Аннотация:Investigation of morphology, evolution and taxonomy of plants was a leading scientific area at the botanical departments of institutional predecessors of University of Szeged.The Department of Plant Physiology was established in 1952 and the first experiments focused on actions of plant hormones on growth and development of cultivated plants.The free radical research started in the middle of 1990s when Professor László Erdei was appointed as a head of the Department.Since then the investigations focused on the role of reactive oxygen and nitrogen species in the mechanism of plant hormones action and in the acclimation of plants to adverse environmental conditions.This article shows the development of free radical research and the main topics in progress at the Department of Plant Biology, University of Szeged.