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Zakharov A, Awan M, Cheng T, Gopinath A, Lee SJJ, Ramasubramanian AK, Dasbiswas K. Clots reveal anomalous elastic behavior of fiber networks. Sci Adv 2024; 10:eadh1265. [PMID: 38198546 PMCID: PMC10780871 DOI: 10.1126/sciadv.adh1265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Accepted: 12/06/2023] [Indexed: 01/12/2024]
Abstract
The adaptive mechanical properties of soft and fibrous biological materials are relevant to their functionality. The emergence of the macroscopic response of these materials to external stress and intrinsic cell traction from local deformations of their structural components is not well understood. Here, we investigate the nonlinear elastic behavior of blood clots by combining microscopy, rheology, and an elastic network model that incorporates the stretching, bending, and buckling of constituent fibrin fibers. By inhibiting fibrin cross-linking in blood clots, we observe an anomalous softening regime in the macroscopic shear response as well as a reduction in platelet-induced clot contractility. Our model explains these observations from two independent macroscopic measurements in a unified manner, through a single mechanical parameter, the bending stiffness of individual fibers. Supported by experimental evidence, our mechanics-based model provides a framework for predicting and comprehending the nonlinear elastic behavior of blood clots and other active biopolymer networks in general.
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Affiliation(s)
- Andrei Zakharov
- Department of Physics, University of California, Merced, Merced, CA 95343, USA
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Myra Awan
- Department of Chemical and Materials Engineering, San José State University, San José, CA 95192, USA
| | - Terrence Cheng
- Department of Chemical and Materials Engineering, San José State University, San José, CA 95192, USA
| | - Arvind Gopinath
- Department of Bioengineering, University of California, Merced, Merced, CA 95343, USA
| | - Sang-Joon John Lee
- Department of Mechanical Engineering, San José State University, San José, CA 95192, USA
| | - Anand K. Ramasubramanian
- Department of Chemical and Materials Engineering, San José State University, San José, CA 95192, USA
| | - Kinjal Dasbiswas
- Department of Physics, University of California, Merced, Merced, CA 95343, USA
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Yu Y, Beyene G, Villmer J, Duncan KE, Hu H, Johnson T, Doust AN, Taylor NJ, Kellogg EA. Grain shattering by cell death and fracture in Eragrostis tef. Plant Physiol 2023; 192:222-239. [PMID: 36756804 PMCID: PMC10152664 DOI: 10.1093/plphys/kiad079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 12/15/2022] [Accepted: 01/11/2023] [Indexed: 05/03/2023]
Abstract
Abscission, known as shattering in crop species, is a highly regulated process by which plants shed parts. Although shattering has been studied extensively in cereals and a number of regulatory genes have been identified, much diversity in the process remains to be discovered. Teff (Eragrostis tef) is a crop native to Ethiopia that is potentially highly valuable worldwide for its nutritious grain and drought tolerance. Previous work has suggested that grain shattering in Eragrostis might have little in common with other cereals. In this study, we characterize the anatomy, cellular structure, and gene regulatory control of the abscission zone (AZ) in E. tef. We show that the AZ of E. tef is a narrow stalk below the caryopsis, which is common in Eragrostis species. X-ray microscopy, scanning electron microscopy, transmission electron microscopy, and immunolocalization of cell wall components showed that the AZ cells are thin walled and break open along with programmed cell death (PCD) at seed maturity, rather than separating between cells as in other studied species. Knockout of YABBY2/SHATTERING1, documented to control abscission in several cereals, had no effect on abscission or AZ structure in E. tef. RNA sequencing analysis showed that genes related to PCD and cell wall modification are enriched in the AZ at the early seed maturity stage. These data show that E. tef drops its seeds using a unique mechanism. Our results provide the groundwork for understanding grain shattering in Eragrostis and further improvement of shattering in E. tef.
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Affiliation(s)
- Yunqing Yu
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO 63132, USA
| | - Getu Beyene
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO 63132, USA
| | - Justin Villmer
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO 63132, USA
| | - Keith E Duncan
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO 63132, USA
| | - Hao Hu
- Department of Plant Biology, Ecology, and Evolution, Oklahoma State University, Stillwater, OK 74078, USA
| | - Toni Johnson
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO 63132, USA
| | - Andrew N Doust
- Department of Plant Biology, Ecology, and Evolution, Oklahoma State University, Stillwater, OK 74078, USA
| | - Nigel J Taylor
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO 63132, USA
| | - Elizabeth A Kellogg
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO 63132, USA
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Nam JW, Jenkins LM, Li J, Evans BS, Jaworski JG, Allen DK. A General Method for Quantification and Discovery of Acyl Groups Attached to Acyl Carrier Proteins in Fatty Acid Metabolism Using LC-MS/MS. Plant Cell 2020; 32:820-832. [PMID: 32060179 PMCID: PMC7145485 DOI: 10.1105/tpc.19.00954] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 02/03/2020] [Accepted: 02/12/2020] [Indexed: 06/10/2023]
Abstract
Acyl carrier proteins (ACPs) are the scaffolds for fatty acid biosynthesis in living systems, rendering them essential to a comprehensive understanding of lipid metabolism. However, accurate quantitative methods to assess individual acyl-ACPs do not exist. We developed a robust method to quantify acyl-ACPs to the picogram level. We successfully identified acyl-ACP elongation intermediates (3-hydroxyacyl-ACPs and 2,3-trans-enoyl-ACPs) and unexpected medium-chain (C10:1, C14:1) and polyunsaturated long-chain (C16:3) acyl-ACPs, indicating both the sensitivity of the method and how current descriptions of lipid metabolism and ACP function are incomplete. Such ACPs are likely important to medium-chain lipid production for fuels and highlight poorly understood lipid remodeling events in the chloroplast. The approach is broadly applicable to type II fatty acid synthase systems found in plants and bacteria as well as mitochondria from mammals and fungi because it capitalizes on a highly conserved Asp-Ser-Leu-Asp amino acid sequence in ACPs to which acyl groups attach. Our method allows for sensitive quantification using liquid chromatography-tandem mass spectrometry with de novo-generated standards and an isotopic dilution strategy and will fill a gap in our understanding, providing insights through quantitative exploration of fatty acid biosynthesis processes for optimal biofuels, renewable feedstocks, and medical studies in health and disease.
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Affiliation(s)
- Jeong-Won Nam
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, Missouri 63132
| | - Lauren M Jenkins
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, Missouri 63132
- USDA-ARS, Plant Genetics Research Unit, 975 North Warson Road, St. Louis, Missouri 63132
| | - Jia Li
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, Missouri 63132
| | - Bradley S Evans
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, Missouri 63132
| | - Jan G Jaworski
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, Missouri 63132
| | - Doug K Allen
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, Missouri 63132
- USDA-ARS, Plant Genetics Research Unit, 975 North Warson Road, St. Louis, Missouri 63132
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