Transformation of sundew: pitfalls and promises

Functional studies and exploitation of pharmacological potential of sundews (Droseraceae) require efficient and reliable transformation protocol. However, the routine applicability of available procedures appears limited and transformation of sundew remains a difficult task. Here we report on in-depth evaluation of the previously published method and bring some modifications. We suggest addition of glutathione in cultivation media and protection from light for suppression of necrosis. Further we show that sundew leaf extracts exert antimicrobial activity, therefore we recommend selection of tolerant Agrobacterium strain. At the same time we conclude that A. rhizogenes is not suitable for sundew transformation since produces only albino plants. To support regeneration of transformed shoots we propose to use GFP as a vital marker for early identification and removal of escapes and chimeras. The modified protocol we provide enables a routine and reliable selection of stably transformed sundew plants.