Abstract
Role of nucleic acids and insoluble polysaccharides in the tissue differentiation was studied on the anther tissue-sections of Zea mays L. using light microscope. The results obtained were discussed in the light of available reports in this regard.
Archesporium and sporogenous tissues are characterized by rich RNA content. RNA quantity is reduced very much in PMCs and the meiotic derivatives. Young anther wall layers, as they differentiate centripetally, show rich RNA content which is reduced as they grow older, at the periphery of the anther locule. Tapetum since its inception is rich in RNA and maintains this quantity until it disintegrates. It is so even in the tapetal cells differentiated from the connective by dedifferentiation. DNA concentration in the early sporogenous tissue is high, resembling primordial tissues surrounding it. In successive growth phases, DNA quantity is reduced to a faint level in the tissue, but, however, increases in PMCs prior to meiosis. The tapetum remains rich in DNA.
The cytoplasm of sporogenous tissue shows faint PAS-positive tinge and at no stage starch was recorded in this, PMCs and haploid spores, but tapetum contains PAS-positive grains until meiosis is over. PAS-positive additional wall is formed around PMCs which persists until the completion of meiosis. Anther wall layers are rich in starch storage. Rich starch storage in endothecium is of specific importance, as it contributes to the differentiation of endothecial thickenings in the mature anther.
The insoluble polysaccharides occur in anther tissues in the form of additional PAS-positive thickening around PMCs-a “molecular filter” (Heslop-Harrison, 1964), endothecial thickenings and starch, a primary source of energy. Therefore, they greatly contribute to the histochemical differentiation of anther tissues.
