Photon production in expanding gluon plasma with an initially small ad
mixture of quarks is considered. Photons are created in the lowest ord
er (in alpha(s)) processes that involve quarks. Chemical equilibration
of quarks is governed by rate equations based on the lowest order (in
alpha(s)) processes gg reversible arrow <q(q)over bar>. Expansion slo
ws down quark production. A drastic reduction of intermediate-energy p
hotons in relation to standard-local equilibrium estimates is obtained
if the initial quark admixture is 20% below the chemical-saturation d
ensity. Higher initial temperatures increase significantly the yield o
f high-energy photons and overcompensate this reduction.