Pulsed electric field (PEF), among numerous stresses, provides a large potential as an external stimulus to enhance secondary metabolite biosynthesis from plant cell cultures. PEF treatment was combined with the sub-culturing technique to increase phenylalanine ammonia lyase (PAL) activity, the key enzyme for secondary metabolite synthesis from tomato cell culture. In reference to the analysis, maximum accumulation of total phenolic (TP) compounds in the cells was determined as a function of stress reaction time (SRT). Also, PEF application increased PAL activity. PEF resulted in an increase in the porosity of the cell membrane, thus decreasing cell vitality. On the other hand, SRT decreased vitality, while increasing TP content. Sub-culturing enhanced the cell structure and improved the cell membrane permeability. PEF treatment potentially offers an alternative to other methods for increasing PAL activity in plant cell cultures. (C) 2016 Elsevier Ltd. All rights reserved.