Central oxygen abundance (row a panels), the abundance at the galaxy effective radius (row b panels), and at the optical radius (row c panels) as a function of the stellar mass M_sp (left column panels), as a function of M_sp/R_e, g (middle column panels), and as a function of (right column panels). The grey points in each panel represent the data for individual MaNGA galaxes from our sample, while the dark points are the binned mean values.