Novel and Efficient System for Xylem Vessel Element Formation by Activating Transcription Factors

Abstract

NAC domain proteins, Vascular-Related NAC Domain Protein6 (VND6) and VND7, are master transcription factors that control xylem vessel element differentiation (Kubo et al, 2005, Genes Dev). Here we succeeded in the induction of xylem vessel element differentiation by activating the master transcription factors. We generated transgenic Arabidopsis plants, tobacco BY-2 cells, and Arabidopsis T87 cells, in which VND6 or VND7 fused to the VP16 transactivation domain and the glucocorticoid receptor (GR) is overexpressed under the control CaMV35S constitutive promoter. In the transgenic Arabidopsis plants, various types of cells including root hairs and trichomes transdifferentiated efficiently into vessel elements after the DEX-treatment. Activation of VND7 in BY2 and T87 also effectively induced the transdifferentiation. The detailed morphological observation of the transdifferentiated cells and analysis of cell wall composition during the transdifferentiation are now underway.