Exploring the Transcriptome of the Glucosinolate/Myrosinase System in Broccoli (Brassica oleracea var. italica)

The glucosinolate/myrosinase system is a plant defense system found in the Brassicaceae family, which includes the genera of Brassica and Arabidopsis.  This system has been linked primarily to plant defense against insect herbivory and pathogen infection, but also has been shown to affect human health.  Several glucosinolate hydrolysis products, the active compounds created from the reaction of glucosinolates and myrosinase, have been shown to be bioactive in humans.  Specifically, the ingestion of these compounds can increase the transcription rates, and consequently the enzymatic activity, of certain detoxification enzymes in the human body.  This has led to these compounds being described as having cancer-preventive activity, making the ability to accurately manipulate this system an important breeding objective in the Brassica vegetable market.  In this research, we show the effect of spraying the stress elicitor compound, methyl jasmonate (MeJA), on the transcriptome of the glucosinolate/ myrosinase system as well as final glucosinolate content and measurable cancer-preventive bioactivity.  In addition, we have explored the feasibility of using transcriptomic data of genes from this system to build predictive models for final phenotypes, such as glucosinolate levels or measureable cancer-preventive bioactivity.  If viable, this type of transcriptomic selection could be used in breeding programs focused on manipulating these traits.