17] Binary ti vectors for plant transformation and promoter analysis

Abstract

This chapter discusses binary Ti vectors for plant transformation and promoter analysis. In recent years, several studies have demonstrated the use of the naturally occurring Ti plasmids as transformation vectors for higher plants. In the technique, exogeneous DNA is either inserted into the tDNA region of the Ti plasmid by homologous recombination using an intermediate vector system or directly into one of the recently designed binary vectors. The binary vector system is a convenient way to transform higher plants, because foreign DNA can first be inserted into the vector and manipulated using E. coli as a host. The chapter illustrates an example of binary Ti vector and the important features of the molecule, pGA482, which is 13.2 kbp long for simple and efficient plant transformation. The chapter describes the two different methods that are used to move the binary vector to Agrobacterium triparental mating and direct DNA transfer. The chapter mentions that clonal transformation is enhanced by the protoplast cocultivation method. Cultured tobacco calli can be transformed by the Ti vector system.