Explain the role of tapetum in the formation of pollen-grain wall.
Explanation The innermost layer of the microsporangium is called the tapetum. The major role of tapetum is to provide nourishment to the male gametophyte, i.e. the developing pollen grains. The tapetum produces precursors of sporopollenin, which in turn, changes into sporopollenin. The sporopollenin helps in the formation of the exine which is responsible for providing nourishment to the pollen grains. The cells of the tapetum also produce enzymes, amino acids, hormones and other nutritious substances which help in the development of the pollen grain. Final answer The tapetum is a layer present between the anther wall and the sporogenous tissue. The cells of the tapetum usually have more than one nucleus per cell. The tapetum also helps in the synthesis of callase enzyme, which helps in the separation of the microspore tetrad.
