MSc Defence: Morten Egevang Jørgensen

BSc Morten Egevang Jørgensen will defend his MSc Thesis / 4+4 Qualification exam 20 December 2012.

Title of Thesis

Regulation of glucosinolate transport
-Effects of phosphorylation on AtGTR1 and AtGTR2 transport activity

Censor

Professor Erik Andreasson, Swedish University of Agricultural Sciences

Supervisors

Professor Barbara Ann Halkier and Associate Professor Hussam Nour-Eldin, University of Copenhagen

Summary

Transport processes are important for the reallocation of defence compounds during development and preda-tion. A recent identification of two glucosinolate transporters provided the long sought tool to study a range of questions regarding the mechanisms underlying distribution of defence compounds using glucosinolates as a model system (Nour-Eldin et al. 2012). The aim of this study was to investigate whether and in what con-text phosphorylation regulates the transport activity of AtGTR1 and AtGTR2.

The results presented in this thesis indicate a role for phosphorylation in decreasing AtGTR1 and AtGTR2 transport activity. We used publicly available phosphoproteomics data to search for phosphorylation sites in AtGTR1 and AtGTR2. Phosphorylation mimics of AtGTR1and AtGTR2 showed decreased transport activity whereas dephosphorylation mimics had wild type transport activity. We employed co-expression analysis to search for likely kinase candidates and identified two kinases of the AtCIPK and AtCDPK family. Preliminary results indicate that an AtCIPK protein decrease the transport of both transports whereas an AtCDPK decrease the transport of AtGTR2 only.
We hypothesize that AtGTR inactivation by phosphorylation is involved in a defence response to pathogen infection by preventing transport of glucosinolates out of the apoplast. In perspective, the research could fur-ther our understanding of the regulation of transport processes involved in defence compound distribution at the cellular, tissue and organ level.

Everybody is welcome!