Isolation of pea matrix attachment region and study on its function in transgenic tobaccos

A DNA fragment containing consensus sequence of matrix attachment region (M AR) has been isolated from pea genome. Compared with original DNA sequence, one 115 bp-long repeat sequence is deleted! in the obtained DNA sequence. DNA fragments located upstream and downstream of repeat DNA sequence respec tively share 84% and 93% homology to the corresponding original sequence, a nd contain A-box or T-box and TATAA sequence, which is characteristics shor t sequence of MARS. To test the function of the DNA sequence, the plant exp ression vectors in which beta -glucuronidase gene (GUS, uidA) was used as r eporter gene were constructed and transferred into tobaccos via Agrobacteri um-mediated transformation procedure. Quantitative GUS assay showed that th e average level of uidA expression was increased twofold for the presence o f MAR, and the highest level of GUS activity of transgenic plants could be increased six times. The results cited above suggest that the isolated DNA sequence contains consensus sequence of MARs and has capability to increase expression level of gene in transgenic plants.