Spatially-resolved information of gas-phase emission provided by integral
field units (IFUs) are allowing us to perform a new generation of emission-line
surveys, based on large samples of HII regions and full two-dimensional
coverage. Here we present two highlights of our current studies employing this
technique: 1) A statistical approach to the abundance gradients of spiral
galaxies, which indicates an -universal- radial gradient for oxygen abundance;
and 2) The discovery of a new scaling relation of HII regions in spiral
galaxies, the "local" mass-metallicity relation of star-forming galaxies.Comment: 6 pages, to appear in Highlights of Spanish Astrophysics VII,
Proceedings of the X Scientific Meeting of the Spanish Astronomical Society
held on July 9-13, 2012, in Valencia, Spai