Cloning And Functional Analysis Of DULL1 And Shrunken 1 Gene Promoters Of Zea Mays

In the plant genetic engineering.constitute promoters have been used to make foreign gene express efficiently in transgenic plants.However.the substance and energy in cell have been burdened by continual expression of foreign genes.By using tissue-specific promoters,the foreign gene expression can be effectively driven in specific tissues.The research mainly focus on sequences cloned of DULL I and Shrunken 1 gene promoters of maize, then introduced into rice by Agrobacterium-mediated transformation, the expression characteristics were analyzed. The activity site was confirmed by 5’end deletion of DULL1 gene promoter. The main results were as follows;1. The promoter sequences of DULL 1 and Shrunken 1 of maize were cloned by PCR, DULL land Shrunken 1 gene promoters sequence were analyzed with internet database, The result showed that:DULL1 and Shrunken 1 gene promoter all had the basic core cis-acting element, DULL1 gene promoter also included the endosperm-specific motifs, such as GCN4_motif and Skn-1_motif,they can drive the promoter express in endosperm tissue specifically.2. DULL1 and Shrunken 1 gene promoters was fused with GUS gene of pCAMBIA1301 plasmid, two novel plant expression vectors were constructed, then by transforming of rice, thirteen and nine transgenic plants were obtained respectively, through GUS histochemical staining showed that:GUS gene was driven by DULL1 gene promoter only expressed in endosperm tissue, did not express in the other tissues, which stated that DULL1 gene promoter is a endosperm specific promoter.GUS gene driven by the promoter can expressed in root, stem, leaf, sheath and glume tissue, can not express in flower and endosperm tissue, it means that the promoter is a vegetative organs specific promoter.3.5’end deletion of DULL 1 gene promoter with four different length segments, then introduced into rice, relevant transgenic plants were obtained, through GUS histochemical staining, deletion segments PDU1-3and PDU1-4 were only expressed in endosperm tissue, it means that PDU1-3and PDU1-4 were also the endosperm specific promoter. But deletion segments PDU1-1 and PDU1-2did not expressed in any tissue. According to the quantitative detection of GUS, we known DULL 1 gene promoter had a highest activity of enzyme, PDU1-3and PDU1-4 had a higher activity than PDU1-land PDU1-2. The deletion experiment showed that different length had different functions, the zone of-740～-8bp is the mainly activity region of DULL 1 gene promoter.Comparing with the deletion segments, the enzyme activity of DULL1 gene promoter is the best.