Bacillus megaterium strain KGA3 increases saline–alkaline tolerance of maize by recruiting keystone taxa in rhizosphere soil

Bacillus megaterium strain KGA3 increases saline–alkaline tolerance of maize by recruiting keystone taxa in rhizosphere soil | 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 Bacillus megaterium strain KGA3 increases saline–alkaline tolerance of maize by recruiting keystone taxa in rhizosphere soil Lijuan Jia, Shengnan Zhang, Yuan Xu, Xiangjian Tu, Lei Ji This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6884528/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 and Aims Available phosphorus (AP) deficiency in severely saline–alkaline soil adversely affects crop growth. To increase soil AP and promote crop growth, a phosphorus-solubilizing bacteria (PSB) named KGA3, which is a strain of Bacillus megaterium, was inoculated on maize. Methods A field experiment was conducted with CK and KGA3 treatment. Co-occurrence network (CoNet) was constructed to identify the keystone taxa, and redundancy analysis (RDA) was carried out to explore the relationships between keystone taxa and soil properties under different treatments to reveal the mechanism by which strain KGA3 promotes crop growth. Results Inoculation with KGA3 significantly increased contents of soil available nitrogen and potassium, activities of dehydrogenase and protease enzymes, and contents of the soil ions water-soluble K+, water-soluble Ca2+, and SO42–. According to co-occurrence networks, PSB community structure was stable with KGA3 treatment. In addition, KGA3 recruited beneficial keystone taxa such as Cyanobacteria to increase soil AP and promote maize growth. Conclusion We demonstrated that Bacillus megaterium KGA3 has potential as a biofertilizer to reduce the application of P fertilizers as well as increase crop productivity under severely saline–alkaline soils in semiarid regions. severely saline alkaline soil bpp gene Bacillus megaterium keystone taxa maize Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Full Text Additional Declarations Table are available in the Supplementary Files section. Supplementary Files Table.docx Supplementarymaterials.docx 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. 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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-6884528","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":473260309,"identity":"eeddd3fa-ffac-4e05-a9ad-a9289ebc64d1","order_by":0,"name":"Lijuan Jia","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Lijuan","middleName":"","lastName":"Jia","suffix":""},{"id":473260310,"identity":"d8834b18-2aca-4d96-9e83-3b2837d3d03b","order_by":1,"name":"Shengnan Zhang","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Shengnan","middleName":"","lastName":"Zhang","suffix":""},{"id":473260311,"identity":"52b1a184-0d6c-4c73-b2a5-01497f272fd9","order_by":2,"name":"Yuan Xu","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Yuan","middleName":"","lastName":"Xu","suffix":""},{"id":473260312,"identity":"a3324f7a-303a-4b3f-82ec-579335339c15","order_by":3,"name":"Xiangjian Tu","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Xiangjian","middleName":"","lastName":"Tu","suffix":""},{"id":473260313,"identity":"854723ae-7b54-44d2-8e12-45768ee6713d","order_by":4,"name":"Lei Ji","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAvUlEQVRIiWNgGAWjYBACxmbmBoYEIIOfmfnwAyK1MEK0SLazpRkQa08DmDI4z6MgQZQG5nbGxgcPag7bGx/mYTBgqLGJJsZhzQYJxw4nbjvMe+ABw7G03AYitLRJJDYcTjA7zJdgwNhwmCgt7T+AWuyNm3kMJIjV0sYA1MK4gZkELc0SCcfSE2ccBgZyAjF+Mew/fPDjjxpre/7+w4cffKixIUILREUzhJdASDkIyEOoOmLUjoJRMApGwUgFAPBvPzk0J42/AAAAAElFTkSuQmCC","orcid":"","institution":"Chinese Academy of Agricultural Sciences Grassland Research Institute","correspondingAuthor":true,"prefix":"","firstName":"Lei","middleName":"","lastName":"Ji","suffix":""}],"badges":[],"createdAt":"2025-06-13 04:35:56","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6884528/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6884528/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":85083849,"identity":"1cffccb9-be0c-4f03-b0af-79c0b3cc7fb5","added_by":"auto","created_at":"2025-06-20 18:37:18","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":247806,"visible":true,"origin":"","legend":"\u003cp\u003eBeta diversity analysis of the phosphorus-solubilizing bacterial community in the rhizosphere of maize with and without (CK) strain KGA3 inoculation in saline–alkaline soil.\u003c/p\u003e","description":"","filename":"Fig.1.png","url":"https://assets-eu.researchsquare.com/files/rs-6884528/v1/b1d66ca50129bab56bd238f2.png"},{"id":85083690,"identity":"64f4cdec-3f55-40d4-a395-c852b7d4f0fb","added_by":"auto","created_at":"2025-06-20 18:29:19","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":1177685,"visible":true,"origin":"","legend":"\u003cp\u003eRelative abundance of (a) phyla and (b) genera of phosphorus-solubilizing bacterial communities in the rhizosphere of maize with and without (CK) strain KGA3 inoculation in saline–alkaline soil.\u003c/p\u003e","description":"","filename":"Fig.2.png","url":"https://assets-eu.researchsquare.com/files/rs-6884528/v1/3a464aac79ed938e1e285e0a.png"},{"id":85083692,"identity":"998d0d38-e0d4-405a-8a81-34b49bba7445","added_by":"auto","created_at":"2025-06-20 18:29:19","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":201271,"visible":true,"origin":"","legend":"\u003cp\u003eWilcoxon test of differences in proportions of genera in phosphorus-solubilizing bacterial\u003c/p\u003e\n\u003cp\u003ecommunities in the rhizosphere of maize with and without (CK) strain KGA3 inoculation in saline–alkaline soil. *0.01 \u0026lt; P ≤ 0.05 and **0.001 \u0026lt; P ≤ 0.01 at 99.9% confidence intervals.\u003c/p\u003e","description":"","filename":"Fig.3.png","url":"https://assets-eu.researchsquare.com/files/rs-6884528/v1/f97ad3f5b1c5c5d52cc93ecc.png"},{"id":85083695,"identity":"d6bd4edc-3573-4e75-b6cf-65aaae7a86f3","added_by":"auto","created_at":"2025-06-20 18:29:19","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":1168617,"visible":true,"origin":"","legend":"\u003cp\u003eCo-occurrence network analysis of phosphorus-solubilizing bacterial communities in the rhizosphere of maize in saline–alkaline soil under (a) CK (without KGA3 inoculation) and (b) KGA3\u003c/p\u003e\n\u003cp\u003einoculation.\u003c/p\u003e","description":"","filename":"Fig.4.png","url":"https://assets-eu.researchsquare.com/files/rs-6884528/v1/deb1f568a7ce6f9672b128ae.png"},{"id":85083694,"identity":"5d78c475-f76e-47c3-bf15-76722003fd66","added_by":"auto","created_at":"2025-06-20 18:29:19","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":268416,"visible":true,"origin":"","legend":"\u003cp\u003eRedundancy analysis (RDA) of the effects of keystone taxa in phosphorus-solubilizing bacterial\u003c/p\u003e\n\u003cp\u003ecommunities on soil attributes in the rhizosphere of maize with strain KGA3 inoculation and without\u003c/p\u003e\n\u003cp\u003e(CK) in saline–alkaline soil. MBN, microbial biomass nitrogen; MBC, microbial biomass carbon; SOM, soil organic matter; AN, available nitrogen; AP, available phosphorus; AK, available potassium; EC, electrical conductivity.\u0026nbsp;\u003c/p\u003e","description":"","filename":"Fig.5.png","url":"https://assets-eu.researchsquare.com/files/rs-6884528/v1/dede57d7aa45b4aaed0cff82.png"},{"id":91892872,"identity":"e9367b8b-c2f0-45da-9b60-d765694401a8","added_by":"auto","created_at":"2025-09-22 16:54:04","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":877117,"visible":true,"origin":"","legend":"","description":"","filename":"Manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6884528/v1_covered_be186f41-8170-4893-87d1-ea2239c59c87.pdf"},{"id":85083688,"identity":"132bed3e-0af2-4c1d-9968-d9e1625cf21f","added_by":"auto","created_at":"2025-06-20 18:29:18","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":18064,"visible":true,"origin":"","legend":"","description":"","filename":"Table.docx","url":"https://assets-eu.researchsquare.com/files/rs-6884528/v1/165fcad7edb51c4a3f6deec2.docx"},{"id":85083850,"identity":"7c78f5fe-6118-4917-9dbd-eb157c32b1e5","added_by":"auto","created_at":"2025-06-20 18:37:19","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":14773,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementarymaterials.docx","url":"https://assets-eu.researchsquare.com/files/rs-6884528/v1/1208d0e19677f6092bcc4c9c.docx"}],"financialInterests":"\u003cp\u003eTable are available in the Supplementary Files section.\u003c/p\u003e","formattedTitle":"\u003cp\u003e\u003cem\u003eBacillus megaterium\u003c/em\u003e strain KGA3 increases saline–alkaline tolerance of maize by recruiting keystone taxa in rhizosphere soil\u003c/p\u003e","fulltext":[],"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":true,"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":"severely saline, alkaline soil, bpp gene, Bacillus megaterium, keystone taxa, maize","lastPublishedDoi":"10.21203/rs.3.rs-6884528/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6884528/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eBackground and Aims\u0026nbsp;\u0026nbsp;Available phosphorus (AP) deficiency in severely saline–alkaline soil adversely affects crop growth. To increase soil AP and promote crop growth, a phosphorus-solubilizing bacteria (PSB) named KGA3, which is a strain of Bacillus megaterium, was inoculated on maize.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eMethods\u0026nbsp;\u0026nbsp;A field experiment was conducted with CK and KGA3 treatment. Co-occurrence network (CoNet) was constructed to identify the keystone taxa, and redundancy analysis (RDA) was carried out to explore the relationships between keystone taxa and soil properties under different treatments\u0026nbsp;to reveal the mechanism by which strain KGA3 promotes crop growth.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eResults\u0026nbsp;\u0026nbsp;Inoculation with KGA3 significantly increased contents of soil available nitrogen and potassium, activities of dehydrogenase and protease enzymes, and contents of the soil ions water-soluble K+, water-soluble Ca2+, and SO42–. According to co-occurrence networks, PSB community structure was stable with KGA3 treatment. In addition, KGA3 recruited beneficial keystone taxa such as Cyanobacteria to increase soil AP and promote maize growth.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eConclusion\u0026nbsp;\u0026nbsp;We demonstrated that Bacillus\u0026nbsp;megaterium KGA3 has potential as a biofertilizer to reduce the application of P fertilizers as well as increase crop productivity under severely saline–alkaline soils in semiarid regions.\u003c/p\u003e","manuscriptTitle":"Bacillus megaterium strain KGA3 increases saline–alkaline tolerance of maize by recruiting keystone taxa in rhizosphere soil","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-06-20 18:29:14","doi":"10.21203/rs.3.rs-6884528/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":"09a2325f-db53-4005-8e4f-ef8c399203ce","owner":[],"postedDate":"June 20th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-09-22T16:45:52+00:00","versionOfRecord":[],"versionCreatedAt":"2025-06-20 18:29:14","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6884528","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6884528","identity":"rs-6884528","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}