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

Hemoglobin gene SLR2097 was cloned from Synechocystis sp. PCC 6803, which was 375 bp in length and encodes a 123-amino acid polypeptide chain involved in truncated hemoglobin family. Hemoglobin can bind oxygen and coordinate 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 transferred into rapeseed cultivar Ningyou 12 with Agrobacterium-mediated transformation method. According to phenotyping analysis, the expression of gene SLR2097 facilitated growth and development of the transgenic rapeseed with shortened growth duration and early maturity.