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

构建了水稻蛋白基因启动子和GUS基因的融合基因，并通过电穿孔的方法将其导入水稻原生质体。对转基因水稻植株进行再生，并检测报告基因GUS的表达。在转基因水稻种子中特异性检测到GUS活性。由于乳铁蛋白是牛奶中常见的一种蛋白质，且乳铁蛋白及其N端肽具有抗菌活性，因此选择牛奶乳铁蛋白作为转基因水稻种子表达的模型蛋白。化学合成编码乳铁蛋白N端肽的寡核苷酸，将双链DNA片段插入表达载体pUC，转化大肠杆菌。由此获得了乳铁蛋白的编码基因。将该基因与上述启动子DNA片段连接，并导入水稻原生质体。转基因水稻现在正在再生。

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.