Cloning DDSA Gene, The Key Gene Of CoQ₁₀ Biosyhthesis Pathway And Transformating Into Rice

Almost a half of peopel in the world feed on rice (Oryza sativa L. ), so the merits of the nutritional quality of rice have a direct impact on human health.In rice the main content is coenzyme Q9(CoQ9), but CoQ10 is necessary for people. In this paper, we transformated the decaprenyl diphosphate synthase(DDSA) which plays a critical role in the biosynthesis of CoQ by the genetic engineering into the rice, expecting obtain the rice which can produce CoQ10 rice effective in improving the quality of rice. The main results were as followed.1. DDSA gene was isolated and cloned from G.oxydans ATCC 621 by PCR, which was composed of 948bp, encoding 315 amino acids, molecular weight of protein is about 33.9 KDa, and its nucleic acid sequence had 99% homology with G.oxydans 621 which had been reported. Its amino acid sequence had seven typical conservative regions compared with polyisoprene pyrophosphate synthase. This suggested that we successfully cloned the gene of DDSA from G.oxydans ATCC 621 and may have capacity of encoding polyisoprene pyrophosphate synthase.2. The GT1 promoter of rice and DDSA gene and NOS terminator were respectively inserted into multiple cloning sites of pCAMBIA1301 plasmid by step. Constructed plant expression vector pCAMBIA1301-Gt1-DDSA-NOS which can endosperm-specific express the DDSA in rice.3. Above these works, the expression vector transformated into rice of Taijing 9 by the method of agrobacterium-mediated. Transgenic calli differentiated and regenerated 6 resistant plants. Total DNA of resistant plants were tested by PCR, result show four transgenic rices were positive.