Efficient regeneration and genetic transformation of fig (Ficus carica) from stem thin cell layer explants

In this study, a rapid, efficient, and stable Agrobacterium-mediated genetic transformation system was successfully developed using stem slices of fig cultivar ‘117D’ as explants. In the Murashige and Skoog (MS) basal medium supplemented with 2 mg·L^-1 thidiazuron (TDZ) and 0.05 mg·L^-1 1-naphthaleneacetic acid (NAA), the highest shoot-induction rate was 53.33%, while the medium with a hormone ratio of 3 mg·L^-1 TDZ and 0.05 mg·L^-1 NAA achieved a maximum callus-induction rate of 78.89%. The optimal infection parameters for fig callus and stem slices were obtained by infecting thin cell layers (TCLs) with Agrobacterium tumefaciens K599 (OD₆₀₀ = 0.6) under vacuum for 10 min, and shaking at 120 r · min⁻¹, 28 ℃ for 30 min. Finally, transgenic callus and plants were identified through green fluorescent protein (GFP) screening, β-glucuronidase (GUS) staining, PCR analysis, and Western blot analysis, successfully obtaining positive FcMYB114-overexpressing (FcMYB114-OE) callus and three transgenic plants. Utilizing these FcMYB114 transgenic callus and plants allows us to gain deeper insights into their roles in the growth, development, and metabolism of fig. In the future, we aim to identify new regulatory factors and leverage this efficient transgenic technology to investigate the regulatory mechanisms of key molecules in fig. The advancement of fig regeneration and transgenic systems provides a valuable tool for validating genetic functions in fruit trees and enhancing the agronomic traits of fig.