A minimal peach type II chlorophyll a/b-binding protein promoter retains tissue-specificity and light regulation in tomato

The promoter from SlREO, a highly-expressed, root-specific Solanum lycopersicum gene, directs expression to cortex of mature roots

Root-specific promoters are valuable tools for targeting transgene expression, but many of those already described have limitations to their general applicability. We present the expression characteristics of SlREO, a novel gene isolated from tomato (Solanum lycopersicum L.). This gene was highly expressed in roots but had a very low level of expression in aerial plant organs. A 2.4-kb region representing the SlREO promoter sequence was cloned upstream of the uidA GUS reporter gene and shown to direct expression in the root cortex. In mature, glasshouse-grown plants this strict root specificity was maintained. Furthermore, promoter activity was unaffected by dehydration or wounding stress but was somewhat suppressed by exposure to NaCl, salicylic acid and jasmonic acid. The predicted protein sequence of SlREO contains a domain found in enzymes of the 2-oxoglutarate and Fe(II)-dependent dioxygenase superfamily. The novel SlREO promoter has properties ideal for applications requiring strong and specific gene expression in the bulk of tomato root tissue growing in soil, and is also likely to be useful in other Solanaceous crops.

pBINPLUS/ARS: an improved plant transformation vector based on pBINPLUS

Binary plant transformation vectors are widely used for introduction of transgenes into plants via Agrobacterium tumefaciens-mediated transformation. We report the construction of a binary plant vector pBINPLUS/ARS based on the pBINPLUS vector. Improvements introduced into pBINPLUS/ARS include the use of nonproprietary (ubiquitin-3 gene of Solanum tuberosum) promoter and terminator sequences for transcription of the NptII selectable marker and introduction of rare 8-bp restriction enzyme sites flanking both the NptII coding sequence (PmeI) and the entire selectable marker gene (FseI). This vector offers all of the advantages of its predecessor pBINPLUS and its helper plasmid pUCAP, which use the proprietary nopaline synthase promoter and terminator, while allowing for facile modification of selectable marker sequences in complex binary vector constructs. pBINPLUS/ARS has been used to introduce transgenes into potato and other crop species and is available to all researchers in academic, government, and industrial laboratories for proof-of-principle and commercial applications.