Cytological detection of poly (ADP-ribose) polymerase

An attempt was made to demonstrate poly (ADP-ribose) polymerase cytologically. In vitro incorporation from the nucleotide, ³H]NAD was detected in frozen sections of onion embryo and meristematic tissue by autoradiography. In meristematic tissue, there was a correlation between the number of cells displaying intensein vitro incorporation from ³H]NAD and cytological DNA polymerase activity. Performed enzymes effecting a distinct incorporation from ³H]NAd were localized in the nuclei of all tissues of the ungerminated seed except the endosperm. Evidence for poly (ADP-ribose) polymerase has been obtained for the first time from higher plant cells and localized cytologically.