Assisted the development of a seed? (5)
I believe the answer is:
eased
'assisted' is the definition.
(easing is a kind of assisting)
'development of a seed?' is the wordplay.
'development of' indicates an anagram (letters developed in another way).
'a'+'seed'='aseed'
'aseed' with letters rearranged gives 'EASED'.
'the' is the link.
(Other definitions for eased that I've seen before include "Relieved, mitigated" , "rested" , "Lessened, pain or discomfort, say" , "Made less difficult or trying" , "Alleviated" .)