Fusicoccin‐induced membrane depolarization, K+ efflux and extracellular alkalinization in leaves of Vigna unguiculata

摘要: Abstract. In leaves of three different cultivars cowpeas (Vigna unguiculata), the fungal toxin fusi-coccin (FC) induced a plasmalemma depolarization from -175 to -100mV, value slightly below N2-determined diffusion potential in dark, and lesser extent light. The was preceded by usual initial membrane hyperpolarization (up 18mV). accompanied considerable K+ efflux extracellular alkalinization. Primary secondary as well stem tissue plants, grown under long-day conditions or dark responded similarly. Dark O2 uptake hypocotyls stimulated FC up 77 87%, respectively. contrast, caused typical Em hyperpolarization, influx, acidification smaller stimulation respiration (50%) other legumes such mungbean radiata), soybean (Glycine max). Leaves navy beans (Phaseolus vulgaris) revealed an intermediate response FC. unusual effect Vigna might be related production toxic catabolites during degradation fermentation storage products necessary meet strong energy requirement pm-H+ ATPase.