Improved Efficiency of Agrobacterium Mediated Genetic Transformation of Plants

Dramatically Improves In Vitro Plantlet Regeneration, Suggesting Potential to Modify Crop Species Previously Impossible to Engineer

Agrobacterium is widely used to introduce new genetic material into various plant species. But the success of this method for genetic transformation requires successful in vitro regeneration of plantlets through tissue culture. The success of the tissue culture step is highly variable, depending on both plant species and cultivar, with some crop species being very difficult to genetically engineer. Adding a vector expressing one or more wound-induced transcription factors improves the efficiency of genetic transformation by promoting de novo regeneration of shoots in adult plants following mechanical injury.

Researchers at the University of Florida have further refined the use of Agrobacterium-mediated gene transfer for genetic engineering. The inclusion of a vector expressing one or more developmental regulators and in planta transformation at a wound site improves transformation efficiency and enables modification of economically important crop species previously difficult or impossible to engineer.

Application

Refined use of Agrobacterium mediated gene transfer for the genetic engineering of a wide variety of plant species previously difficult to modify and improve

Advantages

• Improves well-established technology, exogenous DNA delivery to plant cells through Agrobacterium infection, by including a specialized expression vector, greatly reducing the experimentation needed to regenerate the modified plants in tissue culture
• Accelerates the generation of transgenic plants for testing
• Improves efficiency and reduces time required to genetically engineer a wide variety of plants, especially those previously difficult to regenerate from tissue culture, such as perennial plant species

Technology

Plant genetic transformation is crucial for applying biotechnology, such as genome editing, to basic and applied plant science research. Its success primarily relies on the efficiency of gene delivery into plant cells and the ability to regenerate transgenic plants. University of Florida scientists exploited the potential of these wounding-induced transcription factors and developmental regulators for de novo shoot regeneration after mechanical injuries and in vitro shoot regeneration. Developmental regulators PLETHORA (PLT5) and WOUND INDUCED DEDIFFERENTIATION 1 (WIND1) are included in an expression vector, and applied by injection of Agrobacterium tumefaciens, promoting calli formation and regeneration of transformed shoots at the wound positions of aerial stems. These development regulators improve shoot regeneration and transformation in a wide variety of plant species. The results demonstrate manipulation of specific developmental regulators is an effective approach to improve in planta and in vitro transformation efficiency. This transformation system can be used to facilitate the application of genome editing and other genetic engineering of agricultural crops.