1. It supplies nutrition to the developing micro spores. 2. It contributes sporopollenin through ubisch bodies thus plays an important role in pollen wall formation. 3. The pollenkitt material is contributed by tapetal cells and is later transferred to the pollen surface. 4. Exine proteins responsible for ‘rejection reaction’ of the stigma are present in the cavities of the exine. These proteins are derived from tapetal cells.