Cyanide detoxification in plants

Cyanide detoxification in plants
Danish title: Cyanid nedbrydning i planter

 

The aim of this research project is to elucidate the function of plant nitrilases and nitrilase-related proteins in relation to cyanide detoxification mechanisms in cyanogenic plants. Arabidopsis and tobacco each contain several nitrilase isoforms. In both plants, NIT4 is capable of converting b-cyanoalanine to aspartic acid and asparagine, thus shifting the function of this nitrilase into cyanide detoxification. Likewise, a cyanoalanine hydrolyase (or hydratase) isolated from blue lupin was shown to be a NIT4 homolog and to display high nitrile hydratase activity. Current research is focussed on functional characterization of two isolated and heterologously expressed NIT4 homologs from Lotus japonicus and of three homologs from sorghum. The majority of these NIT4 enzymes do not hydrolyze b-cyanoalanine. The ability of some of these NIT4 homologs to utilize aliphatic cyanogenic glucosides (linamarin and lotaustralin) or other nitrile compounds as direct substrates and the dependency of substrate specificity on hetero-dimer formation with other nitrilase-isoforms is currently being studied.

 

This research project has been initiated by Professor Markus Piotrowski, Universität Bochum, Germany, during his stay as Visiting Professor in our research group and is continued as a joint collaboration where our task is to produce transgenic Lotus japonicus plants with aberrant ability to metabolize hydrogen cyanide.

 

Researchers involved: Markus Piotrowski, Birger Lindberg Møller, Anne Vinther Rasmussen, Shigeki Saito, Søren Bak

 

Financial support: Danish National Research Foundation, KVL PhD-stipend, Universität Bochum, Germany