Evolution of Plant Secondary Metabolites

Kliebenstein Lab

UC Davis Plant Sciences

Genetic Control of Glucosinolate Hydrolysis

Glucosinolate hydrolysis is controlled by a large collection of different proteins. We are attempting to identify these proteins to better control how glucosinolates are hydrolyzed to improve human nutrition and crop/pest resistance.

Project Summary

· Proteins control the activation of glucosinolates into either nitriles or isothiocyanates.

· Isothiocyanates provide anti-cancer/anti-herbivory activity whereas nitriles do not.

· Identifying the proteins can allow for the breeding of improved crops at multiple levels.

· These proteins are naturally variable allowing for studies of the genetic and evolutionary forces controlling this variation.

Glucosinolates are plant secondary metabolites that are specific to the crucifers, including crops such as canola, cabbage, broccoli and wasabi. These compounds are important for both human nutrition and plant/pest interactions. This biological activity requires activation by the enzyme myrosinase and several associated proteins. We are studying how these associated proteins determine whether hydrolysis produces an isothiocyanate (anti-cancer, anti-herbivory) or nitrile (unknown biological activity) derivatives.

 

This involves the cloning of QTL that control this conversion and an understanding of how the encoded proteins function. While we focus on the model plant, Arabidopsis thaliana, the same proteins and functions are present in the majority of cruciferous vegetables and our findings are being extended into these crops by a broad group of researchers. This analysis will allow us to study both the evolution of the glucosinolate system as well as potentially allowing for improved human nutrition

Differential Insect Herbivory Between Leaves Making Isothiocyanates (top) and Those Making Nitriles (bottom) from Glucosinolates.

To contact us:

Phone: 530-754-7775
Fax: 530-752-9569
E-mail:
kliebenstein@ucdavis.edu

Text Box: Sample Publication
Wentzell, A.M., Boeye, I., Zhang, Z.-Y. and D.J. Kliebenstein. (2008) “Genetic networks controlling structural outcome of glucosinolate activation across development.” PLoS Genetics 4(10)e1000234 (Open Access) 

Agee, A.E., Surpin, M. Sohn, E.J., Girke, T., Rosado, A., Kram, B.W., Carter, C., Wentzell, A.M., Kliebenstein, D.J., Jin, H.C., Park, O.K., Jin, H., Hicks, G.R., and N. Raikhel. (2010) “MODIFIED VACUOLE PHENOTYPE1 is an Arabidopsis myrosinase-associated protein involved in endomembrane protein trafficking.” Plant Physiology 152(1)120-132. (Pubmed Link)