The pollen tube enter the embryo sac through

Pollen tube, after reaching the ovary, enters the ovule through the micropyle and then enters one of the degenerating synergids through the filiform apparatus. Many recent studies have shown that filiform apparatus present at the micropylar part of the synergids guides the entry of pollen tube. All these events–from pollen deposition on the stigma until pollen tubes enter the ovule–are together referred to as pollen-pistil interaction.