Asta Žukauskaitė, Iñigo Saiz-Fernández, Kristýna Bieleszová, Monika Iškauskienė, Chao Zhang, Iva Smýkalová, Karolina Dzedulionytė, Martin F. Kubeš, Michaela Sedlářová, Barbora Pařízková, Iva Pavlović, Thomas Vain, Ivan Petřík, Vida Malinauskienė, Algirdas Šačkus, Miroslav Strnad, Stéphanie Robert, Richard Napier, Ondřej Novák, Karel Doležal

Previously reported anti-auxin PEO-IAA, which blocks auxin signalling through binding to TIR1 receptor and inhibiting the expression of auxin-responsive genes, has been successfully used to facilitate hemp micropropagation. Herein, we report a set of new PEO-IAA-inspired anti-auxins capable of antagonizing auxin responses in vivo. The capacity of these compounds to bind to the TIR1 receptor was confirmed in vitro by SPR analysis. Using DESI-MSI analysis, we evaluated the uptake and distribution of the compounds at the whole plant level. Finally, we characterized the effect of the compounds on the organogenesis of hemp explants, where they showed to be able to improve beneficial morphological traits, such as the balanced growth of all the produced shoots and enhanced bud proliferation.

Journal of Plant Growth Regulation. May 2023