Evolution of metallicity gradient with redshift. Red squares represent lensed galaxies from the present study (L15). Green squares are the four lensed galaxies in Jones et al. (2013, J13). Other data points are measured from a lensed starburst dwarf (Jones et al. 2015, J15), a lensed galaxy (Yuan et al. 2011, Y11), non-lensed galaxies observed with adaptive optics (Swinbank et al. 2012, S12), and Milky Way planetary nebulae (Maciel et al. 2003, M03). Open and filled symbols represent kinematically well-ordered and disturbed systems, respectively. Turquoise lines show predictions from the hydrodynamical simulations of Gibson et al. (2013, G13) emphasizing the strong sensitivity to the incorporated feedback.