Poplar esterified cell wall transformations and metabolic integration (PECTIN) study
EMSL Project ID
51078
Abstract
Polysaccharides are major components of plant cell walls that can be converted into fuels by microbial fermentation, making plant biomass an important bioenergy resource. However, a substantial fraction of plant cell wall polysaccharides are chemically modified with methyl and acetyl groups that can reduce fermentation yields. Although little is known about the biochemical and physiological functions of those cell wall modifications in trees, recent evidence in Arabidopsis suggests that they are critical for proper development and functioning of xylem vessels and leaf stomata. Generally assumed to be derived from demethylation of pectin, plants have been documented to emit high rates of methanol into the atmosphere from all ecosystems studied during both growth and stress processes with global models concluding that plant-derived methanol is 100 Tg annually. However, quantitative information linking changes in cell wall esterification and plant-atmosphere emissions is lacking and little to no information exists on biosphere-atmosphere fluxes and plant source(s) of acetic acid. We recently demonstrated that the volatiles methanol and acetic acid, which are known to be released from cell wall esters following hydrolysis, may be both emitted to the atmosphere via stomata and integrated into central C1 and C2 plant metabolism. However, methanol and acetic acid are not captured by traditional metabolomics analysis, representing an important gap in our knowledge of cell wall metabolism and its interactions with the environment. To address these knowledge gaps, a DOE early career project (PI: K. Jardine) was funded at LBNL termed, "Poplar esterified cell wall transformations and metabolic integration (PECTIN) study", which was launched in FY19 with an exploratory project at EMSL focusing on the role of methanol delivered to Populus trichocarpa trees to alleviate negative impacts of high temperature stress. Together with a parallel study at LBNL to quantify emissions of methanol and acetic acid during leaf desiccation and its relationships with changes in cell wall methylation and acetylation, this research has led to the potential discovery of abiotic stress-induced increase of O-acetylation of leaf cell walls which requires an FY20 exploratory EMSL research project to verify as a general response to abiotic stress in poplar leaves, the molecular mechanism(s) by which it occurs, and its biological significance(s) during abiotic stress.
Project Details
Project type
Exploratory Research
Start Date
2019-11-26
End Date
2021-06-30
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
Team Members