In order to improve our understanding of the mechanisms that drive the evolution of disk galaxies we analyze the full bi-dimensional spectral cube of the nearby spiral galaxy NGC5668 covering a total area of 2x3 arcmin^2, obtained with the PPAK Integral Field Unit at the CAHA 3.5m. From these data we obtain the bidimensional spatial distribution maps of the attenuation of the ionized gas and oxygen chemical abundances. We find the ionized-gas attenuation to be larger than the continuum attenuation by a factor of 3. We also find that, while inwards of r~36 arcsec (=4.4kpc) the derived O/H ratio follows the radial gradient typical of the disks of spiral galaxies, the abundance gradient beyond r~36 arcsec flattens out. The multi-wavelength surface brightness profiles of NGC5668 are compared with those predicted by chemo-spectrophotometric evolutionary models of galaxy disks in the context of the inside-out scenario of disk formation. Both the deviations of the color profiles and the shape of the metallicity radial distribution indicate that a secondary mechanism, possibly gas transfer induced by the presence of a young bar, must have played a role in shaping the recent chemical and star formation histories of NGC5668 beyond what is predicted by the inside-out scenario. This study demonstrates the strength of the combination of IFU and multi-wavelength imaging data.

MEGARA, the future optical IFU and MOS for GTC, will fill the gap currently existing in astronomical instrumentation with high spectral resolution and large area coverage simultaneously addressing such fundamental issues in galactic structure and evolution.