Authors : L. LE GOFF, M. BELJANSKI
Proc. Fifth Int. Conf. Plant Path. Bact. Cali, 1981, p. 295-307
Available in English only
ABSTRACT: The effects of the carcinogen dimethylbenz (a)anthracene, of antimitotic drugs (cyclophosphamide and daunorubicin), of the plant hormone (auxin IAA) and the antimitotic mitomycin C were investigated in vitro on cancer and healthy DNA from pea seedings, inoculated or not, with oncogenic agrobacterium tumefaciens. These substances stimulate in vitro both synthesis and strand separation of Crown-gall DNA as well as oncogenic A. tumefaciens DNA, while they have little effect on normal plant DNA as is the case with E.coli and non-oncogenic A. tumefaciens DNA. This correlates with the substance-enhancing-power on in vivo Crown-gall cell multiplication. Growth-stimulatory or inhibitory-effects are antagonized by the tumorless action of E. coli small size RNA-fragments. Plant ribonuclease is under control of all these compounds and the RNA-fragments compensate for increased or decreased ribonuclease activity induced by cyclophosphamide, daunorubicin, dimethylbenz(a) anthracene or auxin. There appears to be a correlation between ribonuclease activity and Crown-gall cell development.