Gene editing via grafting

---

Gene editing via grafting

Something we cannot ignore is our need for better plants. Plants that can deal better with extremes, like drought, heat, or salt. Plants that are better protected against pests. That have a higher yield. That are more nutritious. A whole shopping list. And rather yesterday than today. Techniques like gene editing can help to get there quickly. But unfortunately, we cannot use it on all crops. Now a team of German scientist thinks it has found a solution.

In order to perform gene editing, researchers place the editing machinery, like the Cas enzyme, together with a guid RNA into some of a plant cells. Only in these cells gene editing takes place. Using tissue culture researchers grow these cells back into a whole plant, with in each cell containing the editing change. This last part, growing a new plant from a single cell using tissue culture, is not something researchers can do for all crops.

To avoid this barrier, German researchers ask themselves the question if it was possible using grafts to transfer from one plant to another the gene editing machinery and guide RNA. Plants use for their communication mobile signals, of which mobile RNAs are one. The researchers used this knowledge. They added a mobility signal to the gene editing machinery and the guide RNA, and place those into Arabidopsis, tale cress.

---

The first steps of a promising technique

---

Subsequently they grafted the roots of a plant with the gene editing machinery onto a shoot of a plant without the gene editing machinery and analysed the result. In plants with gene editing machinery without the mobile signal not much happened. But when the mobility signal was there, then the researchers observed gene editing in the shoot. Moreover, offspring of these plants had the editing change in their DNA but not the gene editing machinery.

To test if they could use this method to change genes in distantly related species, the researchers grafted an oilseed rape shoot onto tale cress roots. And just like before, the researchers observed gene editing taking place in the shoot.

With this technique it is possible to use gene editing on plants that can not be grown from a single cell with tissue culture. The first steps of a promising technique. Hopefully one that will help to make all our crops future proof.

Literature

Yang, L., Machin, F., Wang, S., Saplaoura, E., and Kragler, F. (2023) Heritable transgene-free genome editing in plants by grafting of wild-type shoots to transgenic donor rootstocks. Nat Biotechnol. https://doi.org/10.1038/s41587-022-01585-8