蓝细菌血畿飞逝基因的克隆及其向甘蓝型油菜中的转化

血红蛋白存在于动物、植物、细菌、真菌、酵母、藻类、原生动物等生物体中。利用PCR方法克隆了蓝细菌Synechocystis sp. PCC 680的血红蛋白基因SLR2097，该基因属于“truncated”血红蛋白家族，大小为375 bp，编码123个氨基酸残基。数据库搜索的结果显示所有的血红蛋白都有一个保守基序，即‘F-[L]-x(4)-[G]-G-[T]-x(2)-[Y]-x-[G]-[R]-x-[M]-x(3)-H’, “truncated”血红蛋白家族也有该结构，表明它们的进化祖先相同。将获得的SLR2097连接到双元载体pCAMBIA1300-CaMV35S上，并转化甘蓝型油菜品种宁油12。转基因油菜表型分析表明，血红蛋白基因SLR2097在油菜中的表达促进油菜的生长并缩短发育期，引起早熟，这些表型对改良油菜的农艺性状有重要的应用价值。

Cloning and Analysis of Hemoglobin Gene in Cyanobacterium and Transformation into Brassica napus L.

Hemoglobin exists in most organisms including animals, plants, protozoa, algae, bacteria and fungi. In the paper, hemoglobin gene SLR2097 was cloned from Synechocystis sp. PCC 6803, which is 375 bp in size and encodes123 amino acid polypeptide chains belonging to the truncated hemoglobin family. Hemoglobin canbind oxygen and co-ordinate the heme iron with protein ligation. Database search showed that a motif ‘F-[L]-x(4)-[G]-G-[T]-x(2)-[Y]-x-[G]-[R]-x-[M]-x(3)-H’ occurred in hemoglobins. Therefore, the truncated hemoglobins might evolve from the same ancestor of hemoglobin. The hemoglobin gene SLR2097 was ligated into binary vector pCAMBIA1300-CaMV35S, and then transformed into rapeseed cultivar Ningyou 12 with Agrobacterium mediated transformation method. Phenotype analysis indicated that the expression of hemoglobin gene SLR2097 led to the earlier maturity of transgenic rapeseed. These phenotype variations have a potential application in the rapeseed production in the future.