Figure 4

Organogenesis patterns on a matrix of shoot induction medium. (A) Representative calli grown on each combinatorial medium. The 16 different combinations of IAA (0.05, 0.1, 0.15, and 0.25 mg/L) and N⁶-Δ²-isopentenyladenine (1, 3, 5, and 7 mg/L) were tested with each callus. 3-9 calli per each concentration were tested. Shown are composite photos of calli arranged after growth on each medium. (B) Degree of shoot induction in specific medium. The labeling for the three axes shown on the dwf7-1 chart is applicable to the Ws-2 graph. Arbitrary unit representing shoot induction rate, ranging from 0 to 2, was plotted against the combination of auxin and cytokinin. A number close to 2 indicates that each callus tested on the specific medium tended to regenerate shoots successfully. (C) Direct induction of shoots from root explants. Roots were briefly exposed to callus induction media, then transferred to shoot induction media to induce shoots from each genotype. Wild type displays discernable structures of leaves and inflorescences, whereas these morphologies are relatively primordial in dwf7-1 mutant. Scale bar = 0.5 cm.