Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark; Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Australia
Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Australia; Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, Barcelona, Spain
Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Australia; Metabolomics Australia, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Australia; School of Pharmacy, The University of Queensland, Brisbane, Australia
Lars Schrübbers
Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark; Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Australia
Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Australia; CSIRO Synthetic Biology Future Science Platform, Brisbane, Australia
Volatile isoprenoids produced by plants are emitted in vast quantities into the atmosphere, with substantial effects on global carbon cycling. Yet, the molecular mechanisms regulating the balance between volatile and non-volatile isoprenoid production remain unknown. Isoprenoids are synthesised via sequential condensation of isopentenyl pyrophosphate (IPP) to dimethylallyl pyrophosphate (DMAPP), with volatile isoprenoids containing fewer isopentenyl subunits. The DMAPP:IPP ratio could affect the balance between volatile and non-volatile isoprenoids, but the plastidic DMAPP:IPP ratio is generally believed to be similar across different species. Here we demonstrate that the ratio of DMAPP:IPP produced by hydroxymethylbutenyl diphosphate reductase (HDR/IspH), the final step of the plastidic isoprenoid production pathway, is not fixed. Instead, this ratio varies greatly across HDRs from phylogenetically distinct plants, correlating with isoprenoid production patterns. Our findings suggest that adaptation of HDR plays a previously unrecognised role in determining in vivo carbon availability for isoprenoid emissions, directly shaping global biosphere-atmosphere interactions.
