(N/A) Pollen-pistil interaction is a dynamic process involving a chemical dialogue between the pollen grain and the stigma.
$1$. Recognition: The pistil has the ability to recognize whether the pollen is of the compatible (right) type or incompatible (wrong) type.
$2$. Acceptance: If the pollen is compatible,the pistil accepts it and promotes post-pollination events,such as pollen germination on the stigma,leading to fertilization.
$3$. Rejection: If the pollen is incompatible (from other species or self-incompatible),the pistil rejects it by preventing pollen germination or pollen tube growth.
$4$. Chemical Dialogue: This interaction is mediated by chemical components and proteins present on the surface of the pollen grain and the stigma. These components facilitate the recognition process.
$5$. Pollen Tube Growth: Upon successful acceptance,the pollen grain germinates on the stigma to produce a pollen tube through one of the germ pores,and the contents of the pollen grain move into the pollen tube.