Pull out of plant storing some DNA from the south (7)
I believe the answer is:
renegue
'pull out of' is the definition.
'plant storing some dna from the south' is the wordplay.
'plant' becomes 'rue' (type of shrub).
'storing' indicates putting letters inside.
'some dna' becomes 'gene'.
'from the south' is a reversal indicator (in a down clue, letters go up).
'gene' back-to-front is 'eneg'.
'rue' going around 'eneg' is 'RENEGUE'.
(Other definitions for renegue that I've seen before include "Break a promise" , "Rue gene (anag.)" , "Default" , "Welsh" , "Fail to fulfil a promise" .)