Data from: Hydroxymethylbutenyl diphosphate accumulation reveals MEP pathway regulation for high CO2-induced suppression of isoprene emission
Data files
Sep 11, 2023 version files 370.09 KB
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Fig_1A.csv
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Fig_1B.csv
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Fig_2A_B_C.csv
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Fig_2D_E_F.csv
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Fig_3B_D.csv
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Fig_3C.csv
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Fig_4.csv
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Fig_S1A_B.csv
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Fig_S2A_B_C_D.csv
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Fig_S4.csv
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Fig_S5.csv
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Fig_S6.csv
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README.md
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Table_1.csv
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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 CO2, is critical to comprehend how plants will respond to climate change. Isoprene emission decreases with increasing CO2 concentration; however, the underlying mechanism of this response is currently unknown. We demonstrated that high-CO2-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 pathway metabolites in poplar leaves harvested at ambient and high CO2 to identify why isoprene emission is reduced under high CO2. We found that hydroxymethylbutenyl diphosphate (HMBDP) was increased and dimethylallyl diphosphate (DMADP) decreased at high CO2. This implies that high CO2 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 ABA-dependent stomatal regulation, it is unrelated as abscisic acid treatment did not alter the effect of elevated CO2 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 CO2.
Give a brief summary of dataset contents, contextualized in experimental procedures and results.
This dataset contains-
- Isoprene emission data from poplar leaves measured using the Fast Isoprene Sensor
- Assimilation rates or photosynthesis (A), intercellular CO2 concentration (Ci), and stomatal conductance (gsw) measured using LI-COR 6800
- MEP pathway metabolite levels measured by LC-MS/MS
Using these data, we showed that the decline in isoprene emission at high CO2 is due to accumulation of HMBDP which is an upstream precursor and reduction in DMADP, an immediate precursor of isoprene. We also showed that the CO2 responsiveness of isoprene is independent of the ABA-dependent stomatal signaling pathway. Furthermore, high CO2 mediated suppression of isoprene emission is independent of varying light intensities but decreases at high temperature.
Description of the data and file structure
Raw data that were used to make the plots are provided as individual .csv files and each file name contains the figure number.
*Fig 1A. Isoprene emission measured at an interval of 1 min over 48 min as CO2 partial pressure is changed from 39 Pa to 78 Pa and back to 39 Pa
*Fig 1B. Isoprene emission measured in 14 poplar leaves at 39 Pa CO2 and 78 Pa CO2. Relative change in isoprene emission between 39 Pa and 78 Pa CO2 is calculated for each leaf.
- Mean: Mean of isoprene emission at 39 Pa and 78 Pa CO2
- SD: standard deviation
- p-value: calculated by Student's t-test (2 tailed, paired)
a. Data for isoprene emission was collected using the Fast Isoprene Sensor (FIS)
b. Measurements of photosynthesis (A), stomatal conductance (gsw), intercellular CO2 (Ci) were conducted in a LI-COR 6800.
c. Metabolite analysis was conducted on a Xevo TQ-XS mass spectrometer.