The new gene-edited mushrooms in the US have generated a lot of debate in the UK about what constitutes GM foodstuffs and what is allowable to be imported into the UK. The idea of importing fresh mushrooms from the US seems fanciful too, but with extended shelf lives and perhaps some canny transport and logistics economics, one never knows.
There is also the new trade deal between Europe and the US which is being hammered out in secret , called the Transatlantic Trade and Investment Partnership (TTIP) - that seems to be muddying the waters of what can and can’t be traded between the two massive trading blocs.
We live in interesting times that’s for sure and the future direction of markets and trade is never certain.