Strigolactone-Like Bioactivity via Parasitic Plant Germination Bioassay

Strigolactones are a class of plant hormones involved in shoot branching, growth of symbiotic arbuscular mycorrhizal fungi, and germination of parasitic plant seeds. Assaying new molecules or compound exhibiting strigolactone-like activities is therefore important but unfortunately time-consuming and hard to implement because of the extremely low concentrations at which they are active. Seeds of parasite plants are natural integrator of these hormones since they can perceive molecule concentrations in the picomolar to nanomolar range stimulating their germination. Here we describe a simple and inexpensive method to evaluate the activity of these molecules by scoring the germination of parasitic plant seeds upon treatment with these molecules. Up to four molecules can be assayed from a single 96-well plate by this method. A comparison of SL-like bioactivities between molecules is done by determining the EC50 and the maximum percentage of germination.