Getting editing tools into plant cells

Published

Designing an edit is the easy part. Getting the tool through a plant cell wall, and then growing a whole plant from that cell, is where most of the work goes.

How do gene-editing tools get into plant cells?

Editing tools are carried into plant cells by a soil bacterium called Agrobacterium, fired in on tiny metal particles, or delivered into protoplasts, which are cells with their walls removed. The edited cell then has to be regrown into a whole plant through tissue culture.

The main routes

Gao's 2021 review lists the current delivery methods as particle bombardment, Agrobacterium-mediated transformation, polyethylene glycol, viral vectors and nanoparticles [1]. Two of them, Agrobacterium and particle bombardment, have been in use for more than three decades [2].

  • Agrobacterium: a soil bacterium that naturally transfers a stretch of its own DNA into plant cells, adapted to carry chosen DNA instead [3].
  • Particle bombardment: tiny metal particles coated with DNA or RNA are fired into cells, piercing the wall without killing them [4].
  • Protoplasts: cells with their walls removed, which can take up editing reagents directly [1].

Delivering without DNA

The tool does not have to arrive as DNA. Gao explains that editing reagents can also be delivered as RNA or as a ready-made protein and RNA complex, and that these transient forms ‘do not result in genomic integration events into the plant genome’ [1]. The transgene-free page explains why this matters.

The real bottleneck: regrowing the plant

After delivery, the edited cell must grow back into a whole plant through tissue culture. Gao calls this regeneration step ‘extremely challenging in most crops’ [1].

Altpeter and colleagues list long tissue culture periods and low frequencies of stably transformed plants among the main challenges, and note that efficient Agrobacterium transformation is usually limited to a narrow range of genotypes within a species [2]. ‘Often, cells that are readily transformed cannot be regenerated, and vice versa’ [2].

Guides in this section

Frequently asked questions

Why is it hard to get tools into plant cells?

Plant cells have a rigid wall. Bacteria, fast-moving particles or wall-free protoplasts are used to get past it.

Does every crop variety respond the same way?

No. Efficient transformation is often limited to a narrow range of genotypes within a species, and many established varieties are hard to regenerate.

Is the tool always delivered as DNA?

No. It can be delivered as RNA or as a protein and RNA complex, which does not integrate into the plant genome.

Which gene-editing methods are there?

Five are widely described. Zinc finger nucleases, TALENs and CRISPR/Cas9 cut both DNA strands at a chosen site, while base editing and prime editing change the sequence without a double-strand break.

References

  1. Cell (2021). Genome engineering for crop improvement and future agriculture (Gao)
  2. The Plant Cell, via PubMed Central (2016). Advancing crop transformation in the era of genome editing (Altpeter and others)
  3. Microbiology and Molecular Biology Reviews (2003). Agrobacterium-mediated plant transformation: the biology behind the gene-jockeying tool (Gelvin)
  4. Nature (1987). High-velocity microprojectiles for delivering nucleic acids into living cells (Klein and others)

Last reviewed 2026-09-26. Edited by Mark Turner.