Abstract: Using CRISPR/Cas9 gene editing technology, the polyphenol oxidase （PPO） family gene member LOC107810501 of tobacco（Nicotiana tabacum L.） varieties Zunyan 6 and K326 was targeted and knocked out. The results showed that after knocking out the LOC107810501 gene, no expression of this gene was detected in the positive edited plants of tobacco. At the same time, the relative expression levels of LOC107821546, LOC107786520,LOC107773093, LOC107787563, and LOC107805360 genes were significantly reduced. The study obtained T₀ mutant plants of tobacco with low PPO activity, and T₁ generation sequencing confirmed that the mutant trait could be stably inherited.

Key words: tobacco（Nicotiana tabacum L.）, variety, polyphenol oxidase, gene editing, Zunyan 6, K326