Rose scent mostly covered by commercial journalist (8)
I believe the answer is:
ascended
'rose' is the definition.
('ascend' can be a synonym of 'rise')
'scent mostly covered by commercial journalist' is the wordplay.
'mostly' means to remove the last letter (most but not all of the word).
'covered by' indicates putting letters inside.
'commercial' becomes 'ad' (abbreviation for advertisement).
'journalist' becomes 'ed' (short for editor).
'scent' with its last letter taken away is 'scen'.
'scen' going into 'ad' is 'ascend'.
'ascend'+'ed'='ASCENDED'
(Other definitions for ascended that I've seen before include "R [ROSE]" , "Climbed, went up" .)