  We investigate the dynamics of an arbitrary Dirichlet (D-) string in presence
of general curved backgrounds following a path-integral formalism. In
particular, we consider the interaction of D-string with the massless
excitations of closed string in open bosonic string theory. The background
fields induce invariant curvatures on the D-string manifold and the extrinsic
curvature can be seen to contain a divergence at the disk boundary. The
re-normalization of D-string coordinates, next to the leading order in its
derivative expansion, is performed to handle the divergence. Then we obtain the
generalized Dirac-Born-Infeld action representing the effective dynamics of
D-string in presence of the non-trivial backgrounds. On the other hand,
D-string acts as a source for the Ramond-Ramond two-form which induces an
additional (lower) form due to its coupling to the U(1) gauge invariant fields
on the D-string. These forms are reviewed in this formalism for an arbitrary
D-string and is encoded in the Wess-Zumino action. Quantization of the D-string
collective coordinates, in the U(1) gauge sector, is performed by taking into
account the coupling to the lower form and the relevant features of D-string
are analyzed in presence of the background fields.
