plone.app.discussion/plone/app/discussion/profiles/default/rolemap.xml

<?xml version="1.0"?>
<rolemap>
    <permissions>
        <permission name="Review comments" acquire="True">
            <role name="Manager"/>
	        <role name="Site Administrator"/>
            <role name="Reviewer"/>
        </permission>
        <permission name="Edit comments" acquire="True">
            <role name="Manager"/>
	        <role name="Site Administrator"/>
            <role name="Reviewer"/>
            <role name="Owner"/>
        </permission>
        <permission name="Delete comments" acquire="True">
            <role name="Manager"/>
            <role name="Site Administrator"/>
            <role name="Reviewer"/>
        </permission>
        <permission name="Reply to item" acquire="False">
            <role name="Authenticated"/>
        </permission>
    </permissions>
</rolemap>