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.
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A cytochrome P450 CYP87A4 imparts sterol side-chain cleavage in digoxin biosynthesis
Digoxin extracted from the foxglove plant is a widely prescribed natural product for treating heart failure. It is listed as an essential medicine by the World Health Organization. However, how the foxglove plant synthesizes digoxin is mostly unknown, especially the cytochrome P450 sterol side chain cleaving enzyme (P450scc), which catalyzes the first and rate-limiting step. Here we identify the long-speculated foxglove P450sccthrough differential transcriptomic analysis. This enzyme converts cholesterol and campesterol to pregnenolone, suggesting that digoxin biosynthesis starts from both sterols, unlike previously reported. Phylogenetic analysis indicates that this enzyme arises from a duplicated cytochrome P450
- NSF-PAR ID:
- 10430137
- Publisher / Repository:
- Nature Publishing Group
- Date Published:
- Journal Name:
- Nature Communications
- Volume:
- 14
- Issue:
- 1
- ISSN:
- 2041-1723
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract BACKGROUND As a soilborne fungus,
Fusarium oxysporum can cause vascular wilt in numerous economically important crops. Application of antifungal drugs is the primary method for the control ofF. oxysporum . Cyp51, a key enzyme of sterol biosynthesis is the main target of sterol demethylation inhibitors.RESULTS The
F. oxysporum genome contains three paralogousCYP51 genes (namedFoCYP51A ,FoCYP51B andFoCYP51C ) that putatively encode sterol 14α‐demethylase enzymes. Each of the three genes was able to partially complement theSaccharomyces cerevisiae ERG11 mutant. Growth assays demonstrated that deletion mutants ofFoCYP51B , but notFoCYP51A andFoCYP51C were significantly retarded in hyphal growth. Deletion ofFoCYP51A (ΔFoCyp51A and ΔFoCyp51AC) led to increased sensitivity to 11 sterol demethylation inhibitors (DMIs). Interestingly,FoCYP51B deletion mutants (ΔFoCyp51B and ΔFoCyp51BC) exhibited significantly increased sensitivity to only four DMIs (two of which are in common with the 11 DMIs mentioned earlier). Deletion ofFoCYP51C did not change DMI sensitivity ofF. oxysporum . None of the threeFoCYP51 s are involved inF. oxysporum virulence. The sensitivity ofF. oxysporum isolates increased significantly when subjected to a mixture of different subgroups of DMIs classified based on the different sensitivities ofFoCYP51 mutants to DMIs compared to the individual components.CONCLUSIONS FoCYP51A andFoCYP51B are responsible for sensitivity to different azoles. These findings have direct implications for fungicide application strategies of plant and human diseases caused byF. oxysporum . © 2018 Society of Chemical Industry
