Cadmium-Induced Programmed Cell Death Signaling in Tomato Suspension Cells

ABSTRACT

Here we present a summary of our study on cadmium-induced cell death signaling in a model system of suspension-cultured tomato cells. Exposure of the cells to CdSO₄ induced typical for PCD (cytoplasm shrinkage and nuclear condensation) morphological changes of the dead cells. Ethylene and hydrogen peroxide were established to increase in response to Cd stress. By inhibitory studies we have demonstrated that CdSO₄ induces cell death in tomato suspension cells that involve plant caspase-like proteases, indicating that Cd-triggered cell death is a form of programmed cell death. It is also shown that serine peptidases, oxidative stress, lipid signaling and ethylene are players in the Cd-induced cell death signaling. Cd-induced cell death in tomato suspension cells was categorised as non-lysosomal type.

Keywords:

• cadmium
• ethylene
• lipid signaling
• oxidative stress
• programmed cell death