CRISPR/Cas9 Genome Editing of Rubber-Producing Dandelion

Rubber dandelion (Taraxacum kok-saghyz; TK) is notable for its ability to produce rubber in its roots and a potential alternative source of natural rubber. In order to accelerate the domestication of TK, Brian Iaffaldano and his team from Ohio State University have established a simple strategy to use CRISPR/Cas9 in this species to target the fructan:fructan 1-fructosyltransferase (1-FFT) gene, implicated in inulin synthesis. This gene was targeted as inulin is an expected antagonist of rubber production.

TK plantlets were inoculated with Agrobacterium rhizogenes harboring a plasmid encoding a Cas9 and single guide RNA targeting TK 1-FFT. The team was able to rapidly induce hairy roots harboring knockout alleles. Mutagenesis was confirmed by observing a loss of restriction sites within 1-FFT.

Out of 11 hairy root samples, 10 showed the presence of genome editing, with mutation rates as high as 88.9%, suggesting a high efficiency mutagenesis induced by CRISPR/Cas9 via A. rhizogenes-mediated transformation. Whole TK plants were then generated from hairy roots harboring knockout alleles. The regenerated plants contained knockout alleles, with mutation rates as high as 80.0%.

The application of high efficiency CRISPR/Cas9 genome editing could facilitate the rapid domestication and commercialization of TK as a rubber producing crop, and may accelerate basic research on the regulation of rubber synthesis.

For more information, read the article in Industrial Crops and Products.