Auxin has always been at the forefront of research in plant physiology and development. Since the earliest contemplations by Julius von Sachs and Charles Darwin, more than a century-long struggle has been waged to understand its function. This largely reflects the failures, successes, and inevitable progress in the entire field of plant signaling and development. Here I present 14 stations on our long and sometimes mystical journey to understand auxin. These highlights were selected to give a flavor of the field and to show the scope and limits of our current knowledge. A special focus is put on features that make auxin unique among phytohormones, such as its dynamic, directional transport network, which integrates external and internal signals, including self-organizing feedback. Accented are persistent mysteries and controversies. The unexpected discoveries related to rapid auxin responses and growth regulation recently disturbed our contentment regarding understanding of the auxin signaling mechanism. These new revelations, along with advances in technology, usher us into a new, exciting era in auxin research.
Cold Spring Harbor Perspectives in Biology
The author thanks the whole community of researchers consciously or unconsciously working on questions related to auxin, whose hard work and enthusiasm contributed to development of this exciting story. Particular thanks go to many brilliant present and past members of the Friml group and our numerous excellent collaborators, without whom my own personal journey would not be possible. The way of the cross with its 14 stations is a popular devotion among Roman Catholics and inspires them to make a spiritual pilgrimage through contemplation of Christ on his last day. Its aspects of gradual progress, struggle, passion, and revelation served as an inspiration for the formal depiction of our journey to understanding auxin as described in this review. It is in no way intended to reflect the personal beliefs of the author and readers. I am grateful to Nick Barton, Eva Benková, Lenka Caisová, Matyáš Fendrych, Lukáš Fiedler, Monika Frátriková, Jarmila Frimlová, Michelle Gallei, Jakub Hajný, Lukas Hoermayer, Alexandra Mally, Ondrˇej Novák, Jan Petrášek, Aleš Pěnčík, Steffen Vanneste, Tongda Xu, and Zhenbiao Yang for their valuable comments. Special thanks go to Michelle Gallei for her invaluable assistance with the figures.
Friml J. Fourteen stations of auxin. Cold Spring Harbor Perspectives in Biology. 2022;14(5). doi:10.1101/cshperspect.a039859
Friml, J. (2022). Fourteen stations of auxin. Cold Spring Harbor Perspectives in Biology. Cold Spring Harbor Laboratory. https://doi.org/10.1101/cshperspect.a039859
Friml, Jiří. “Fourteen Stations of Auxin.” Cold Spring Harbor Perspectives in Biology. Cold Spring Harbor Laboratory, 2022. https://doi.org/10.1101/cshperspect.a039859 .
J. Friml, “Fourteen stations of auxin,” Cold Spring Harbor Perspectives in Biology, vol. 14, no. 5. Cold Spring Harbor Laboratory, 2022.
Friml J. 2022. Fourteen stations of auxin. Cold Spring Harbor Perspectives in Biology. 14(5), a039859.
Friml, Jiří. “Fourteen Stations of Auxin.” Cold Spring Harbor Perspectives in Biology, vol. 14, no. 5, a039859, Cold Spring Harbor Laboratory, 2022, doi:10.1101/cshperspect.a039859 .