A role for the root cap in root branching revealed by the non-auxin probe naxillin

作者：De Rybel Bert; Audenaert Dominique; Xuan Wei; Overvoorde Paul; Strader Lucia C; Kepinski Stefan; Hoye Rebecca; Bri**ois Ronald; Parizot Boris; Vanneste Steffen; Liu Xing; Gilday Alison; Graham Ian A; Nguyen Long; Jansen Leentje; Njo Maria Fransiska; Inze Dirk; Bartel Bonnie; Beeckman Tom^*

来源：Nature Chemical Biology, 2012, 8(9): 798-805.

DOI：10.1038/NCHEMBIO.1044

The acquisition of water and nutrients by plant roots is a fundamental aspect of agriculture and strongly depends on root architecture. Root branching and expansion of the root system is achieved through the development of lateral roots and is to a large extent controlled by the plant hormone auxin. However, the pleiotropic effects of auxin or auxin-like molecules on root systems complicate the study of lateral root development. Here we describe a small-molecule screen in Arabidopsis thaliana that identified naxillin as what is to our knowledge the first non-auxin-like molecule that promotes root branching. By using naxillin as a chemical tool, we identified a new function for root cap-specific conversion of the auxin precursor indole-3-butyric acid into the active auxin indole-3-acetic acid and uncovered the involvement of the root cap in root branching. Delivery of an auxin precursor in peripheral tissues such as the root cap might represent an important mechanism shaping root architecture.

• 出版日期2012-9