Figure 1.

WRKY75 expression during Pi deprivation and its subcellular localization. A, RNA-blot analysis of WRKY75 gene expression. Arabidopsis plants were grown either hydroponically or in liquid culture conditions for 7 d and then transferred to medium containing Pi (P+) or lacking Pi (P−), where they were grown for an additional 7 d. Roots, rosette leaves, and flowers were collected from mature plants grown hydroponically, whereas roots and shoots were collected from young seedlings grown in liquid culture. Ten micrograms of total RNA from these samples was separated electrophoretically and blotted onto a nylon membrane that was then probed with a ³²P-labeled WRKY75 cDNA. The membrane was subsequently stripped and rehybridized with an elongation factor (EF1α) gene probe used as a loading control. B, Subcellular localization of a GFP∷WRKY75 fusion protein. Microscopic images of root cells from Arabidopsis plants transformed with a control gene, 35S∷GFP (left), or a 35S∷GFP∷WRKY75 fusion gene (right). C, Amino acid sequence of WRKY75 showing the highly conserved WRKY domain WRKYGQK and the novel C2H2 zinc finger motif in red and blue letters, respectively.