Abstract
Axis formation is one of the fundamental events in early development. In the Arabidopsis embryo, the main body axis is evident by the asymmetric division of the zygote forming a small embryonic apical cell and a large basal cell with mostly extra-embryonic fate. The homeobox gene WOX8 (WUSCHEL RELATED HOMEOBOX8) is expressed in the zygote and its basal derivatives and is crucial for axis development. Nevertheless, how polar WOX8 expression is achieved was totally unknown. We identified the transcription factors binding to WOX8 cis-elements. The mutants of these factors affected not only WOX8 expression, but also the zygotic polarity and the embryonic axis, indicating that these genes are the novel regulators of axis initiation. Based on these results, the mechanism regulating plant axis development will be presented.
