Dear fellow colleages 

I have come across the idea of splicing bioluminesent bactirium with the asian pear to create a super food. That eminates its own heat through the interation of oxygen and luciferin. Could we use this to create a crop that could survive a mild frost in lighter climates. Even go far enough to sustain growth in lower tempetures. 

That is not what splicing means. I assume you mean to clone luciferase gene into a crop. Well for starters you could look at the thermodynamics and estimate how much energy is released and also note that most of it is released as light. Then contrast it with other exothermic reactions that normally occur and figure out whether it would put a dent into the heat budget (hint: nope).

But I would direct you to read up on thermogenic plants.

A whole lot easier to just utilize  fruit walls like they did in The Middle Ages

https://www.lowtechmagazine.com/2015/12/fruit-walls-urban-farming.html