Lateral branching oxidoreductase acts in the final stages of strigolactone biosynthesis in Arabidopsis

Philip B. Brewer, Kaori Yoneyama, Fiona Filardo, Emma Meyers, Adrian Scaffidi, Tancred Frickey, Kohki Akiyama, Yoshiya Seto, Elizabeth A. Dun, Julia E. Cremer, Stephanie C. Kerr, Mark T. Waters, Gavin R. Flematti, Michael G. Mason, Georg Weiller, Shinjiro Yamaguchi, Takahito Nomura, Steven M. Smith, Koichi Yoneyama, Christine A. Beveridge

    Research output: Contribution to journalArticle

    81 Citations (Scopus)

    Abstract

    Strigolactones are a group of plant compounds of diverse but related chemical structures. They have similar bioactivity across a broad range of plant species, act to optimize plant growth and development, and promote soil microbe interactions. Carlactone, a common precursor to strigolactones, is produced by conserved enzymes found in a number of diverse species. Versions of the MORE AXILLARY GROWTH1 (MAX1) cytochrome P450 from rice and Arabidopsis thaliana make specific subsets of strigolactones from carlactone. However, the diversity of natural strigolactones suggests that additional enzymes are involved and remain to be discovered. Here, we use an innovative method that has revealed a missing enzyme involved in strigolactone metabolism. By using a transcriptomics approach involving a range of treatments that modify strigolactone biosynthesis gene expression coupled with reverse genetics, we identified LATERAL BRANCHING OXIDOREDUCTASE (LBO), a gene encoding an oxidoreductase-like enzyme of the 2-oxoglutarate and Fe(II)-dependent dioxygenase superfamily. Arabidopsis lbo mutants exhibited increased shoot branching, but the lbo mutation did not enhance the max mutant phenotype. Grafting indicated that LBO is required for a graft-transmissible signal that, in turn, requires a product of MAX1. Mutant lbo backgrounds showed reduced responses to carlactone, the substrate of MAX1, and methyl carlactonoate (MeCLA), a product downstream of MAX1. Furthermore, lbo mutants contained increased amounts of these compounds, and the LBO protein specifically converts MeCLA to an unidentified strigolactone-like compound. Thus, LBO function may be important in the later steps of strigolactone biosynthesis to inhibit shoot branching in Arabidopsis and other seed plants.

    Original languageEnglish
    Pages (from-to)6301-6306
    Number of pages6
    JournalProceedings of the National Academy of Sciences of the United States of America
    Volume113
    Issue number22
    DOIs
    Publication statusPublished - 2016 May 31

    Keywords

    • Arabidopsis
    • Biosynthesis
    • Branching
    • Plant
    • Strigolactone

    ASJC Scopus subject areas

    • General

    Fingerprint Dive into the research topics of 'Lateral branching oxidoreductase acts in the final stages of strigolactone biosynthesis in Arabidopsis'. Together they form a unique fingerprint.

  • Cite this

    Brewer, P. B., Yoneyama, K., Filardo, F., Meyers, E., Scaffidi, A., Frickey, T., Akiyama, K., Seto, Y., Dun, E. A., Cremer, J. E., Kerr, S. C., Waters, M. T., Flematti, G. R., Mason, M. G., Weiller, G., Yamaguchi, S., Nomura, T., Smith, S. M., Yoneyama, K., & Beveridge, C. A. (2016). Lateral branching oxidoreductase acts in the final stages of strigolactone biosynthesis in Arabidopsis. Proceedings of the National Academy of Sciences of the United States of America, 113(22), 6301-6306. https://doi.org/10.1073/pnas.1601729113