Hi,
Nginx does not embed PHP into its own process like Apache does, this mean that Nginx has no effect on the execution of PHP and if word press plugins do not work then it's either due to the plugins relying on Apache via mod_rewrite or because you have misconfigured PHP.
If it's a mod_rewrite problem then we can potentially help, but we'll need to know what it expects from .htaccess, if it's the latter then this is probably the wrong mailing list.