Impact of beauvericin on membrane properties of young initial leaves of maize with different susceptibility to Fusarium

Abstract

In the present study the impact of beauvericin (BEA) on the cell membrane properties and respiration of young initial leaves of maize were studied using two maize cultivars differing in their susceptibility to Fusarium sp. BEA significantly depolarized EM of leaf parenchymal cells and this depolarization showed time and dose dependency regardless on the sensitivity of maize cultivars to Fusarium. However, the extent of BEA-induced depolarization was 2-5 times higher in sensitive cv. Pavla than in tolerant cv. Lucia. Membrane permeability and K+ leakage from leaves cells treated with BEA was higher in sensitive cv. Pavla but the differences were not so considerable than the depolarization of EM. Treatment of maize young initial leaves with 40 μmol BEA significantly inhibited respiration. In accord with electrophysiological measurements inhibition of respiration was higher in sensitive cv. Pavla showing 70% inhibition already after 90 min of BEA treatment while in tolerant cv. Lucia inhibition represented only 27%. The biological activity of BEA seems to be mediated by the ability of BEA to affect membrane permeability and ion transport. This is probably the initial effect of BEA on plant cell leading to subsequent effect on other cell organelles (mitochondria) and cell metabolism.

Keywords

• beauvericin
• membrane potential
• membrane permeability
• respiration
• phytotoxicity
• young maize leaves
• zea mays l