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Mi C, Zhang Y, Zhao Y, Lin L. Mechanisms of low nighttime temperature promote oil accumulation in Brassica napus L. based on in-depth transcriptome analysis. PHYSIOLOGIA PLANTARUM 2024; 176:e14372. [PMID: 38812077 DOI: 10.1111/ppl.14372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 04/08/2024] [Indexed: 05/31/2024]
Abstract
Rape (Brassica napus L.; AACC) is an important oil-bearing crop worldwide. Temperature significantly affects the production of oil crops; however, the mechanisms underlying temperature-promoted oil biosynthesis remain largely unknown. In this study, we found that a temperature-sensitive cultivar (O) could accumulate higher seed oil content under low nighttime temperatures (LNT,13°C) compared with a temperature-insensitive cultivar (S). We performed an in-depth transcriptome analysis of seeds from both cultivars grown under different nighttime temperatures. We found that low nighttime temperatures induced significant changes in the transcription patterns in the seeds of both cultivars. In contrast, the expression of genes associated with fatty acid and lipid pathways was higher in the O cultivar than in the S cultivar under low nighttime temperatures. Among these genes, we identified 14 genes associated with oil production, especially BnLPP and ACAA1, which were remarkably upregulated in the O cultivar in response to low nighttime temperatures compared to S. Further, a WGCNA analysis and qRT-PCR verification revealed that these genes were mainly regulated by five transcription factors, WRKY20, MYB86, bHLH144, bHLH95, and NAC12, whose expression was also increased in O compared to S under LNT. These results allowed the elucidation of the probable molecular mechanism of oil accumulation under LNT conditions in the O cultivar. Subsequent biochemical assays verified that BnMYB86 transcriptionally activated BnLPP expression, contributing to oil accumulation. Meanwhile, at LNT, the expression levels of these genes in the O plants were higher than at high nighttime temperatures, DEGs (SUT, PGK, PK, GPDH, ACCase, SAD, KAS II, LACS, FAD2, FAD3, KCS, KAR, ECR, GPAT, LPAAT, PAP, DGAT, STERO) related to lipid biosynthesis were also upregulated, most of which are used in oil accumulation.
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Affiliation(s)
- Chao Mi
- Agricultural Research Institute, Xizang Academy of Agriculture and Animal Husbandry Sciences, Lhasa, China
- College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, China
| | - Yusong Zhang
- Industrial Crops Research Institute, Yunnan Academy of Agricultural Sciences, Kunming, China
| | - Yanning Zhao
- Vegetable Research Institute, Xizang Academy of Agriculture and Animal Husbandry Sciences, Lhasa, China
| | - Liangbin Lin
- College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, China
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Lipowsky R, Ghosh R, Satarifard V, Sreekumari A, Zamaletdinov M, Różycki B, Miettinen M, Grafmüller A. Leaflet Tensions Control the Spatio-Temporal Remodeling of Lipid Bilayers and Nanovesicles. Biomolecules 2023; 13:926. [PMID: 37371505 DOI: 10.3390/biom13060926] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 05/24/2023] [Accepted: 05/26/2023] [Indexed: 06/29/2023] Open
Abstract
Biological and biomimetic membranes are based on lipid bilayers, which consist of two monolayers or leaflets. To avoid bilayer edges, which form when the hydrophobic core of such a bilayer is exposed to the surrounding aqueous solution, a single bilayer closes up into a unilamellar vesicle, thereby separating an interior from an exterior aqueous compartment. Synthetic nanovesicles with a size below 100 nanometers, traditionally called small unilamellar vesicles, have emerged as potent platforms for the delivery of drugs and vaccines. Cellular nanovesicles of a similar size are released from almost every type of living cell. The nanovesicle morphology has been studied by electron microscopy methods but these methods are limited to a single snapshot of each vesicle. Here, we review recent results of molecular dynamics simulations, by which one can monitor and elucidate the spatio-temporal remodeling of individual bilayers and nanovesicles. We emphasize the new concept of leaflet tensions, which control the bilayers' stability and instability, the transition rates of lipid flip-flops between the two leaflets, the shape transformations of nanovesicles, the engulfment and endocytosis of condensate droplets and rigid nanoparticles, as well as nanovesicle adhesion and fusion. To actually compute the leaflet tensions, one has to determine the bilayer's midsurface, which represents the average position of the interface between the two leaflets. Two particularly useful methods to determine this midsurface are based on the density profile of the hydrophobic lipid chains and on the molecular volumes.
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Affiliation(s)
- Reinhard Lipowsky
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14424 Potsdam, Germany
| | - Rikhia Ghosh
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14424 Potsdam, Germany
- Icahn School of Medicine Mount Sinai, New York, NY 10029, USA
| | - Vahid Satarifard
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14424 Potsdam, Germany
- Yale Institute for Network Science, Yale University, New Haven, CT 06520, USA
| | - Aparna Sreekumari
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14424 Potsdam, Germany
- Department of Physics, Indian Institute of Technology Palakkad, Palakkad 678 623, India
| | - Miftakh Zamaletdinov
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14424 Potsdam, Germany
| | - Bartosz Różycki
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14424 Potsdam, Germany
- Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, 02-668 Warsaw, Poland
| | - Markus Miettinen
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14424 Potsdam, Germany
- Department of Chemistry, University of Bergen, 5020 Bergen, Norway
| | - Andrea Grafmüller
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14424 Potsdam, Germany
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Complexes of Cationic Pyridylphenylene Dendrimers with Anionic Liposomes: The Role of Dendrimer Composition in Membrane Structural Changes. Int J Mol Sci 2023; 24:ijms24032225. [PMID: 36768548 PMCID: PMC9917332 DOI: 10.3390/ijms24032225] [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: 12/23/2022] [Revised: 01/18/2023] [Accepted: 01/19/2023] [Indexed: 01/26/2023] Open
Abstract
In the last decades, dendrimers have received attention in biomedicine that requires detailed study on the mechanism of their interaction with cell membranes. In this article, we report on the role of dendrimer structure in their interaction with liposomes. Here, the interactions between cationic pyridylphenylene dendrimers of the first, second, and third generations with mixed or completely charged pyridyl periphery (D16+, D215+, D229+, and D350+) with cholesterol-containing (CL/Chol/DOPC) anionic liposomes were investigated by microelectrophoresis, dynamic light scattering, fluorescence spectroscopy, and conductometry. It was found that the architecture of the dendrimer, namely the generation, the amount of charged pyridynium groups, the hydrophobic phenylene units, and the rigidity of the spatial structure, determined the special features of the dendrimer-liposome interactions. The binding of D350+ and D229+ with almost fully charged peripheries to liposomes was due to electrostatic forces: the dendrimer molecules could be removed from the liposomal surfaces by NaCl addition. D350+ and D229+ did not display a disruptive effect toward membranes, did not penetrate into the hydrophobic lipid bilayer, and were able to migrate between liposomes. For D215+, a dendrimer with a mixed periphery, hydrophobic interactions of phenylene units with the hydrocarbon tails of lipids were observed, along with electrostatic complexation with liposomes. As a result, defects were formed in the bilayer, which led to irreversible interactions with lipid membranes wherein there was no migration of D215+ between liposomes. A first-generation dendrimer, D16+, which was characterized by small size, a high degree of hydrophobicity, and a rigid structure, when interacting with liposomes caused significant destruction of liposomal membranes. Evidently, this interaction was irreversible: the addition of salt did not lead to the dissociation of the complex.
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Efimova AA, Abramova TA, Popov AS, Grokhovskaya TE. Interaction of Chitosan with Anionic Liquid Liposomes: Reversibility of Structural Rearrangements in Lipid Bilayer. RUSS J GEN CHEM+ 2022. [DOI: 10.1134/s1070363222110275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Sreekumari A, Lipowsky R. Large stress asymmetries of lipid bilayers and nanovesicles generate lipid flip-flops and bilayer instabilities. SOFT MATTER 2022; 18:6066-6078. [PMID: 35929498 DOI: 10.1039/d2sm00618a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Much effort has been devoted to lipid bilayers and nanovesicles with a compositional asymmetry between the two leaflets of the bilayer membranes. Here, we address another fundamental asymmetry related to lipid densities and membrane tensions. To avoid membrane rupture, the osmotic conditions must be adjusted in such a way that the bilayer membranes are subject to a relatively low bilayer tension. However, even for vanishing bilayer tension, the individual leaflets can still experience significant leaflet tensions if one leaflet is stretched whereas the other leaflet is compressed. Such a stress asymmetry between the two leaflets can be directly controlled in molecular dynamics simulations by the initial assembly of the lipid bilayers. This stress asymmetry is varied here over a wide range to determine the stability and instability regimes of the asymmetric bilayers. The stability regime shrinks with decreasing size and increasing membrane curvature of the nanovesicle. In the instability regimes, the lipids undergo stress-induced flip-flops with a flip-flop rate that increases with increasing stress asymmetry. The onset of flip-flops can be characterized by a cumulative distribution function that is well-fitted by an exponential function for planar bilayers but has a sigmoidal shape for nanovesicles. In addition, the bilayer membranes form transient non-bilayer structures that relax back towards ordered bilayers with a reduced stress asymmetry. Our study reveals intrinsic limits for the possible magnitude of the transbilayer stress asymmetry and shows that the leaflet tensions represent key parameters for the flip-flop rates.
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Affiliation(s)
- Aparna Sreekumari
- Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, 14424 Potsdam, Germany.
| | - Reinhard Lipowsky
- Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, 14424 Potsdam, Germany.
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Nielsen J, Lund R. Molecular Transport and Growth of Lipid Vesicles Exposed to Antimicrobial Peptides. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:374-384. [PMID: 34902242 PMCID: PMC8757467 DOI: 10.1021/acs.langmuir.1c02736] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/01/2021] [Indexed: 05/20/2023]
Abstract
It is well-known that lipids constituting the cytoplasmic membrane undergo continuous reorganization to maintain the appropriate composition important for the integrity of the cell. The transport of lipids is controlled by mainly membrane proteins, but also spontaneous lipid transport between leaflets, lipid "flip-flop", occurs. These processes do not only occur spontaneously under equilibrium, but also promote structural rearrangements, morphological transitions, and growth processes. It has previously been shown that intravesicular lipid "flip-flop" and intervesicular lipid exchange under equilibrium can be deduced indirectly from contrast variation time-resolved small-angle neutron scattering (TR-SANS) where the molecules are "tagged" using hydrogen/deuterium (H/D) substitution. In this work, we show that this technique can be extended to simultaneously detect changes in the growth and the lipid "flip-flop" and exchange rates induced by a peptide additive on lipid vesicles consisting of DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine), d-DMPC (1,2-dimyristoyl-d54-sn-glycero-3-phosphocholine), DMPG (1,2-dimyristoyl-sn-glycero-3-phospho-(1'-rac-glycerol)), and small amounts of DMPE-PEG (1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000]). Changes in the overall size were independently monitored using dynamic light scattering (DLS). We find that the antimicrobial peptide, indolicidin, accelerates lipid transport and additionally induces limited vesicular growth. Moreover, in TR-SANS experiments using partially labeled lipid mixtures to separately study the kinetics of the lipid components, we show that, whereas peptide addition affects both lipids similarly, DMPG exhibits faster kinetics. We find that vesicular growth is mainly associated with peptide-mediated lipid reorganization that only slightly affects the overall exchange kinetics. This is confirmed by a TR-SANS experiment of vesicles preincubated with peptide showing that after pre-equilibration the kinetics are only slightly slower.
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Affiliation(s)
| | - Reidar Lund
- Department of Chemistry, University of Oslo, Postboks 1033 Blindern, Oslo 0315, Norway
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Perez-Salas U, Garg S, Gerelli Y, Porcar L. Deciphering lipid transfer between and within membranes with time-resolved small-angle neutron scattering. CURRENT TOPICS IN MEMBRANES 2021; 88:359-412. [PMID: 34862031 DOI: 10.1016/bs.ctm.2021.10.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This review focuses on time-resolved neutron scattering, particularly time-resolved small angle neutron scattering (TR-SANS), as a powerful in situ noninvasive technique to investigate intra- and intermembrane transport and distribution of lipids and sterols in lipid membranes. In contrast to using molecular analogues with potentially large chemical tags that can significantly alter transport properties, small angle neutron scattering relies on the relative amounts of the two most abundant isotope forms of hydrogen: protium and deuterium to detect complex membrane architectures and transport processes unambiguously. This review discusses advances in our understanding of the mechanisms that sustain lipid asymmetry in membranes-a key feature of the plasma membrane of cells-as well as the transport of lipids between membranes, which is an essential metabolic process.
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Affiliation(s)
- Ursula Perez-Salas
- Physics Department, University of Illinois at Chicago, Chicago, IL, United States.
| | - Sumit Garg
- Physics Department, University of Illinois at Chicago, Chicago, IL, United States
| | - Yuri Gerelli
- Department of Life and Environmental Sciences, Universita` Politecnica delle Marche, Ancona, Italy
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Aoki H, Liu Y, Yamashita T. Deep learning approach for an interface structure analysis with a large statistical noise in neutron reflectometry. Sci Rep 2021; 11:22711. [PMID: 34811432 PMCID: PMC8608885 DOI: 10.1038/s41598-021-02085-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 11/08/2021] [Indexed: 11/09/2022] Open
Abstract
Neutron reflectometry (NR) allows us to probe into the structure of the surfaces and interfaces of various materials such as soft matters and magnetic thin films with a contrast mechanism dependent on isotopic and magnetic states. The neutron beam flux is relatively low compared to that of other sources such as synchrotron radiation; therefore, there has been a strong limitation in the time-resolved measurement and further advanced experiments such as surface imaging. This study aims at the development of a methodology to enable the structural analysis by the NR data with a large statistical error acquired in a short measurement time. The neural network-based method predicts the true NR profile from the data with a 20-fold lower signal compared to that obtained under the conventional measurement condition. This indicates that the acquisition time in the NR measurement can be reduced by more than one order of magnitude. The current method will help achieve remarkable improvement in temporally and spatially resolved NR methods to gain further insight into the surface and interfaces of materials.
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Affiliation(s)
- Hiroyuki Aoki
- Materials and Life Science Division, J-PARC Center, Japan Atomic Energy Agency, 2-4, Shirakata, Tokai, Ibaraki, 319-1195, Japan. .,Institute of Materials Structure Science, High Energy Accelerator Research Organization, 203-1, Shirakata, Tokai, Ibaraki, 319-1106, Japan.
| | - Yuwei Liu
- Institute of Materials Structure Science, High Energy Accelerator Research Organization, 203-1, Shirakata, Tokai, Ibaraki, 319-1106, Japan
| | - Takashi Yamashita
- AdvanceSoft, Corp., 4-3, Kandasurugadai, Chiyoda, Tokyo, 101-0062, Japan
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Efimova AA, Abramova TA, Popov AS. Complexes of Negatively Charged Liposomes with Chitosan: Effect of Phase State of the Lipid Bilayer. RUSS J GEN CHEM+ 2021. [DOI: 10.1134/s1070363221100025x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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