The new DNA study showing that we have two DNA codes and not only one unique code
Perhaps you are referring to so-called "duons" (dual-use codons) discovered by Stergachis et al.. This paper was published a bit more than six years ago. A recent paper within the last 2-3 years references duons implicated in photosynthesis.

Duons essentially extend the idea that conserved coding DNA encodes proteins, but can in fact also preferentially encode sites which bind transcription factors, at the same time. DNA can code proteins as well as code that controls regulatory regions, which in turn are switches that control how proteins get made.

Disclaimer: I am a contributing author in the linked Science paper.