Which diseases are caused by viroids?
Viroids are a pretty recent discovery as far as infectious agents go, and there are a lot of ongoing research about how they replicate and how they disrupt normal host function. True viroids are odd ducks� they are the only infectious agents that don't encode any proteins in their (tiny) RNA genome...
As far we know, they only infect specific plants, and probably hijack a normal host process called "RNA silencing" to cause stunted growth, malformation, and bleached leaves. Particularly affected are nightshades (e.g. potatoes and tomatoes), but avocadoes, chrysanthemums and peaches are also affected by different viroids.
Answered By: Dr. Paul Gordon