Generation of marker-free and backbone-free transgenic plants using Agrobacterium containing a plasmid comprising a transfer DNA gene and a plant hormone biosynthesis gene

摘要

A method of producing a transformed plant that does not contain a selectable marker in its genome that comprises the steps: (a) Infecting a cell of a plant with Agrobacterium containing a plasmid that comprises (i) a transfer-DNA sequence that does not contain a selectable marker gene and (ii) an expression cassette containing a selectable marker positioned in the plasmid's backbone outside of the transfer-DNA sequence, for expressing a cytokinin biosynthetic gene, so as to produce at least one transformed plant cell; (b) Culturing the plant cell on either (i) a hormone-free medium to produce shoots or (ii) on a medium that contains an amount of a hormone at a concentration sufficient to cause or improve the regeneration of the transformed shoot, but is insufficient to promote the regeneration of untransformed shoots; and (c) Identifying either in the shoots or in a plant grown from the shoots the presence of the transfer DNA sequence in the genomic DNA of the plant but not the cytokinin biosynthetic gene expression cassette.