RACK1A positively regulates opening of the apical hook in <i>Arabidopsis thaliana</i> via suppression of its auxin response gradient
Abstract
Apical hook development is an ideal model for studying differential growth in plants and is controlled by complex phytohormonal crosstalk, with auxin being the major player. Here, we identified a bioactive small molecule that decelerates apical hook opening in Arabidopsis thaliana . Our genetic studies suggest that this molecule enhances or maintains the auxin maximum found in the inner hook side and requires certain auxin signaling components to modulate apical hook opening. Using biochemical approaches, we then revealed the WD40 repeat scaffold protein RECEPTOR FOR ACTIVATED C KINASE 1A (RACK1A) as a direct target of this compound. We present data in support of RACK1A playing a positive role in apical hook opening by activating specific auxin signaling mechanisms and negatively regulating the differential auxin response gradient across the hook, thereby adjusting differential cell growth, an essential process for organ structure and function in plants.
Article Details
Journal Info
Proceedings of the National Academy of Sciences
National Academy of Sciences
Authors (16)
Qian Ma
State Key Laboratory of Electroanalytical Chemistry
Sijia Liu
Siamsa M. Doyle
Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
Sara Raggi
Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
Barbora Pařízková
Laboratory of Growth Regulators, Faculty of Science of Palacký University & Institute of Experimental Botany of the Czech Academy of Sciences
Deepak Kumar Barange
Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
Hemamshu Ratnakaram
Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
Edward G. Wilkinson
Department of Biology, Duke University
Isidro Crespo Garcia
BL13-XALOC Beamline, Experiments Division, ALBA Synchrotron, Cerdanyola del Vallès
Joakim Bygdell
Computational Life Science Cluster, Department of Chemistry, Umeå University
Gunnar Wingsle
Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
Dirk Roeland Boer
BL13-XALOC Beamline, Experiments Division, ALBA Synchrotron, Cerdanyola del Vallès
Lucia C. Strader
Department of Biology, Duke University
Fredrik Almqvist
Department of Chemistry, Umeå University
Ondřej Novák
Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
Stéphanie Robert
Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences