New PEO-IAA-Inspired Anti-Auxins: Synthesis, Biological Activity, and Possible Application in Hemp (Cannabis Sativa L.) Micropropagation

• Published in: Journal of plant growth regulation Vol. 42; no. 12; pp. 7547 - 7563
• Main Authors: Žukauskaitė, Asta, Saiz-Fernández, Iñigo, Bieleszová, Kristýna, Iškauskienė, Monika, Zhang, Chao, Smýkalová, Iva, Dzedulionytė, Karolina, Kubeš, Martin F., Sedlářová, Michaela, Pařízková, Barbora, Pavlović, Iva, Vain, Thomas, Petřík, Ivan, Malinauskienė, Vida, Šačkus, Algirdas, Strnad, Miroslav, Robert, Stéphanie, Napier, Richard, Novák, Ondřej, Doležal, Karel
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.12.2023; Springer Nature B.V
• Subjects: Agriculture; Apical dominance; Auxins; Biological activity; Biomedical and Life Sciences; Cannabis; Cell differentiation; Cell division; Cytokinins; Elongation; Explants; Gene expression; Hemp; Indoleacetic acid; Life Sciences; Micropropagation; Organogenesis; Plant Anatomy/Development; Plant growth; Plant Physiology; Plant Sciences; Receptors; Anti-auxin; Multiple shoot culture; DESI-MSI analysis; Indole-3-acetic acid (IAA); SPR analysis
• ISSN: 0721-7595; 1435-8107
• DOI: 10.1007/s00344-023-11031-x

Auxins play an important role in plant physiology and are involved in numerous aspects of plant development, such as cell division, elongation and differentiation, fruit development, and phototropic response. In addition, through their antagonistic interaction with cytokinins, auxins play a key role in the regulation of root growth and apical dominance. Thanks to this capacity to determine plant architecture, natural and synthetic auxins have been successfully employed to obtain more economically advantageous plants. The crosstalk between auxins and cytokinins determines plant development and thus is of particular importance in the field of plant micropropagation, where the ratios between these two phytohormones need to be tightly controlled to achieve proper rooting and shoot generation. 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.