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Oubohssaine M, Hnini M, Rabeh K. Exploring lipid signaling in plant physiology: From cellular membranes to environmental adaptation. JOURNAL OF PLANT PHYSIOLOGY 2024; 300:154295. [PMID: 38885581 DOI: 10.1016/j.jplph.2024.154295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 05/23/2024] [Accepted: 06/07/2024] [Indexed: 06/20/2024]
Abstract
Lipids have evolved as versatile signaling molecules that regulate a variety of physiological processes in plants. Convincing evidence highlights their critical role as mediators in a wide range of plant processes required for survival, growth, development, and responses to environmental conditions such as water availability, temperature changes, salt, pests, and diseases. Understanding lipid signaling as a critical process has helped us expand our understanding of plant biology by explaining how plants sense and respond to environmental cues. Lipid signaling pathways constitute a complex network of lipids, enzymes, and receptors that coordinate important cellular responses and stressing plant biology's changing and adaptable traits. Plant lipid signaling involves a wide range of lipid classes, including phospholipids, sphingolipids, oxylipins, and sterols, each of which contributes differently to cellular communication and control. These lipids function not only as structural components, but also as bioactive molecules that transfer signals. The mechanisms entail the production of lipid mediators and their detection by particular receptors, which frequently trigger downstream cascades that affect gene expression, cellular functions, and overall plant growth. This review looks into lipid signaling in plant physiology, giving an in-depth look and emphasizing its critical function as a master regulator of vital activities.
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Affiliation(s)
- Malika Oubohssaine
- Microbiology and Molecular Biology Team, Center of Plant and Microbial Biotechnology, Biodiversity and Environment, Faculty of Sciences, Mohammed V University in Rabat, Avenue Ibn Battouta, BP 1014, Rabat, 10000, Morocco.
| | - Mohamed Hnini
- Microbiology and Molecular Biology Team, Center of Plant and Microbial Biotechnology, Biodiversity and Environment, Faculty of Sciences, Mohammed V University in Rabat, Avenue Ibn Battouta, BP 1014, Rabat, 10000, Morocco
| | - Karim Rabeh
- Microbiology and Molecular Biology Team, Center of Plant and Microbial Biotechnology, Biodiversity and Environment, Faculty of Sciences, Mohammed V University in Rabat, Avenue Ibn Battouta, BP 1014, Rabat, 10000, Morocco
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Arias-Gaguancela O, Herrell E, Chapman KD. Ex vivo lipidomics reveal monoacylglycerols as substrates for a fatty acid amide hydrolase in the legume Medicago truncatula. FEBS Lett 2024; 598:1839-1854. [PMID: 38831473 DOI: 10.1002/1873-3468.14944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 05/09/2024] [Accepted: 05/10/2024] [Indexed: 06/05/2024]
Abstract
Fatty acid amide hydrolase (FAAH) is a conserved hydrolase in eukaryotes with promiscuous activity toward a range of acylamide substrates. The native substrate repertoire for FAAH has just begun to be explored in plant systems outside the model Arabidopsis thaliana. Here, we used ex vivo lipidomics to identify potential endogenous substrates for Medicago truncatula FAAH1 (MtFAAH1). We incubated recombinant MtFAAH1 with lipid mixtures extracted from M. truncatula and resolved their profiles via gas chromatography-mass spectrometry (GC-MS). Data revealed that besides N-acylethanolamines (NAEs), sn-1 or sn-2 isomers of monoacylglycerols (MAGs) were substrates for MtFAAH1. Combined with in vitro and computational approaches, our data support both amidase and esterase activities for MtFAAH1. MAG-mediated hydrolysis via MtFAAH1 may be linked to biological roles that are yet to be discovered.
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Affiliation(s)
- Omar Arias-Gaguancela
- Department of Biological Sciences, BioDiscovery Institute, University of North Texas, Denton, TX, USA
| | - Emily Herrell
- Department of Biological Sciences, BioDiscovery Institute, University of North Texas, Denton, TX, USA
| | - Kent D Chapman
- Department of Biological Sciences, BioDiscovery Institute, University of North Texas, Denton, TX, USA
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Arias-Gaguancela O, Aziz M, Chapman KD. Fatty acid amide hydrolase and 9-lipoxygenase modulate cotton seedling growth by ethanolamide oxylipin levels. PLANT PHYSIOLOGY 2023; 191:1234-1253. [PMID: 36472510 PMCID: PMC9922431 DOI: 10.1093/plphys/kiac556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
Polyunsaturated N-acylethanolamines (NAEs) can be hydrolyzed by fatty acid amide hydrolase (FAAH) or oxidized by lipoxygenase (LOX). In Arabidopsis (Arabidopsis thaliana), the 9-LOX product of linoleoylethanolamide, namely, 9-hydroxy linoleoylethanolamide (9-NAE-HOD), is reported to negatively regulate seedling development during secondary dormancy. In upland cotton (Gossypium hirsutum L.), six putative FAAH genes (from two diverged groups) and six potential 9-LOX genes are present; however, their involvement in 9-NAE-HOD metabolism and its regulation of seedling development remain unexplored. Here, we report that in cotton plants, two specific FAAH isoforms (GhFAAH Ib and GhFAAH IIb) are needed for hydrolysis of certain endogenous NAEs. Virus-induced gene silencing (VIGS) of either or both FAAHs led to reduced seedling growth and this coincided with reduced amidohydrolase activities and elevated quantities of endogenous 9-NAE-HOD. Transcripts of GhLOX21 were consistently elevated in FAAH-silenced tissues, and co-silencing of GhLOX21 and GhFAAH (Ib and/or IIb) led to reversal of seedling growth to normal levels (comparable with no silencing). This was concomitant with reductions in the levels of 9-NAE-HOD, but not of 13-NAE-HOD. Pharmacological experiments corroborated the genetic and biochemical evidence, demonstrating that direct application of 9-NAE-HOD, but not 13-NAE-HOD or their corresponding free fatty acid oxylipins, inhibited the growth of cotton seedlings. Additionally, VIGS of GhLOX21 in cotton lines overexpressing AtFAAH exhibited enhanced growth and no detectable 9-NAE-HOD. Altogether, we conclude that the growth of cotton seedlings involves fine-tuning of 9-NAE-HOD levels via FAAH-mediated hydrolysis and LOX-mediated production, expanding the mechanistic understanding of plant growth modulation by NAE oxylipins to a perennial crop species.
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Shan F, Wu Y, Du R, Yang Q, Liu C, Wang Y, Zhang C, Chen Y. Evolutionary analysis of the OSCA gene family in sunflower ( Helianthus annuus L) and expression analysis under NaCl stress. PeerJ 2023; 11:e15089. [PMID: 37090105 PMCID: PMC10117387 DOI: 10.7717/peerj.15089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 02/26/2023] [Indexed: 04/25/2023] Open
Abstract
Hyperosmolality-gated calcium-permeable channels (OSCA) are Ca2 + nonselective cation channels that contain the calcium-dependent DUF221 domain, which plays an important role in plant response to stress and growth. However, the OSCA gene has not been fully identified and analyzed in sunflowers. In this study, we comprehensively analyzed the number, structure, collinearity, and phylogeny of the OSCA gene family in the sunflower, six Compositae species (Arctium lappa, Chrysanthemum morifolium, Cichorium endivia, Cichorium intybus, Lactuca sativa var. Angustata, and Carthamus tinctorius), and six other plants (soybean, Arabidopsis thaliana, rice, grape, and maize). The expression of the sunflower OSCA gene in nine different tissues, six different hormones, and NaCl stress conditions were analyzed based on transcriptome data and qRT-PCR. A total of 15 OSCA proteins, distributed on 10 chromosomes, were identified in the sunflower, and all of them were located in the endoplasmic reticulum. Using the phylogenetic tree, collinearity, gene structure, and motif analysis of the six Compositae species and six other plants, we found that the sunflower OSCA protein had only three subfamilies and lacked the Group 4 subfamily, which is conserved in the evolution of Compositae and subject to purification selection. The OSCA gene structure and motif analysis of the sunflower and six Compositae showed that there was a positive correlation between the number of motifs of most genes and the length of the gene, different subfamilies had different motifs, and the Group 4 subfamily had the smallest number of genes and the simplest gene structure. RNA-seq and qRT-PCR analysis showed that the expression levels of most OSCA genes in the sunflower changed to varying degrees under salt stress, and HaOSCA2.6 and HaOSCA3.1 were the most important in the sunflower's response to salt stress. The coexpression network of the sunflower genes under salt stress was constructed based on weighted gene co-expression network analysis (WGCNA). In conclusion, our findings suggest that the OSCA gene family is conserved during the sunflower's evolution and plays an important role in salt tolerance. These results will deepen our understanding of the evolutionary relationship of the sunflower OSCA gene family and provide a basis for their functional studies under salt stress.
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Affiliation(s)
- Feibiao Shan
- Hetao College, Bayannur, China
- Inner Mongolia Traditional Chinese & Mongolian Medical Research Institute, Hohhot, China
- Bayannur Institute of Agricultural and Animal Sciences, Bayannur, China
| | - Yue Wu
- Bayannur Institute of Agricultural and Animal Sciences, Bayannur, China
| | - Ruixia Du
- Bayannur Institute of Agricultural and Animal Sciences, Bayannur, China
| | - Qinfang Yang
- Bayannur Institute of Agricultural and Animal Sciences, Bayannur, China
| | - Chunhui Liu
- Bayannur Institute of Agricultural and Animal Sciences, Bayannur, China
| | - Yongxing Wang
- Bayannur Institute of Agricultural and Animal Sciences, Bayannur, China
| | | | - Yang Chen
- Hetao College, Bayannur, China
- Bayannur Institute of Agricultural and Animal Sciences, Bayannur, China
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Lin XY, Zhang NN, Yao BH, Zhang X, Liu WY, Zhang WQ, Zhang JH, Wei GH, Chen J. Interactions between hydrogen sulphide and rhizobia modulate the physiological and metabolism process during water deficiency-induced oxidative defense in soybean. PLANT, CELL & ENVIRONMENT 2022; 45:3249-3274. [PMID: 36043459 DOI: 10.1111/pce.14431] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 08/23/2022] [Accepted: 08/29/2022] [Indexed: 06/15/2023]
Abstract
Hydrogen sulphide (H2 S), a new gas signal molecule, participates in the regulation of various abiotic stresses in plants. However, how the tandem working of H2 S and rhizobia affects the adaptation of soybean to water deficiency is still unclear. In this study, we investigated the adaptation mechanism of H2 S and rhizobia in soybean to water deficiency. Our results revealed that H2 S and rhizobia jointly enhanced the leaf chlorophyll content and relative water content in plants, and caused an increase in the biomass of soybean seedlings under water deficiency. Besides, in the absence of water, H2 S enhanced the biomass by affecting the number of nodules and nitrogenase activity during vegetative growth. The expression of nodulation marker genes including early nodulin 40 (GmENOD40), ERF required for nodulation (GmERN) and nodulation inception genes (GmNIN1a, GmNIN2a and GmNIN2b) were upregulated by H2 S and rhizobia in the nodules. Moreover, the combined effect of H2 S and rhizobia was proved to affect the enzyme activities and gene expression level of antioxidants, as well as osmotic protective substance content and related gene expression levels under water deficiency in soybean seedlings. In addition, the metabolomic results suggested that the combined effect of H2 S and rhizobia remarkably promoted the contents of lipids and lipid-like molecules. Our results indicated that H2 S and rhizobia synergistically reduced the oxidative damage caused by water deficiency through increasing the accumulation of metabolites and strengthening the plant antioxidant capacity.
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Affiliation(s)
- Xue-Yuan Lin
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Ni-Na Zhang
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Bai-Hui Yao
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Xin Zhang
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Wu-Yu Liu
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Wei-Qin Zhang
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Jian-Hua Zhang
- Department of Biology, Hong Kong Baptist University, and State Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Hong Kong, People's Republic of China
| | - Ge-Hong Wei
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Juan Chen
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
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Arias‐Gaguancela O, Adhikari B, Aziz M, Chapman KD. Enhanced seedling growth by 3- n-pentadecylphenolethanolamide is mediated by fatty acid amide hydrolases in upland cotton ( Gossypium hirsutum L.). PLANT DIRECT 2022; 6:e421. [PMID: 35844778 PMCID: PMC9277032 DOI: 10.1002/pld3.421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 06/16/2022] [Accepted: 06/19/2022] [Indexed: 05/25/2023]
Abstract
Fatty acid amide hydrolase (FAAH) is a conserved amidase that is known to modulate the levels of endogenous N-acylethanolamines (NAEs) in both plants and animals. The activity of FAAH is enhanced in vitro by synthetic phenoxyacylethanolamides resulting in greater hydrolysis of NAEs. Previously, 3-n-pentadecylphenolethanolamide (PDP-EA) was shown to exert positive effects on the development of Arabidopsis seedlings by enhancing Arabidopsis FAAH (AtFAAH) activity. However, there is little information regarding FAAH activity and the impact of PDP-EA in the development of seedlings of other plant species. Here, we examined the effects of PDP-EA on growth of upland cotton (Gossypium hirsutum L. cv Coker 312) seedlings including two lines of transgenic seedlings overexpressing AtFAAH. Independent transgenic events showed accelerated true-leaf emergence compared with non-transgenic controls. Exogenous applications of PDP-EA led to increases in overall seedling growth in AtFAAH transgenic lines. These enhanced-growth phenotypes coincided with elevated FAAH activities toward NAEs and NAE oxylipins. Conversely, the endogenous contents of NAEs and NAE-oxylipin species, especially linoleoylethanolamide and 9-hydroxy linoleoylethanolamide, were lower in PDP-EA treated seedlings than in controls. Further, transcripts for endogenous cotton FAAH genes were increased following PDP-EA exposure. Collectively, our data corroborate that the enhancement of FAAH enzyme activity by PDP-EA stimulates NAE-hydrolysis and that this results in enhanced growth in seedlings of a perennial crop species, extending the role of NAE metabolism in seedling development beyond the model annual plant species, Arabidopsis thaliana.
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Affiliation(s)
- Omar Arias‐Gaguancela
- BioDiscovery Institute, Department of Biological SciencesUniversity of North TexasDentonTXUSA
| | | | - Mina Aziz
- BioDiscovery Institute, Department of Biological SciencesUniversity of North TexasDentonTXUSA
| | - Kent D. Chapman
- BioDiscovery Institute, Department of Biological SciencesUniversity of North TexasDentonTXUSA
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Hamany Djande CY, Steenkamp PA, Piater LA, Tugizimana F, Dubery IA. Hordatines and Associated Precursors Dominate Metabolite Profiles of Barley (Hordeum vulgare L.) Seedlings: A Metabolomics Study of Five Cultivars. Metabolites 2022; 12:metabo12040310. [PMID: 35448497 PMCID: PMC9030721 DOI: 10.3390/metabo12040310] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 02/06/2023] Open
Abstract
In the process of enhancing crop potential, metabolomics offers a unique opportunity to biochemically describe plant metabolism and to elucidate metabolite profiles that govern specific phenotypic characteristics. In this study we report an untargeted metabolomic profiling of shoots and roots of barley seedlings performed to reveal the chemical makeup therein at an early growth stage. The study was conducted on five cultivars of barley: ‘Overture’, ‘Cristalia’, ‘Deveron’, ‘LE7′ and ‘Genie’. Seedlings were grown for 16 days post germination under identical controlled conditions, and methanolic extracts were analysed on an ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC–HRMS) system. In addition, an unsupervised pattern identification technique, principal component analysis (PCA), was performed to process the generated multidimensional data. Following annotation of specific metabolites, several classes were revealed, among which phenolic acids represented the largest group in extracts from both shoot and root tissues. Interestingly, hordatines, barley-specific metabolites, were not found in the root tissue. In addition, metabolomic profiling revealed metabolites potentially associated with the plants’ natural protection system against potential pathogens. The study sheds light on the chemical composition of barley at a young developmental stage and the information gathered could be useful in plant research and biomarker-based breeding programs.
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Zoong Lwe Z, Sah S, Persaud L, Li J, Gao W, Raja Reddy K, Narayanan S. Alterations in the leaf lipidome of Brassica carinata under high-temperature stress. BMC PLANT BIOLOGY 2021; 21:404. [PMID: 34488625 PMCID: PMC8419912 DOI: 10.1186/s12870-021-03189-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 08/13/2021] [Indexed: 05/21/2023]
Abstract
BACKGROUND Brassica carinata (A) Braun has recently gained increased attention across the world as a sustainable biofuel crop. B. carinata is grown as a summer crop in many regions where high temperature is a significant stress during the growing season. However, little research has been conducted to understand the mechanisms through which this crop responds to high temperatures. Understanding traits that improve the high-temperature adaption of this crop is essential for developing heat-tolerant varieties. This study investigated lipid remodeling in B. carinata in response to high-temperature stress. A commercial cultivar, Avanza 641, was grown under sunlit-controlled environmental conditions in Soil-Plant-Atmosphere-Research (SPAR) chambers under optimal temperature (OT; 23/15°C) conditions. At eight days after sowing, plants were exposed to one of the three temperature treatments [OT, high-temperature treatment-1 (HT-1; 33/25°C), and high-temperature treatment-2 (HT-2; 38/30°C)]. The temperature treatment period lasted until the final harvest at 84 days after sowing. Leaf samples were collected at 74 days after sowing to profile lipids using electrospray-ionization triple quadrupole mass spectrometry. RESULTS Temperature treatment significantly affected the growth and development of Avanza 641. Both high-temperature treatments caused alterations in the leaf lipidome. The alterations were primarily manifested in terms of decreases in unsaturation levels of membrane lipids, which was a cumulative effect of lipid remodeling. The decline in unsaturation index was driven by (a) decreases in lipids that contain the highly unsaturated linolenic (18:3) acid and (b) increases in lipids containing less unsaturated fatty acids such as oleic (18:1) and linoleic (18:2) acids and/or saturated fatty acids such as palmitic (16:0) acid. A third mechanism that likely contributed to lowering unsaturation levels, particularly for chloroplast membrane lipids, is a shift toward lipids made by the eukaryotic pathway and the channeling of eukaryotic pathway-derived glycerolipids that are composed of less unsaturated fatty acids into chloroplasts. CONCLUSIONS The lipid alterations appear to be acclimation mechanisms to maintain optimal membrane fluidity under high-temperature conditions. The lipid-related mechanisms contributing to heat stress response as identified in this study could be utilized to develop biomarkers for heat tolerance and ultimately heat-tolerant varieties.
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Affiliation(s)
- Zolian Zoong Lwe
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC, 29634, USA
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, 66506, USA
| | - Saroj Sah
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Starkville, MS, 39762, USA
| | - Leelawatti Persaud
- Plant and Soil Sciences, Mississippi State University, Starkville, MS, 39762, USA
| | - Jiaxu Li
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Starkville, MS, 39762, USA
| | - Wei Gao
- USDA UVB Monitoring and Research Program, Natural Resource Ecology Laboratory, Department of Ecosystem Science and Sustainability, Colorado State University, Fort Collins, CO, 80523, USA
| | - K Raja Reddy
- Plant and Soil Sciences, Mississippi State University, Starkville, MS, 39762, USA.
| | - Sruthi Narayanan
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC, 29634, USA.
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Cannon AE, Chapman KD. Lipid Signaling through G Proteins. TRENDS IN PLANT SCIENCE 2021; 26:720-728. [PMID: 33468433 DOI: 10.1016/j.tplants.2020.12.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 12/10/2020] [Accepted: 12/19/2020] [Indexed: 06/12/2023]
Abstract
N-Acylethanolamine (NAE) signaling has received considerable attention in vertebrates as part of the endocannabinoid signaling system, where anandamide acts as a ligand for G protein-coupled cannabinoid receptors. Recent studies indicate that G proteins also are required for some types of NAE signaling in plants. The genetic ablation of the Gβγ dimer or loss of the full set of extra-large G proteins strongly attenuated NAE-induced chloroplast responses in seedlings. Intriguing parallels and distinct differences have emerged between plants and animals in NAE signaling, despite the conserved use of these lipid mediators to modulate cellular processes. Here we compare similarities and differences and identify open questions in a fundamental lipid signaling pathway in eukaryotes with components that are both conserved and diverged in plants.
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Affiliation(s)
- Ashley E Cannon
- Wheat Health, Genetics, and Quality Research Unit, Agriculture Research Service, U.S. Department of Agriculture, Pullman, WA 99163, USA; Department of Crop and Soil Science, Washington State University, Pullman, WA 99163, USA.
| | - Kent D Chapman
- BioDiscovery Institute, Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA.
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Cannon AE, Yan C, Burks DJ, Rao X, Azad RK, Chapman KD. Lipophilic signals lead to organ-specific gene expression changes in Arabidopsis seedlings. PLANT DIRECT 2020; 4:e00242. [PMID: 32775951 PMCID: PMC7403840 DOI: 10.1002/pld3.242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 06/16/2020] [Accepted: 06/19/2020] [Indexed: 05/10/2023]
Abstract
In plants, N-acylethanolamines (NAEs) are most abundant in desiccated seeds and their levels decline during germination and early seedling establishment. However, endogenous NAE levels rise in seedlings when ABA or environmental stress is applied, and this results in an inhibition of further seedling development. When the most abundant, polyunsaturated NAEs of linoleic acid (18:2) and linolenic acid (18:3) were exogenously applied, seedling development was affected in an organ-specific manner. NAE 18:2 primarily affected primary root elongation and NAE 18:3 primarily affected cotyledon greening and expansion and overall seedling growth. The molecular components and signaling mechanisms involved in this pathway are not well understood. In addition, the bifurcating nature of this pathway provides a unique system in which to study the spatial aspects and interaction of these lipid-specific and organ-targeted signaling pathways. Using whole transcriptome sequencing (RNA-seq) and differential expression analysis, we identified early (1-3 hr) transcriptional changes induced by the exogenous treatment of NAE 18:2 and NAE 18:3 in cotyledons, roots, and seedlings. These two treatments led to a significant enrichment in ABA-response and chitin-response genes in organs where the treatments led to changes in development. In Arabidopsis seedlings, NAE 18:2 treatment led to the repression of genes involved in cell wall biogenesis and organization in roots and seedlings. In addition, cotyledons, roots, and seedlings treated with NAE 18:3 also showed a decrease in transcripts that encode proteins involved in growth processes. NAE 18:3 also led to changes in the abundance of transcripts involved in the modulation of chlorophyll biosynthesis and catabolism in cotyledons. Overall, NAE 18:2 and NAE 18:3 treatment led to lipid-type and organ-specific gene expression changes that include overlapping and non-overlapping gene sets. These data will provide future, rich opportunities to examine the genetic pathways involved in transducing early signals into downstream physiological changes in seedling growth.
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Affiliation(s)
- Ashley E. Cannon
- BioDiscovery Institute and Department of Biological SciencesUniversity of North TexasDentonTXUSA
| | - Chengshi Yan
- BioDiscovery Institute and Department of Biological SciencesUniversity of North TexasDentonTXUSA
| | - David J. Burks
- BioDiscovery Institute and Department of Biological SciencesUniversity of North TexasDentonTXUSA
| | - Xiaolan Rao
- BioDiscovery Institute and Department of Biological SciencesUniversity of North TexasDentonTXUSA
| | - Rajeev K. Azad
- BioDiscovery Institute and Department of Biological SciencesUniversity of North TexasDentonTXUSA
- Department of MathematicsUniversity of North TexasDentonTXUSA
| | - Kent D. Chapman
- BioDiscovery Institute and Department of Biological SciencesUniversity of North TexasDentonTXUSA
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Comparative Lipidomic Analysis Reveals Heat Stress Responses of Two Soybean Genotypes Differing in Temperature Sensitivity. PLANTS 2020; 9:plants9040457. [PMID: 32260392 PMCID: PMC7238245 DOI: 10.3390/plants9040457] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Revised: 04/01/2020] [Accepted: 04/01/2020] [Indexed: 01/20/2023]
Abstract
Heat-induced changes in lipidome and their influence on stress adaptation are not well-defined in plants. We investigated if lipid metabolic changes contribute to differences in heat stress responses in a heat-tolerant soybean genotype DS25-1 and a heat-susceptible soybean genotype DT97-4290. Both genotypes were grown at optimal temperatures (OT; 30/20 °C) for 15 days. Subsequently, half of the plants were exposed to heat stress (38/28 °C) for 11 days, and the rest were kept at OT. Leaf samples were collected for lipid and RNA extractions on the 9th and 11th days of stress, respectively. We observed a decline in the lipid unsaturation level due to a decrease in the polyunsaturated linolenic acid (18:3) content in DS25-1. When examined under OT conditions, DS25-1 and DT97-4290 showed no significant differences in the expression pattern of the Fatty Acid Desaturase (FAD) 2-1A, FAD2-2B, FAD2-2C, FAD3A genes. Under heat stress conditions, substantial reductions in the expression levels of the FAD3A and FAD3B genes, which convert 18:2 lipids to 18:3, were observed in DS25-1. Our results suggest that decrease in levels of lipids containing 18:3 acyl chains under heat stress in DS25-1 is a likely consequence of reduced FAD3A and FAD3B expression, and the decrease in 18:3 contributes to DS25-1′s maintenance of membrane functionality and heat tolerance.
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Aziz M, Wang X, Tripathi A, Bankaitis VA, Chapman KD. Structural analysis of a plant fatty acid amide hydrolase provides insights into the evolutionary diversity of bioactive acylethanolamides. J Biol Chem 2019; 294:7419-7432. [PMID: 30894416 PMCID: PMC6509493 DOI: 10.1074/jbc.ra118.006672] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 03/20/2019] [Indexed: 01/09/2023] Open
Abstract
N-Acylethanolamines (NAEs) are fatty acid derivatives that in animal systems include the well-known bioactive metabolites of the endocannabinoid signaling pathway. Plants use NAE signaling as well, and these bioactive molecules often have oxygenated acyl moieties. Here, we report the three-dimensional crystal structures of the signal-terminating enzyme fatty acid amide hydrolase (FAAH) from Arabidopsis in its apo and ligand-bound forms at 2.1- and 3.2-Å resolutions, respectively. This plant FAAH structure revealed features distinct from those of the only other available FAAH structure (rat). The structures disclosed that although catalytic residues are conserved with the mammalian enzyme, AtFAAH has a more open substrate-binding pocket that is partially lined with polar residues. Fundamental differences in the organization of the membrane-binding "cap" and the membrane access channel also were evident. In accordance with the observed structural features of the substrate-binding pocket, kinetic analysis showed that AtFAAH efficiently uses both unsubstituted and oxygenated acylethanolamides as substrates. Moreover, comparison of the apo and ligand-bound AtFAAH structures identified three discrete sets of conformational changes that accompany ligand binding, suggesting a unique "squeeze and lock" substrate-binding mechanism. Using molecular dynamics simulations, we evaluated these conformational changes further and noted a partial unfolding of a random-coil helix within the region 531-537 in the apo structure but not in the ligand-bound form, indicating that this region likely confers plasticity to the substrate-binding pocket. We conclude that the structural divergence in bioactive acylethanolamides in plants is reflected in part in the structural and functional properties of plant FAAHs.
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Affiliation(s)
- Mina Aziz
- From the BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203 and
| | - Xiaoqiang Wang
- From the BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203 and
| | - Ashutosh Tripathi
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas 77843
| | - Vytas A Bankaitis
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas 77843
| | - Kent D Chapman
- From the BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203 and
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Changes in Retinal N-Acylethanolamines and their Oxylipin Derivatives During the Development of Visual Impairment in a Mouse Model for Glaucoma. Lipids 2016; 51:857-66. [PMID: 27221132 DOI: 10.1007/s11745-016-4161-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 05/05/2016] [Indexed: 10/21/2022]
Abstract
Neurons are especially susceptible to oxidative damage, which is increasingly implicated in neurodegenerative disease. Certain N-acylethanolamines (NAEs) have been shown to protect neurons from oxidative stress. Since glaucoma may be considered a neurodegenerative disorder and the survival of retinal neurons could also be influenced by N-acylethanolamines, our goal was to quantify changes in certain N-acylethanolamine species and their oxylipin derivatives in the retina of a mouse model for glaucoma. We also sought to identify relationships between these and parameters of glaucoma disease development, specifically intraocular pressure, visual acuity, and contrast sensitivity. Five N-acylethanolamine species and three NAE oxylipin derivatives were quantified in retina from young and aged DBA/2Crl mice. N-Acylethanolamines and NAE-oxylipins in retinal extracts were quantified against deuterated standards by isotope dilution gas chromatography-mass spectrometry. Levels (nmol/g dry weight) of N-arachidonoylethanolamine (anandamide; NAE 20:4) were significantly (p = 0.008) decreased in aged (2.875 ± 0.6702) compared to young animals (5.175 ± 0.971). Conversely, the anandamide oxylipin, 15(S)-HETE ethanolamide (15(S)-HETE EA), was significantly (p = 0.042) increased in aged (0.063 ± 0.009) compared to young animals (0.039 ± 0.011). Enzymatic depletion of the anandamide pool by 15-lipoxygenase and consequent accumulation of 15(S)-HETE ethanolamine may contribute to decreased visual function in glaucomatous mice. Since N-acylethanolamines effectively attenuate glaucoma pathogenesis and associated visual impairment, our data provides additional rationale and novel targets for glaucoma therapies.
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Nalam VJ, Alam S, Keereetaweep J, Venables B, Burdan D, Lee H, Trick HN, Sarowar S, Makandar R, Shah J. Facilitation of Fusarium graminearum Infection by 9-Lipoxygenases in Arabidopsis and Wheat. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2015; 28:1142-52. [PMID: 26075826 DOI: 10.1094/mpmi-04-15-0096-r] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Fusarium graminearum causes Fusarium head blight, an important disease of wheat. F. graminearum can also cause disease in Arabidopsis thaliana. Here, we show that the Arabidopsis LOX1 and LOX5 genes, which encode 9-lipoxygenases (9-LOXs), are targeted during this interaction to facilitate infection. LOX1 and LOX5 expression were upregulated in F. graminearum-inoculated plants and loss of LOX1 or LOX5 function resulted in enhanced disease resistance in the corresponding mutant plants. The enhanced resistance to F. graminearum infection in the lox1 and lox5 mutants was accompanied by more robust induction of salicylic acid (SA) accumulation and signaling and attenuation of jasmonic acid (JA) signaling in response to infection. The lox1- and lox5-conferred resistance was diminished in plants expressing the SA-degrading salicylate hydroxylase or by the application of methyl-JA. Results presented here suggest that plant 9-LOXs are engaged during infection to control the balance between SA and JA signaling to facilitate infection. Furthermore, since silencing of TaLpx-1 encoding a 9-LOX with homology to LOX1 and LOX5, resulted in enhanced resistance against F. graminearum in wheat, we suggest that 9-LOXs have a conserved role as susceptibility factors in disease caused by this important fungus in Arabidopsis and wheat.
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Affiliation(s)
- Vamsi J Nalam
- 1 Department of Biological Sciences, University of North Texas, Denton, TX 76203, U.S.A
- 2 Department of Biology, Indiana University-Purdue University, Fort Wayne, IN 46805, U.S.A
| | - Syeda Alam
- 1 Department of Biological Sciences, University of North Texas, Denton, TX 76203, U.S.A
| | - Jantana Keereetaweep
- 1 Department of Biological Sciences, University of North Texas, Denton, TX 76203, U.S.A
| | - Barney Venables
- 1 Department of Biological Sciences, University of North Texas, Denton, TX 76203, U.S.A
| | - Dehlia Burdan
- 3 Department of Plant Pathology, Kansas State University, Manhattan, KS 66506, U.S.A
| | - Hyeonju Lee
- 3 Department of Plant Pathology, Kansas State University, Manhattan, KS 66506, U.S.A
| | - Harold N Trick
- 3 Department of Plant Pathology, Kansas State University, Manhattan, KS 66506, U.S.A
| | - Sujon Sarowar
- 1 Department of Biological Sciences, University of North Texas, Denton, TX 76203, U.S.A
| | - Ragiba Makandar
- 1 Department of Biological Sciences, University of North Texas, Denton, TX 76203, U.S.A
- 4 Department of Plant Sciences, University of Hyderabad, Gachibowli, Hyderabad, India
| | - Jyoti Shah
- 1 Department of Biological Sciences, University of North Texas, Denton, TX 76203, U.S.A
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Keereetaweep J, Blancaflor EB, Hornung E, Feussner I, Chapman KD. Lipoxygenase-derived 9-hydro(pero)xides of linoleoylethanolamide interact with ABA signaling to arrest root development during Arabidopsis seedling establishment. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 82:315-27. [PMID: 25752187 DOI: 10.1111/tpj.12821] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 02/16/2015] [Accepted: 02/23/2015] [Indexed: 05/10/2023]
Abstract
Ethanolamide-conjugated fatty acid derivatives, also known as N-acylethanolamines (NAEs), occur at low levels (μg per g) in desiccated seeds, and endogenous amounts decline rapidly with seedling growth. Linoleoylethanolamide (NAE18:2) is the most abundant of these NAEs in seeds of almost all plants, including Arabidopsis thaliana. In Arabidopsis, NAE18:2 may be oxidized by lipoxygenase (LOX) or hydrolyzed by fatty acid amide hydrolase (FAAH) during normal seedling establishment, and this contributes to the normal progression of NAE depletion that is coincident with the depletion of abscisic acid (ABA). Here we provide biochemical, genetic and pharmacological evidence that a specific 9-LOX metabolite of NAE18:2 [9-hydro(pero)xy linoleoylethanolamide (9-NAE-H(P)OD)] has a potent negative influence on seedling root elongation, and acts synergistically with ABA to modulate the transition from embryo to seedling growth. Genetic analyses using mutants in ABA synthesis (aba1 and aba2), perception (pyr1, pyl1, pyl2, pyl4, pyl5 and pyl8) or transcriptional activation (abi3-1) indicated that arrest of root growth by 9-NAE-H(P)OD requires an intact ABA signaling pathway, and probably operates to increase ABA synthesis as part of a positive feedback loop to modulate seedling establishment in response to adverse environmental conditions. These results identify a specific, bioactive ethanolamide oxylipin metabolite of NAE18:2, different from those of ethanolamide-conjugated linolenic acid (NAE18:3), as well as a molecular explanation for its inhibitory action, emphasizing the oxidative metabolism of NAEs as an important feature of seedling development.
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Affiliation(s)
- Jantana Keereetaweep
- Department of Biological Sciences, Center for Plant Lipid Research, University of North Texas, Denton, TX, 76203, USA
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Faure L, Cavazos R, Khan BR, Petros RA, Koulen P, Blancaflor EB, Chapman KD. Effects of synthetic alkamides on Arabidopsis fatty acid amide hydrolase activity and plant development. PHYTOCHEMISTRY 2015; 110:58-71. [PMID: 25491532 DOI: 10.1016/j.phytochem.2014.11.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 10/28/2014] [Accepted: 11/06/2014] [Indexed: 05/25/2023]
Abstract
Alkamides and N-acylethanolamines (NAEs) are bioactive, amide-linked lipids that influence plant development. Alkamides are restricted to several families of higher plants and some fungi, whereas NAEs are widespread signaling molecules in both plants and animals. Fatty acid amide hydrolase (FAAH) has been described as a key contributor to NAE hydrolysis; however, no enzyme has been associated with alkamide degradation in plants. Herein reported is synthesis of 12 compounds structurally similar to a naturally occurring alkamide (N-isobutyl-(2E,6Z,8E)decatrienamide or affinin) with different acyl compositions more similar to plant NAEs and various amino alkyl head groups. These "hybrid" synthetic alkamides were tested for activity toward recombinant Arabidopsis FAAH and for their effects on plant development (i.e., cotyledon expansion and primary root length). A substantial increase in FAAH activity was discovered toward NAEs in vitro in the presence of some of these synthetic alkamides, such as N-ethyllauroylamide (4). This "enhancement" effect was found to be due, at least in part, to relief from product inhibition of FAAH by ethanolamine, and not due to an alteration in the oligomerization state of the FAAH enzyme. For several of these alkamides, an inhibition of seedling growth was observed with greater results in FAAH knockouts and less in FAAH over-expressing plants, suggesting that these alkamides could be hydrolyzed by FAAH in planta. The tight regulation of NAE levels in vivo appears to be important for proper seedling establishment, and as such, some of these synthetic alkamides may be useful pharmacological tools to manipulate the effects of NAEs in situ.
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Affiliation(s)
- Lionel Faure
- Center for Plant Lipid Research, Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
| | - Ronaldo Cavazos
- Department of Chemistry, University of North Texas, Denton, TX 76203, USA
| | - Bibi Rafeiza Khan
- The Samuel Roberts Noble Foundation, Plant Biology Division, Ardmore, OK 73401, USA
| | - Robby A Petros
- Department of Chemistry, University of North Texas, Denton, TX 76203, USA.
| | - Peter Koulen
- Center for Plant Lipid Research, Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA; Vision Research Center, Department of Ophthalmology, School of Medicine, University of Missouri - Kansas City, Kansas City, MO, USA; Department of Basic Medical Science, School of Medicine, University of Missouri - Kansas City, Kansas City, MO, USA
| | - Elison B Blancaflor
- Center for Plant Lipid Research, Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA; The Samuel Roberts Noble Foundation, Plant Biology Division, Ardmore, OK 73401, USA
| | - Kent D Chapman
- Center for Plant Lipid Research, Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA.
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Okazaki Y, Saito K. Roles of lipids as signaling molecules and mitigators during stress response in plants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 79:584-96. [PMID: 24844563 DOI: 10.1111/tpj.12556] [Citation(s) in RCA: 172] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 04/30/2014] [Accepted: 05/06/2014] [Indexed: 05/20/2023]
Abstract
Lipids are the major constituents of biological membranes that can sense extracellular conditions. Lipid-mediated signaling occurs in response to various environmental stresses, such as temperature change, salinity, drought and pathogen attack. Lysophospholipid, fatty acid, phosphatidic acid, diacylglycerol, inositol phosphate, oxylipins, sphingolipid, and N-acylethanolamine have all been proposed to function as signaling lipids. Studies on these stress-inducible lipid species have demonstrated that each lipid class has specific biological relevance, biosynthetic mechanisms and signaling cascades, which activate defense reactions at the transcriptional level. In addition to their roles in signaling, lipids also function as stress mitigators to reduce the intensity of stressors. To mitigate particular stresses, enhanced syntheses of unique lipids that accumulate in trace quantities under normal growth conditions are often observed under stressed conditions. The accumulation of oligogalactolipids and glucuronosyldiacylglycerol has recently been found to mitigate freezing and nutrition-depletion stresses, respectively, during lipid remodeling. In addition, wax, cutin and suberin, which are not constituents of the lipid bilayer, but are components derived from lipids, contribute to the reduction of drought stress and tissue injury. These features indicate that lipid-mediated defenses against environmental stress contributes to plant survival.
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Affiliation(s)
- Yozo Okazaki
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
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Blancaflor EB, Kilaru A, Keereetaweep J, Khan BR, Faure L, Chapman KD. N-Acylethanolamines: lipid metabolites with functions in plant growth and development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 79:568-583. [PMID: 24397856 DOI: 10.1111/tpj.12427] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 12/18/2013] [Accepted: 12/23/2013] [Indexed: 06/03/2023]
Abstract
Twenty years ago, N-acylethanolamines (NAEs) were considered by many lipid chemists to be biological 'artifacts' of tissue damage, and were, at best, thought to be minor lipohilic constituents of various organisms. However, that changed dramatically in 1993, when anandamide, an NAE of arachidonic acid (N-arachidonylethanolamine), was shown to bind to the human cannabinoid receptor (CB1) and activate intracellular signal cascades in mammalian neurons. Now NAEs of various types have been identified in diverse multicellular organisms, in which they display profound biological effects. Although targets of NAEs are still being uncovered, and probably vary among eukaryotic species, there appears to be remarkable conservation of the machinery that metabolizes these bioactive fatty acid conjugates of ethanolamine. This review focuses on the metabolism and functions of NAEs in higher plants, with specific reference to the formation, hydrolysis and oxidation of these potent lipid mediators. The discussion centers mostly on early seedling growth and development, for which NAE metabolism has received the most attention, but also considers other areas of plant development in which NAE metabolism has been implicated. Where appropriate, we indicate cross-kingdom conservation in NAE metabolic pathways and metabolites, and suggest areas where opportunities for further investigation appear most pressing.
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Affiliation(s)
- Elison B Blancaflor
- Plant Biology Division, The Samuel Roberts Noble Foundation Inc., 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA
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19
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Keereetaweep J, Blancaflor EB, Hornung E, Feussner I, Chapman KD. Ethanolamide oxylipins of linolenic acid can negatively regulate Arabidopsis seedling development. THE PLANT CELL 2013; 25:3824-40. [PMID: 24151297 PMCID: PMC3877782 DOI: 10.1105/tpc.113.119024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 09/24/2013] [Accepted: 10/08/2013] [Indexed: 05/20/2023]
Abstract
N-Acylethanolamines (NAEs) are fatty-acid derivatives with potent biological activities in a wide range of eukaryotic organisms. Polyunsaturated NAEs are among the most abundant NAE types in seeds of Arabidopsis thaliana, and they can be metabolized by either fatty acid amide hydrolase (FAAH) or by lipoxygenase (LOX) to low levels during seedling establishment. Here, we identify and quantify endogenous oxylipin metabolites of N-linolenoylethanolamine (NAE 18:3) in Arabidopsis seedlings and show that their levels were higher in faah knockout seedlings. Quantification of oxylipin metabolites in lox mutants demonstrated altered partitioning of NAE 18:3 into 9- or 13-LOX pathways, and this was especially exaggerated when exogenous NAE was added to seedlings. When maintained at micromolar concentrations, NAE 18:3 specifically induced cotyledon bleaching of light-grown seedlings within a restricted stage of development. Comprehensive oxylipin profiling together with genetic and pharmacological interference with LOX activity suggested that both 9-hydroxy and 13-hydroxy linolenoylethanolamides, but not corresponding free fatty-acid metabolites, contributed to the reversible disruption of thylakoid membranes in chloroplasts of seedling cotyledons. We suggest that NAE oxylipins of linolenic acid represent a newly identified, endogenous set of bioactive compounds that may act in opposition to progression of normal seedling development and must be depleted for successful establishment.
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Affiliation(s)
- Jantana Keereetaweep
- Department of Biological Sciences, University of North Texas, Center for Plant Lipid Research, Denton, Texas 76203
| | - Elison B. Blancaflor
- Samuel Roberts Noble Foundation, Plant Biology Division, Ardmore, Oklahoma 73401
| | - Ellen Hornung
- Department of Plant Biochemistry, Georg-August-University, Albrecht-von-Haller-Institute for Plant Sciences, D-37077 Gottingen, Germany
| | - Ivo Feussner
- Department of Plant Biochemistry, Georg-August-University, Albrecht-von-Haller-Institute for Plant Sciences, D-37077 Gottingen, Germany
| | - Kent D. Chapman
- Department of Biological Sciences, University of North Texas, Center for Plant Lipid Research, Denton, Texas 76203
- Address correspondence to
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Kilaru A, Tamura P, Isaac G, Welti R, Venables BJ, Seier E, Chapman KD. Lipidomic analysis of N-acylphosphatidylethanolamine molecular species in Arabidopsis suggests feedback regulation by N-acylethanolamines. PLANTA 2012; 236:809-24. [PMID: 22673881 PMCID: PMC3579225 DOI: 10.1007/s00425-012-1669-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2012] [Accepted: 05/20/2012] [Indexed: 05/25/2023]
Abstract
N-Acylphosphatidylethanolamine (NAPE) and its hydrolysis product, N-acylethanolamine (NAE), are minor but ubiquitous lipids in multicellular eukaryotes. Various physiological processes are severely affected by altering the expression of fatty acid amide hydrolase (FAAH), an NAE-hydrolyzing enzyme. To determine the effect of altered FAAH activity on NAPE molecular species composition, NAE metabolism, and general membrane lipid metabolism, quantitative profiles of NAPEs, NAEs, galactolipids, and major and minor phospholipids for FAAH mutants of Arabidopsis were determined. The NAPE molecular species content was dramatically affected by reduced FAAH activity and elevated NAE content in faah knockouts, increasing by as much as 36-fold, far more than the NAE content, suggesting negative feedback regulation of phospholipase D-mediated NAPE hydrolysis by NAE. The N-acyl composition of NAPE remained similar to that of NAE, suggesting that the NAPE precursor pool largely determines NAE composition. Exogenous NAE 12:0 treatment elevated endogenous polyunsaturated NAE and NAPE levels in seedlings; NAE levels were increased more in faah knockouts than in wild-type or FAAH overexpressors. Treated seedlings with elevated NAE and NAPE levels showed impaired growth and reduced galactolipid synthesis by the "prokaryotic" (i.e., plastidic), but not the "eukaryotic" (i.e., extraplastidic), pathway. Overall, our data provide new insights into the regulation of NAPE-NAE metabolism and coordination of membrane lipid metabolism and seedling development.
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Affiliation(s)
- Aruna Kilaru
- East Tennessee State University, Department of Biological Sciences, Johnson City, TN 37614, USA
- University of North Texas, Center for Plant Lipid Research, Department of Biological Sciences, Denton, TX 76203, USA
| | - Pamela Tamura
- Kansas State University, Kansas Lipidomics Research Center, Division of Biology, Manhattan, KS 66506, USA
| | - Giorgis Isaac
- Kansas State University, Kansas Lipidomics Research Center, Division of Biology, Manhattan, KS 66506, USA
| | - Ruth Welti
- Kansas State University, Kansas Lipidomics Research Center, Division of Biology, Manhattan, KS 66506, USA
| | - Barney J. Venables
- University of North Texas, Center for Plant Lipid Research, Department of Biological Sciences, Denton, TX 76203, USA
| | - Edith Seier
- East Tennessee State University, Department of Mathematics and Statistics, Johnson City, TN 37614, USA
| | - Kent D. Chapman
- University of North Texas, Center for Plant Lipid Research, Department of Biological Sciences, Denton, TX 76203, USA
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Nalam VJ, Keeretaweep J, Sarowar S, Shah J. Root-derived oxylipins promote green peach aphid performance on Arabidopsis foliage. THE PLANT CELL 2012; 24:1643-53. [PMID: 22474183 PMCID: PMC3398569 DOI: 10.1105/tpc.111.094110] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Revised: 01/30/2012] [Accepted: 03/16/2012] [Indexed: 05/19/2023]
Abstract
Oxylipins function as signaling molecules in plant growth and development and contribute to defense against stress. Here, we show that oxylipins also facilitate infestation of Arabidopsis thaliana shoots by the phloem sap-consuming green peach aphid (GPA; Myzus persicae), an agronomically important insect pest. GPAs had difficulty feeding from sieve elements and tapping into the xylem of lipoxygenase5 (lox5) mutant plants defective in LOX activity. These defects in GPA performance in the lox5 mutant were accompanied by reduced water content of GPAs and a smaller population size of GPAs in the mutant compared with the wild-type plant. LOX5 expression was rapidly induced in roots in response to infestation of shoots by GPAs. In parallel, levels of LOX5-derived oxylipins increased in roots and in petiole exudates of GPA-colonized plants. Application of 9-hydroxyoctadecadienoic acid (an oxylipin produced by the LOX5 enzyme) to roots restored water content and GPA population size in lox5 plants, thus confirming that a LOX5-derived oxylipin promotes infestation of the foliage by GPAs. Micrografting experiments demonstrated that GPA performance on foliage is influenced by the LOX5 genotype in roots, thus demonstrating the importance of root-derived oxylipins in colonization of aboveground organs by an insect.
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Affiliation(s)
- Vamsi J Nalam
- Department of Biological Sciences and Center for Plant Lipid Research, University of North Texas, Denton, Texas 76203, USA
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Coulon D, Faure L, Salmon M, Wattelet V, Bessoule JJ. N-Acylethanolamines and related compounds: aspects of metabolism and functions. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2012; 184:129-140. [PMID: 22284717 DOI: 10.1016/j.plantsci.2011.12.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 12/16/2011] [Accepted: 12/16/2011] [Indexed: 05/31/2023]
Abstract
N-Acylethanolamines (NAE) are fatty acid derivates that are linked with an ethanolamine group via an amide bond. NAE can be characterized as lipid mediators in the plant and animal kingdoms owing to the diverse functions throughout the eukaryotic domain. The functions of NAE have been widely investigated in animal tissues in part due to their abilities to interact with the cannabinoid receptors, vanilloid receptors or peroxisome proliferator activated receptors. However, the interest of studying the functions of these lipids in plants is progressively becoming more apparent. The number of publications about the functions related to NAE and to structural analogs (homoserine lactone and alkamides) is greatly increasing, showing the importance of these lipids in various plant physiological processes. This review sheds light on their role in different processes such as seedling development, plant pathogen interaction, phospholipase D alpha inhibition and senescence of cut flowers, and underlines the interaction between NAE and NAE-related molecules with plant hormone signaling. The different metabolic pathways promoting the synthesis and degradation of NAE are also discussed, in particular the oxygenation of polyunsaturated N-acylethanolamines, which leads to NAE-oxylipins, a new family of bioactive lipids.
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Affiliation(s)
- Denis Coulon
- Laboratoire de Biogenèse Membranaire, Univ. de Bordeaux, UMR 5200, F-33000 Bordeaux, France.
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Bajsa J, Pan Z, Duke SO. Serine/threonine protein phosphatases: multi-purpose enzymes in control of defense mechanisms. PLANT SIGNALING & BEHAVIOR 2011; 6:1921-1925. [PMID: 22105028 PMCID: PMC3337179 DOI: 10.4161/psb.6.12.18146] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Depending on the threat to a plant, different pattern recognition receptors, such as receptor-like kinases, identify the stress and trigger action by appropriate defense response development. The plant immunity system primary response to these challenges is rapid accumulation of phytohormones, such as ethylene (ET), salicylic acid (SA), and jasmonic acid (JA) and its derivatives. These phytohormones induce further signal transduction and appropriate defenses against biotic threats. Phytohormones play crucial roles not only in the initiation of diverse downstream signaling events in plant defense but also in the activation of effective defenses through an essential process called signaling pathway crosstalk, a mechanism involved in transduction signals between two or more distinct, "linear signal transduction pathways simultaneously activated in the same cell."
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