Figure 6.

rpt5a rpt5b Gametophytic Mutants Are Defective in cycA3 Degradation.

(A) to (F) cycA3:GUS staining in pollen from plants homozygous for the pAL101 construct (cyclinA3-GUS reporter construct) ([A] to [F]). At late meiosis/tetrad stage ([A] to [C] for enlargement: pistil length = 0.8 mm), all pollen grains are stained. GUS staining disappears at later stages of male gametophyte development (pistil length = 1.2 mm) during pollen mitosis in wild-type AABB background (D), whereas some staining remains in some Aa4Bb1grains ([E] and [F]). A GUS-stained degenerating pollen grain is indicated by an arrow in (F).

(G) to (J) cycA3:GUS staining in ovule. No GUS staining accumulated in the AABB wild-type background (G), whereas some strong staining could be seen in Aa4Bb1 pistils (H). Staining appeared as staining one (I) or two nuclei (J) of the arrested embryo sac.

Bars = 200 μm in (A) to (F) and 50 μm in (G) to (J).