[Absentia]

Hello all,

I'm having problems trying to understand how RNA interference works.

From what I understood, in simple terms there is this  dsRNA which is fragmented into siRNA by the enzyme called Dicer, and those siRNA make the RISC complex active, which leads to the degradation of mRNA which are complementary to one of the strands of the original dsRNA.

Said this (which I don't even know if it is correct), how this relates to the petunias experiment? From what I understood the researchers put into the petunias an enzyme that coded for the pigment and not strands of dsRNA which then would have created the inhibition...

What am I missing? 

PS. I don't have technical knowledge about Technologies so excuse me in case I said wrong things.

Thanks in advance everyone.