The Promoter Analysis And Genetic Transformation Of ZmGST23 In Maize (Zea Mays L.)

Maize(Zea mays L.) is the major food, feed and industrial materials which plays an important role in the world. Chinese is the second largest maize producing country only to the United States, owning a sown area of 36,666,667 hm2 in 2014.But various biotic and abiotic stresses such as drought, salinity, high temperature, low temperature, water-logging and disease can seriously affect the growth and yield formation of maize. However, the development of plant molecular biology, genomics and functional genomics pave the way for the breeding and improvement of stress tolerance crop varieties.Promoter is an important part of gene,it is the DNA sequence which can recognize and bind to the RNA polymerase of contiguous gene.Strong promoter is widely used in plant genetic engineering research at present, but it is often caused by abnormal growth of transgenic plants.Useing inducible promoter for the genetic transformation of plants can make the target gene expressed only in particular conditions, and it can greatly improve the efficiency of gene. Plant Glutathione S-transferases(GSTs) are a superfamily of multifunctional enzymes which catalyse the conjugation of electrophilic xenobiotic substrates with GSH, play an important role in stress defense system.Research shows that the expression of Zm GST23 was significantly increased when the corn is subjected to abiotic stresses(drought, low temperature, high temperature and herbicide, salt stress), which indicated that the gene could be induced by various stress conditions.We were cloned the promoter sequence of Zm GST23 gene from the maize inbred line F83, and analysised the promoter activity, determined the core sequence of the promoter, and aims to provide basis for follow-up stress transgenic research study.At the same time, Through Agrobacterium tumefaciens mediated maked Zm GST23 over expression in maize, in oder to provide theoretical reference for improving the stress tolerance of maize gene. The main results are as follows:1.Cloning the Zm GST23 promoter in maize genome DNA, bioinformation analysis of these sequences showed that the promoter had the core promoter element TATA box、CAAT box and cis acting elements.2.With the way of sub cloning,we obtained four promoter fragments according to the characteristics of the promoter sequence,and constructed the expression vector of deletion and analysised the promoter activity in leaves of tobacco by Agrobacterium infection showed that four promoter fragments can drive the gus gene transient expression.3. The expression of Zm GST23 promoter driven target gene in Arabidopsis and onion epidermis found that the promoter driven gus gene expression in Arabidopsis root,stem and leaf veins;And it driven gfp gene is mainly expressed in the cell wall and the cell’s nucleus in subcellular level.4. Constructing the plant expression vector p CAMBIA3300-Ubi-Zm GST23-bar, and conducted genetic transformation of Zheng 58 by Agrobacterium mediated, and obtained 8 resistant plants.