Non-destructive transformation ofArabidopsis

Culture conditions are reported in which roots ofArabidopsis thaliana grow abundantly along the surface of, rather than down into, a solid matrix. Such root segments can be explanted without killing of the plant, which can then complete its life cycle. Non-destructive explanting permits transformation of heterozygous plants without preventing subsequent segregation and of plants that can only be obtained from a population segregating for a marker expressed late in growth. Moreover, the speed and abundance of surface root growth provides a rapid non-destructive phenotypic assay of response to selective conditions.