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Abstract Aldoximes are amino acid derivatives that serve as intermediates for numerous specialized metabolites including cyanogenic glycosides, glucosinolates, and auxins. Aldoxime formation is mainly catalyzed by cytochrome P450 monooxygenases of the 79 family (CYP79s) that can have broad or narrow substrate specificity. Except for SbCYP79A1, aldoxime biosynthetic enzymes in the cereal sorghum (Sorghum bicolor) have not been characterized. This study identified nine CYP79-encoding genes in the genome of sorghum. A phylogenetic analysis of CYP79 showed that SbCYP79A61 formed a subclade with maize ZmCYP79A61, previously characterized to be involved in aldoxime biosynthesis. Functional characterization of this sorghum enzyme using transient expression in Nicotiana benthamiana and stable overexpression in Arabidopsis thaliana revealed that SbCYP79A61 catalyzes the production of phenylacetaldoxime (PAOx) from phenylalanine but, unlike the maize enzyme, displays no detectable activity against tryptophan. Additionally, targeted metabolite analysis after stable isotope feeding assays revealed that PAOx can serve as a precursor of phenylacetic acid (PAA) in sorghum and identified benzyl cyanide as an intermediate of PAOx-derived PAA biosynthesis in both sorghum and maize. Taken together, our results demonstrate that SbCYP79A61 produces PAOx in sorghum and may serve in the biosynthesis of other nitrogen-containing phenylalanine-derived metabolites involved in mediating biotic and abiotic stresses.
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Liguleless narrow and narrow odd dwarf act in overlapping pathways to regulate maize development and metabolism
Significance Statement Narrow odd dwarf ( nod ) and Liguleless narrow ( Lgn ) are pleiotropic maize mutants that severely disrupt growth and development. Here, we share our unexpected discovery that the NOD and LGN proteins physically interact at the plasma membrane. Using a combination of genetics, functional genomics and metabolomics, we then show that nod and Lgn impact overlapping stress–response and developmental patterning pathways in maize.
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- Award ID(s):
- 1733606
- PAR ID:
- 10462357
- Date Published:
- Journal Name:
- The Plant Journal
- Volume:
- 112
- Issue:
- 4
- ISSN:
- 0960-7412
- Page Range / eLocation ID:
- 881 to 896
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1111/tpj.15988
