Optimization of Key Bombardment Parameters in Biolistic Mediated Transformation in Wheat

Abstract

Biolistic mediated method is an important approach in wheat genetic transformation. The objective of this study was to optimize the bombardment parameters and establish an efficient and stable biolistic transformation system using common wheat (Triticum aestivum L.) variety Kenong 199 with 12 treatments of parameter combinations composed of gold particle size, target distance, and acceleration pressure. The results indicated that different combinations of parameters had different effects on the transient expression of GUS gene encoding β-glucuronidase, regeneration of calli, and final transformation efficiency. The parameter combination of 0.6 μm gold, 5.5 cm target distance, and 650 psi acceleration pressure exhibited good regeneration and the highest level GUS transient expression. Furthermore, stable expression of GUS gene in transgenic lines was confirmed by histochemical staining assay. Of the 28 transgenic T0 plants obtained, 12 were from the treatment with the above optimized parameter combination, with an average transformation efficiency of 2.45%.