Data from: Application of CRISPR/Cas9 to Tragopogon (Asteraceae), an evolutionary model for the study of polyploidy

Tragopogon (Asteraceae) is an excellent natural system for studies of
recent polyploidy. Development of an efficient CRISPR/Cas9-based genome
editing platform in Tragopogon will facilitate novel studies of the
genetic consequences of polyploidy. Here, we report our initial results of
developing CRISPR/Cas9 in Tragopogon. We have established a feasible
tissue culture and transformation protocol for Tragopogon. Through
protoplast transient assays, use of the TragCRISPR system (i.e. the
CRISPR/Cas9 system adapted for Tragopogon) was capable of introducing
site-specific mutations in Tragopogon protoplasts. Agrobacterium-mediated
transformation with Cas9-sgRNA constructs targeting the phytoene
desaturase gene (TraPDS) was implemented in this model polyploid system.
Sequencing of PCR amplicons from the target regions indicated simultaneous
mutations of two alleles and four alleles of TraPDS in albino shoots from
T. porrifolius (2x) and T. mirus (4x), respectively. The average
proportions of successfully transformed calli with the albino phenotype
were 87% and 78% in the diploid and polyploid, respectively. This appears
to be the first demonstration of CRISPR/Cas9-based genome editing in any
naturally formed neopolyploid system. Although a more efficient tissue
culture system should be developed in Tragopogon, application of a robust
CRISPR/Cas9 system will permit unique studies of biased fractionation, the
gene-balance hypothesis and cytonuclear interactions in polyploids. In
addition, the CRISPR/Cas9 platform enables investigations of those genes
involved in phenotypic changes in polyploids and will also facilitate
novel functional biology studies in Asteraceae. Our workflow provides a
guide for applying CRISPR/Cas9 to other non-genetic model plant systems.