--- _id: '6259' abstract: - lang: eng text: The plant hormone auxin has crucial roles in almost all aspects of plant growth and development. Concentrations of auxin vary across different tissues, mediating distinct developmental outcomes and contributing to the functional diversity of auxin. However, the mechanisms that underlie these activities are poorly understood. Here we identify an auxin signalling mechanism, which acts in parallel to the canonical auxin pathway based on the transport inhibitor response1 (TIR1) and other auxin receptor F-box (AFB) family proteins (TIR1/AFB receptors)1,2, that translates levels of cellular auxin to mediate differential growth during apical-hook development. This signalling mechanism operates at the concave side of the apical hook, and involves auxin-mediated C-terminal cleavage of transmembrane kinase 1 (TMK1). The cytosolic and nucleus-translocated C terminus of TMK1 specifically interacts with and phosphorylates two non-canonical transcriptional repressors of the auxin or indole-3-acetic acid (Aux/IAA) family (IAA32 and IAA34), thereby regulating ARF transcription factors. In contrast to the degradation of Aux/IAA transcriptional repressors in the canonical pathway, the newly identified mechanism stabilizes the non-canonical IAA32 and IAA34 transcriptional repressors to regulate gene expression and ultimately inhibit growth. The auxin–TMK1 signalling pathway originates at the cell surface, is triggered by high levels of auxin and shares a partially overlapping set of transcription factors with the TIR1/AFB signalling pathway. This allows distinct interpretations of different concentrations of cellular auxin, and thus enables this versatile signalling molecule to mediate complex developmental outcomes. article_processing_charge: No article_type: original author: - first_name: Min full_name: Cao, Min last_name: Cao - first_name: Rong full_name: Chen, Rong last_name: Chen - first_name: Pan full_name: Li, Pan last_name: Li - first_name: Yongqiang full_name: Yu, Yongqiang last_name: Yu - first_name: Rui full_name: Zheng, Rui last_name: Zheng - first_name: Danfeng full_name: Ge, Danfeng last_name: Ge - first_name: Wei full_name: Zheng, Wei last_name: Zheng - first_name: Xuhui full_name: Wang, Xuhui last_name: Wang - first_name: Yangtao full_name: Gu, Yangtao last_name: Gu - first_name: Zuzana full_name: Gelová, Zuzana id: 0AE74790-0E0B-11E9-ABC7-1ACFE5697425 last_name: Gelová orcid: 0000-0003-4783-1752 - first_name: Jiří full_name: Friml, Jiří id: 4159519E-F248-11E8-B48F-1D18A9856A87 last_name: Friml orcid: 0000-0002-8302-7596 - first_name: Heng full_name: Zhang, Heng last_name: Zhang - first_name: Renyi full_name: Liu, Renyi last_name: Liu - first_name: Jun full_name: He, Jun last_name: He - first_name: Tongda full_name: Xu, Tongda last_name: Xu citation: ama: Cao M, Chen R, Li P, et al. TMK1-mediated auxin signalling regulates differential growth of the apical hook. Nature. 2019;568:240-243. doi:10.1038/s41586-019-1069-7 apa: Cao, M., Chen, R., Li, P., Yu, Y., Zheng, R., Ge, D., … Xu, T. (2019). TMK1-mediated auxin signalling regulates differential growth of the apical hook. Nature. Springer Nature. https://doi.org/10.1038/s41586-019-1069-7 chicago: Cao, Min, Rong Chen, Pan Li, Yongqiang Yu, Rui Zheng, Danfeng Ge, Wei Zheng, et al. “TMK1-Mediated Auxin Signalling Regulates Differential Growth of the Apical Hook.” Nature. Springer Nature, 2019. https://doi.org/10.1038/s41586-019-1069-7. ieee: M. Cao et al., “TMK1-mediated auxin signalling regulates differential growth of the apical hook,” Nature, vol. 568. Springer Nature, pp. 240–243, 2019. ista: Cao M, Chen R, Li P, Yu Y, Zheng R, Ge D, Zheng W, Wang X, Gu Y, Gelová Z, Friml J, Zhang H, Liu R, He J, Xu T. 2019. TMK1-mediated auxin signalling regulates differential growth of the apical hook. Nature. 568, 240–243. mla: Cao, Min, et al. “TMK1-Mediated Auxin Signalling Regulates Differential Growth of the Apical Hook.” Nature, vol. 568, Springer Nature, 2019, pp. 240–43, doi:10.1038/s41586-019-1069-7. short: M. Cao, R. Chen, P. Li, Y. Yu, R. Zheng, D. Ge, W. Zheng, X. Wang, Y. Gu, Z. Gelová, J. Friml, H. Zhang, R. Liu, J. He, T. Xu, Nature 568 (2019) 240–243. date_created: 2019-04-09T08:37:05Z date_published: 2019-04-11T00:00:00Z date_updated: 2023-09-05T14:58:41Z day: '11' ddc: - '580' department: - _id: JiFr doi: 10.1038/s41586-019-1069-7 ec_funded: 1 external_id: isi: - '000464412700050' pmid: - '30944466' file: - access_level: open_access checksum: 6b84ab602a34382cf0340a37a1378c75 content_type: application/pdf creator: dernst date_created: 2020-11-13T07:37:41Z date_updated: 2020-11-13T07:37:41Z file_id: '8751' file_name: 2019_Nature _Cao_accepted.pdf file_size: 4321328 relation: main_file success: 1 file_date_updated: 2020-11-13T07:37:41Z has_accepted_license: '1' intvolume: ' 568' isi: 1 language: - iso: eng month: '04' oa: 1 oa_version: Submitted Version page: 240-243 pmid: 1 project: - _id: 261099A6-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '742985' name: Tracing Evolution of Auxin Transport and Polarity in Plants publication: Nature publication_identifier: eissn: - 1476-4687 issn: - 0028-0836 publication_status: published publisher: Springer Nature quality_controlled: '1' related_material: link: - description: News on IST Homepage relation: press_release url: https://ist.ac.at/en/news/newly-discovered-mechanism-of-plant-hormone-auxin-acts-the-opposite-way/ scopus_import: '1' status: public title: TMK1-mediated auxin signalling regulates differential growth of the apical hook type: journal_article user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1 volume: 568 year: '2019' ...