An Efficient Pollen Tube Pathway-Mediated Transformation Technique of Primula forbesii

Abstract Background: Primula forbesii is a biennial herb of the genus Primula, with short growth cycle and long flowering period. It is an excellent material for investigating the phenomenon of heterostyly. However there is no stable genetic transformation system so far. In order to provide tool for molecular research of P. forbesii, we provide a simple, cost-efficient pollen tube pathway-mediated transformation method. Result: Using S-morph and L-morph plants of P. forbesii as materials, anthocyanin synthesis gene AtPAP1 as marker gene, the optimal infection method was explored. The best infection time is 8-12 h after pollination. Using 1/2 MS+5 % sucrose solution as infection buffer (pH=5.6), Agrobacterium cell density with OD600 1.0, adding 0.02 % Silwet-77 before infection, adding 3 drops of infection solution using a sterile syringe on the stigma is the best infection method. The gene had been successfully transformed into P. forbesii, and the transformation efficiency reached 5.33 %. The leaves of the transgenic plants were obviously red, the anthocyanin content was increased by 6 - 49 times, the expression of the target gene was increased by about 200 - 2000 times. Conclusion: The pollen tube pathway-mediated transformation technique of P. forbesii was established for the first time, and the exogenous gene can be transformed simply and quickly, which provides a powerful tool for the molecular research of P. forbesii.