Studies On The Transformation Of Wheat With Genes Resistant To PHS By Microprojectile Bombardment

Wheat faces preharvest sprouting (PHS) as serious threat to its yield loses which makes farmers depressed. For a long time, the traditional breeding method is hardly to improve the resistance to PHS, as a result, using transgenic technology to transferr the resistance gene of Pre-harvest Sprouting into wheat, become an effective measure to increase the resistance.The Character of Pre-harvest Sprouting is co-regulated by polygenic, stable inheritance, but vulnerable to environmental fluctuations. Transferring the exogenous Gene—Gpcr (ABA cell surface receptors) into wheat genome, for improving the sensitivity to the ABA. Then transfer the monocotyledon expression vector (silence the CYP707A1 gene) into wheat genome, which can influence the ABA metabolism pathway. This can raise the ABA content, prolonging the seed dormancy and improve the resistance to Pre-harvest Sprouting.In this study, the resistance gene of PHS such as CypA、CypB、CypC、Gpcr and Vp1 were introduced into wheat varieties Zhengmai 9023 simultaneously via biolistic co-bombardment. According to the resistance identification by mannose or bialaphos and PCR identification, we had obtained transgenic wheat plants containing these genes. The main results were as follows:(1) We have obtained 7 To transgenic plants contain Gpcr gene and 11 To transgenic plants which silenced CYP707A1 gene via particle bombardment, using the minimal expression cassette with bar as the selection marker. For PCR and RT-PCR indentify of later generation,1 T3 transgenic line which contains Gpcr gene and CypB gene can hereditary stability, and the target genes were properly transcribed in wheat embryo.(2) We have obtained 16 To transgenic plants containing Vpl gene via particle bombardment, using the minimal expression cassette with bar or PMI as the selection marker.5 transgenic wheat plants were obtained among 53 regenerated plants by PMI/mannose selective system, while 11 transgenic wheat plants were obtained among 152 regenerated plants by bar/bialaphos selective system.(3) Choose T3 generation transgenic plant seeds which silenced CYP707A1 gene to test endogenous ABA level, result showed that endogenous ABA leve of transgenic plant seeds were increased 20% more than non-transgenic plant seeds. Proved that through silenced CYP707A1 gene to regulate ABA contant is available in wheat.(4) PHS analysis of transgenic lines. Through the seed germination assay and PHS assay of T3 transgenic plants containing CypB and Gpcr, result showed that drgee of PHS and germination index of transgenic plants had reduced compare to non-tansgenic plants.