  QCD evolution equations that naturally include longitudinal (non-propagating)
fields and heavy quarks are derived. We start with the integral equations of
quantum field kinetics and obtain the master equations, similar to DGLAP
evolution equations after several consecutive approximations. We demonstrate
that in their primary form, the evolution equations include a new element,
feed-back via longitudinal fields, leading to a low-x enhancement in the e-p
DIS cross section. We show that the structure function F_L is very sensitive to
the dynamics of the longitudinal fields and that the heavy quarks in evolution
equations make this effect even more pronounced.
