Hormonal Control of Embryo and Seedling

Growth of embryos differs in many respects from that of seedlings. Embryos, like animal tissue, increase in size principally by cell proliferation. Seedlings, on the other hand, increase in size mainly by cell enlargement. Hence one may assume that the factors controlling growth of embryos are different from those controlling elongation of seedlings. The meristematic areas in seedlings, however, are embryonic regions, and for this reason may be controlled by factors similar to those controlling growth and development of embryos. In the present paper an attempt is made to discuss some aspects of growth both by proliferation and by elongation, by discussing A) growth factors of embryos, and B) growth factors of seedlings.