Pion distribution amplitudes within the instanton model of QCD vacuum

Pion transition form factor for the process $\gamma ^{\star}\gamma ^{\star}\to \pi ^{0}$ at space-like values of photon momenta is calculated within the effective quark-meson model with the interaction induced by instanton exchange. The leading and next-to-leading order power asymptotics of the form factor and the relation between the light-cone pion distribution amplitudes of twists 2 and 4 and the dynamically generated quark mass are found.