In situ detection of programmed cell death in Nicotiana tabacum leaves during senescence

Leaf senescence is a highly regulated developmental process, during which cell constituents are dismantled in an ordered progression. The final death phase of senescence is a type of programmed cell death (PCD). We showed DNA fragmentation characteristic for PCD by terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) assay not only in senescing leaves but also in young, still developing tobacco leaves.