pRI 101 DNA vectors are binary plant transformation vectors intended for foreign gene expression in plant cells. These agrobacterium-mediated plant transformation vectors carry the 35S promoter of caµliflower mosaic virus (CaMV) and the 5’ non-coding region (5’-UTR) of the alcohol dehydrogenase (ADH) gene. The 5’-UTR of ADH functions as a translation enhancer in plants. There are two types of pRI 101 DNA vectors, the pRI 101-AN DNA vector, which carries the 5’-UTR of Arabidopsis ADH (AtADH 5’-UTR), and the pRI 101 ON DNA vector, which carries the 5’-UTR of rice ADH (OsADH 5’-UTR). The pRI 101-AN DNA vector is for dicotyledonous plants such as tobacco or Arabidopsis while the pRI 101-ON DNA vector is for monocotyledonous plants such as rice.
Although the pRI 101 DNA vectors are shuttle vectors and replicate autonomously in E. coli and Rhizobium (Agrobacterium), they are high copy number plasmids because they contain the same replication origin as pUC-type plasmids (ColE1 ori). These vectors are also stably maintained in Rhizobium (Agrobacterium) containing the mutant-type replication origin Ri (Ri-ori). The pRI 101 DNA vectors are capable of stably integrating target genes into plant chromosomes because the vector cloning sites are located closer to the Right Border (RB) of T-DNA than the selection marker (NPT II) of the plant, so the target gene is not deleted.