Doctor in river pulled up plant (5)
I believe the answer is:
embed
'plant' is the definition.
(I've seen this before)
'doctor in river pulled up' is the wordplay.
'doctor' becomes 'mb' (Bachelor of Medicine, Medicinae Baccalaureus).
'in' means one lot of letters goes inside another.
'river' becomes 'dee' (River Dee).
'pulled up' shows that the letters should be reversed in order.
'dee' in reverse letter order is 'eed'.
'mb' put inside 'eed' is 'EMBED'.
(Other definitions for embed that I've seen before include "Firmly put down" , "Fix fast in something solid" , "bringing plant inside" , "the opposite of 19 [DEBUNK]?" , "Become firmly fixed" .)