Please see the 'Boxes and Panels' section in this article "Introduction to Common Root Phenotyping Methods". See the attached pictures of roots growing in a (glass) box from the article. If this is what you want, I am wondering how this method can be used for assessing metals take up ability, since it is a 'phenotyping' method. Unless you want to see how the metals affect the growth/development of the roots.

[ http://www.plantstress.com/methods/Root%20Methods%20PORTAL/Root%20methods.htm]

This is very helpful! Thanks a lot