Diazotroph diversity associated with scleractinian corals and its relationships with environmental variables in the South China Sea

Diazotroph diversity associated with scleractinian corals and its relationships with environmental variables in the South China Sea | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research article Diazotroph diversity associated with scleractinian corals and its relationships with environmental variables in the South China Sea Jiayuan Liang, Kefu Yu, Yinghui Wang, Xueyong Huang, Wen Huang, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.2.17643/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background: Coral reef ecosystems cannot operate normally without an effective nitrogen cycle. For oligotrophic coral reef areas, coral-associated diazotrophs are indispensable participants in the nitrogen cycle. How coral-associated diazotrophs will change in order to adapt to environmental changes resulting from global warming and human activities is a topic of concern for researchers. To this end, 68 colonies of scleractinian coral were collected from 6 coral reefs areas with different environmental variables in the South China Sea to investigate the composition of associated diazotrophs based on nifH gene amplification using high-throughput sequencing. The six coral reefs can be clearly divided into two types (fringing reefs and island reefs), are affected by varying degrees of human activities and are located at different latitudes from 9°20′06′′N to 22°34′55′′N with different seawater temperatures. Results: Alpha- and beta-diversity analyses showed that the distribution of diazotrophs among coral reefs exhibited greater geographical fluctuations than interspecific fluctuations. The predominant bacterial phyla included Proteobacteria, Chlorobi, Cyanobacteria, and two unclassified phyla. Chlorobi exhibited an abundance of 47–96% in coral samples from the high-latitude Daya Bay fringing reef affected by eutrophication. Unclassified bacteria II, with an abundance of 28–87%, was found in all coral samples from the midlatitude Luhuitou fringing reef affected by eutrophication. However, unclassified bacteria I and Proteobacteria dominated (> 80% abundance) in most of the coral samples from the Weizhou Island fringing reef, which is far from land, and three island reefs (Huangyan Island, Xinyi Reef, and Sanjiao Reef) at relatively low latitudes. At the genus level, some core diazotrophs were found in different coral sample groups. In addition, the correlation analysis with various environmental variables revealed that the variables correlated positively or negatively with different diazotrophic genera. Conclusions: We found that coral-associated diazotrophs were common among coral individuals. The presence of these diazotrophs was not affected by the external environment, but their population abundances were closely related to the different environmental variables. These results provide insights into the ecological characteristics of coral-associated diazotrophs and their relationships with critical environmental variables in the South China Sea. Agroecology Coral reef ecosystem Associated diazotrophs nifH gene Geographical differences Different latitudes Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Full Text Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8275","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research article","associatedPublications":[],"authors":[{"id":225226,"identity":"f7dc4380-44b1-4b1b-8b07-7306c8b0a35c","order_by":1,"name":"Jiayuan Liang","email":"","orcid":"","institution":"Guangxi University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Jiayuan","middleName":"","lastName":"Liang","suffix":""},{"id":225227,"identity":"caa0f945-8b38-4ba3-9abd-3f674752d3f2","order_by":2,"name":"Kefu Yu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAy0lEQVRIiWNgGAWjYBACCQbGB0DKBogZG4jVwmwApNJI13KYBIdJtjezSfO2nbfn7z/c+IChxo6BfzYB26R5DoO03E6ccSOx2YDhWDKDxJ0D+LXISeQfA2lJMJBgbJNgYDvAYCCRQECL/GOQLefsDfgPArX8I0KLtAQzSMsBxg0MiW1Ai4jQItmTzGw551wyxC+Jfck8EjcIaJE4fpjxxpsyO2CIHX/44MM3Ozn+GQS0gAATD4wFVMyDRyECMP4gStkoGAWjYBSMWAAADcY6dDoZ8VgAAAAASUVORK5CYII=","orcid":"https://orcid.org/0000-0003-3409-9945","institution":"Guangxi University","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Kefu","middleName":"","lastName":"Yu","suffix":""},{"id":225228,"identity":"094797c6-3cbf-49ee-a26e-e778895a6945","order_by":3,"name":"Yinghui Wang","email":"","orcid":"","institution":"Guangxi University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Yinghui","middleName":"","lastName":"Wang","suffix":""},{"id":225229,"identity":"b684e85c-6ac4-46c9-b9ef-4b8c8f08d0ac","order_by":4,"name":"Xueyong Huang","email":"","orcid":"","institution":"Guangxi University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Xueyong","middleName":"","lastName":"Huang","suffix":""},{"id":225230,"identity":"3e9b6a44-13c8-44ff-853a-abec0856fe3d","order_by":5,"name":"Wen Huang","email":"","orcid":"","institution":"GuangXi University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Wen","middleName":"","lastName":"Huang","suffix":""},{"id":225231,"identity":"513c36d9-bb8d-4a01-a4f6-1e1bf3766204","order_by":6,"name":"Zhenjun Qin","email":"","orcid":"","institution":"GuangXi University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Zhenjun","middleName":"","lastName":"Qin","suffix":""},{"id":225232,"identity":"8ec297e5-8157-4ad5-a11e-b21c2e0cb49b","order_by":7,"name":"Guanghua Wang","email":"","orcid":"","institution":"GuangXi University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Guanghua","middleName":"","lastName":"Wang","suffix":""},{"id":225233,"identity":"4184c259-dc00-49b6-a9f7-dd22e4683ef4","order_by":8,"name":"Hongfei Su","email":"","orcid":"","institution":"Guangxi University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Hongfei","middleName":"","lastName":"Su","suffix":""},{"id":225234,"identity":"86b4ba83-3514-4fd1-852f-c1b31f36632b","order_by":9,"name":"Biao Chen","email":"","orcid":"","institution":"Guangxi University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Biao","middleName":"","lastName":"Chen","suffix":""},{"id":225235,"identity":"7dad492a-8b4d-4cef-95e8-8177ea96c515","order_by":10,"name":"Zhengchao Wu","email":"","orcid":"","institution":"Chinese Academy of Sciences","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Zhengchao","middleName":"","lastName":"Wu","suffix":""}],"badges":[],"createdAt":"2019-11-21 11:38:39","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.2.17643/v1","doiUrl":"https://doi.org/10.21203/rs.2.17643/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":176276,"identity":"8485768f-e195-4feb-9f43-8566884037ec","added_by":"auto","created_at":"2019-11-22 22:53:53","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":607529,"visible":true,"origin":"","legend":"Test for differences in alpha-diversity indices of coral-associated diazotrophs between sample groups at the OTU level. (A) ACE between coral reefs, (B) ACE between coral species, (C) Shannon index between coral reefs, and (D) Shannon index between coral species. The test used was Student's t-test. The black square (■) shows the average. n = number of coral individuals, m = number of coral species. Different coral reefs are represented in (A) and (C) by the abbreviations DyB (Daya Bay), HyI (Huangyan Island), Lht (Luhuitou), SjR (Sanjiao Reef), XyR (Xinyi Reef), and WzI (Weizhou Island); different coral species in (B) and (D) are represented by the abbreviations Pl (Porites lutea), Pv (Plesiastrea versipora), Fp (Favia palauensis), Gr (Goniastrea retiformis), and Pc (Plesiastrea curta).","description":"","filename":"1fig.jpg","url":"https://assets-eu.researchsquare.com/files/3d38ec66-72fc-4fa7-9c90-359db3770bb1/v1/1fig.jpg"},{"id":176280,"identity":"6246c3dd-22ec-4fd6-a6ea-90005d66a76e","added_by":"auto","created_at":"2019-11-22 22:53:54","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":951827,"visible":true,"origin":"","legend":"PCoA plot at the OTU level of all the coral samples collected from six different coral reefs. Coral samples were grouped according to (A) collection site and or (B) species with ≥ 5 colonies from the same coral reef. Scatter plot showing principal coordinate 1 (PC1) vs principal coordinate 2 (PC2). PC1 and PC2 represent the principal factors affecting the composition of coral-associated diazotrophs. Abbreviations are the same as in Fig. 1.","description":"","filename":"Figure2.jpg","url":"https://assets-eu.researchsquare.com/files/3d38ec66-72fc-4fa7-9c90-359db3770bb1/v1/Figure 2.jpg"},{"id":176283,"identity":"b4243735-3a66-4315-be8e-5c1abd0c2304","added_by":"auto","created_at":"2019-11-22 22:53:55","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":2852791,"visible":true,"origin":"","legend":"Composition profiles of diazotrophs. Taxonomic classification of bacterial reads retrieved from all the coral samples at the phylum level using RDP Classifier.","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/3d38ec66-72fc-4fa7-9c90-359db3770bb1/v1/3.jpg"},{"id":176285,"identity":"529a5eb6-ec8c-4288-812f-cfc3254aadd9","added_by":"auto","created_at":"2019-11-22 22:53:55","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":729063,"visible":true,"origin":"","legend":"Venn diagrams showing the number of diazotrophs at the genus level from different coral reefs (A) and coral species (B). Abbreviations are the same as in Fig. 1.","description":"","filename":"Figure4.jpg","url":"https://assets-eu.researchsquare.com/files/3d38ec66-72fc-4fa7-9c90-359db3770bb1/v1/Figure 4.jpg"},{"id":176287,"identity":"6439bc8a-d121-4c07-8216-2fade5f2de2d","added_by":"auto","created_at":"2019-11-22 22:53:55","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":989803,"visible":true,"origin":"","legend":"Correlation analyses between environmental parameters and populations of diazotrophs at the genus level. The diazotrophs analyzed were the top 20 genera in terms of total abundance. Hierarchical clustering of environmental variables was performed based on the raw data, while diazotrophic species were clustered based on averages. Significant differences are indicated by different numbers of asterisks (0.01 \u003c p ≤ 0.05 *, 0.001 \u003c p ≤ 0.01 **, p ≤ 0.001 ***). Nonsignificant correlations do not have an asterisk. The R value represents the correlation coefficient, and the closer it is to 1, the more significant the correlation is. Some of the environmental variables are represented by abbreviations, including Lat (latitude), SRP (PO43-), SiO3 (SiO32-), DIN (dissolved inorganic nitrogen, NH4+ + NO3- + NO2-), Tur (turbidity), DO (dissolved oxygen), Sal (salinity), Tem (temperature), and Lng (longitude).","description":"","filename":"Figure5.jpg","url":"https://assets-eu.researchsquare.com/files/3d38ec66-72fc-4fa7-9c90-359db3770bb1/v1/Figure 5.jpg"},{"id":801747,"identity":"601f6442-0078-460a-9a34-b0515cee28d0","added_by":"auto","created_at":"2020-03-31 15:35:16","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":7023629,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8275/v1/manuscript.pdf"},{"id":191292,"identity":"f4bac6bf-2568-439c-82cf-8fd9b1d94368","added_by":"auto","created_at":"2019-11-29 15:52:17","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1295803,"visible":true,"origin":"","legend":"","description":"","filename":"Manuscriptedited.pdf","url":"https://assets-eu.researchsquare.com/files/3d38ec66-72fc-4fa7-9c90-359db3770bb1/v1/Manuscript_edited.pdf"},{"id":176322,"identity":"04647c73-94d7-468b-8c92-6ba81cbcda70","added_by":"auto","created_at":"2019-11-22 22:54:24","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1355159,"visible":true,"origin":"","legend":"","description":"","filename":"Manuscriptedited.pdf","url":"https://assets-eu.researchsquare.com/files/3d38ec66-72fc-4fa7-9c90-359db3770bb1/v1/Manuscript.pdf"},{"id":13479921,"identity":"a783ce5c-84f6-4bc4-824f-dc5fd7591682","added_by":"auto","created_at":"2021-09-16 21:41:15","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1633523,"visible":true,"origin":"","legend":"","description":"","filename":"Manuscriptedited.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8275/v1_covered.pdf"}],"financialInterests":"","formattedTitle":"Diazotroph diversity associated with scleractinian corals and its relationships with environmental variables in the South China Sea","fulltext":[{"header":"Full Text","content":"\u003cp\u003eThis preprint is available for \u003ca href='/article/rs-8275/latest.pdf' target='_blank'\u003edownload as a PDF\u003c/a\u003e.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Coral reef ecosystem, Associated diazotrophs, nifH gene, Geographical differences, Different latitudes","lastPublishedDoi":"10.21203/rs.2.17643/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.2.17643/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eBackground: Coral reef ecosystems cannot operate normally without an effective nitrogen cycle. For oligotrophic coral reef areas, coral-associated diazotrophs are indispensable participants in the nitrogen cycle. How coral-associated diazotrophs will change in order to adapt to environmental changes resulting from global warming and human activities is a topic of concern for researchers. To this end, 68 colonies of scleractinian coral were collected from 6 coral reefs areas with different environmental variables in the South China Sea to investigate the composition of associated diazotrophs based on nifH gene amplification using high-throughput sequencing. The six coral reefs can be clearly divided into two types (fringing reefs and island reefs), are affected by varying degrees of human activities and are located at different latitudes from 9°20′06′′N to 22°34′55′′N with different seawater temperatures. \u003c/p\u003e\u003cp\u003eResults: Alpha- and beta-diversity analyses showed that the distribution of diazotrophs among coral reefs exhibited greater geographical fluctuations than interspecific fluctuations. The predominant bacterial phyla included Proteobacteria, Chlorobi, Cyanobacteria, and two unclassified phyla. Chlorobi exhibited an abundance of 47–96% in coral samples from the high-latitude Daya Bay fringing reef affected by eutrophication. Unclassified bacteria II, with an abundance of 28–87%, was found in all coral samples from the midlatitude Luhuitou fringing reef affected by eutrophication. However, unclassified bacteria I and Proteobacteria dominated (\u0026gt; 80% abundance) in most of the coral samples from the Weizhou Island fringing reef, which is far from land, and three island reefs (Huangyan Island, Xinyi Reef, and Sanjiao Reef) at relatively low latitudes. At the genus level, some core diazotrophs were found in different coral sample groups. In addition, the correlation analysis with various environmental variables revealed that the variables correlated positively or negatively with different diazotrophic genera. \u003c/p\u003e\u003cp\u003eConclusions: We found that coral-associated diazotrophs were common among coral individuals. The presence of these diazotrophs was not affected by the external environment, but their population abundances were closely related to the different environmental variables. These results provide insights into the ecological characteristics of coral-associated diazotrophs and their relationships with critical environmental variables in the South China Sea.\u003c/p\u003e","manuscriptTitle":"Diazotroph diversity associated with scleractinian corals and its relationships with environmental variables in the South China Sea","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2019-11-22 22:53:49","doi":"10.21203/rs.2.17643/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"62023910-a8d6-45d0-8eff-93c66a87eda6","owner":[],"postedDate":"November 22nd, 2019","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":37944,"name":"Agroecology"}],"tags":[],"updatedAt":"","versionOfRecord":[],"versionCreatedAt":"2019-11-22 22:53:49","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8275","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"identity":"rs-8275","version":["v1"]},"buildId":"7rjqhiLT3MXkJMwkYKINL","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}