Abstract

Rice (Oryza sativa L.) is the major nutritional source for more than half of the world’s population. Rice tungro, a complex viral disease caused by the combination of Rice tungro spherical virus (RTSV) and Rice tungro bacilliform virus (RTBV) virus, is the most widespread and devastating disease of rice. Considering the economic importance of rice and the devastating effects of rice tungro disease, the present work developed tungro virus resistant transgenic indica rice (cv. PB-1) plants by the introduction of viral genes from both RTBV and RTSV. Several putative rice transgenics were raised with RTBV-CP. The transgenic lines showed single as well as multiple copy insertions of the transgene. The expression levels of transgene at the transcript as well as at the protein level were studied. A varied level of the expression of CP was observed. The viral resistant assays were performed in T₂ generation. A positive correlation was observed between the levels of CP expression and viral resistance i.e minimum virus accumulation was found in the transgenic line expressing maximum CP. Several putative transgenic rice plants were generated using the tRNA binding site of RTBV an antisense orientation. The developed rice transgenics containing genes derived from RTBV and RTSV would provide new insights regarding the behavior and symptomology of the virus in the Indian scenario.