000K utf8 1100 2025$c2025-09-09 1500 eng 2050 urn:nbn:de:gbv:27-dbt-67730-5 2051 10.1111/tpj.70459 3000 Körber, Karl Ludwig 3010 Barth, Emanuel 3010 Dorfner, Maja 3010 Feistel, Felix 3010 Furch, Alexandra C. U. 3010 Klein, Jan 3010 Munkert, Jennifer 3010 Oklestkova, Jana 3010 Oktay, Ceren 3010 Oppermann, Henk 3010 Paul, Sudip 3010 Strnad, Miroslav 4000 Progestogens and androgens influence root morphology of angiosperms in a brassinosteroid‐independent manner [Körber, Karl Ludwig] 4060 25 Seiten 4209 Significance Statement Plants produce progesterone and androgens, which alter root morphology in A. thaliana and 60% of tested angiosperms. Brassinosteroids seem uninvolved. Understanding the mechanism is like navigating an unknown city—exemplarily Dittelbrunn (a small village in Bavaria)—where the expected shortcut (interaction with brassinosteroids) is blocked, requiring a longer scientific route. image Brassinosteroids are well‐characterised phytohormones involved in plant growth, yet plants also synthesise other steroids such as progestogens and androgens, whose physiological roles remain largely unknown. Here, we demonstrate for the first time that exogenous progesterone and testosterone alter root morphology in Arabidopsis thaliana and various angiosperms, independently of brassinosteroid biosynthesis or signalling. These findings prompt a reconsideration of the functional relevance of non‐canonical plant steroids and lay the foundation for future investigations into their biological significance. 4209 SUMMARY Progestogens and androgens are steroids found in a wide range of plants, but little is known about their physiological functions. In this study, we sowed seeds of angiosperms on progestogen‐ and androgen‐containing medium and analysed their morphological effects. We further investigated the effects of progesterone and testosterone on brassinosteroid profiles and gene expression in A. thaliana . Additionally, we examined the effects of progesterone and testosterone on A. thaliana plants overexpressing the steroid 5α‐reductase DET2. We found that progestogens and androgens have strong negative effects on root length, especially in Brassicaceae species. In addition, these steroids led to uncoordinated cell growth and increased lateral root formation. We failed to detect an effect on endogenous brassinosteroid levels and gene expression of brassinosteroid‐regulated genes. The overexpression of DET2 led to increased root growth, but the effects of progesterone and testosterone were not reduced. We conclude that progestogens and androgens act in a brassinosteroid‐independent manner. This suggests that progestogens and androgens could represent a potential new class of plant steroid signalling molecules. 4950 https://doi.org/10.1111/tpj.70459$xR$3Volltext$534 4950 https://nbn-resolving.org/urn:nbn:de:gbv:27-dbt-67730-5$xR$3Volltext$534 4961 https://www.db-thueringen.de/receive/dbt_mods_00067730 5051 580 5550 androgens 5550 Arabidopsis thaliana 5550 brassinosteroids 5550 DET2 5550 phytohormones 5550 progestogens 5550 root development 5550 signalling molecules