Viroids are a group of single-stranded covalently closed RNA molecules, which belong in two families Pospiviroidae and Avsunviroidae. They are the smallest plant pathogens, that can elicit disease state at host plants (potato, tomato, hops, vine, citruses …). Pathogenesis can be triggered with interaction between the mature RNA molecule and plant proteins (structurally specific) or via viroid small interfering RNA molecules, which are produced in DCL processing (nucleotide sequence specific). Understanding how viroids work, methods for viroid-tolerant plants are being developed. The greatest potential is presented by transgenesis approaches, where plants can be protected by insertion of hairpin RNA or artificial small RNA through the activation of RNA interference.
|