  Single-particle spectral properties near the Mott transition in the
one-dimensional Hubbard model are investigated by using the dynamical
density-matrix renormalization group method and the Bethe ansatz. The
pseudogap, hole-pocket behavior, spectral-weight transfer, and upper Hubbard
band are explained in terms of spinons, holons, antiholons, and doublons. The
Mott transition is characterized by the emergence of a gapless mode whose
dispersion relation extends up to the order of hopping t (spin exchange J) in
the weak (strong) interaction regime caused by infinitesimal doping.
