Figure 1.—

psc leaves display chlorotic regions that hyperaccumulate starch. (A) Wild-type (WT) leaves have uniform green coloration. (B) Wild-type leaves cleared and IKI stained showing that the leaf contains little starch after the dark period. (C) psc leaves display chlorotic and green tissues. (D) psc leaves cleared and IKI stained showing that chlorotic regions hyperaccumulate starch after the dark period, whereas green regions do not. Free-hand leaf cross-sections of (E) wild-type, (F) psc green, and (G) psc chlorotic tissues. psc chlorotic tissue hyperaccumulates starch in both the bundle sheath and mesophyll cells (arrow in G), whereas wild-type and psc green tissues contain trace amounts of starch in the bundle sheath cells (arrowheads in E and F) after the dark period. Bar, 100 μm for panels E–G.