metal concentrations in plant parts

[ramonawalls]

As part of an environmental health project I am working on, @kaiiam and I are creating new terms for the concentration of different metals in plant parts such as fruits or leaves. We feel that TO would be a better long term home for these traits than ENVO.

We want these to correspond to a set of ENVO concentration terms we are creating, but TO has terms for content rather than concentration. These terms are not yet logically defined, however. Would you be open to defining them based on PATO_0000033 (concentration of) using the design pattern:

concentration of X in Y is equivalent to 'concentration of' and 'inheres in' some (X and 'part of' some Y) as used at https://github.com/EnvironmentOntology/envo/blob/master/src/envo/patterns/chemical_concentration.yaml?

This should also lead to TO_0000465 (mineral and ion content) being a subclass of PATO concentration of.

If this is acceptable, I am happy to create the terms and do a pull request.