Stable transformation of Medicago truncatula cv. Jemalong for gene analysis using Agrobacterium tumefaciens.

Medicago truncatula is a model legume that has all the genomic resources to be suitable as a model for functional genomics. Transformation to produce transgenic plants is part of this toolkit, enabling a spectrum of approaches to study gene function: including knockdown, overexpression, reporter genes for gene expression, and proteins tagged with fluorescent proteins such as GFP. A special genetic line is necessary for transformation and Jemalong 2HA derived from cv. Jemalong is used in the methods described. Leaf explants can be used for the transformation of the embryonic stem cells to produce the transgenic somatic embryos for regeneration. An auxin and a cytokinin are the key hormone requirements for regeneration by somatic embryogenesis but other hormones such as abscisic acid can be used to augment the system. As the explants used in this system are from leaves, rather than immature embryos or meristematic tissues often used in other species, it is a quite straightforward system. Agrobacterium tumefaciens containing a binary vector suitable for the particular objectives is used to deliver the transgene of interest.