Explain the role of tapetum in the formation of pollen grain wall

Tapetum is the innermost layer of the microsporangium.It produces the exine layer of the pollen grains, which is composed of the sporopollenin, the most resistant fatty substance. During microsporogenesis, the cells of ’ tapetum produce various enzymes, hormones, amino acids and other nutritious materials required for the development of pollen grains.