Genotypic variation of glucosinolates and their breakdown products in leaves of Brassica rapa
An in-depth glucosinolate (GLS) profiling was performed on a core collection of 91 Brassica rapa accessions, representing divers morphotypes of heterogenous geographical origin, to better understand the natural variation in GLS accumulation and GLS breakdown product formation. Leaves of the 91 B. rapa accessions were analyzed for their GLS composition by UHPLC-DAD and the corresponding breakdown products by GC–MS. Fifteen different GLS were identified and aliphatic GLS prevailed regarding diversity and concentration. Twenty-three GLS breakdown products were identified, among them nine isothiocyanates, ten nitriles and four epithionitriles. Epithionitriles were the prevailing breakdown products due to the high abundance of alkenyl GLS. The large scale data set allowed the identification of correlations in abundance of specific GLS or of GLS breakdown products. Discriminant function analysis identified subspecies with high levels of similarity in the acquired metabolite profiles. In general, the five main subspecies grouped significantly in terms of their GLS profiles.
Klopsch, R.; Witzel, K.; Artemyeva, A.; Ruppel, S.; Hanschen, F. 2018. Genotypic variation of glucosinolates and their breakdown products in leaves of Brassica rapa. Journal of Agricultural and Food Chemistry 66, 5481-5490.