What is tapetum ? What is its function ?

Explanation

Tapetum. It is the inner specialised nourishing layer of microsporangial wall. The cell have dense cytoplasm. They become large, multinucleate and polyploid through endomitosis a endopolyploidy. Tapetum is of two types
(a) Amoeboid (Invasive)
(b) Secretory or Glandular.
Functions.
(i) Inward transport of nutrients to pollen mother cells.
(ii) Secretions of enzymes and hormones. e.g., IAA.
(iii) Production of ubisch gramules which form sporopollenin, a component of exine of the pollen wall.
(iv) Secretion of an oily layer called pollen kit over and outside the mature pollen.