Analysis of particle bombardment parameters to optimise DNA delivery into wheat tissues

The objective of this study was to identify the major parameters controllin g DNA delivery by particle bombardment to wheat (Triticum aestivum L.) scut ellum and inflorescence tissue. The main factors studied were the DNA/gold precipitation process, bombardment parameters and tissue culture variables. Efficiency of DNA (uidA gene) delivery was assessed by scoring transient G US expression in bombarded tissues. Of the parameters analysed, amount of p lasmid DNA, spermidine concentration, presence of Catt ions, calcium chlori de concentration, amount of gold particles, gold particle size, acceleratio n pressure, chamber vacuum pressure, bombardment distance, osmotic conditio ning of tissues and type of auxin had a clear influence on transient gene e xpression. A bombardment procedure suitable for elite wheat varieties was d eveloped which allowed high-efficiency DNA delivery combined with reduced d amage to target tissues.