Figure 2.

δVPE Is Specifically Localized in Two Cell Layers of the Inner Integuments of the Seed Coats in Developing Arabidopsis Seeds.

(A) Immunoblot analysis showing the organ-specific expression of δVPE. Total proteins were extracted from each organ (2 mg fresh weight) of Arabidopsis plants and were subjected to immunoblotting with anti-δVPE antibodies. The molecular masses are given on the right in kilodaltons.

(B) Immunoblot analysis showing the tissue-specific expression of δVPE. Total proteins were extracted from each tissue of one young silique and were subjected to immunoblotting with anti-δVPE antibodies.

(C) to (H) Immunofluorescence analysis of developing seeds at walking-stick-shaped-embryo stage with anti-δVPE antibodies. Green fluorescent images (anti-δVPE), differential interference contrast (DIC) images, and merged images (merge) are shown. (D), (F), and (H) are enlarged images of boxed regions in (C), (E), and (G), respectively. oi, outer integument; ii, inner integument. Bars = 100 μm in (C), (E), and (G) and 25 μm in (D), (F), and (H).

(I) A control experiment with developing wild-type seeds and preimmune serum (PI). Bars = 100 μm.

(J) A control experiment with developing δvpe-1 seeds and anti-δVPE antibodies. Bars = 100 μm.

(K) An illustration of the organization of the cell layers in the seed coat of a developing seed having a walking-stick-shaped embryo. The seed coat is composed of two kinds of integuments: outer integument (oi) of two cell layers (oi1 and oi2) and inner integument (ii) of three cell layers (ii1, ii2, and ii3). Green indicates the cell layers (ii2 and ii3) that express δVPE.