Full Length Research Paper

Cloning and transformation of SCMV CP gene and regeneration of transgenic maize plants showing resistance to SCMV strain MDB

Xiaohong Liu¹*, Zhenbo Tan¹, Wanchen Li², Hongmei Zhang³ and Daowen He¹

¹College of Life Sciences, China West Normal University, Nanchong City, Sichuan Province, 637009, P. R.  China.

²Maize Research Institute, Sichuan Agricultural University, Ya’an City, Sichuan Province, 625014, P. R. China.

³Maize Research Institute, Shanxi Academy of Agricultural Sciences, Xinzhou City, Shanxi Province, 034000, P. R. China.

*Corresponding author. E-mail: lxhxhsfdx@yahoo.com.cn. Tel.: +8608172887939.

Accepted 1 June, 2009

The coated protein gene of sugarcane mosaic virus (SCMV CP gene) was cloned from maize (Zea mays L.) leaves showing dwarf mosaic symptoms by reverse-transcription polymerase chain reaction (RT-PCR) with degraded primers. The results of sequencing and homologous comparison indicated that the cloned gene was from SCMV strain MDB, with 920 bp in length, including an open reading frame (ORF) encoding 219 amino acids and a 3' untranslated region (3'UTR). This gene was constructed into the expression vector p35SCPrBar in the antisense orientation, under the control of CaMV35S promoter, the plasmid p35SCPrBar was introduced into embryogenic calli induced from the immature embryos of maize inbred line 18-599(red) that is highly susceptible to SCMV-MDB via particle bombardment, the results of polymerase chain reaction (PCR) and Southern blotting hybridization demonstrated that the SCMV CP gene had been integrated into maize genome. The plants regenerated from T₁ transgenic seeds were challenged with SCMV-MDB by artificial inoculation, as a result, transgenic progenies showed resistance to the inoculated virus to different extent. This work is beneficial for extending the planting regions for the elite inbred line 18-599(red).

Key words: Maize (Zea mays L.), sugarcane mosaic virus (SCMV), coat protein gene, cloning and transformation.