Genotypic, electrophysiological responses of leaf cells to NaCl salinity in Olea europaea L.

Astudy of electrophysiological responses obtained from olive (Olea europaea L.) leaf cells subjected to treatments with NaCl at 25 and 100 mM is reported. Trials were conducted on two cultivars characterized by different salt sensitivities: ‘Frantoio’ and ‘Leccino’. In both cultivars, the response to salt is articulated in three sequential phases: depolarization, lag and repolarization. From an energetic perspective, the first phase was revealed to be a passive process while the last phase demonstrated a close metabolic dependence. In ‘Frantoio’ (the more tolerant cultivar), the repolarization phase was greater and was completed more quickly than in ‘Leccino’. Activation of a plasmalemma ATP-driven proton pump appears to be a common event in the response to NaCl. Other causes, however, are not to be excluded (such as alteration of the membrane selectivity) to explain the different behavior in the two cultivars. Considering the ease with which material can be obtained and the relatively brief time required for testing, these electrophysiological responses can constitute an integrative tool in salt tolerance screening.