|Jing Zhang, etc. Strigolactones inhibit auxin feedback on PIN-dependent auxin transport canalization. DOI: 10.1038/s41467-020-17252-y|
Strigolactones inhibit auxin feedback on PIN-dependent auxin transport canalization
Jing Zhang, Ewa Mazur, Jozef Balla, Michelle Gallei, Petr Kalousek, Zuzana Medveďová, Yang Li,Yaping Wang, Tomáš Prát, Mina Vasileva, Vilém Reinöhl, Stanislav Procházka, Rostislav Halouzka,Petr Tarkowski, Christian Luschnig, Philip B. Brewer & Jiří Friml
Directional transport of the phytohormone auxin is a versatile, plant-specific mechanism regulating many aspects of plant development. The recently identified plant hormones, strigolactones (SLs), are implicated in many plant traits; among others, they modify the phenotypic output of PIN-FORMED (PIN) auxin transporters for fine-tuning of growth and developmental responses. Here, we show in pea and Arabidopsis that SLs target processes dependent on the canalization of auxin flow, which involves auxin feedback on PIN subcellular distribution. D14 receptor- and MAX2 F-box-mediated SL signaling inhibits the formation of auxin-conducting channels after wounding or from artificial auxin sources, during vasculature de novo formation and regeneration. At the cellular level, SLs interfere with auxin effects on PIN polar targeting, constitutive PIN trafficking as well as clathrin-mediated endocytosis. Our results identify a non-transcriptional mechanism of SL action, uncoupling auxin feedback on PIN polarity and trafficking, thereby regulating vascular tissue formation and regeneration. Strigolactones are a newly identified, but incompletely characterized class of plant hormones play crucial roles in plant development. Here the authors show that strigolactones prevent an auxin feedback-effect on PIN-FORMED (PIN) polarity and trafficking, thereby regulating vascular tissue formation and regeneration.