Researches On Mechanism Of Nuclear Matrix Attachment Regions(MAR) From Tobacoo And Their Application

Gene transfer technology is used into enhance agronomic performance or improve quality traits in a wide variety of crop species, and has become a fundamental tool for basic research in many subdisciplines of plant biology. But the applications of the technology in practical and basic research are sometimes handicapped by gene silencing and gene instable expression. Gene silencing was caused by many factors, such as DNA methylation, position effect, co-suppression, chromatin structure and trans-inactivation. It is important to adopt efficient strategies to overcome gene silencing and increase transgene expression level for optimizing transgenic technology. Recently, MARs were proved to have the ability to enhance transgene expression level, reduce the variance between transgenic events and help gene expression in progeny plants when flanking transgene cassette. Therefore, MAR is an efficient regulatory element to improve transgene expression and stabilize the expression level in the progeny. It is very important to isolate efficient MARs with strong enhancing ability for constructing high efficient expression vector. In the present paper, we studied the function of enhancing transgene expression level and transformation frequency of two nuclear matrix attachment regions from tobacco. One of them is TM2, which is cloned by our lab with the Genbank number of AF373415. The other is 220MAR cloned by Spiker lab. At the same time, we want to know whether different promoters affect the function of two MARs, also we want to know whether...