Figure 2.

ZIP3 Is VPS35A.

(A) The ZIP3 locus was mapped between two cleaved-amplified polymorphic sequence markers, F5J6 and T13L16 on chromosome 2. A nonsense mutation was found at the twelfth Trp in the At2g17790 gene in the zip3-1 zig-1 mutant. The gene structure of At2g17790 is shown schematically; exons are indicated by boxes (open boxes, untranslated region; closed boxes, coding regions), and introns are indicated by lines between boxes.

(B) and (C) Complementation analysis.

(B) Aerial part of 5-week-old zip3-1 zig-1 T2 plant bearing the At2g17790 genomic fragment indicated in (A). Note that it shows a zig-1-like phenotype. Bar = 3 cm.

(C) Gravitropic response of wild-type (closed circles), zip3-1 zig-1 (red open squares), zig-1 (open circles), and eight independent T2 lines of zip3-1 zig-1 containing the At2g17790 genomic fragment (T2-1 to T2-8; open colored circles). Ten individuals of each transgenic line were examined. Bars represent se.

(D) and (E) Endodermis-specific expression of VPS35A extinguished the suppressive effect of zip3-1 on the zig-1 phenotype.

(D) Gravitropic response of wild-type (closed circles), zip3-1 zig-1 (red open squares), zig-1 (open circles), and independent eight T2 lines of zip3-1 zig-1 containing SCRpro:ZIP3/cVPS35A (T2-1 to T2-8; open colored circles). Ten individuals of each transgenic line were examined. Bars represent se.

(E) Expression of ZIP3/VPS35A derived from the transgene was confirmed by RT-PCR analyses of the eight transgenic lines. Analysis of the untransformed double mutant line is shown in the lane at the far right.