Impact of fusaproliferin on primary roots of maize cultivars differing in their susceptibility to Fusarium

Abstract

Effects of fusaproliferin (FUS) on membrane potential (EM), electrolyte leakage, enzymes activity and respiration of roots, were studied in two maize cultivars (Zea mays L.), differing in their susceptibility to this toxin. In short-term experiments (≤ 6 h), EM has been rapidly and significantly depolarized by FUS. The rapidity of EM depolarization in tolerant cv. Lucia was more expressive in comparison with susceptible cv. Pavla, but the extent of EM depolarization was higher in cv. Pavla. In both maize cultivars, higher depolarization of EM was registered in cells of root zone I. In long-term experiments after the first EM depolarization, which occurred during the first 6 h of FUS treatment, gradual depolarization continued up to 24 h and was represented not only by the active component (EP) but also by the passive component (ED) of EM. The decrease in EM and ED was followed by a loss of K+ ions from FUS treated roots of both cultivars. The leak of K+ ions from the root cells of both root zones as well as both maize cultivars increased with the time of FUS treatment and was significantly higher in susceptible cv. Pavla than in tolerant cv. Lucia. FUS treatment of maize roots resulted in a significant decrease of root respiration which was higher in susceptible cv. Pavla than in tolerant cv. Lucia.