Plant Stress in a Changing Environment: Using Plant Metabolomics to Improve Predictions of Biogenic Secondary Organic Aerosol Production
EMSL Project ID
49798
Abstract
This research addresses a critical barrier in our understanding of the processes controlling biogenic secondary organic aerosol formation (SOA), and how they are evolving in a changing environment. Increasing frequency and intensity of herbivore outbreaks leads to plant stress and alters the composition and emission rates of plant volatiles--the dominant precursors to SOA production. This study uses laboratory experiments that link plant metabolomics with aerosol formation and chemistry. Plant herbivore stress responses to two different sap-feeding aphids will be studied using the riparian plant species, Baccharis salicifolia. Plant metabolomics analysis will include leaf- and emission-level data. Leaf-level metabolomics data will be obtained at EMSL using two complementary analytical techniques to measure both central and secondary metabolites from all three treatment groups (control and two different herbivore types). Emission-level metabolomics data will be collected at UC Irvine using on-line continuous measurements of plant volatile emissions supplemented with off-line analysis of adsorbent samples to provide high time resolution and molecular identification information, respectively. Plant emissions from different treatment groups will be used to generate SOA in an oxidation flow reactor. SOA efficiency curves will be compared between treatment groups to identify unifying molecular properties that drive overall SOA formation from a complex pool of plant emissions. Particle samples will be collected from the flow reactor for off-line analysis at EMSL using high resolution mass spectrometry and microscopy. Leaf-level metabolomics data will be used to assess phenotype plasticity to herbivore stress with twenty replicate plants in each treatment group. Multivariate analyses will be used (including supervised regression models such as PLS-DA and OPLS-DA) to link variations in plant metabolomics and SOA composition data with explanatory variables corresponding to treatment group. This data will be used to identify the key plant volatiles contributing to SOA production from unstressed and herbivore-stressed plants. Furthermore, SOA composition between different treatment groups will be compared to determine implications for climate-relevant aerosol properties (such as radiative properties). The goal is to combine information on phenotype plasticity and metabolomics-aerosol connections to develop a predictive model for plant stress responses and aerosol formation from this plant-herbivore test system. The detailed molecular-scale analysis provided through EMSL capabilities and expertise enable this comprehensive investigation. This work will fill a critical gap for improving predictive capabilities about biogenic SOA formation processes, how they will change in the future, and how they can be managed.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2017-10-01
End Date
2019-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members