PubMed · 2026-05-28
Scientists used CRISPR gene editing to prove that a protein called Ycf54 is essential for barley to make chlorophyll — the green pigment that powers photosynthesis. Plants with broken copies of this gene turned completely yellow and could not survive.
Four different CRISPR-generated mutations were created; frameshifting deletions of 1 or 2 base pairs knocked out Ycf54 function completely, producing lethal yellow (chlorophyll-free) plants.
In-frame deletions of 6 or 27 base pairs left Ycf54 functional, and those plants remained fully green with normal chlorophyll levels, demonstrating the protein tolerates minor structural changes.
Ycf54 loss-of-function is lethal — yellow mutants could only be maintained as heterozygotes, confirming Ycf54 is an essential gene for photosynthetic viability in barley.