Generation of transgenic Linum perenne by Agrobacterium-mediated transformation

Here we report new methods for tissue culture, plant regeneration, and Agrobacterium-mediated transformation of perennial flax (Linum perenne). To generate transgenic plants, L. perenne hypocotyls were co-cultivated with Agrobacterium harboring a binary vector (pBI121 or pRI909) for 2 days. The transgenic calli and shoots were induced on Murashige-Skoog medium supplemented with 10 mu M 6-benzylaminopurine and 0.3 mu M 1-naphthalenacetic acid under selection with 100 mg l(-1) kanamycin. For root induction from the shoots, 0.1 mg l(-1) indole-3-butyric acid was found to be most efficient. We transformed four types of binary vectors encoding a florigen gene under the control of 35S or phloem-specific promoters. Transgenic plants were obtained with high efficiency (4-24%) and exhibited early flowering phenotypes. Our transformation method will contribute to future studies of L. perenne that require transgenic plants.