Symbionts and Parasites Affecting Plant Productivity

Parasitic weeds can harm crop plants while soil-borne microbes can benefit selected plant species. The regulation of such interactions is studied in two projects.

Parasitic weed interactions; parasitic weeds cause significant damage to agriculture and are difficult to manage because they are more closely related to their hosts than other pests. We are using different molecular, biochemical and bioimaging approaches to understand what determines a successful interaction of these weeds with their hosts. Currently our group is characterizing secreted proteins of the parasitic plant Cuscuta reflexa and identifying enzymes with high cellulose and pectin degrading activity. Such enzymes may be suitable for environmentally friendly biofuel production from agricultural waste products.

Plant–microbe symbiosis; nitrogen deficiency is often found to be a limiting factor to plant growth and has significant ecological and agricultural implications -- a paradox based on the fact that the atmosphere around us is comprised by 80% nitrogen (N2). Atmospheric nitrogen is a chemically stable gas and only some groups of prokaryotes are capable of reducing N2 to a form which can be assimilated biologically. Bacteria of the genus Rhizobiaceae are able to interact with the roots of leguminous plants to form nodules in which N2 can be converted to ammonia. In our group we are interested in the identification of genes and molecules enabling bacteria to colonize, invade and make nitrogen-fixing structures on the roots of their host plants.