Natural variation in glucosinolate profiles in Camelina sativa and its wild relatives

Glucosinolates (GSs) are the major limiting factor for the use of Camelina sativa seed meal in animal feed. In addition to their bitter taste, GSs can be toxic at high levels. The goal of our work was to evaluate GS composition in C. sativa and its wild relatives to determine whether there is potential for introducing wild germplasm into breeding programs. Three major glucosinolates were identified in our study using LC-MS/MS and were shown to have species-specific patterns. Principal component analysis revealed similar clustering at the metabolome level suggesting that GSs are chemotaxonomic markers for Camelina species.
Quantification by HPLC showed that C. microcarpa cytotypes 4x and 6x had the lowest total GS levels. Interestingly, these same species had relatively higher amounts of GS nitrile (GSn) and GS isothiocyanate (GSi) degradation products indicating that there are species-specific differences in GS catabolism. C. laxa and the two C. hispida subspecies, which also had relatively low total GS levels, had the lowest GS catabolite levels. Based on differences in GS composition and metabolism, some wild relatives could be incorporated into breeding programs to reduce GS levels in C. sativa.