Title: A robust and efficient method for the extraction of plant extracellular surface lipids as applied to the analysis of silks and seedling leaves of maize

Abstract

Aerial plant organs possess a diverse array of extracellular surface lipids, including both non-polar and amphipathic constituents that collectively provide a primary line of defense against environmental stressors. Extracellular surface lipids on the stigmatic silks of maize are composed primarily of saturated and unsaturated linear hydrocarbons, as well as fatty acids, and aldehydes. To efficiently extract lipids of differing polarities from maize silks, five solvent systems (hexanes; hexanes:diethyl ether (95:5); hexanes:diethyl ether (90:10); chloroform:hexanes (1:1) and chloroform) were tested by immersing fresh silks in solvent for different extraction times. Surface lipid recovery and the relative composition of individual constituents were impacted to varying degrees depending on solvent choice and duration of extraction. Analyses were performed using both silks and leaves to demonstrate the utility of the solvent- and time-optimized protocol in comparison to extraction with the commonly used chloroform solvent. Overall, the preferred solvent system was identified as hexanes:diethyl ether (90:10), based on its effectiveness in extracting surface hydrocarbons and fatty acids as well as its reduced propensity to extract presumed internal fatty acids. Metabolite profiling of wildtype and glossy1 seedlings, which are impaired in surface lipid biosynthesis, demonstrated the ability of the preferred solvent to extract extracellular surface lipidsmore » rich in amphipathic compounds (aldehydes and alcohols). In addition to the expected deficiencies in dotriacontanal and dotriacontan-1-ol for gl1 seedlings, an unexpected increase in fatty acid recovery was observed in gl1 seedlings extracted in chloroform, suggesting that chloro-form extracts lipids from internal tissues of gl1 seedlings. This highlights the importance of extraction method when evaluating mutants that have altered cuticular lipid compositions. Lastly, metabolite profiling of silks from maize inbreds B73 and Mo17, exposed to different environments and harvested at different ages, revealed differences in hydrocarbon and fatty acid composition, demonstrating the dynamic nature of surface lipid accumulation on silks.« less

Authors:

Loneman, Derek M. ^[1]; Peddicord, Layton ^[2]; Al-Rashid, Amani ^[3]; Nikolau, Basil J. ^[2]; Lauter, Nick ^[2]; Yandeau-Nelson, Marna D.  ^[3];

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• Search DOE PAGES for ORCID "0000-0002-2742-7384"

Andrade, Paula B. ^[4]

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+ Show Author Affiliations

1. Case Western Reserve Univ., Cleveland, OH (United States); Dept. of Genetics, Development & Cell Biology, Ames, IA (United States); Iowa State Univ., Ames, IA (United States)
2. Iowa State Univ., Ames, IA (United States)
3. Dept. of Genetics, Development & Cell Biology, Ames, IA (United States); Iowa State Univ., Ames, IA (United States)
4. Univ. do Porto (Portugal)

Publication Date:

Tue Jul 11 00:00:00 EDT 2017

Research Org.:

Iowa State Univ., Ames, IA (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1393507

Grant/Contract Number:  

1354799; 2011-67003-30342

Resource Type:

Accepted Manuscript

Journal Name:

PLoS ONE

Additional Journal Information:

Journal Volume: 12; Journal Issue: 7; Journal ID: ISSN 1932-6203

Publisher:

Public Library of Science

Country of Publication:

United States

Language:

English

Subject:

59 BASIC BIOLOGICAL SCIENCES; 60 APPLIED LIFE SCIENCES; lipids; fatty acids; lipid metabolism; hydrocarbons; chloroform; ethers; metabolites; seedlings