  We study the response functions (chromo-electric susceptibilities) of
quark-gluon plasma as a function of temperature in the presence of
interactions. We consider two equations of state for hot QCD. The first one is
fully perturbative, of $O(g^5)$ EOS and, and the second one which is
$O[g^6\ln(1/g)+\delta]$, incorporates some non-perturbative effects. Following
a recent work (Physical Review {\bf C 76}, 054909(2007)), the interaction
effects contained in the EOS are encapsulated in terms of effective chemical
potentials($\tilde\mu$) in the equilibrium distribution functions for the
partons.By using them in another recent formulation of the response
functions({\tt arXiv:0707.3697}), we determine explicitly the chromo-electric
susceptibilities for QCD plasma. We find that it shows large deviations from
the ideal behavior. We further study the modification in the heavy quark
potential due to the medium effects. In particular, we determine the
temperature dependence of the screening lengths by fixing the effective
coupling constant $Q$ which appears in the transport equation by comparing the
screening in the present formalism with exact lattice QCD results. Finally, we
study the dissociation phenomena of heavy quarkonium states such as $c\bar{c}$
and $b\bar{b}$, and determine the dissociation temperatures. Our results are in
good agreement with recent lattice results.
