Characterization of strigolactones produced by Physcomitrella patens

Abstract

Strigolactones (SLs) are plant secondary metabolites which function as host recognition signals for arbuscular mycorrhizal fungi and root parasitic plants, Striga and Orobanche. Recently, strigolactones have been identified as a novel class of plant hormones inhibiting shoots branching. However, the biosynthetic pathway of SLs in plants remains elusive. In this study, strigolactones produced by Physcomitrella patens subsp. patens, a bryophyte which is a basal lineage of land plants, were examined. Chloronemas of both wild type (WT) and the loss-of-function mutant of carotenoid cleavage dioxygenase 8 (Ppccd8) of P. patens were found to produce SLs including 7-oxoorobanchyl acetate, 7α-hydroxyorobanchyl acetate and orobanchyl acetate at similar levels. This result indicates that other genes are redundant with the CCD8 homolog in chloronema of P. patens.