The Strigolactone Pathway Genes in Populus

Strigolactones are a new class of plant hormones that play key roles in controlling shoot branching, stimulating seed germination of root parasitic plants and promoting hyphal branching and root colonization of symbiotic arbuscular mycorrhizal fungi. Studies of branching mutants in Arabidopsis, pea, rice and petunia have identified several key genes involved in strigolactone biosynthesis or signaling pathways. Here we report the genome-wide identification of strigolactone pathway genes in the woody perennial plant Populus. We identified sequence homologues of each key gene involved in strigolactone biosynthesis or signaling in the genome of Populus. We determined the expression patterns of strigolactone pathway genes across various tissues and organs in Populus. Furthermore, we performed genetic complementation experiments using Arabidopsis mutants defective in strigolactone biosynthesis or signaling. Collectively, our findings provide evidence to support that the strigolactone pathways are conserved in the woody perennial plants.