Abscisic acid in the reproductive organs of Petunia hybrida and Lilium longiflorum

Styles, ovaries, anthers and pollen of Petunia hybrida and pollen of Liliun longiflorum were analysed for the presence of abscisic acid (ABA) by means of high performance liquid chromatography (HPLC) combined with UV and fluorometric detection. All these reproductive organs were shown to contain endogenous ABA. However, styles have a particular high content in comparison with that of ovaries, anthers and pollen. In addition the ABA content of styles increased rapidly during flower development prior to anthesis, while in ovaries and anthers after an initial decrease the ABA content remained constant at a comparatively low level. After compatible cross-pollination the ABA content of styles in particular, but also of ovaries, was significantly reduced compared with incompatible self-pollination. Lilium longiflorum pollen also contained ABA. Upon germination in vitro the ABA content of Lilium pollen decreased rapidly, while at the same time a large amount ABA was released into the germination medium, possibly due to enzymic hydrolysis of ABA conjugates present in pollen.