背景回顾：Generation of stable gene-edited plant lines using clustered regularly interspaced short palindromic repeats (CRISPR)–CRISPR-associated protein 9 (Cas9) requires a lengthy process of outcrossing to eliminate CRISPR–Cas9-associated sequences and produce transgene-free lines. 

结果：We have addressed this issue by designing fusions of Cas9 and guide RNA transcripts to tRNA-like sequence motifs that move RNAs from transgenic rootstocks to grafted wild-type shoots (scions) and achieve heritable gene editing, as demonstrated in wild-type Arabidopsis thaliana and Brassica rapa. The graft-mobile gene editing system enables the production of transgene-free offspring in one generation without the need for transgene elimination, culture recovery and selection, or use of viral editing vectors. 

结论：We anticipate that using graft-mobile editing systems for transgene-free plant production may be applied to a wide range of breeding programs and crop plants.

利用CRISPR-Cas9技术创制稳定的基因编辑植物株系，需要漫长的异交过程以消除CRISPR-Cas9相关的序列，从而获得不含转基因的株系。作者通过对CRSIPR-Cas9系统进行设计，将Cas9和gRNA融合一个可以从转基因砧木转移至野生型嫁接条的tRNA-like序列基序，从而解决了上述不含转基因株系的创制问题，在拟南芥和白菜中实现了可遗传的基因编辑。这套嫁接-移动基因编辑系统能够在一个世代里获得不含转基因的子代，并且不需要转基因消除，组培恢复和选择，亦或是使用病毒编辑载体。作者预期可以利用嫁接-移动基因编辑系统来进行不含转基因植株的生产，从而广泛用于作物的育种项目中。

** Friedrich Kragler **