Ablation of glucosinolate accumulation in the oil crop <i>Camelina sativa</i> by targeted mutagenesis of genes encoding the transporters <scp>GTR1</scp> and <scp>GTR2</scp> and regulators of biosynthesis <scp>MYB28</scp> and <scp>MYB29</scp>
Georg Hölzl, Barno Ruzimurodovna Rezaeva, Jochen Kumlehn, Peter Dörmann
Abstract
Camelina sativa is an oil crop with low input costs and resistance to abiotic and biotic stresses. The presence of glucosinolates, plant metabolites with adverse health effects, restricts the use of camelina for human and animal nutrition. Cas9 endonuclease-based targeted mutagenesis of the three homeologs of each of the glucosinolate transporters CsGTR1 and CsGTR2 caused a strong decrease in glucosinolate amounts, highlighting the power of this approach for inactivating multiple genes in a hexaploid crop. Mutagenesis of the three homeologs of each of the transcription factors CsMYB28 and CsMYB29 resulted in the complete loss of glucosinolates, representing the first glucosinolate-free Brassicaceae crop. The oil and protein contents and the fatty acid composition of the csgtr1csgtr2 and csmyb28csmyb29 mutant seeds were not affected. The decrease and elimination of glucosinolates improves the quality of the oil and press cake of camelina, which thus complies with international standards regulating glucosinolate levels for human consumption and animal feeding.