Functional potential of the APETALA2 transcription factors StAP2-13/18 in modulating tuberization under long-day (LD) conditions in potato

Functional potential of the APETALA2 transcription factors StAP2-13/18 in modulating tuberization under long-day (LD) conditions in potato | 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 Functional potential of the APETALA2 transcription factors StAP2-13/18 in modulating tuberization under long-day (LD) conditions in potato Zefeng Zhai, Haicai Li, Jinfu Lv, Yongguang Liu, Honglian Gu, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9101945/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 21 You are reading this latest preprint version Abstract Background Tuberization represents the most critical biological process during the growth and development of potato ( Solanum tuberosum L.), as it directly dictates the final yield and quality of the crop. The APETALA2 (AP2) family of transcription factors (TFs) serves as key regulators of plant development, orchestrating diverse processes including organogenesis, hormone signaling, and environmental adaptation. Nevertheless, the precise functions of StAP2 genes in potato tuberization remain elusive, limiting our understanding of the molecular regulatory network underlying this agriculturally important trait. Results A total of 18 StAP2 genes, designated StAP2-1 to StAP2-18 according to their chromosomal positions in the potato genome, were identified. Herein, we present a comprehensive genome-wide systematic analysis of these StAP2 genes, encompassing their phylogenetic relationships, conserved motif characteristics, and tuberization-related expression profiles. Our expression data demonstrated that StAP2-13 and StAP2-18 are most likely involved in potato tuberization, as evidenced by their marked upregulation in tuberization-related leaves and developing tubers, respectively. In addition, both StAP2 genes exhibit distinct circadian rhythmic expression patterns - a regulatory feature known to modulate potato tuberization via crosstalk with photoperiod signaling. Yeast two-hybrid experiment verified that StAP2-13 and StAP2-18 physically interact with the key tuberization regulatory factor StCDF1. Furthermore, yeast one-hybrid experiment and dual-luciferase reporter assays confirmed that StAP2-13 and StAP2-18 directly bind to the promoter of the tuber-inducing gene StSP6A and activate its transcriptional activity. More importantly, transgenic overexpression of StAP2-13 or StAP2-18 markedly promoted tuber initiation in potato plants under long-day conditions, a non-favorable photoperiod for tuberization in most potato cultivars. Conclusions These results provide a comprehensive genome-wide characterization of the StAP2 gene family in potato, and identify StAP2-13 and StAP2-18 as promising candidate targets for genetic improvement of tuberization-related traits in potato, particularly for enhancing productivity under long-day growing environments. Potato AP2 Tuberization Photoperiod Overexpression Long-day condition Full Text Additional Declarations No competing interests reported. Supplementary Files Supplementarymaterial.rar Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 14 Apr, 2026 Reviews received at journal 13 Apr, 2026 Reviewers agreed at journal 12 Apr, 2026 Reviewers agreed at journal 10 Apr, 2026 Reviewers agreed at journal 10 Apr, 2026 Reviewers agreed at journal 10 Apr, 2026 Reviewers agreed at journal 10 Apr, 2026 Reviewers agreed at journal 10 Apr, 2026 Reviewers agreed at journal 10 Apr, 2026 Reviews received at journal 10 Apr, 2026 Reviews received at journal 08 Apr, 2026 Reviewers agreed at journal 30 Mar, 2026 Reviewers agreed at journal 25 Mar, 2026 Reviewers agreed at journal 25 Mar, 2026 Reviewers agreed at journal 23 Mar, 2026 Reviewers agreed at journal 23 Mar, 2026 Reviewers invited by journal 23 Mar, 2026 Editor invited by journal 17 Mar, 2026 Editor assigned by journal 15 Mar, 2026 Submission checks completed at journal 15 Mar, 2026 First submitted to journal 12 Mar, 2026 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. 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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-9101945","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":610904999,"identity":"e9bbfdd2-3a01-4300-bfe8-02906b7f1f12","order_by":0,"name":"Zefeng Zhai","email":"","orcid":"","institution":"Weifang University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Zefeng","middleName":"","lastName":"Zhai","suffix":""},{"id":610905001,"identity":"ce686a1e-8c42-453f-96ea-5a352b3f8e1e","order_by":1,"name":"Haicai Li","email":"","orcid":"","institution":"Agricultural Genomics Institute at Shenzhen, Chinese 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potato","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"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":"bmc-genomics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"gics","sideBox":"Learn more about [BMC Genomics](http://bmcgenomics.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/gics","title":"BMC Genomics","twitterHandle":"#BMCGenomics","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Potato, AP2, Tuberization, Photoperiod, Overexpression, Long-day condition","lastPublishedDoi":"10.21203/rs.3.rs-9101945/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9101945/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eTuberization represents the most critical biological process during the growth and development of potato (\u003cem\u003eSolanum tuberosum\u003c/em\u003e L.), as it directly dictates the final yield and quality of the crop. The APETALA2 (AP2) family of transcription factors (TFs) serves as key regulators of plant development, orchestrating diverse processes including organogenesis, hormone signaling, and environmental adaptation. Nevertheless, the precise functions of \u003cem\u003eStAP2\u003c/em\u003e genes in potato tuberization remain elusive, limiting our understanding of the molecular regulatory network underlying this agriculturally important trait.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eA total of 18 \u003cem\u003eStAP2\u003c/em\u003e genes, designated \u003cem\u003eStAP2-1\u003c/em\u003e to \u003cem\u003eStAP2-18\u003c/em\u003e according to their chromosomal positions in the potato genome, were identified. Herein, we present a comprehensive genome-wide systematic analysis of these \u003cem\u003eStAP2\u003c/em\u003e genes, encompassing their phylogenetic relationships, conserved motif characteristics, and tuberization-related expression profiles. Our expression data demonstrated that \u003cem\u003eStAP2-13\u003c/em\u003e and \u003cem\u003eStAP2-18\u003c/em\u003e are most likely involved in potato tuberization, as evidenced by their marked upregulation in tuberization-related leaves and developing tubers, respectively. In addition, both \u003cem\u003eStAP2\u003c/em\u003e genes exhibit distinct circadian rhythmic expression patterns - a regulatory feature known to modulate potato tuberization via crosstalk with photoperiod signaling. Yeast two-hybrid experiment verified that StAP2-13 and StAP2-18 physically interact with the key tuberization regulatory factor StCDF1. Furthermore, yeast one-hybrid experiment and dual-luciferase reporter assays confirmed that StAP2-13 and StAP2-18 directly bind to the promoter of the tuber-inducing gene \u003cem\u003eStSP6A\u003c/em\u003e and activate its transcriptional activity. 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