Studies underpinning rise of tabloid plots (7)
I believe the answer is:
gardens
'plots' is the definition.
(garden is a kind of plot)
'studies underpinning rise of tabloid' is the wordplay.
'studies' becomes 'dens' (I've seen this in other clues).
'underpinning' means one lot of letters go next to another (I've seen this in other clues).
'rise of' says the letters should be written in reverse (in a down clue, letters go up).
'tabloid' becomes 'rag' (informal term for a tabloid newspaper).
'rag' reversed gives 'gar'.
'dens' after 'gar' is 'GARDENS'.
(Other definitions for gardens that I've seen before include "Cultivated grounds" , "Ornamental grounds" , "Personal plots of ground" , "Green public spaces" , "In which you find weeds" .)