Worry dry wine agent's backers (7)
I believe the answer is:
perturb
'worry' is the definition.
(I've seen this before)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for perturb that I've seen before include "Ruffle the composure (of)" , "Disturb - trouble" , "Worry" , "upset" , "Discountenance" .)