PROCERA is a gene involved in growth regulation in tomato. Destructing the
proteins made from this gene induces growth. In a previous study, this gene
was edited to lose its function in tomato so that the plant will be dwarfed.
To verify if this gene is responsible for the dwarf trait, the mutated
version of the gene is modified back to its original. If the original trait
is obtained, the targeted gene can be concluded to be responsible for the
trait of interest.
Researcher Neil Olszewski from University of Minnesota and colleagues
modified the PROCERA gene using TALENs and obtained tall plants. Then, these
plants were applied with CRISPR-Cas9, and the dwarf trait was obtained.
Thus, this gene can be said to be responsible for the height difference in
the plants with mutation generated using TALENs and the plants with mutation
generated using CRISPR-Cas9.