The Role of SV Ion Channels Under the Stress of Mycotoxins Induced in Wheat Cells—Protective Action of Selenium Ions

Mycotoxin stress, one of the currently intensively studied, was stimulated in wheat hypocotyl cells through the application of zearalenone, produced by Fusarium fungi. The differences of reactions in the activation of the SV ion channels between stress-tolerant (Parabola) and sensitive (Raweta) wheat cultivars have been studied by the patch-clamp technique. No impact of zearalenone on SV channel activity was observed in Parabola. However, in the sensitive cultivar, mycotoxin (30 µmol L−1) evoked a significant decrease in the unitary conductance of the channels—from 22 ± 0.4 pS (n = 5) in the control to 18 ± 0.5 pS (n = 7) in zearalenone-treated vacuoles (potential clamped at 100 mV). A combined treatment of zearalenone and selenium (5 µmol L−1 of Na2SeO4) abolished this effect totally, indicating the importance of this element in the defense mechanism of cells under the stress of mycotoxins. The role of differences in the membrane structure between tolerant and sensitive cultivars induced in stress conditions, as one of the main factors in mechanical stability of channels, has been discussed.