Establishment of A Rapid and Stable Infected System by Agrobacterium-Mediated Transformation of Germination Seeds in Diploid Strawberry.

Abstract Background Strawberry (Fragaria) is regarded as a model plant for both Rosaceae and non-climacteric fruit ripening. Although much progress has been made in identification of gene function using stable and transient genetic transformation systems in strawberry, the limitation is, more or less, are present. To this end, development of a rapid, efficient, and stable transformation system is required for strawberry research and breeding. Results Here, using diploid Hawaii-4 (Fragaria vesca) seeds and a reporter gene of CHLH (the H subunit of magnesium chelatase magnesium chelatase) key to chlorophyll synthesis, we first develop a rapid, efficient, and stable infected system by the Agrobacterium-mediated seed infection to silence the reporter gene, reaching an infection frequency with 28.3% through a series of optimization elements, including seed 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 tagged with fluorescence label. Taken together, radicle-emergence germination seeds, appropriate Agrobacterium concentration and infection time are critical for successful infection, finally obtaining the infected kanamycin-resistant seedlings of T1 generation by infected wild seeds within 1 month and T2 generation-infected plants within 4 months. Conclusions The Agrobacterium-mediated infection of germinating seeds (AMTGS) in diploid strawberry (F. vesca) is first established, providing a useful tool for gene function identification and improved agronomic traits in strawberry.