We use a density matrix theory to describe the photoinduced electron transfer dynamics of betaine-30 in solution, including environmental effects which may lead to relaxation and dephasing. We restrict ourselves to only one reaction coordinate. The remaining degrees of freedom of the molecule and the solvent form the environment which is bilinearly coupled to the relevant system. We investigate the S-1-->S-0 reverse electron transfer of betaine-30 in solution, which occurs in the Marcus inverted region. We compare the temperature dependence of our theoretical results with experimental data and other theoretical predictions.