Establishment of a Rapid and Stable Transgenic System by Agrobacterium-Mediated Transformation of the Germination Seeds in Diploid Strawberry.

Abstract BackgroundStrawberry (Fragaria) is regarded as a model plant for both Rosaceae and non-climacteric fruit ripening. Although much progress has been made in the identification of gene function using traditional, stable and transient genetic transformation systems in strawberry, the limitation is, more or less, present. Thus, development of a rapid, efficient, and stable transformation system is required for strawberry research and breeding.ResultsHere, using diploid Hawaii-4 (Fragaria vesca) seeds and a reporter gene of CHLH (the H subunit of magnesium chelatase magnesium chelatase) , we first develop a new, rapid, efficient, and stable transgenic system by the Agrobacterium-mediated seed transformation to silence the reporter gene, obtaining a transformation frequency with 10 % through a series of optimization conditions, including full imbibition and initial germination, shaking infection for 24 h, dark cultivation on MS medium for 3 d at 24 ℃, light culture on MS-Tim medium for 1 week at 24 ℃, and vector construction carried fluorescence label. Taken together, radicle-emergence germination seeds, appropriate Agrobacterium concentration and infection time are critical for successful transformation, obtaining transgenic kanamycin-resistant seedlings within 1 month and T2 generation transgenic plants within 4 months. ConclusionsWe first have successfully established Agrobacterium-mediated transformation of germinating seeds (AMTGS) in diploid strawberry (F. vesca), providing a useful tool for studying non-climacteric fruit ripening and strawberry breeding.