Fig. 5. Experimental manipulation of vein formation and mesophyll development. (A-O) Athb8-GUS expression, abaxial view, DIC microscopy. (B,E,H,K,N) Enlargements of boxed areas in A,D,G,J,M, respectively. (C,F,I,L,O) Enlargements of boxed areas in B,E,H,K,N, respectively. Upper right: primordium age in DAI (days after primordium initiation) and position in IA (intercostal area). Lower left: growth condition (A, B or C, as outlined in Materials and methods). Red numbers indicate vein order. Arrows point to examples of chloroplasts in mesophyll cells. (P,Q) Polygonal cells classified as GM (P) and mesophyll cells (Q) from leaves expressing the LTI6b::YFP plasma membrane marker. Left panel: cleared leaf, abaxial view, DIC microscopy; right panel: LTI6b::YFP expression (green) and chloroplast autofluorescence (red), abaxial view, CLS microscopy. CLS micrographs in P and Q were taken with identical microscope settings. Scale bars: (A,D,G) 50 µm; (B,E,H,J,K,M,N) 25 µm; (C,F,I,L,O,P,Q) 10 µm.