Small‐molecule auxin inhibitors that target YUCCA are powerful tools for studying auxin function

• DOI: 10.1111/tpj.13032
• Publication Date: 2015-09-24T12:50:53Z
• Authors: Yusuke Kakei; Chiaki Yamazaki; Masashi Suzuki; Ayako Nakamura; Akiko Sato; Yosuke Ishida; Rie Kikuchi; Shouichi Higashi; Yumiko Kokudo; Takahiro Ishii; Kazuo Soeno; Yukihisa Shimada
• Keywords: Yucca; Coleoptile; Indole-3-acetic acid

Auxin is essential for plant growth and development, this makes it difficult to study the biological function of auxin using auxin-deficient mutants. Chemical genetics have potential overcome difficulty by temporally reducing inhibitors. Recently, indole-3-pyruvate (IPyA) pathway was suggested be a major biosynthesis in Arabidopsis thaliana L. indole-3-acetic acid (IAA), most common member family. In pathway, YUCCA, flavin-containing monooxygenase (YUC), catalyzes last step conversion from IPyA IAA. study, we screened effective inhibitors, 4-biphenylboronic (BBo) 4-phenoxyphenylboronic (PPBo), which target YUC. These compounds inhibited activity recombinant YUC vitro, reduced endogenous IAA content, primary root elongation lateral formation wild-type seedlings. Co-treatment with inhibitory effects. Kinetic studies BBo PPBo showed that they are competitive inhibitors substrate IPyA. Inhibition constants (Ki ) were 67 56 nm, respectively. addition, did not interfere response auxin-marker genes when co-treated IAA, suggesting an inhibitor sensing or signaling. We propose these class small molecules powerful tools chemical genetic analysis function.