How to get the string in xml attributes as lower cases in clojure

I have the following xml

<?xml version="1.0" encoding="utf-8"?>
    <Transformation>
        <ColumnValidations>
            <Column ColumnName="Column1"/>
            <Column ColumnName="Column2" MinInclusive="100" MaxExclusive="10000"/>
            <Column ColumnName="GREGORIAN_DATE" IsDate="Yes" Format="MM/DD/YYYY"/>
               </ColumnValidations>
    </Transformation>

Using xml/parse and tree seq, it will generate something like {:ColumnName "Column1"}, is there is simple way to convert all the values into lower caes in the map (which is also the attribute value)

xml-content (->>(xml/parse file)
                        (tree-seq :content :content))