Ultrastructural modifications in the apertural intine of Parietaria judaica L. (Urticaceae) pollen during the early stages of hydration

Abstract

Hydration and activation of the Parietaria judaica L. (Urticaceae) pollen result in ultrastructural modifications in the apertural region. The particularly distinct intine under the apertures forms convex onci that undergo short but significant and reversible changes during the 10 first minutes of pollen grain hydration and activation. Such changes seem to involve the rough endoplasmic reticulum and show that the oncus is a dynamic structure. This confirms the elasticity of the intine and shows a new pattern of activity in this structure during hydration and activation of pollen germination in vitro.