The Establishment Of Transformation System For Mature Wheat Embryos

Wheat (Triticum aestivum L.) is one of the most important crops worldwide. It is great important to improve wheat quality, to enhance wheat stress-resistance and to increase wheat yield by genetic engineering. The success of wheat transformation relies on the high frequency of wheat regeneration system, suitable expression vector, powerful transformation methods, transgene molecular analysis and production of homozygote transgenic lines. So that it is essential to establish the high frequency of plant regenration system from elite wheat cultivar with excellent agronomical characters and the powerful transformation methods.In this paper, mature seeds from elite wheat cultivar EM12 in Hubei province were used as the target materials. Factors which affect frequencies of the embryogenesis and plant regeneration were studied by using wheat mature seeds in order to obtain the high frequency of plant regeneration from the targets are different pretreatments of the seeds for germinating, different kinds and concentration of hormones, and the medium addition with CuSO4, different kinds of explants and placing manners. The optimized system of plant regeneration for mature wheat seeds was established and the conditions for this system were that mature seeds were pretreated for 12 hours at 26℃ and the culture medium containing 1.0mg/L picloram. This system gave the highest regeneration value of 33.60% from cultured scutella. In the meantime, the experimental results also indicated that the frequency of callus induction reached 100% from whole mature wheat embryo; when removing the buds from the original embryos and transferring them to regeneration medium, its frequency of plant regeneration reached 42.50%. On the basis of the established high frequency of plant regeneration system from mature embryo of elite wheat variety EM12, we attempted to apply Agrobacterium mediated transformation for wheat genetic engineering. Different Agrobacterium strains and the effects of acetosyringone had been concerned. The results indicated that the Agrobacterium strain AGL1 harboring the binary vector pAL154/156 gave positive effects.