Identification of a Prunus MAX1 homolog as a unique strigol synthase

Abstract

Summary Strigol is the first identified and one of the most important strigolactones (SLs), but the biosynthetic pathway remains elusive. We functionally identified a strigol synthase (cytochrome P450 711A enzyme) in the Prunus genus through rapid gene screening in a set of SL‐producing microbial consortia, and confirmed its unique catalytic activity (catalyzing multistep oxidation) through substrate feeding experiments and mutant analysis. We also reconstructed the biosynthetic pathway of strigol in Nicotiana benthamiana and reported the total biosynthesis of strigol in the Escherichia coli‐yeast consortium, from the simple sugar xylose, which paves the way for large‐scale production of strigol. As proof of concept, strigol and orobanchol were detected in Prunus persica root extrudes. This demonstrated a successful prediction of metabolites produced in plants through gene function identification, highlighting the importance of deciphering the sequence–function correlation of plant biosynthetic enzymes to more accurately predicate plant metabolites without metabolic analysis. This finding revealed the evolutionary and functional diversity of CYP711A (MAX1) in SL biosynthesis, which can synthesize different stereo‐configurations of SLs (strigol‐ or orobanchol‐type). This work again emphasizes the importance of microbial bioproduction platform as an efficient and handy tool to functionally identify plant metabolism.

Strigolactones and Shoot Branching: What Is the Real Hormone and How Does It Work?

“…Functional diversity of CYP711A subfamily members and P450 enzymes from at least four other subfamilies, CYP706C, CYP712G, CYP722C and CYP728B, contribute to differential SL production during the subsequent steps of the canonical SL biosynthesis pathway downstream of CL, whereby distinct reactions to produce different SLs are catalyzed by different but related enzymes ( Wu et al., 2023 , Koichi Yoneyama et al. 2018 , Zhang et al.…”