{"_id":"23174","oa_version":"Preprint","year":"2025","type":"preprint","language":[{"iso":"eng"}],"acknowledgement":"We gratefully acknowledge Dr. Andrea Bleckmann, creator of pBLAX000 vector and Dr. Shiqiang Gao for donation of template used in XXM-ER cloning. This research was supported by the Laboratory Support Facility, the Plant Facility, the IT Facility and the Imaging and Optical Facility of the Institute of Science and Technology Austria. The graphical elements used in Fig. 5 were adapted and modified from Servier, https://smart.servier.com, and are used under CC BY 3.0 licence. The authors acknowledge the use of AI-tools (Microsoft Copilot, Gemini) for language refinement. All content was critically reviewed by authors.\r\n\r\nFunder Information Declared\r\nEuropean Research Council, 101142681 CYNIPS\r\nAustrian Science Fund, P 37051-B","title":"Cytosolic Ca2+ as a universal signal for rapid root growth regulation","day":"17","publication":"bioRxiv","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","tmp":{"name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","short":"CC BY (4.0)"},"related_material":{"record":[{"status":"for_moderation","id":"23145","relation":"dissertation_contains"}]},"corr_author":"1","fulldoi":"https://doi.org/10.1101/2025.10.17.683082","date_published":"2025-10-17T00:00:00Z","oa":1,"department":[{"_id":"JiFr"}],"biorxivid":1,"main_file_link":[{"url":"https://doi.org/10.1101/2025.10.17.683082","open_access":"1"}],"article_processing_charge":"No","abstract":[{"text":"Roots must continuously adapt their growth and have evolved the ability to rapidly respond to diverse environmental and hormonal cues, including the phytohormone auxin. Auxin-induced cellular responses involve membrane depolarization, cytosolic calcium (Ca²⁺) elevation, and extracellular pH increase, but how these processes lead to rapid growth regulation remains unclear. Here, we show that cytosolic Ca²⁺ acts as a universal signal integrating diverse cues for rapid regulation of root growth. Using live imaging, microfluidics, and optogenetics in Arabidopsis, we demonstrate that a swift rise in cytosolic Ca²⁺ is the primary target of auxin signaling affecting growth inhibition. Disruption of Ca²⁺ influx abolishes these responses, whereas light-gated Ca²⁺ influx from the apoplast or endoplasmic reticulum stores inhibits growth. Multiple unrelated stimuli—including auxin, extracellular ATP, RALF peptides, and hydrogen peroxide—converge on this Ca²⁺-dependent mechanism. Cytosolic Ca²⁺ elevation thus represents a necessary and sufficient step for rapid growth inhibition, revealing a unifying principle of root signaling.","lang":"eng"}],"doi":"10.1101/2025.10.17.683082","author":[{"first_name":"Marek","full_name":"Randuch, Marek","last_name":"Randuch","id":"6ac4636d-15b2-11ec-abd3-fb8df79972ae"},{"full_name":"Kulich, Ivan","first_name":"Ivan","last_name":"Kulich","id":"57a1567c-8314-11eb-9063-c9ddc3451a54"},{"last_name":"Vladimirtsev","id":"60466724-5355-11ee-ae5a-fa55e8f99c3d","first_name":"Dmitrii","full_name":"Vladimirtsev, Dmitrii"},{"last_name":"Huang","first_name":"Shouguang","full_name":"Huang, Shouguang"},{"full_name":"Hedrich, Rainer","first_name":"Rainer","last_name":"Hedrich"},{"last_name":"Friml","id":"4159519E-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-8302-7596","full_name":"Friml, Jiří","first_name":"Jiří"}],"citation":{"short":"M. Randuch, I. Kulich, D. Vladimirtsev, S. Huang, R. Hedrich, J. Friml, BioRxiv (n.d.).","ista":"Randuch M, Kulich I, Vladimirtsev D, Huang S, Hedrich R, Friml J. Cytosolic Ca2+ as a universal signal for rapid root growth regulation. bioRxiv, <a href=\"https://doi.org/10.1101/2025.10.17.683082\">10.1101/2025.10.17.683082</a>.","chicago":"Randuch, Marek, Ivan Kulich, Dmitrii Vladimirtsev, Shouguang Huang, Rainer Hedrich, and Jiří Friml. “Cytosolic Ca2+ as a Universal Signal for Rapid Root Growth Regulation.” <i>BioRxiv</i>, n.d. <a href=\"https://doi.org/10.1101/2025.10.17.683082\">https://doi.org/10.1101/2025.10.17.683082</a>.","ama":"Randuch M, Kulich I, Vladimirtsev D, Huang S, Hedrich R, Friml J. Cytosolic Ca2+ as a universal signal for rapid root growth regulation. <i>bioRxiv</i>. doi:<a href=\"https://doi.org/10.1101/2025.10.17.683082\">10.1101/2025.10.17.683082</a>","ieee":"M. Randuch, I. Kulich, D. Vladimirtsev, S. Huang, R. Hedrich, and J. Friml, “Cytosolic Ca2+ as a universal signal for rapid root growth regulation,” <i>bioRxiv</i>. .","apa":"Randuch, M., Kulich, I., Vladimirtsev, D., Huang, S., Hedrich, R., &#38; Friml, J. (n.d.). Cytosolic Ca2+ as a universal signal for rapid root growth regulation. <i>bioRxiv</i>. <a href=\"https://doi.org/10.1101/2025.10.17.683082\">https://doi.org/10.1101/2025.10.17.683082</a>","mla":"Randuch, Marek, et al. “Cytosolic Ca2+ as a Universal Signal for Rapid Root Growth Regulation.” <i>BioRxiv</i>, doi:<a href=\"https://doi.org/10.1101/2025.10.17.683082\">10.1101/2025.10.17.683082</a>."},"OA_place":"repository","status":"public","date_created":"2026-10-19T11:44:48Z","OA_type":"green","external_id":{"biorxivid":["10.1101/2025.10.17.683082"]},"month":"10","project":[{"name":"Cyclic nucleotides as second messengers in plants","grant_number":"101142681","_id":"8f347782-16d5-11f0-9cad-8c19706ee739"},{"name":"Guanylate cyclase activity of TIR1/AFBs auxin receptors","grant_number":"P37051","_id":"7bcece63-9f16-11ee-852c-ae94e099eeb6"}],"date_updated":"2026-10-19T12:49:25Z","publication_status":"draft"}