AGROBACTERIUM-MEDIATED TRANSFORMATION AND EXPRESSION OF FOREIGN GENESIN MEDICAGO-TRUNCATULA

Medicago truncatula Gaertn. (barrel medic) is a pasture legume and a m odel plant for studying the molecular genetics of the Rhizobium-legume symbiosis. Using the highly regenerable seed line Jemalong 2HA and Ag robacterium tumefaciens (LBA4404), Medicago truncatula can be reliably transformed. The binary vector utilised was pBI121 containing the npt II and uidA genes under the control of the NOS and CaMV 35S promoters, respectively. Kanamycin-resistant embryogenic calli were produced fro m 17% of the initial leaf explants and on ave!rage each one of these e mbryogenic calli produced a single regenerated plantlet. Regenerated p lants showed varying gene copy number and gene location. GUS activity was detected in roots, stems and leaves. The progeny of a regenerated plant containing a single gene copy segregated in a Mendelian fashion. This study confirms the value of Jemalong 2HA for producing transgeni c plants for biological and agricultural studies.