Abstract
The plant vasculature is produced continuously and has well-organized radial pattern, which are governed by cell-cell interactions. We have identified secretary molecules mediating cell-cell interactions using Zinnia xylogenic culture. Of them, TDIF, which was isolated as an inhibitory factor of tracheary element differentiation, is a dodeca-CLE (CLV3/ESR) peptide with two hydroxyproline residues.
To elucidate the in vivo function of TDIF, we performed a detailed analysis using chemically synthesized TDIF. The Arabidopsis seedling grown with TDIF showed abnormal xylem vessel formation, although the entire morphology, the venation pattern, and the phloem formation were not affected. These results suggest that TDIF may be a signaling molecule regulating the plant vascular formation by its specific inhibitory effect on the xylem vessel formation in situ.
