Wild-type and mutant iodine-staining phenotype.
Iodine stain of cell patches incubated for 7 d on solid
nitrogen-deprived medium. Genotypes with respect to starch are
indicated for our reference strains.
sta2-27::ARG7, sta3-1, and
sta7-5::ARG7 correspond to defects, respectively,
in GBSS, SS, and debranching enzyme (Delrue et al., 1992; Fontaine et
al., 1993; Mouille et al., 1996). +, Wild type. The original mutant
strain BafV13 (sta8-1) and two recombinants, BGM77 and
BGM105, display the dark green stain of sta8-1 mutants,
whereas the BGM87 strain shows a typical yellow stain of low-starch
mutants and were proved by complementation test to carry mutations
sta7 and sta8.