Kiwifruit (Actinidia deliciosa) is an important fruit crop but has limited
technologies for its genetic improvement. The CRISPR-Cas9 system has been
successfully used in many crops, but it has not been used in kiwifruit.
Furthermore, optimizing the conditions for its use in a particular plant
species is needed to achieve efficient genome editing.
The team of Zupeng Wang from the Chinese Academy of Sciences aimed to apply
CRISPR-Cas in kiwifruit. The team created a synthetic guide RNA (sgRNA)-Cas9
vector that targets the kiwifruit phytoene desaturase gene (AcPDS). Albino
kiwifruit plants were successfully obtained, a phenotype caused by a
knocked-out AcPDS gene.
The vectors used were compared with other vectors that contain different
sgRNA. While all vectors can induce albino phenotype of kiwifruit, they
found that the polycistronic tRNA-sgRNA cassette (PTG-Cas9) system was
significantly more efficient in kiwifruit genome editing.
This study proves that the CRISPR-Cas9 system can be applied in kiwifruit
genome editing. The sgRNA in this system can also be optimized, as
exemplified by the PTG-Cas9, and can provide clues for optimizing
CRISPR-Cas9 system in other plants.