Application of the comet assay in studies of programmed cell death (PCD) in plants

Programmed cell death (PCD) in plants is an intensively investigated proces s. One of the main characteristics of PCD in both animal and plant organism s is the non-random, internucleosomal fragmentation of nuclear DNA, usually analysed using total DNA gel electrophoresis or TUNEL method. In this pape r we present application of the "comet assay" (Single Cell Gel Electrophore sis) for detection of nDNA degradation in studies of PCD during plant life cycle. We analyzed three types of tissue: anther tapetum, endosperm and mes ophyll which were prepared in different ways to obtain a suspension of viab le cells (without cell walls). The comet assay gives a possibility of exami nation of the nDNA degradation in individual cell. This method is significa nt for studies of the plant tissue differentiation and senescence especiall y in the cases when it is not possible to isolate large number of cells at the same developmental stage.