{"doi":"10.1038/s41586-021-03976-4","title":"TMK-based cell-surface auxin signalling activates cell-wall acidification","abstract":"Abstract The phytohormone auxin controls many processes in plants, at least in part through its regulation of cell expansion 1 . The acid growth hypothesis has been proposed to explain auxin-stimulated cell expansion for five decades, but the mechanism that underlies auxin-induced cell-wall acidification is poorly characterized. Auxin induces the phosphorylation and activation of the plasma membrane H + -ATPase that pumps protons into the apoplast 2 , yet how auxin activates its phosphorylation remains unclear. Here we show that the transmembrane kinase (TMK) auxin-signalling proteins interact with plasma membrane H + -ATPases, inducing their phosphorylation, and thereby promoting cell-wall acidification and hypocotyl cell elongation in Arabidopsis . Auxin induced interactions between TMKs and H + -ATPases in the plasma membrane within seconds, as well as TMK-dependent phosphorylation of the penultimate threonine residue on the H+-ATPases. Our genetic, biochemical and molecular evidence demonstrates that TMKs directly phosphorylate plasma membrane H + -ATPase and are required for auxin-induced H + -ATPase activation, apoplastic acidification and cell expansion. Thus, our findings reveal a crucial connection between auxin and plasma membrane H + -ATPase activation in regulating apoplastic pH changes and cell expansion through TMK-based cell surface auxin signalling.","journal":"Nature","year":2021,"id":145906,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":290,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9523,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":619249,"name":"Xiang Zhou","orcid":"0000-0001-7848-367X","position":1,"is_corresponding":false},{"id":619250,"name":"Wenxin Tang","orcid":"0000-0002-7221-7685","position":2,"is_corresponding":false},{"id":619251,"name":"Koji Takahashi","orcid":"0000-0001-5438-7624","position":3,"is_corresponding":false},{"id":619252,"name":"Xue Pan","orcid":"0000-0001-9415-8316","position":4,"is_corresponding":false},{"id":620012,"name":"Jiawei Dai","orcid":null,"position":5,"is_corresponding":false},{"id":578777,"name":"Hong Yu Ren","orcid":"0000-0002-8402-0468","position":6,"is_corresponding":false},{"id":499396,"name":"Xiaoyue Zhu","orcid":"0000-0002-7308-6584","position":7,"is_corresponding":false},{"id":77568,"name":"Songqin Pan","orcid":null,"position":8,"is_corresponding":false},{"id":399850,"name":"Haiyan Zheng","orcid":"0000-0003-1955-1817","position":9,"is_corresponding":false},{"id":233103,"name":"William M. Gray","orcid":"0000-0002-1320-290X","position":10,"is_corresponding":false},{"id":619253,"name":"Tongda Xu","orcid":"0000-0003-3398-9217","position":11,"is_corresponding":false},{"id":619254,"name":"Toshinori Kinoshita","orcid":"0000-0001-7621-1259","position":12,"is_corresponding":false},{"id":619255,"name":"Zhenbiao Yang","orcid":"0000-0001-7482-6540","position":13,"is_corresponding":false},{"id":619248,"name":"Wenwei Lin","orcid":"0000-0003-0098-6386","position":0,"is_corresponding":true}],"reference_count":52,"raw_metadata":null,"created_at":"2026-07-18T23:42:12.871665Z","pmid":"34707287","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}