Oligochitosan induces programmed cell death in tobacco suspension cells

► Oligochitosan induces PCD which was mediated by cytochrome c in tobacco cells. ► Oligochitosan triggers [Ca2+]cyt elevation, NO and H2O2 production in PCD. ► Ca2+ and NO prevent oligochitosan-induced PCD by modulating cytochrome c release. ► H2O2 is involved in oligochitosan-induced PCD, but its role remains unclear.