signaling pathways. In the carbon fixation system of <em>U. prolifera</em>, there are characteristics of both biophysical and biochemical CCMs. After 24 h of inorganic carbon limitation, the biophysical CCMs becomes more effective under conditions of inorganic carbon depletion. This study aids in exploring the CCMs of <em>U. prolifera</em> and their evolution in response to environmental changes<em>.</em></div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142316091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Production of extracellular superoxide contributes to photosynthesis via elimination of reducing power and regeneration of NADP+ in the red-tide-forming raphidophyte Chattonella marina complex 在形成红色潮汐的虹彩叶藻 Chattonella marina 复合体中,细胞外超氧化物的产生通过消除还原力和再生 NADP+ 促进光合作用
IF 5.5 1区 生物学
Harmful Algae Pub Date : 2024-09-13 DOI: 10.1016/j.hal.2024.102712
{"title":"Production of extracellular superoxide contributes to photosynthesis via elimination of reducing power and regeneration of NADP+ in the red-tide-forming raphidophyte Chattonella marina complex","authors":"","doi":"10.1016/j.hal.2024.102712","DOIUrl":"10.1016/j.hal.2024.102712","url":null,"abstract":"<div><p>The raphidophyte <em>Chattonella marina</em> complex (hereafter <em>Chattonella</em>) consists of noxious red-tide-forming algae that are damaging to fish farms. <em>Chattonella</em> produces and secretes large amounts of the superoxide anion (•O<sub>2</sub><sup>−</sup>), and the production of extracellular •O<sub>2</sub><sup>−</sup> has been associated with fish mortality. We reported previously that photosynthetic electron transport is correlated with the production of •O<sub>2</sub><sup>−</sup> in the genus <em>Chattonella</em>. However, the physiological roles of the production of extracellular •O<sub>2</sub><sup>−</sup> remain to be clarified. In the present study, we examined the effects of the production of extracellular •O<sub>2</sub><sup>−</sup> on photosynthesis and cell proliferation in two strains of <em>Chattonella</em>, namely, Ago03, a highly toxic strain that produces large amounts of •O<sub>2</sub><sup>−</sup> externally, and Ago04, a low-toxicity strain that produces very small amounts of •O<sub>2</sub><sup>−</sup>. Both the growth rate and the net photosynthetic activity of Ago04 were higher than those of Ago03. In Ago04, levels of Rubisco and 3-phosphoglycerate, the product of the reaction catalyzed by Rubisco, were 4-fold higher than those in Ago03, suggesting the higher photosynthetic activity of Ago04. In the presence of glycolaldehyde, a specific inhibitor of the Calvin-Benson cycle, the levels of NADP<sup>+</sup> and the photosynthetic parameter qP declined under strong light in Ago04. By contrast, levels of NADP<sup>+</sup> and qP in Ago03 changed less significantly than those in Ago04. Given that •O<sub>2</sub><sup>−</sup> is produced by a putative NADPH oxidase that converts O<sub>2</sub> to •O<sub>2</sub><sup>−</sup> in <em>Chattonella</em>, it seems likely that the production of •O<sub>2</sub><sup>−</sup> might play a role not only in the elimination of excess reducing power of NADPH from the cell, via •O<sub>2</sub><sup>−</sup>, but also in the regeneration of NADP<sup>+</sup>, as a result of the action of NADPH oxidase, which oxidizes NADPH, to maintain photosynthetic electron transport.</p></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1568988324001458/pdfft?md5=0faa71a246e0adac6716c6df333523f0&pid=1-s2.0-S1568988324001458-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142272449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Diversity, toxicity, and distribution of potentially toxic diatoms in Antarctic waters––With description of Pseudo-nitzschia meridionalis sp. nov. and P. glacialis sp. nov. 南极水域潜在有毒硅藻的多样性、毒性和分布--附对Pseudo-nitzschia meridionalis sp.
IF 5.5 1区 生物学
Harmful Algae Pub Date : 2024-09-12 DOI: 10.1016/j.hal.2024.102724
{"title":"Diversity, toxicity, and distribution of potentially toxic diatoms in Antarctic waters––With description of Pseudo-nitzschia meridionalis sp. nov. and P. glacialis sp. nov.","authors":"","doi":"10.1016/j.hal.2024.102724","DOIUrl":"10.1016/j.hal.2024.102724","url":null,"abstract":"<div><div>Diatoms of the genus <em>Pseudo-nitzschia</em>, known for their potential toxicity, are integral to the phytoplankton community of the Southern Ocean, which surrounds Antarctica. Despite their ecological importance, the diversity and toxicity of <em>Pseudo-nitzschia</em> in this region remain underexplored. Globally, these diatoms are notorious for forming harmful algal blooms in temperate and tropical waters, causing significant impacts on marine life, ecosystems, and coastal economies. However, detailed information on the diversity, morphology, and toxicity of <em>Pseudo-nitzschia</em> species in Antarctic waters is limited, with molecular characterizations of these species being particularly scarce.</div><div>During three research expeditions to the Southern Ocean, monoclonal strains of <em>Pseudo-nitzschia</em> were isolated and cultivated. Stored samples from a fourth expedition, the Brategg expedition, were used to complete the description of particularly <em>P. turgidula</em>. Through electron microscopy and molecular analysis, two novel species were identified—<em>Pseudo-nitzschia meridionalis</em> sp. nov. and <em>Pseudo-nitzschia glacialis</em> sp. nov.—alongside the previously described species <em>P. subcurvata, P. turgiduloides</em>, and <em>P. turgidula</em>. Toxin assays revealed no detectable levels of domoic acid in <em>P. turgiduloides, P. turgidula, P. meridionalis</em> sp. nov. and <em>P. glacialis</em> sp. nov. Conversely, <em>P. subcurvata</em> was reported in a related study to produce domoic acid and its isomer, isodomoic acid C.</div><div>These findings emphasize the need for comprehensive research on the phytoplankton of Antarctic waters, which is currently a largely uncharted domain. With the looming threat of climate change, understanding the dynamics of potentially harmful algal populations in this region is becoming increasingly critical.</div></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1568988324001574/pdfft?md5=7e59ef19d51e6398fbe85782b7c1ad4b&pid=1-s2.0-S1568988324001574-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Enhanced eDNA monitoring for detection of viable harmful algal bloom species using propidium monoazide 利用单氮化丙啶加强电子 DNA 监测,以检测有害藻华的存活物种
IF 5.5 1区 生物学
Harmful Algae Pub Date : 2024-09-12 DOI: 10.1016/j.hal.2024.102725
{"title":"Enhanced eDNA monitoring for detection of viable harmful algal bloom species using propidium monoazide","authors":"","doi":"10.1016/j.hal.2024.102725","DOIUrl":"10.1016/j.hal.2024.102725","url":null,"abstract":"<div><p>This study investigated the use of propidium monoazide (PMA) to improve the accuracy of environmental DNA (eDNA) monitoring by selectively detecting intracellular DNA (iDNA) from living cells, while excluding extracellular DNA (exDNA) from dead organisms. eDNA samples were collected from various depths off the coast of Tongyeong, South Korea, and analyzed alongside environmental factors, such as temperature, dissolved oxygen, turbidity, and nutrient levels. The results showed that PMA-treated iDNA provided a more accurate estimate of viable harmful algal bloom species (HABs) than total eDNA and DNase-treated iDNA. Strong correlations were found between iDNA (PMA) and environmental factors, particularly nutrient levels and turbidity, suggesting its effectiveness in biological environments. The iDNA (PMA) concentrations were higher in the surface and bottom layers, indicating that these layers were more indicative of living organisms in marine environments. The application of PMA in eDNA monitoring reduces false positives and enhances the detection accuracy of viable HAB species, representing a promising tool for real-time monitoring and management of marine ecosystems.</p></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142232184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Intracellular abundance, localization, and enzymatic activity of a saxitoxin biosynthesis enzyme, SxtG, in two sister subclones of the dinoflagellate Alexandrium catenella with extremely different levels of paralytic shellfish toxins 在麻痹性贝类毒素含量极度不同的甲藻亚历山大藻的两个姐妹亚克隆中,沙西毒素生物合成酶 SxtG 的细胞内丰度、定位和酶活性
IF 5.5 1区 生物学
Harmful Algae Pub Date : 2024-09-12 DOI: 10.1016/j.hal.2024.102723
{"title":"Intracellular abundance, localization, and enzymatic activity of a saxitoxin biosynthesis enzyme, SxtG, in two sister subclones of the dinoflagellate Alexandrium catenella with extremely different levels of paralytic shellfish toxins","authors":"","doi":"10.1016/j.hal.2024.102723","DOIUrl":"10.1016/j.hal.2024.102723","url":null,"abstract":"<div><p>Paralytic shellfish poisoning is caused by saxitoxin (STX), and its analogues (paralytic shellfish toxins (PSTs)) produced by marine dinoflagellates. SxtA and SxtG are the most essential enzymes in STX biosynthesis. Previous studies investigated the abundance and subcellular localization (<em>i.e.</em>, chloroplasts) of SxtA in dinoflagellates using immunostaining. The present study characterized SxtG, and positive signals were detected in sister subclones of <em>Alexandrium catenella</em> (Group I) with extremely different levels of PSTs. Multiplex fluorescence immunostaining detection of a PST-positive subclone revealed co-localization of SxtA and SxtG, suggesting that SxtG localizes to chloroplasts. <em>In vitro</em> amidino-transfer from arginine to Int-A’, the first intermediate product in the biosynthesis, was presumed to be catalyzed by SxtG, and the reaction was established using crude extracts of PST-positive and negative <em>A. catenella</em> subclones. These analyses suggested that the PST-negative subclone expresses active SxtG but not SxtA. These findings support our hypothesis that decrease of SxtA leads to the loss of toxicity in the PST-negative subclone of <em>A. catenella</em>. Our results identified a key reaction that could enhance understanding of the biochemistry of STX biosynthesis in dinoflagellates.</p></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1568988324001562/pdfft?md5=fee179787431db79717ed90aee60f386&pid=1-s2.0-S1568988324001562-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142239857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Temperature-dependent akinete formation strategies of the harmful cyanobacterium Dolichospermum circinale 有害蓝藻 Dolichospermum circinale 的内含体形成策略与温度有关
IF 5.5 1区 生物学
Harmful Algae Pub Date : 2024-09-07 DOI: 10.1016/j.hal.2024.102722
{"title":"Temperature-dependent akinete formation strategies of the harmful cyanobacterium Dolichospermum circinale","authors":"","doi":"10.1016/j.hal.2024.102722","DOIUrl":"10.1016/j.hal.2024.102722","url":null,"abstract":"<div><p>Cyanobacteria from the orders Nostocales and certain Stigonematales form akinetes, spore-like dormant cells that allow them to survive adverse environmental conditions. Temperature is known to be one of the key factors affecting akinete formation, but there is currently little known about akinete formation during cell growth over a wide range of temperature conditions and its relation to the overall survival strategy of cyanobacteria. Therefore, in the current study, we conducted a temperature-controlled experiment to analyze the akinete formation of a harmful cyanobacterium <em>Dolichospurmum circinale</em> using a growth chamber. We measured the concentration and size of both vegetative cells and different types of akinetes (free, attached, and empty type) under varying temperatures (5–25 °C). We also analyzed the buoyant ability and vertical migration velocity of trichomes along with changes in the volume of vegetative cells and akinetes. The total akinete concentration and ratio (number of akinetes to total number of cells) were both found to be higher at high temperatures (20–25°C) than they were at low temperatures (5–10°C) (p&lt;0.05). Meanwhile, the rate of formation of akinetes (both free and attached akinetes) was highest at low temperature (10 °C) and decreased with increasing temperature. The rate of empty akinete formation increased with increasing temperature and was highest at 25°C, indicating that most of the akinetes produced under high temperature conditions germinated. The change in vegetative cell size was proportional to the increase in the growth rate in response to increasing temperature (p&lt;0.05). At high temperature, vegetative cells exhibited positive buoyancy and higher vertical migration velocity, while at low temperature, they exhibited negative buoyancy and relatively low migration velocity. Akinete size was larger at low temperature than it was at high temperature. These findings suggest that akinetes play an important role in maintaining populations in the water column, with a link between akinete formation and germination during summer cyanobacteria blooms. This information is expected to contribute to a deeper understanding of the <em>D. circinale</em> life cycle.</p></div>","PeriodicalId":12897,"journal":{"name":"Harmful Algae","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1568988324001550/pdfft?md5=750f603cbc5db879adfb904424002aef&pid=1-s2.0-S1568988324001550-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142164739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信