Fungal elicitor-induced cell death in Taxus chinensis suspension cells is mediated by ethylene and polyamines

Abstract

The involvements of ethylene and polyamines in cell death induced by fungal elicitor from Asperillus niger in Taxus chinensis suspension cells were studied. Exogenous fungal elicitor stimulated cell death and enhanced ethylene production and polyamine putrescine, spermidine and spermine concentrations compared with the control. Cell death, ethylene production and putrescine concentration induced by elicitor were increased by the precursor of ethylene biosynthesis 1-aminocyclopropane-1-carboxylic acid (ACC), while were overcome by ACC together with the inhibitor of ACC synthase aminoethoxyvinylycin. In contrast, fungal elicitor-induced cell death was decreased by, and ethylene production and putrescine concentration were enhanced by the inhibitor of ethylene action silver thiosulphate. Since the biosynthetic pathways of ethylene and polyamines are linked through S-adenosylmethionine (SAM), this promoted further probation into the roles of polyamines in cell death. Exogenous polyamines putrescine, spermidine and spermine all reduced elicitor-induced ethylene production and cell death. Blocking endogenous polyamine concentrations with methylglyoxal ( bis-guanylhydrazone) stimulated elicitor-induced ethylene production and cell death. These results indicated that ethylene promoted while polyamines alleviated elicitor-induced cell death.