The retraction of the protoplast during PCD is an active, and interruptible, calcium-flux driven process.

The protoplast retracts during apoptosis-like programmed cell death (AL-PCD) and, if this retraction is an active component of AL-PCD, it should be used as a defining feature for this type of programmed cell death. We used an array of pharmacological and genetic tools to test if the rates of protoplast retraction in cells undergoing AL-PCD can be modulated. Disturbing calcium flux signalling, ATP synthesis and mitochondrial permeability transition all inhibited protoplast retraction and often also the execution of the death programme.

Mitochondrial Markers of Programmed Cell Death in Arabidopsis thaliana.

In plants, apoptosis-like programmed cell death (AL-PCD) is readily distinguished from other forms of programmed cell death (PCD) through a distinct morphology. Detection of cytochrome c release from mitochondria and changes in mitochondrial morphology are the earliest markers for detection of this form of PCD in plants. In this chapter we provide detailed technical methods for the visualization of both of these mitochondrial markers of AL-PCD in Arabidopsis.