Identification of mebendazole as an ethylene signaling activator reveals a role of ethylene signaling in the regulation of lateral root angles
Wenrong He,
Hai An Truong,
Ling Zhang,
Min Cao,
Neal Arakawa,
Yao Xiao,
Kaizhen Zhong,
Yingnan Hou,
Wolfgang Busch
Affiliations
Wenrong He
Plant Molecular and Cellular Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
Hai An Truong
Plant Molecular and Cellular Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
Ling Zhang
Plant Molecular and Cellular Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
Min Cao
Plant Molecular and Cellular Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
Neal Arakawa
Environmental and Complex Analysis Laboratory (ECAL), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
Yao Xiao
Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
Kaizhen Zhong
Plant Molecular and Cellular Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
Yingnan Hou
Department of Microbiology and Plant Pathology, Center for Plant Cell Biology, University of California, Riverside, Riverside, CA 92521, USA; School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
Wolfgang Busch
Plant Molecular and Cellular Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Integrative Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Corresponding author
Summary: The lateral root angle or gravitropic set-point angle (GSA) is an important trait for root system architecture (RSA) that determines the radial expansion of the root system. The GSA therefore plays a crucial role for the ability of plants to access nutrients and water in the soil. Only a few regulatory pathways and mechanisms that determine GSA are known. These mostly relate to auxin and cytokinin pathways. Here, we report the identification of a small molecule, mebendazole (MBZ), that modulates GSA in Arabidopsis thaliana roots and acts via the activation of ethylene signaling. MBZ directly acts on the serine/threonine protein kinase CTR1, which is a negative regulator of ethylene signaling. Our study not only shows that the ethylene signaling pathway is essential for GSA regulation but also identifies a small molecular modulator of RSA that acts downstream of ethylene receptors and that directly activates ethylene signaling.
