Fig. 1. The var3 mutant. (A-C) Leaves of 20-day-old, wild type (Ler), var3 grown under high light and immutans (im) under low light. (D-F) Second or third true leaves at 28 days. (G-H) Light micrographs of cross sections of 12-day-old Ler and var3 leaves. Scale bars, 100 µm. (I-J) Scanning electron micrographs of first true leaves of 12-day-old Ler and var3. Scale bars, 100 µm. (K-P) Confocal images with merged red and Nomarsky channels. Scale bars, 50 µm for K,O; 5 µm for L,N,P; 20 µm for M. K and N are of live material, other images are of formaldehyde fixated tissue. (K) Leaf initial before emergence at the shoot tip. (L) Detail from K showing cells with normal, reduced and undetectable chloroplast development. (M) Variegation in pre-emergent leaf. (N) Detail from M of chloroplasts with normal and arrested development. (O) Light patch with reduced or no chloroplast development, surrounded by normal mesophyll cells in a 16-day-old third leaf. (P) Plastids from the leaf in O with reduced development.