Comparative spatial lipidomics analysis reveals cellular lipid remodelling in different developmental zones of barley roots in response to salinity

• Published in: Plant, cell and environment cell and environment, 2020-02, Vol.43 (2), p.327-343
• Main Authors: Sarabia, Lenin D., Boughton, Berin A., Rupasinghe, Thusitha, Callahan, Damien L., Hill, Camilla B., Roessner, Ute
• Format: Article
• Language: English
• Subjects: Abiotic stress; atomic absorption spectrometry; Barley; ceramides; Ceramides - analysis; Chemical composition; Chromatography, Liquid - methods; Cultivars; desorption; elemental composition; Gene Expression Regulation, Plant; glycerophosphocholine; Glycerophospholipids - analysis; Hordeum - drug effects; Hordeum - genetics; Hordeum - metabolism; Hordeum vulgare; hydroxylation; image analysis; Inductively coupled plasma mass spectrometry; Ionization; ions; Ions - metabolism; Lecithin; lipid composition; Lipid Metabolism - genetics; Lipidomics - methods; Lipids; Lipids - analysis; Liquid chromatography; MALDI; Mass spectrometry; mass spectrometry imaging; Mass spectroscopy; matrix-assisted laser desorption-ionization mass spectrometry; messenger RNA; Metabolome; Metabolomics; Original; Phosphatidylcholine; phosphatidylcholines; Plant roots; Plant Roots - drug effects; Plant Roots - genetics; Plant Roots - metabolism; Plant tissues; Polymerase chain reaction; Reverse transcription; Roots; Salinity; Salinity effects; salt stress; Salt Stress - genetics; Salt Stress - physiology; Salts; Salts - pharmacology; Scientific imaging; Seedlings; Spatial analysis; spatial metabolomics; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization - methods; Spectroscopy; tandem mass spectrometry; Tandem Mass Spectrometry - methods; transcriptome
• ISSN: 0140-7791; 1365-3040
• DOI: 10.1111/pce.13653

Salinity‐induced metabolic, ionic, and transcript modifications in plants have routinely been studied using whole plant tissues, which do not provide information on spatial tissue responses. The aim of this study was to assess the changes in the lipid profiles in a spatial manner and to quantify the changes in the elemental composition in roots of seedlings of four barley cultivars before and after a short‐term salt stress. We used a combination of liquid chromatography–tandem mass spectrometry, inductively coupled plasma mass spectrometry, matrix‐assisted laser desorption/ionization mass spectrometry imaging, and reverse transcription – quantitative real time polymerase chain reaction platforms to examine the molecular signatures of lipids, ions, and transcripts in three anatomically different seminal root tissues before and after salt stress. We found significant changes to the levels of major lipid classes including a decrease in the levels of lysoglycerophospholipids, ceramides, and hexosylceramides and an increase in the levels of glycerophospholipids, hydroxylated ceramides, and hexosylceramides. Our results revealed that modifications to lipid and transcript profiles in plant roots in response to a short‐term salt stress may involve recycling of major lipid species, such as phosphatidylcholine, via resynthesis from glycerophosphocholine. Accumulation of glycerophosphocholine may be a component in the salt stress response of seminal roots of barley seedlings by acting as an osmolyte and a substrate for phosphatidylcholine resynthesis following a short‐term salt stress.