Oligochitosan induces cell death and hydrogen peroxide accumulation in tobacco suspension cells

Abstract

Oligochitosan has been shown to induce several plant defense responses. In the present work, the effect of oligochitosan on tobacco cell survival was investigated. The results showed that oligochitosan caused tobacco cell death in a dose-dependent manner. About 40.6 % tobacco cells died when cultured for 72 h after 500 μg ml −1 oligochitosan treatment. Certain aspects of this cell death process appeared to be similar to apoptosis in animal cells. These included shrinkage of cytoplasm and condensation of chromatin. Oligochitosan also induced H 2O 2 accumulation in tobacco cell suspension culture. The role of H 2O 2 in the signal transduction that leads to cell death was investigated. Co-treatment of tobacco cells with oligochitosan and catalase inhibited H 2O 2 accumulation but did not inhibit the induction of cell death. The results suggested that apoptosis-like cell death of tobacco cells induced by oligochitosan is independent of H 2O 2 signal pathway.