MSc Exit Seminar- Stefan Schuetz

“Characterizing the basis of strigolactone perception by HYPOSENSITIVE TO LIGHT/KARRIKIN INSENSITIVE 2”

Abstract:

The HYPOSENSITIVE TO LIGHT/KARRIKIN INSENSITIVE 2 (HTL/KAI2) α/β hydrolases likely play a critical role in the life cycle of parasitic plants of the genus Striga. Several of these hydrolases serve as receptors for strigolactones (SLs), a class of compounds exuded by the roots of some plants, including many economically significant crops. Upon perception of minute levels of SLs, Striga seeds germinate and parasitize the nearby host, often leading to massive losses in crop yields in affected regions. We have produced a series of mutant variants of the Arabidopsis thaliana homolog of HTL/KAI2, which is only weakly responsive to SL. By substituting certain key amino acids in the protein’s active site, we have created a receptor conferring increased Arabidopsis germination under inhibitory conditions in the presence of SL. Additional study of this mutant receptor may offer insight into the biochemical basis of Striga’s SL sensitivity.

Supervisor: Prof. Shelley Lumba