Water relations may account for the premature death of the species Tachigali vulgaris L.F. Gomes da Silva & H.C. Lima

Water relations may account for the premature death of the species Tachigali vulgaris L.F. Gomes da Silva & H.C. Lima | 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 Case Report Water relations may account for the premature death of the species Tachigali vulgaris L.F. Gomes da Silva & H.C. Lima Adler Salomon, Francisco de Almeida Lobo, Ana Paula de Souza Caetano, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6430507/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 Tachigali vulgaris is a fast-growing pioneer tree species with a short lifespan, yet the causes behind its premature death remain unclear. Over the past decade, the Brazilian Cerrado has faced recurrent droughts, intensifying die-off events of this species. This study aimed to investigate physiological traits related to water relations to identify potential factors contributing to its decline. During the dry season, T. vulgaris maintained high leaf hydraulic conductivity 7.10 mmol m² s⁻¹ MPa⁻¹, similar to that observed in the rainy season 8.02 mmol m² s⁻¹ MPa⁻¹, due to a consistent transpiration rate. However, this persistence led to a significant drop in water potential in both leaves -2.31 MPa and stems -2.10 MPa, approaching the osmotic potential at incipient plasmolysis -2.36 MPa, suggesting an imminent risk of internal water stress. Despite this, cells did not collapse thanks to the high elasticity of their walls, volumetric elastic modulus of 3.01 MPa, allowing the maintenance of positive turgor pressure and a high relative water content 79.95% at plasmolysis. The species also showed remarkable thermotolerance: the maximum quantum yield of Photosystem II ( Fv/Fm ) remained high up to 36.97°C, with critical thresholds reached only below 8.69°C or above 65.26°C. Dark respiration followed a similar pattern, peaking at 36.66°C and decreasing by 50% at temperatures below 18.52°C or above 54.79°C. Nonetheless, persistent transpiration during drought, combined with high hydraulic conductivity, may increase the likelihood of xylem cavitation and hydraulic failure. While T. vulgaris displays strong heat tolerance, these traits alone may not be enough to withstand the increasing frequency and severity of droughts. Further research is needed to determine whether its high hydraulic conductivity plays a central role in its vulnerability and premature mortality. bulk elasticity modulus hydraulic conductivity osmotic potential relative water content water potential Full Text Additional Declarations No competing interests reported. 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-6430507","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":464761398,"identity":"64950a3e-de79-4515-84e1-05866e8cbc07","order_by":0,"name":"Adler Salomon","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA/ElEQVRIiWNgGAWjYFCC5AYwxQcmKyBiH4A4AbeWRIgWNjB5BkwyzgBqIFILYxsRWvjbExsfVzDUybOxdyc+LpxXJ2dwgMew6eYPhjzzBuxaJM48bDY8w3DYsI3n7GbjmdsOG4O0NOckMBTLHMBhzY3ENskGhgOMbRK526R5tx1I3HCAx/wxUEviDBw65G8ktv9sYKizh2iZUwfSArYFpxYDoC2MDQzMiRAtDcyEtRgC/SLZYHA4GewXnmOHjSUPsxU256RJFEvg0CJ3PPngx4aKOtt+9t6Nj3lq6uT4jjdvbM6xscnDpQXqPGQOM5jEr2EUjIJRMApGAX4AACckWWBOxXYTAAAAAElFTkSuQmCC","orcid":"","institution":"Federal University of Mato Grosso","correspondingAuthor":true,"prefix":"","firstName":"Adler","middleName":"","lastName":"Salomon","suffix":""},{"id":464761399,"identity":"acdf61a7-2887-43b5-91f9-8b786dbc1b2a","order_by":1,"name":"Francisco de Almeida Lobo","email":"","orcid":"","institution":"Federal University of Mato Grosso","correspondingAuthor":false,"prefix":"","firstName":"Francisco","middleName":"de Almeida","lastName":"Lobo","suffix":""},{"id":464761400,"identity":"adbbcf68-374a-4859-a0b3-97d852c0d4d4","order_by":2,"name":"Ana Paula de Souza Caetano","email":"","orcid":"","institution":"Federal University of Mato Grosso","correspondingAuthor":false,"prefix":"","firstName":"Ana","middleName":"Paula de Souza","lastName":"Caetano","suffix":""},{"id":464761401,"identity":"25830571-572d-4ec9-aa08-dc35d4ada36e","order_by":3,"name":"Carmen Eugenia Rodríguez Ortíz","email":"","orcid":"","institution":"Federal University of Mato Grosso","correspondingAuthor":false,"prefix":"","firstName":"Carmen","middleName":"Eugenia Rodríguez","lastName":"Ortíz","suffix":""},{"id":464761402,"identity":"26e3511f-5f59-48db-9d72-507955746a10","order_by":4,"name":"Cyro Matheus Cometti Favalessa","email":"","orcid":"","institution":"Federal University of Mato Grosso","correspondingAuthor":false,"prefix":"","firstName":"Cyro","middleName":"Matheus Cometti","lastName":"Favalessa","suffix":""},{"id":464761403,"identity":"f14e217c-be27-41c0-9b01-5126ec0666a2","order_by":5,"name":"Mario Tommasiello Filho","email":"","orcid":"","institution":"University of São Paulo (USP), Luiz de Queiroz College of Agriculture","correspondingAuthor":false,"prefix":"","firstName":"Mario","middleName":"Tommasiello","lastName":"Filho","suffix":""}],"badges":[],"createdAt":"2025-04-11 18:23:10","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6430507/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6430507/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":91074080,"identity":"592f3d02-1c54-4723-bc8c-6baed0a3bb45","added_by":"auto","created_at":"2025-09-11 11:02:10","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":660730,"visible":true,"origin":"","legend":"","description":"","filename":"Salomonetal.2025RevisedManuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6430507/v1_covered_afcd1a85-0c8c-462e-a22e-e1562a70903b.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Water relations may account for the premature death of the species Tachigali vulgaris L.F. Gomes da Silva \u0026 H.C. Lima","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":"bulk elasticity modulus, hydraulic conductivity, osmotic potential, relative water content, water potential","lastPublishedDoi":"10.21203/rs.3.rs-6430507/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6430507/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cem\u003eTachigali vulgaris\u003c/em\u003e is a fast-growing pioneer tree species with a short lifespan, yet the causes behind its premature death remain unclear. Over the past decade, the Brazilian Cerrado has faced recurrent droughts, intensifying die-off events of this species. This study aimed to investigate physiological traits related to water relations to identify potential factors contributing to its decline. During the dry season, \u003cem\u003eT. vulgaris\u003c/em\u003e maintained high leaf hydraulic conductivity 7.10 mmol m² s⁻¹ MPa⁻¹, similar to that observed in the rainy season 8.02 mmol m² s⁻¹ MPa⁻¹, due to a consistent transpiration rate. However, this persistence led to a significant drop in water potential in both leaves -2.31 MPa and stems -2.10 MPa, approaching the osmotic potential at incipient plasmolysis -2.36 MPa, suggesting an imminent risk of internal water stress. Despite this, cells did not collapse thanks to the high elasticity of their walls, volumetric elastic modulus of 3.01 MPa, allowing the maintenance of positive turgor pressure and a high relative water content 79.95% at plasmolysis. \u0026nbsp;The species also showed remarkable thermotolerance: the maximum quantum yield of Photosystem II (\u003cem\u003eFv/Fm\u003c/em\u003e) remained high up to 36.97°C, with critical thresholds reached only below 8.69°C or above 65.26°C. Dark respiration followed a similar pattern, peaking at 36.66°C and decreasing by 50% at temperatures below 18.52°C or above 54.79°C. Nonetheless, persistent transpiration during drought, combined with high hydraulic conductivity, may increase the likelihood of xylem cavitation and hydraulic failure. While \u003cem\u003eT. vulgaris\u003c/em\u003e displays strong heat tolerance, these traits alone may not be enough to withstand the increasing frequency and severity of droughts. Further research is needed to determine whether its high hydraulic conductivity plays a central role in its vulnerability and premature mortality.\u003c/p\u003e","manuscriptTitle":"Water relations may account for the premature death of the species Tachigali vulgaris L.F. Gomes da Silva \u0026amp; H.C. Lima","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-06-02 10:09:55","doi":"10.21203/rs.3.rs-6430507/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":"344e2258-c9fa-47b8-90d4-7d70464644b0","owner":[],"postedDate":"June 2nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-09-11T10:53:53+00:00","versionOfRecord":[],"versionCreatedAt":"2025-06-02 10:09:55","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6430507","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6430507","identity":"rs-6430507","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}