Electrochemical monitoring of plant stress responses

Intact cultured cells of Nicotiana tabacum BY2 cells exhibited the electroc hemical reduction of I, l-benzoquinone (BQ), 2,6-dichloroindophenol (DCIP), hexacyanoferrate (ferricyanide). This was detected by amperometry with fix ed potential (400 mV vs. Ag/AgCl) using a film-coated phi 1.6 mm platinum d isk electrode as a working electrode. The electrochemical activities of BQ, DCIP, and ferricyanide mixed with BY2 cell were changed after the addition of various stress compounds such as elicitors, plant hormones, metabolic a nd electron transport inhibitors. Different stress compounds gave di differ ent electrochemical patterns probably due to the different positions of ele ctron accepters affected by these bio-materials. In addition, we observed t he generation of hydrogen peroxide in BY2 cells treated with various stress compounds, The pattern of chemiluminescence is useful for the determinatio n of the intensity of plant stress responses. High accumulation of hydrogen peroxide was observed in the BY2 cells treated with elicitors (salicylic a cid and ethylene glycol chitin) and plant hormone (2,3-D). A relationship b etween electrochemical patterns and stress compounds were also discussed.