pRI 201 DNA series are designed for expressing target genes in transformed plant cells. This series of vectors retain the backbone of pRI 101 vectors, which includes an alcohol dehydrogenase (ADH) gene-derived 5' untranslated region (5'-UTR) (translational enhancer region) downstream of the 35S promoter from cauliflower mosaic virus (CaMV). In addition, they have a heat shock protein (HSP) gene-derived terminator in place of the nopaline synthase (NOS) gene-derived terminator, allowing higher target gene expression compared with the pRI 101 series. Further, multigene transformation with a single vector is possible by integrating an expression cassette containing another gene (promoter + enhancer + gene of interest + terminator) into the cloning site (MCS2) downstream of the HSP terminator.
The pRI 201 series has two types of vectors: pRI 201-AN DNA and pRI 201-ON DNA. Carrying an Arabidopsis ADH-derived 5' -UTR (AtADH 5'-UTR), pRI 201-AN DNA is suitable for dicotyledonous plants. With a rice ADH-derived x'-UTR (OsADH 5'-UTR), pRI 201-ON DNA is compatible with monocotyledonous plants. Positive control vectors (pRI 201-AN-GUS DNA and pRI 201-ON-GUS DNA) containing the beta-glucuronidase (GUS) gene are available outside the U.S. pRI 201-AN DNA and pRI 201-ON DNA are binary vectors for plant transformation and have a mutant-type replication origin (Ri ori) from the Rhizobium rhizogenes Ri plasmid. These vectors also have both a replication origin (ColE1 ori) derived from pUC plasmids, which allows maintenance at a high-copy-number in E. coli , and a multicloning site located near the right border (RB) of T-DNA relative to the plant selection marker (NPT II), which allows stable integration of the target gene into a plant chromosome.
