We monitored the cellular localization of fluorescently labeled foreign DNA
in living plant cells. After physical delivery of labeled DNA fragments to
the cytoplasm, short fragments up to 1.5 kb in length were found equally d
istributed between the cytoplasm and nucleus after 60 min. In contrast, 2.5
kb DNA fragments did not appear inside the nucleus. Thus, foreign DNA can
enter plant nuclei through the intact nuclear envelope, but the efficiency
of this process declines with increasing size of fragment.