Fig. 3. The effects of B class genes and the third whorl on nectary gland development as analyzed using SEM and sectioned material. (A,B) SEM of nectary glands from 35S::AP3 35S::PI (35S::"B") expressed in wild type and ap2-2 mutant, respectively. (C) Lateral nectary glands from a sup-1 mutant. (D) Longitudinal section of a lateral nectary gland from a plant expressing 35S::AP3 35S::PI. ET668 GUS expression is mainly seen at the tip of the nectary gland. (E,F) SEM of nectary glands from wild-type plants expressing 35S::AP3 and 35S::PI, respectively. (G,H) In situ localization of AP3 mRNA in young and older nectary glands, respectively, as seen in transverse section. ln, lateral nectary gland; mst, medial stamen; lst, lateral stamen; Scale bar,100 µm in A-E and 50 µm in F.