Function Analysis Of CMO Gene Promoter From Suaeda Liaotungensis K.

Choline monooxygenase(CMO)is the key enzyme to synthesize betaine which is a non-toxic osmopretectant and plays an important role in salt-tolerance plant.It can express under salt condition and furthermore the amount of expression increases as the salt concentration grows.The expression of CMO must be concerned with its promoter.This study is about CMO promoter from Suaeda liaotungensis K.and it is important to learn the molecular mechanism of CMO.On the condition that the salt-induced promoter fragment is applied to genetic engineering,it will be very valuable to enhance the salt tolerance of transgenic plant.In this research we made a series of 5'deletion promoter and systematically study their functions.The main results were as follows:1.After analyzing CMO promoter sequence,we found that there were some essential elements besides 3 salt-induced elements and other stress-induced ones.2.The vector pCAMBIA 1301 was based on to construct a set of binary plant expression vectors with the full-length and deletion promoter driving report gene GUS which were conformed by PCR and enzyme digestion.3.The promoter and promoter fragments were transferred into tobaccos via Agrobacterium mediation.The plant resistant to Hy being analyzed by PCR and GUS gene expression showed that the genes had been inserted into tobaccos'genomes and could drive GUS gene to express.4.GUS staining and fluorescent quantitative analysis revealed that all the fragments could make GUS gene express but the amount were not high under non-salt induced; But after salt induced GUS activities were obviously raised.Especially activity of pC5 fragment was 4 times higher than that of non-induced and as 2.4 times as 35S promoter.Therefore,pC5 fragment could be thought to be salt-induced promoter.