| Title: | Hydroxymethylbutenyl diphosphate accumulation reveals MEP pathway regulation for high CO(2)-induced suppression of isoprene emission |
| Author(s): | Sahu A; Mostofa MG; Weraduwage SM; Sharkey TD; |
| Address: | "Department of Energy Plant Research Laboratory, Michigan State University, East Lansing 48824, MI. Plant Resilience Institute, Michigan State University, East Lansing 48824, MI. Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing 48824, MI. Department of Biology and Biochemistry, Bishop's University, Sherbrooke JIE0L3, QC, Canada" |
| ISSN/ISBN: | 1091-6490 (Electronic) 0027-8424 (Linking) |
| Abstract: | "Isoprene is emitted by some plants and is the most abundant biogenic hydrocarbon entering the atmosphere. Multiple studies have elucidated protective roles of isoprene against several environmental stresses, including high temperature, excessive ozone, and herbivory attack. However, isoprene emission adversely affects atmospheric chemistry by contributing to ozone production and aerosol formation. Thus, understanding the regulation of isoprene emission in response to varying environmental conditions, for example, elevated CO(2), is critical to comprehend how plants will respond to climate change. Isoprene emission decreases with increasing CO(2) concentration; however, the underlying mechanism of this response is currently unknown. We demonstrated that high-CO(2)-mediated suppression of isoprene emission is independent of photosynthesis and light intensity, but it is reduced with increasing temperature. Furthermore, we measured methylerythritol 4-phosphate (MEP) pathway metabolites in poplar leaves harvested at ambient and high CO(2) to identify why isoprene emission is reduced under high CO(2). We found that hydroxymethylbutenyl diphosphate (HMBDP) was increased and dimethylallyl diphosphate (DMADP) decreased at high CO(2.) This implies that high CO(2) impeded the conversion of HMBDP to DMADP, possibly through the inhibition of HMBDP reductase activity, resulting in reduced isoprene emission. We further demonstrated that although this phenomenon appears similar to abscisic acid (ABA)-dependent stomatal regulation, it is unrelated as ABA treatment did not alter the effect of elevated CO(2) on the suppression of isoprene emission. Thus, this study provides a comprehensive understanding of the regulation of the MEP pathway and isoprene emission in the face of increasing CO(2)" |
| Keywords: | Carbon Dioxide/metabolism Diphosphates/metabolism Photosynthesis Hemiterpenes Butadienes/pharmacology/metabolism Plants/metabolism *Ozone/metabolism Pentanes/metabolism Plant Leaves/metabolism *Populus/genetics/metabolism MEP pathway chloroplast elevated; |
| Notes: | "MedlineSahu, Abira Mostofa, Mohammad Golam Weraduwage, Sarathi M Sharkey, Thomas D eng IOS-2022495/National Science Foundation (NSF)/ 2023/10/02 Proc Natl Acad Sci U S A. 2023 Oct 10; 120(41):e2309536120. doi: 10.1073/pnas.2309536120. Epub 2023 Oct 2" |
