Expression of foreign proteins in rice seeds with rice protein gene promoters.

构建了水稻蛋白基因启动子与GUS基因的融合基因，并通过电激法将其导入水稻原生质体。再生转化的水稻植株，并检测报告基因GUS的表达。转基因水稻种子中特异性检测到GUS活性。结果表明，谷蛋白基因启动子和分支酶基因启动子适合于转基因水稻种子中外源基因的表达，乳铁蛋白是一种常见的食品乳蛋白，其N端肽段具有抗菌活性，因此选择乳铁蛋白作为转基因水稻种子中外源基因表达的模式蛋白。化学合成编码乳铁蛋白N-末端肽的寡核苷酸，并将双链DNA片段插入质粒pUC中，并用该质粒转化大肠杆菌。由此获得编码乳铁蛋白的cDNA。将cDNA与上述启动子DNA片段连接并导入水稻原生质体中。转基因水稻正在再生。

Fusion genes of rice protein gene promoter and GUS gene were constructed and introduced in rice protoplast by electroporation. Transformed rice plants were regenerated, and expression of the reporter GUS gene was assayd. The GUS activity was specifically detected in seeds of the transgenic rice plants. It was demonstrated that the gluterin gene promoter and the branching enzyme gene promoter were suitable for the expression of foreign genes in seeds of transgenic rice plants.Milk lactoferrin was selected as a model protein to be expressed in seeds of transgenic rice plants, because lactoferrin is a protein in milk commonly consumed as a food and the protein and its N-terminal peptide have anti-bacterial activity. Oligonucleotides encoding the lactoferrin N-terminal peptide chemically synthesized, and double stranded DNA fragment was inserted in a plasmid pUC and E.coli was transformed with the plasmid. The cDNA encoding the lactoferrin was thus obtained. The cDNA was ligated with the above described promoter DNA fragments and were introduced in the rice protoplast. The trangenic rice plants are now regenerating.