Regulatory links between various plant hormone metabolisms include both synergistic and antagonistic interactions and have been described in a number of plant tissues. It is evident that the balance between synergistic and antagonistic relationships is the dominating principle of integral hormone action in plants. A single hormone can regulate an amazingly diverse array of cellular and developmental processes while at the same time multiple hormones often influence a single process. When used in vitro, plant hormones display a very broad and complex action spectrum which implies that exogenous application of plant hormone does pot ensure the same effect in the plant as in the culture medium. This is because, different cells, tissues respond differently to same hormone and different processes are sensitive to different levels of hormones, even in the same cell. Thus, it is difficult to assign any effect seen while experimentation to any single hormone.