Biological and Molecular Evidence for the Transgenosis of Genes from Bacteria to Plant Cells

Specialized transducing phages (λ and ϕ80) have been used as vectors in the transfer of genes (wild type and mutant) from the bacteriumEscherichia coli to haploid cell lines of the plantsLycopersicon esculentum andArabidopsis thaliana . The overall phenomenon of transfer, gene maintenance, transcription, translation, and function has been termed transgenosis. Transgenosis of galactose and lactose operon genes was detected by survival and growth of the plant cells on defined medium with galactose and lactose as sole sources of bulk carbon. Phages carrying a defective operon, unrelated bacterial genes, or no bacterial genes, do not affect the normal result of death on these media, nor do they prevent growth on optimal growth media. Transgenosis of theE. coli genez (lac operon) was confirmed by a biochemical-immunological test specific forE. coli β-galactosidase. Plant cells were unable to effectively suppress anE. coli nonsense mutation. TheE. coli mutant suppressor gene,supF + , specifies insertion of tyrosine at amber (UAG) nonsense codons. Introduction ofsupF + results in a lethal transgenosis on medium normally optimal for plant cell growth. It is concluded that amber codons are vital to the life of plant cells. Differentiating cells ofA. thaliana were not affected bysupF + .