China: Synergistic Design Nearly Triples Potato Base Editing Efficiency
Chinese researchers have built a cytosine base editing system for potato that raises average editing efficiency to 76.7%, about 2.9 times the level of the unoptimized editor, according to a study in Horticulture Research (DOI: 10.1093/hr/uhag122) highlighted in a release issued this week. The team drew on the Agricultural Genomics Institute at Shenzhen under the Chinese Academy of Agricultural Sciences, Henan University and its Shenzhen institute, and the Yunnan Key Laboratory of Potato Biology at Yunnan Normal University.
Potato is a hard crop to edit and to breed. Its genome is highly heterozygous and usually tetraploid, and because it is propagated vegetatively, harmful mutations can accumulate and stay locked next to valuable alleles, where repeated crossing struggles to separate them. Cytosine base editors (CBEs) convert a chosen cytosine to thymine without cutting both DNA strands, which in principle lets breeders disable a bad allele directly — but existing potato systems have suffered from low efficiency and narrow options.
The authors attacked the problem from several directions at once, as they describe in the journal and in a parallel EurekAlert posting. Comparing five cytidine deaminases in a hairy-root assay, they found Sdd7 gave the highest mean efficiency at 46.7% with few unwanted insertions and deletions, while CDA1 offered a broader editing window. They then strengthened expression with an Arabidopsis RPS5A promoter and a TMV Ω enhancer, and added the human FTO protein to loosen chromatin around target sites.
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The largest gain came from chromatin-modulating peptides derived from HMGN1 and histone H1. Stacked onto CDA1, they lifted average efficiency from 25.9% to 80.6% without increasing off-target indels. The final compact editor, RF-Sdd7-HNHN, achieved 65.6% to 87.4% editing across three test loci.
As a proof of use, the team targeted StALS1 and StALS2, the genes behind acetolactate synthase. In stable potato plants the editor changed the target residues in both genes in 85.7% of lines, with no off-target changes at predicted sites. The edited plants rooted and grew on medium containing chlorsulfuron and stayed healthy after greenhouse spraying, while wild-type controls failed to root or wilted.
The authors are careful about limits. Before any agricultural use, the system needs testing across more potato genotypes, multi-season field evaluation, a wider hunt for unintended edits, and a regulatory path for herbicide-resistant germplasm. The same design logic, they say, could be transferred to adenine base editors and prime editors in crops where editing tools are still scarce.
Sources: Newswise / Chinese Academy of Sciences release, October 16, 2026; EurekAlert; the study in Horticulture Research (DOI: 10.1093/hr/uhag122).
