  We update the leading order in $\alpha_s$ QCD amplitude for deep exclusive
neutrino and antineutrino production of a light meson on an unpolarized
nucleon. The factorization theorems of the collinear QCD approach allow us to
write the amplitude as the convolution of generalized parton distributions
(GPDs) and perturbatively calculable coefficient functions. We study both the
pseudoscalar meson and longitudinally polarized vector meson cases. It turns
out that, contrarily to the electroproduction case, the leading twist
scattering amplitudes for $\pi$ and $\rho_L$ productions are proportional to
one another, which may serve as an interesting new test of the leading twist
dominance of exclusive processes at medium scale. The dominance of the gluonic
contribution to most cross sections is stressed.
