Fig. 8.

In situ hybridization analysis of histone H4 gene expression in longitudinal sections of date palm flower at three stages of development. Cells that accumulate histone H4 gene transcripts are stained in purple. In the pistillate flower, histone H4 gene transcripts were accumulated in all primordium at ‘bisexual’ stage V (A) and in the ovule (B,C) while no accumulation of H4 transcripts was observed in staminodes at stages VI (B) and VII (C). In the staminate flower, histone H4 gene expression was observed throughout the primordia at the ‘bisexual’ stage (D), in stamens (E,F), in ovule of pistillodes (F) but no expression was seen in the pistillode at stage VI (E). Abbreviations: C, carpel; O, ovule; Pe, petal; Pi, pistillode; Std, staminodes; St, stamens; S, sepal. Scale bars = 200 µm.