It will work if you turn it to Object
, like:
$rootScope.name = { value:'World'};
And bind it like:
<input type="text" ng-model="name.value"></input>
Working: http://plnkr.co/edit/n4QnivBiRvFMAM91UmIT?p=preview
Here you have a great explanation: What are the nuances of scope prototypal / prototypical inheritance in AngularJS?