Apple regularly supported by workers in factories (6)
I believe the answer is:
plants
'factories' is the definition.
(manufacturing plants)
'apple regularly supported by workers' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
'supported by' says to put letters next to each other (in a down clue, some letters hold up others).
'workers' becomes 'ants' (worker ants).
The alternate letters of 'apple' are 'pl'.
'pl'+'ants'='PLANTS'
'in' acts as a link.
(Other definitions for plants that I've seen before include "Puts into the ground to grow" , "Flora" , "climbers?" , "Living organisms without power of movement" , "Settles" .)