Establishment of sugarcane mosaic virus-based vector for dual gene expression in maize

Abstract Virus-based gene expression is a simple and powerful approach for functional genetic studies in plants. Here, sugarcane mosaic virus (SCMV, Potyvirus sacchari ) was engineered as a dual gene expression vector for simultaneous expression of two heterologous proteins in maize plants. Inoculation of the full-length cDNA clone of SCMV from agro-infiltrated Nicotiana benthamiana resulted in a rapid systemic infection in maize. To assess the possibility of SCMV as the gene expression vector, the marker gene GFP or GUS was inserted into either the NIb/CP or P1/HC-Pro junction site of SCMV to produce single-gene expression vectors. The results showed that these engineered SCMV vectors permitted efficient gene expression in systemically infected leaves and had the genetic capacity of inserts of more than 1800 bp, suggesting that both junction sites are suitable for heterologous gene insertion and expression. Furthermore, two different genes GFP and mCherry could be expressed simultaneously by engineering them into either NIb/CP or P1/HC-Pro junction sites of the same vector. These results clearly demonstrate the suitability of SCMV as a transient dual gene expression vector for maize plants.