An Epigenetic Study of Bacterial NPTII Gene Expression in Agrobacterium Tumefaciens and A. Rhizogenes Mediated Potato Transformants

Abstract

A bacterial nptII gene expression in two different potato (Solanum tuberosum) transformation systems has been studied. The variabiliy of the gene expression observed in Agrobacterium tumefaciens mediated transformants, as compared with A.rhizogenes mediated ones, has been ascribed to the involevement of the DNA methylation processes. The already established inverse correlation between the distribution of the critical 5-methyl cytosine (5mC) into the gene sequence and its expresssion has been demonstrated using specific DNA methylation sensitive methods („in vitro= treatements with the known DNA methyltransferase inhibitor 5-azacytidine and the specific DNA methylation sensitive restriction with the isoschisomeric pair MspI/HpaII). A possible explanation linked with the influence of the intergenic interractions introduced by the two different transformation systems upon the nptII alogene in the transformed potato genome is discussed.