Fig. 4. Genetic interaction of PGPs with PIN1 during embryonic leaf formation. (A-D) Synergistic interaction of pgp1pgp19 and pin1 during cotyledon formation. Typical defects in cotyledon formation during embryogenesis and their postgermination appearance are shown: wild type (A), pin1 (B), pgp1pgp19 (C) and pin1pgp1pgp19 (D). (E) Cup-shaped cotyledons of the pin1pgp1pgp19 seedling that are rarely seen in the pin1 mutant. (F) Strong enhancement of the pin1 phenotype in post-embryonal development by the pgp1pgp19 mutation. An adult, 5-week-old, plant with extremely dwarf appearance, reduced leaf number and apical dominance is shown. (G) Quantification of frequencies of cotyledon defects in different mutants and their combinations (n=200). Scale bars: 1 mm in A-D; 5 mm E,F.