Fig. 5. FY is an essential gene in Arabidopsis. (A-E) Phenotypic analysis of reproductive development in fy-4/FY plants. (A) Gross phenotype of a fy-4/FY silique showing healthy, green seeds alongside brown, aborted siblings (arrow). (B-E) DIC images of healthy and aborted seeds in fy-4/FY siliques; embryos are indicated with arrows. Healthy embryos are shown at globular (B) and heart (D) stage alongside aborted sibling embryos (C and E, respectively). Scale bars: 25 µm. (F-H) Phenotypic analysis of reproductive development in fy-1/FY, fpa-1/fpa-1 plants. (F) Gross phenotype of an fy-1/FY, fpa-1/fpa-1 silique. (G,H) DIC image of wild-type seed at globular stage of embryogenesis (G) and a sibling aborted seed (H) in an fy-1/FY, fpa-1/fpa-1 silique. White arrows indicate the embryo. Scale bars: 25 µm. (I) Quantification of seed abortion in fy, fpa and fca mutant backgrounds. (J) Complementation of fy-4 by the pFY::FY transgene is shown by dCAPs analysis. The lower DNA band on the ethidium bromide-stained gel is the XbaI-digested product from the fy-4 allele. Homozygote fy-4/fy-4 plants are only obtained after transformation with pFY::FY.