Fig. 6. Expression of STY1 in wild type determined by in situ hybridization (A-I) and STY1::GUS histochemical staining (J-Q). (A,B) Transverse consecutive sections of an inflorescence meristem; (A) most apical section. Floral primordia are numbered according to their relative age from P1 to P5. By stage 2 (B) STY1 expression is localized to sepal analgen (s). (C) Longitudinal section of an inflorescence meristem. Expression is seen in sepal primordia and in abaxial parts of the floral meristem (cryptic bract, cb). (D-F) Expression in the elongating gynoecium. (D) Transverse section of the tip of a stage 8 gynoecium. (E) Longitudinal section of a stage 6 bud. (F) Longitudinal section of a stage 9 flower. Signal is restricted to the apical parts of the gynoecium. (G) Longitudinal section of a stage 12 gynoecium showing expression between the style and the stigma, in outer layers of the septum and in outer integuments. (H) Longitudinal section of young ovules. Expression is seen in outer integuments (o i) and in the tip of the nucellus (n). (I) Longitudinal section of a globular stage embryo. Expression is restricted to cotyledon primordia. Red signals are due to artifacts. (J) Inflorescence. (K) Cauline leaf. (L) 8-day-old seedling. (M) Top view of an inflorescence. Compare with D. (N) Medial view of a stage 12 gynoecium. (O,P) Emerging lateral root primordia. (Q) Root tips. Scale bars: 50 µm in A-F,H; 100 µm in G; 40 µm in I.