Figure 3.

Iodine staining of starch synthesis and degradation mutants. A to C, Iodine staining of leaves of mutants obtained from the forward genetic screen and from TILLING. All mutant lines shown here except gwd1-3 and gwd3-4 were derived from outcrosses of the original mutant with MG-20. Each leaflet is from a different plant. Plants were grown in 16 h of light and 8 h of dark and were approximately 4 weeks old at the time of harvest. The name of the mutant allele is given where this is known (Supplemental Table S5). A, Starch synthesis mutants from the forward genetic screen and TILLING. Leaflets were harvested at the end of the day. B and C, Mutants from the forward genetic screen (B) and TILLING (C). Leaf phenotypes of the gwd1-3 and gwd3-4 TILLING mutants are shown in comparison with those of their segregating wild types (WT). Leaflets were harvested at the end of an extended night of up to 44 h. D, Starch contents of roots and embryos of wild-type and starch synthesis mutant plants. Plants were harvested when approximately 3 months old. Roots and embryos were decolorized prior to staining with iodine solution. Note that roots and embryos of wild-type plants have high starch contents, those of pgm1-4 have no detectable starch, those of the aps1-1 mutant have drastically reduced starch contents, and those of pgi1-2 (SL4308-12) appear very similar to the wild type.