TRVd

TRVd refers to Tobacco rattle virus defective RNAs. These are defective interfering RNAs associated with Tobacco rattle virus (TRV), a plant virus in the family Secoviridae with a bipartite genome (RNA1 and RNA2). TRVd molecules arise during TRV infection through deletions or rearrangements of the viral genome and are generally smaller than the parental segments. They retain elements needed for encapsidation by TRV coat protein but usually lack essential genes required for independent replication and movement, making them dependent on the helper TRV genome.

As defective RNAs, TRVd can influence the course of infection. They can compete with the full-length virus for replication resources, potentially altering viral RNA accumulation and symptom development. The specific effects of TRVd on host plants are variable and depend on the particular deletions or rearrangements present, the plant species, and the infection context. TRVd are typically detected in TRV-infected plant material using molecular methods such as RT-PCR, Northern blotting, and sequencing.

In research, defective RNAs like TRVd contribute to understanding virus–host interactions, RNA recombination, and the dynamics of multipartite plant viruses. TRV itself has been widely used as a backbone for virus-induced gene silencing (VIGS) in plants, illustrating how TRV-related RNAs can be harnessed for biotechnology while also raising interest in the roles of defective RNAs during plant viral infections.