TRANSPORTER OF IBA1 links auxin and cytokinin to influence root architecture.

Developmental processes that control root system architecture are critical for soil exploration by plants, allowing for uptake of water and nutrients. Conversion of the auxin precursor indole-3-butyric acid (IBA) to active auxin (indole-3-acetic acid; IAA) modulates lateral root formation. However, mechanisms governing IBA-to-IAA conversion have yet to be elucidated. We identified TRANSPORTER OF IBA1 (TOB1) as a vacuolar IBA transporter that limits lateral root formation. Moreover, TOB1, which is transcriptionally regulated by the phytohormone cytokinin, is necessary for the ability of cytokinin to exert inhibitory effects on lateral root production. The increased production of lateral roots in tob1 mutants, TOB1 transport of IBA into the vacuole, and cytokinin-regulated TOB1 expression provide a mechanism linking cytokinin signaling and IBA contribution to the auxin pool to tune root system architecture.
Cheng-Hsun Ho

Cheng-Hsun Ho

Associate Research Fellow

(02)2787-2123
zcybele3@sinica.edu.tw
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Tel: (02)2787-2124

2024-present
Associate Research Fellow, Agricultural Biotechnology Research Center (ABRC), Academia Sinica
2015-2024
Assistant Research Fellow, Agricultural Biotechnology Research Center (ABRC), Academia Sinica
2011-2015
Senior Research Associate, Department of Plant Biology, Carnegie Institution for Science, Stanford
2009-2011
Academia Sinica Postdoctoral Fellow, Institution of Molecular Biology (IMB), Academia Sinica
2004-2009
Ph.D. Taiwan International Graduate Program, Institute of Molecular Biology, Academia Sinica/Graduate Institute of Life Sciences, National Defense Medical Center
2002-2004
M.S. Institution of Plant Biology, National Taiwan University