Hydroxymethylbutenyl diphosphate accumulation reveals MEP pathway regulation for high CO2-induced suppression of isoprene emission

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 ..., 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., , # Title of Dataset: Hydroxymethylbutenyl diphosphate accumulation reveals MEP pathway regulation for high CO2-induced suppression of isoprene emission

Give a brief summary of dataset contents, contextualized in experimental procedures and results.

This dataset contains-

1. Isoprene emission data from poplar leaves measured using the Fast Isoprene Sensor
2. Assimilation rates or photosynthesis (A), intercellular CO2 concentration (Ci), and stomatal conductance (gsw) measured using LI-COR 6800
3. 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 h...