Arabidopsis ecotypes and mutants that are recalcitrant to Agrobacterium root transformation are susceptible to germ-line transformation

Germ-line transformation (vacuum infiltration) is frequently used to transf orm Arabidopsis thaliana using Agrobacterium tumefaciens. We have recently identified several Arabidopsis ecotypes and T-DNA-tagged mutants that are r ecalcitrant to Agrobacterium-mediated transformation of cut root segments. Some of these ecotypes and mutants are deficient in their ability to bind b acteria. Some are deficient in T-DNA integration. We report here that using a germ-line transformation protocol we transformed these ecotypes and muta nts, including attachment- and integration-defective Arabidopsis plants, wi th a frequency similar to that of highly susceptible wild-type plants. Howe ver, we could not transform otherwise highly susceptible Arabidopsis plants by germ-line or root transformation using several vir and attachment-defic ient Agrobacterium mutants. These results indicate that certain plant facto rs important for transformation may exist in germ-line tissue but may be la cking in some somatic cells.