Evidence for TAM3 activity in transgenic Arabidopsis thaliana

The Antirrhinum majus Tam3 element was introduced into Arabidopsis thaliana protoplasts and plants in order to assess the influence of an in vitro culture phase such as protoplasts and callus culture on the mobility of this transposable element in this plant species. The constructs used contained the Tam3 element inserted in between the CaMV 35S promoter and the gus- or hpt-coding region, allowing a direct selection of excision candidates. From the different approaches used, only a long-term callus culture allowed us to detect Tam3 activity. No Tam3 activity could be detected in protoplasts or protoplast-derived microcolonies. Our data are compared with those previously reported for Tam3 in tobacco and petunia.