Figure 6.

Responses of rescued mutant seeds germinated on media without His. Rescued mutant seeds and wild-type controls were dry harvested from heterozygous plants watered daily with 1 mm His, surface sterilized, and plated on agar media containing 3% Glc and observed for 4 weeks. A to D, Examples of hisn2-1 rescued mutant seeds that failed to germinate (A) or arrested early in germination and remained white (B and C) after 7 d, in contrast to wild-type controls on the same plate (D). E to H, Examples of hisn3-1 (E and F) and hisn2-1 (G and H) rescued mutant seeds that germinated to produce a small seedling that was green after 7 d (E and G) but then stopped growing and turned white or yellow at 14 d (F and H). I to L, Example of a hisn6a-1 rescued mutant seed that germinated to produce a small green seedling that continued to grow slowly after 7 (I), 14 (J), 21 (K), and 28 d (L) without His, reflecting a low level of redundant HISN6B activity. M, Wild-type seedling after 14 d in culture. Scale bar = 5 mm.