Heat Shock Induces Programmed Cell Death in Wheat Leaves

Programmed cell death (PCD) was triggered in wheat leaves by a heat treatment (42 °C). This treatment caused DNA fragmentation as shown in DNA laddering analysis and in terminal deoxynucleotidyl transferase-mediated deoxyuridine-5'-triphosphate (dUTP) nick end labeling (TUNEL) analysis. Methanol and acetone treatment of leaves significantly blocked PCD. Western analysis indicated that a 65 kDa poly(ADP-ribose) polymerase-like protein was degraded during the treatment. However, high temperature (80 °C) treatment caused necrosis but not PCD.