Induction of Resistance Against Sugarcane Mosaic Virus by Pathogen-Derived Resistance and RNA interference Methods in Transgenic Sugarcane

Mosaic disease is the most major devastating pathogen in sugarcane caused by sugarcane mosaic virus (SCMV), otherwise SCMV was also causing mosaic disease in another crops, such as maize and sorghum. It has been reported that sugarcane productivity loss due to SCMV is up to 45 in susceptible sugarcane varieties. Therefore, a new variety for SCMV-resistant sugarcane trait is important to be developed since this strategy will support combating the emerging SCMV in sugarcane field. The coat protein (CP) virus is the most common target for genetic engineering strategies to induce defense mechanism against virus infection. In our studies, the SCMV-resistant transgenic sugarcanes were generated by two different approaches, pathogen-derived resistance (PDR) and RNA interference technologies, and the gene encoding for CP was successfully cloned from the susceptible variety of PS-881 cultivar (MH393888.1). Induction of the resistance using the PDR method that also called protein-based resistance by overexpression of the CP gene resulted in the resistance of transgenic sugarcane against SCMV infection. The full sequence of CP gene produced a highest resistance compared to N-terminally truncated protein. On the other hand, RNA interference (RNAi) approach was also conducted to investigate the efficiency of defense mechanism against SCMV in sugarcane. The transgenic sugarcane expressing intron-hairpin (RNAi) constructs produced a high number of resistances against SCMV infection. In addition, the agronomic performance of transgenic sugarcane under PDR and RNAi approaches targeting the CP gene has also been compared. Based on the observation, the RNAi approach transgenic sugarcane is more resistant against the SCMV infection compared to the PDR approach. This review is to summarize the current promising strategies for generating a new variety of sugarcane that has resistance to SCMV by genetic engineering approach.