In Planta Transformation in Plants: A Review

In planta transformation has been established as an innovative and simple technique involving a direct transformation of plant parts without involving the tedious tissue culture step. Methodologies of in planta transformation involve different plant parts and strategies. Agrobacterium strain carrying the gene of interest is targeted to the specific plant part either directly or in the induction medium. Vacuum infiltration is sometimes used to facilitate foreign gene integration. Initial studies of this novel technique involved treatment of whole plants with the inoculum, and later shifted to treatments of shoot tips and floral parts, and finally, the female reproductive parts have been targeted. Zygotes, embryos, and seeds have recently been used extensively yielding successful transformation. The method is simple, convenient, and overcomes the problem of tissue culture-induced genetic variability in the transformants. The review traces the origin and development in the in planta methodologies used over the past and the various parameters considered by the workers for increased effectiveness viz. developmental stages, Agrobacterium stain, surfactant, induction medium, etc., in the various crops compiled. Based on the review, it may be inferred that there is immense potential in planta transformation, and the ease of regeneration and selection of transformants in the methods described can be utilized for crop improvement.