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Buerck JP, Foster KM, Larson PR, O'Rear EA. Shear stimulated red blood cell microparticles: Effect on clot structure, flow and fibrinolysis. Biorheology 2023; 59:43-59. [PMID: 36970891 DOI: 10.3233/bir-220012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
BACKGROUND Microparticles (MPs) have activity in thrombus promotion and generation. Erythrocyte microparticles (ErMPs) have been reported to accelerate fibrinolysis in the absence of permeation. We hypothesized that shear induced ErMPs would affect fibrin structure of clots and change flow with implications for fibrinolysis. OBJECTIVE To determine the effect of ErMPs on clot structure and fibrinolysis. METHODS Plasma with elevated ErMPs was isolated from whole blood or from washed red blood cells (RBCs) resuspended in platelet free plasma (PFP) after high shear. Dynamic light scattering (DLS) provided size distribution of ErMPs from sheared samples and unsheared PFP controls. Clots were formed by recalcification for flow/lysis experiments and examined by confocal microscopy and SEM. Flow rates through clots and time-to-lysis were recorded. A cellular automata model showed the effect of ErMPs on fibrin polymerization and clot structure. RESULTS Coverage of fibrin increased by 41% in clots formed from plasma of sheared RBCs in PFP over controls. Flow rate decreased by 46.7% under a pressure gradient of 10 mmHg/cm with reduction in time to lysis from 5.7 ± 0.7 min to 12.2 ± 1.1 min (p < 0.01). Particle size of ErMPs from sheared samples (200 nm) was comparable to endogenous microparticles. CONCLUSIONS ErMPs alter the fibrin network in a thrombus and affect hydraulic permeability resulting in decelerated delivery of fibrinolytic drugs.
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Affiliation(s)
- James P Buerck
- School of Chemical, Biological and Materials Engineering, University of Oklahoma, Norman, OK, USA
| | - Kylie M Foster
- School of Chemical, Biological and Materials Engineering, University of Oklahoma, Norman, OK, USA
| | - Preston R Larson
- Samuel Roberts Noble Electron Microscopy Laboratory, University of Oklahoma, Norman, OK, USA
| | - Edgar A O'Rear
- School of Chemical, Biological and Materials Engineering, University of Oklahoma, Norman, OK, USA
- Institute for Biomedical Engineering, Science and Technology, University of Oklahoma, Norman, OK, USA
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2
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Gou J, Fu C, Liu S, Tang C, Debnath S, Flanagan A, Ge Y, Tang Y, Jiang Q, Larson PR, Wen J, Wang ZY. The miR156-SPL4 module predominantly regulates aerial axillary bud formation and controls shoot architecture. New Phytol 2017; 216:829-840. [PMID: 28877340 DOI: 10.1111/nph.14758] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 07/23/2017] [Indexed: 05/06/2023]
Abstract
Grasses possess basal and aerial axillary buds. Previous studies have largely focused on basal bud (tiller) formation but scarcely touched on aerial buds, which may lead to aerial branch development. Genotypes with and without aerial buds were identified in switchgrass (Panicum virgatum), a dedicated bioenergy crop. Bud development was characterized using scanning electron microscopy. Microarray, RNA-seq and quantitative reverse transcription polymerase chain reaction (RT-qPCR) were used to identify regulators of bud formation. Gene function was characterized by down-regulation and overexpression. Overexpression of miR156 induced aerial bud formation in switchgrass. Various analyses revealed that SQUAMOSA PROMOTER BINDING PROTEIN LIKE4 (SPL4), one of the miR156 targets, directly regulated aerial axillary bud initiation. Down-regulation of SPL4 promoted aerial bud formation and increased basal buds, while overexpression of SPL4 seriously suppressed bud formation and tillering. RNA-seq and RT-qPCR identified potential downstream genes of SPL4. Unlike all previously reported genes acting as activators of basal bud initiation, SPL4 acts as a suppressor for the formation of both aerial and basal buds. The miR156-SPL4 module predominantly regulates aerial bud initiation and partially controls basal bud formation. Genetic manipulation of SPL4 led to altered plant architecture with increased branching, enhanced regrowth after cutting and improved biomass yield.
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Affiliation(s)
- Jiqing Gou
- Forage Improvement Division, The Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Chunxiang Fu
- Forage Improvement Division, The Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA
- Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China
| | - Sijia Liu
- Forage Improvement Division, The Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA
- Department of Grassland Science, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, China
| | - Chaorong Tang
- Forage Improvement Division, The Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, Hainan, 571737, China
| | - Smriti Debnath
- Forage Improvement Division, The Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA
| | - Amy Flanagan
- Forage Improvement Division, The Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Yaxin Ge
- Forage Improvement Division, The Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA
| | - Yuhong Tang
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- Plant Biology Division, The Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA
| | - Qingzhen Jiang
- Plant Biology Division, The Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA
| | - Preston R Larson
- Samuel Roberts Noble Microscopy Laboratory, University of Oklahoma, Norman, OK, 73019, USA
| | - Jiangqi Wen
- Plant Biology Division, The Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA
| | - Zeng-Yu Wang
- Forage Improvement Division, The Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
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3
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Kim C, Kendall MR, Miller MA, Long CL, Larson PR, Humphrey MB, Madden AS, Tas AC. Comparison of titanium soaked in 5 M NaOH or 5 M KOH solutions. Mater Sci Eng C Mater Biol Appl 2015; 33:327-39. [PMID: 23565038 DOI: 10.1016/j.msec.2012.08.047] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Commercially pure titanium plates/coupons and pure titanium powders were soaked for 24 h in 5 M NaOH and 5 M KOH solutions, under identical conditions, over the temperature range of 37° to 90 °C. Wettability of the surfaces of alkali-treated cpTi coupons was studied by using contact angle goniometry. cpTi coupons soaked in 5 M NaOH or 5 M KOH solutions were found to have hydrophilic surfaces. Hydrous alkali titanate nanofibers and nanotubes were identified with SEM/EDXS and grazing incidence XRD. Surface areas of Ti powders increased > 50–220 times, depending on the treatment, when soaked in the above solutions. A solution was developed to coat amorphous calcium phosphate, instead of hydroxyapatite, on Ti coupon surfaces. In vitro cell culture tests were performed with osteoblast-like cells on the alkali-treated samples.
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Affiliation(s)
- Christina Kim
- Oklahoma School of Science and Mathematics, Oklahoma City, OK 73104, USA
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4
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Descamps S, Awitor KO, Raspal V, Johnson MB, Bokalawela RSP, Larson PR, Doiron CF. Mechanical Properties of Nanotextured Titanium Orthopedic Screws for Clinical Applications. J Med Device 2013; 7:210051-210055. [PMID: 23904907 DOI: 10.1115/1.4023705] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 01/17/2013] [Indexed: 11/08/2022] Open
Abstract
In this work, we modified the topography of commercial titanium orthopedic screws using electrochemical anodization in a 0.4 wt% hydrofluoric acid solution to produce titanium dioxide nanotube layers. The morphology of the nanotube layers were characterized using scanning electron microscopy. The mechanical properties of the nanotube layers were investigated by screwing and unscrewing an anodized screw into several different types of human bone while the torsional force applied to the screwdriver was measured using a torque screwdriver. The range of torsional force applied to the screwdriver was between 5 and [Formula: see text]. Independent assessment of the mechanical properties of the same surfaces was performed on simple anodized titanium foils using a triboindenter. Results showed that the fabricated nanotube layers can resist mechanical stresses close to those found in clinical situations.
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5
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Kim C, Kendall MR, Miller MA, Long CL, Larson PR, Humphrey MB, Madden AS, Tas AC. Comparison of titanium soaked in 5 M NaOH or 5 M KOH solutions. Mater Sci Eng C Mater Biol Appl 2013. [PMID: 23565038 DOI: 10.1016/j.msec.2012.08.047.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Commercially pure titanium plates/coupons and pure titanium powders were soaked for 24 h in 5 M NaOH and 5 M KOH solutions, under identical conditions, over the temperature range of 37° to 90 °C. Wettability of the surfaces of alkali-treated cpTi coupons was studied by using contact angle goniometry. cpTi coupons soaked in 5 M NaOH or 5 M KOH solutions were found to have hydrophilic surfaces. Hydrous alkali titanate nanofibers and nanotubes were identified with SEM/EDXS and grazing incidence XRD. Surface areas of Ti powders increased > 50–220 times, depending on the treatment, when soaked in the above solutions. A solution was developed to coat amorphous calcium phosphate, instead of hydroxyapatite, on Ti coupon surfaces. In vitro cell culture tests were performed with osteoblast-like cells on the alkali-treated samples.
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Affiliation(s)
- Christina Kim
- Oklahoma School of Science and Mathematics, Oklahoma City, OK 73104, USA
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6
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Wang H, Zou M, Larson PR, Sanchez ES, Hobbs KL, Curtis ME, Johnson MB, Awitor OK. Nanomechanical properties of a Ni nanodot-patterned surface. Nanotechnology 2008; 19:295708. [PMID: 21730613 DOI: 10.1088/0957-4484/19/29/295708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Nanomechanical properties of a Ni nanodot-patterned surface (NDPS) on a Si substrate were investigated using nanoindentation. The Ni NDPS was fabricated by thermal evaporation of Ni through a porous anodized aluminum oxide template onto a Si substrate. Plan-view transmission electron microscopy and nanobeam diffraction were used to characterize the Ni nanodot crystal structure. Scanning electron microscopy and atomic force microscopy were used to characterize the morphology and deformation of the Ni nanodots before and after nanoindentation. The elastic modulus and hardness of the Ni nanodots were found to be 159 ± 22 and 7.7 ± 1.0 GPa, respectively. The critical shear stress for initiating plastic deformation in the Ni nanodot was estimated to be 8.3 ± 1.0 GPa, which is close to the theoretical shear strength of 7.6 GPa in dislocation-free single crystal Ni.
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Affiliation(s)
- H Wang
- Department of Mechanical Engineering, University of Arkansas, Fayetteville, AR 72701, USA
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7
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Wang ZK, Lim HS, Liu HY, Ng SC, Kuok MH, Tay LL, Lockwood DJ, Cottam MG, Hobbs KL, Larson PR, Keay JC, Lian GD, Johnson MB. Spin waves in nickel nanorings of large aspect ratio. Phys Rev Lett 2005; 94:137208. [PMID: 15904029 DOI: 10.1103/physrevlett.94.137208] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2004] [Indexed: 05/02/2023]
Abstract
The spin dynamics of high-aspect-ratio nickel nanorings in a longitudinal magnetic field have been investigated by Brillouin spectroscopy and the results are compared with a macroscopic theory and three-dimensional micromagnetic simulations. Good agreement is found between the measured and calculated magnetic field dependence of the spin wave frequency. Simulations show that as the field decreases from saturation, the rings switch from a "bamboo" to a novel "twisted bamboo" state at a certain critical field, and predict a corresponding dip in the dependence of the spin wave frequency on the magnetic field.
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Affiliation(s)
- Z K Wang
- Department of Physics, National University of Singapore, Singapore 117542, Singapore
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8
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Zhao Q, Luo Y, Surthi S, Li Q, Mathur G, Gowda S, Larson PR, Johnson MB, Misra V. Redox-active monolayers on nano-scale silicon electrodes. Nanotechnology 2005; 16:257-261. [PMID: 21727432 DOI: 10.1088/0957-4484/16/2/013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Uniform arrays of nano-scale electrolyte-molecule-silicon capacitors have been successfully fabricated. This was done by a combination of reactive ion etch and a selective wet etch through an anodic aluminium oxide mask to form nano-holes in silicon oxide/silicon nitride insulator layers on silicon. Self-assembled monolayers of 4-ferrocenylbenzyl alcohol were then attached to the exposed silicon surfaces at the bottom of the nano-holes. Characterization by conventional capacitance and conductance techniques showed very high capacitance and conductance peaks near -0.6 V, that were attributed to the charging and discharging of electrons into and from discrete levels in the monolayer owing to the presence of the redox-active ferrocenes.
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Affiliation(s)
- Qian Zhao
- Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, NC 27695, USA
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9
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Abstract
Inorganic phosphate salts are widely used as food ingredients and in a variety of commercial applications. The United States Food and Drug Administration (FDA) considers inorganic phosphates "Generally Recognized As Safe" (GRAS) (FDA, 1973a, 1979) [FDA: Food and Drug Administration 1973a. GRAS (Generally Recognized as Safe) food ingredients-phosphates. NTIS PB-221-224, FDA, Food and Drug Administration, 1979. Phosphates; Proposed Affirmation of and Deletion From GRAS Status as Direct and Human Food Ingredients. Federal Register 44 (244). 74845-74857, 18 December (1979)] and the European Union (EU) allows inorganic phosphates to be added directly to food (EU Directive 95/2/EC as amended by 98/72/EC). In this review, data on the acute, subchronic and chronic toxicity, genotoxicity, teratogenicity and reproductive toxicity from the published literature and from unpublished studies by the manufacturers are reviewed. Based on the toxicity data and similar chemistry, the inorganic phosphates can be separated into four major classes, consisting of monovalent salts, divalent salts, ammonium salts and aluminum salts. The proposed classification scheme supports the use of toxicity data from one compound to assess the toxicity of another compound in the same class. However, in the case of eye and skin irritation, the proposed classification scheme cannot be used because a wide range of responses exists within each class. Therefore, the eye and skin hazards associated with an individual inorganic phosphate should be assessed on a chemical-by-chemical basis. A large amount of toxicity data exists for all four classes of inorganic phosphates. The large and comprehensive database allows an accurate assessment of the toxicity of each class of inorganic phosphate. Overall, all four classes of inorganic phosphates exhibit low oral, inhalation and dermal toxicities. Based on these data, humans are unlikely to experience adverse effects when the daily phosphorus consumption remains below 70 mg/kg/day (JECFA, 1964, 1982a) [JECFA (Joint FAO/WHO Expert Committee on Food Additives 1964. Specifications for the Identity and Purity of Food Additives and their Toxicological Evaluation) Emulsifiers, Stabilizers, Bleaching, and Maturing Agents. Technical Report Series of the World Health Organization 281; ECFA (Joint FAO/WHO Expert Committee on Food Additives 1982a. Phosphoric Acid and Phosphate Salts. ICS/FA/82)].
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Affiliation(s)
- M L Weiner
- FMC Corporation, Princeton, NJ 08543, USA.
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10
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Findling JW, Shaker JL, Larson PR. Thyroid needle aspiration in a community hospital. Wis Med J 1989; 88:19-22. [PMID: 2815809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Fine needle aspiration of the thyroid has achieved increasing acceptance as a valuable diagnostic aid in the evaluation of nodular thyroid disease. It has been suggested, however, that this procedure should be performed only in major medical centers. We report our experience with thyroid needle aspiration in 400 consecutive patients seen in the ambulatory setting of a community hospital. Benign cytology was found in 80% of patients. Surgery was recommended in 51 patients (12.8%) with either suspicious or malignant cytology, and cancer was found in 31 (61%) of these patients. Non-diagnostic aspirates accounted for 7.2% of patients. Thyroid imaging failed to add anything to the diagnostic evaluation. Our results compare favorably to those from university centers and show that thyroid needle aspiration can be performed well in a community hospital setting. We believe that it should be the initial study in patients with nodular goiter.
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Vogelmann TC, Dickson RE, Larson PR. Comparative Distribution and Metabolism of Xylem-Borne Amino Compounds and Sucrose in Shoots of Populus deltoides. Plant Physiol 1985; 77:418-28. [PMID: 16664069 PMCID: PMC1064530 DOI: 10.1104/pp.77.2.418] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The transport and metabolism of xylem-borne amino compounds and sucrose were investigated in rapidly growing shoots of cottonwood (Populus deltoides Bartr. ex Marsh.). (14)C-labeled glutamine, threonine, alanine, glutamic acid, aspartic acid, and sucrose were applied to the base of severed stems for transport in xylem. Distribution and metabolism of the compounds were followed with autoradiography, microautoradiography, and radioassay. Three utilization patterns were observed: (a) little alanine and sucrose was transported to the laminae of either mature leaves or developing leaves. These compounds were taken up from xylem free-space and utilized in adjacent tissue; (b) threonine also did not move into mature leaves but was translocated to developing leaves or utilized in the stem; (c) glutamic acid and aspartic acid were transported directly into the laminae of mature leaves via the xylem. Relatively less (14)C was retained in stems compared to the other compounds.Metabolism of the test compounds also differed considerably. (14)C from amino acids moved primarily into organic acids and protein. The (14)C from sucrose was widely distributed among the chemical fractions, with a high percentage found in structural carbohydrates. Clearly, cottonwood stems contain efficient uptake and transfer systems that differentiate among various compounds moving from root to shoot in xylem.
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Affiliation(s)
- T C Vogelmann
- United States Department of Agriculture Forest Service, North Central Forest Experiment Station, Rhinelander, Wisconsin 54501
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Dickson RE, Vogelmann TC, Larson PR. Glutamine Transfer from Xylem to Phloem and Translocation to Developing Leaves of Populus deltoides. Plant Physiol 1985; 77:412-7. [PMID: 16664068 PMCID: PMC1064529 DOI: 10.1104/pp.77.2.412] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The distribution of (14)C from xylem-borne [(14)C]glutamine, the major nitrogen compound moving in xylem sap of cottonwood (Populus deltoides Bartr. ex Marsh), was followed in rapidly growing shoots with a combination of autoradiographic, microautoradiographic, and radioassay techniques. Autoradiography and (14)C analyses of tissues showed that xylem-borne glutamine did not move with the transpiration stream into mature leaves. Instead, most of it was transferred from xylem to phloem in the upper stem and then translocated to young developing tissues. Microautoradiography showed that metaxylem parenchyma, secondary xylem parenchyma, and rays were the major areas of uptake from xylem vessels in the stem. Accumulation in phloem (high (14)C concentrations in sieve tubes) took place in internodes subtending recently mature leaves. Little (14)C from xylem-borne glutamine was found in phloem of mature leaves, which indicates restricted retransport of glutamine that did enter the leaf. In the primary tissues of the upper stem, most (14)C was found in the phloem. Cottonwood stems have an efficient uptake and transfer system that enhances glutamine movement to developing tissues of the upper stem.
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Affiliation(s)
- R E Dickson
- United States Department of Agriculture, Forest Service, North Central Forest Experiment Station, Rhinelander, Wisconsin 54501
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Vogelmann TC, Larson PR, Dickson RE. Translocation pathways in the petioles and stem between source and sink leaves of Populus deltoides Bartr. ex Marsh. Planta 1982; 156:345-358. [PMID: 24272580 DOI: 10.1007/bf00397473] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/1982] [Accepted: 08/24/1982] [Indexed: 06/02/2023]
Abstract
Microautoradiography was used to follow the translocation pathways of (14)C-labeled photosynthate from mature source leaves, through the stem, to immature sink leaves three nodes above. Translocation occurred in specific bundles of the midveins and petioles of both the source and sink leaves and in the interjacent internodes. When each of six major veins in the lamina of an exporting leaf was independently spot-fed (14)CO2, label was exported through specific bundles in the petiole associated with that vein. When the whole lamina of a mature source leaf was fed (14)CO2, export occurred through all bundles of the lamina, but acropetal export in the stem was confined to bundles serving certain immature sink leaves. Cross-transfer occurred within the stem via phloem bridges. Leaves approaching maturity translocated photosynthate bidirectionally in adjacent subsidiary bundles of the petiole. That is, petiolar bundles serving the lamina apex were exporting unlabeled photosynthate while those serving the lamina base were simultaneously importing labeled photosynthate. The petioles and midveins of maturing leaves were strong sinks for photosynthate, which was diverted from the export front to differentiating structural tissues. The data support the idea of bidirectional transport in adjacent bundles of the petiole and possibly in adjacent sieve tubes within an individual bundle.
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Affiliation(s)
- T C Vogelmann
- North Central Forest Experiment Station, U.S. Department of Agriculture, Forest Service, Box 898, 54501, Rhinelander, WI, USA
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14
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Dickson RE, Larson PR. (14)C fixation, metabolic labeling patterns, and translocation profiles during leaf development in Populus deltoides. Planta 1981; 152:461-470. [PMID: 24301121 DOI: 10.1007/bf00385364] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/1980] [Accepted: 05/12/1981] [Indexed: 06/02/2023]
Abstract
The incorporation of photosynthetically fixed (14)CO2 and the distribution of (14)C among the main chemical constituents of laminae and petioles were examined in cottonwood (Populus deltoides Bartr. ex Marsh.) leaves ranging in age from Leaf Plastochron Index (LPI) 3 (about one-quarter to one-third expanded) to LPI 30 (beginning of senescence). In addition, carbon flow among chemical fractions and translocation from leaves of LPI 7 and 14 were examined periodically up to 24 h after labeling. Specific activity of (14)C (on dry-weight basis) increased in developing laminae to full leaf expansion, decreased in the mature leaves to LPI 16, then remained constant to LPI 30. In developing leaves (LPI 3-5), after 2 h, most of the (14)C was found in protein, pigments, lipids, and other structural and metabolic components necessary for cell development; only 28% was in the sugar fraction of the lamina. In fully expanded leaves (LPI 6-8), after 2 h, the sugar fraction contained 50-60% and about 90% of fixed (14)C in the lamina and the petiole, respectively. In a pulsechase "kinetic series" with recently mature leaves, 60% of the (14)C was found in the sugar fraction after 15 min of (14)CO2 fixation. Over the 24-h translocation period, (14)C decreased in sugars to 23% and increased in the combined residue fraction (protein, starch, and structural carbohydrates) to about 60% of the total activity left in the lamina. Within 24 h after labeling, the turnover of (14)C-organic acids,-sugar, and-amino acids (either metabolzed or translocated from the leaf) was 30, 70 and 80%, respectively, of that initially incorporated into these fractions by a leaf at LPI 7 (turnover was 55% of (14)C-organic acids, 80% of (14)C-sugar, and 95% of (14)C-amino acids at LPI 14). Anatomical maturity in cottonwood leaves is closely correlated with physiological maturity and with production of translocatable sugar.
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Affiliation(s)
- R E Dickson
- U.S. Department of Agriculture, Forest Service, Forestry Sciences Laboratory, North Central Forest Experiment Station, 54501, Rhinelander, WI, USA
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15
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Larson PR. Phyllotactic transitions in the vascular system of Populus deltoides bartr. as determined by (14)C labeling. Planta 1977; 134:241-249. [PMID: 24419777 DOI: 10.1007/bf00384188] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/1976] [Accepted: 12/14/1976] [Indexed: 06/03/2023]
Abstract
Populus deltoides seedlings progress through 2/5, 3/8, and 5/13 orders of phyllotaxis in attaining Plastochron Index 16 (PI 16). The manner in which the vascular system was reoriented during these phyllotactic transitions was determined by anatomical analysis of serial microsections, whereas the positions of the transitions were determined by (14)C labeling. The midvein at the tip of leaves representing plants of different PI and leaves of different Leaf Plastochron Index (LPI) was fed (14)CO2 photosynthetically, and primordia LPI 0 through LPI-9 were dissected from the buds and analyzed for (14)C. By combining the labeling data with the anatomical observations it was possible to reconstruct the vascular system of a plant of PI 16 and to locate the phyllotactic transitions. Both the anatomical and the labeling data showed a high degree of reproducibility among plants suggesting that the phyllotactic pattern to which the vascular system conforms may be programmed in the plant and transmitted acropetally through the developing leaves and procambial strands. The origin of new primordia and the concepts of orthostichy, ontogenetic helix, and Fibonacci sequence are discussed as they apply to the vascular system of P. deltoides.
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Affiliation(s)
- P R Larson
- North Central Forest Experiment Station, U.S. Department of Agriculture, Forest Service, Box 898, 54501, Rhinelander, WI, USA
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16
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Isebrands JG, Dickson RE, Larson PR. Translocation and incorporation of (14)C into the petiole from different regions within developing cottonwood leaves. Planta 1976; 128:185-193. [PMID: 24430745 DOI: 10.1007/bf00393227] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/1975] [Accepted: 06/27/1975] [Indexed: 06/03/2023]
Abstract
The ability of a developing cottonwood (Populus deltoides Bartr.) leaf to export (14)C-labeled assimilates begins at the lamina tip and progresses basipetally with increasing LPI. This progression indicates that portions of leaves function quasi-independently in their ability to export (14)C-photosynthate. Although most of the exported radioactivity was recovered in the petiole as water-80% alcohol-soluble compounds, there was also substantial incorporation into the chloroform and insoluble fractions. This observation indicates that assimilates translocated from the lamina are used in structural development of the petiole. Freeze substitution and epoxy embedding were used to prepare microautoradiographs for localization of water-soluble compounds. Radioactivity was found in all cell types within specific subsidiary bundles of the petiole. However, radioactive assimilates appeared to move from the translocation pathway in the phloem toward active sinks in the walls of the expanding metaxylem cells. Translocation in the mature xylem vessels was not observed.
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Affiliation(s)
- J G Isebrands
- North Central Forest Experiment Station, U.S. Department of Agriculture, Forest Service, 54501, Rhinelander, Wisconsin, USA
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Dickson RE, Larson PR. Incorporation of C-photosynthate into major chemical fractions of source and sink leaves of cottonwood. Plant Physiol 1975; 56:185-93. [PMID: 16659271 PMCID: PMC541788 DOI: 10.1104/pp.56.2.185] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The incorporation and distribution of photosynthetically fixed (14)CO(2) was followed for 48 hours in a recently matured source leaf (LPI 7) and in young expanding source and sink leaves (LPI 4) of cottonwood (Populus deltoides Bartr.). The major chemical constituents of leaf laminae and petioles were separated by sequential solvent extractions and enzyme hydrolyses. Two hours after labeling, about 80% of the (14)C was found in water-alcohol-soluble constituents in the mature source lamina as compared to about 45% in those of the young expanding leaf. In both mature and expanding source leaves the water-alcohol-soluble constituents decreased while the CHCl(3)-soluble and -insoluble compounds increased with time. After 48 hours, 7 and 37% of the total (14)C was recovered from structural carbohydrates and from protein + CHCl(3)-soluble fractions, respectively, in the mature source leaf; and 4 and 65%, respectively, in the young source leaf. When the distribution of (14)C among major chemical fractions was calculated on per cent dpm/mg basis, the data showed that a young sink leaf incorporated over twice as much (14)C into structural carbohydrates as a young source leaf (11% versus 4%). However, when calculated on an absolute dpm/mg basis, activity in this fraction of the young source leaf exceeded that in the sink leaf by a ratio of about 11:1 (9528 versus 845 dpm/mg). Thus, most of the material for synthesis of structural carbohydrates was derived from in situ photosynthate.The distribution of (14)C in chemical fractions recovered from petioles was similar to that recovered from their respective laminae, except that petioles incorporated greater amounts (up to 24% of total (14)C) into structural carbohydrates. In contrast to lamina tissue, most of the photosynthate for synthesis of structural carbohydrates in the petioles of young developing leaves was imported from mature leaves farther down the stem.
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Affiliation(s)
- R E Dickson
- North Central Forest Experiment Station, United States Department of Agriculture Forest Service, Institute of Forest Genetics, Rhinelander, Wisconsin 54501
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Larson PR, Dickson RE. Distribution of imported (14)C in developing leaves of eastern cottonwood according to phyllotaxy. Planta 1973; 111:95-112. [PMID: 24469506 DOI: 10.1007/bf00386270] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/1972] [Indexed: 05/09/2023]
Abstract
Individual leaves of eastern cottonwood (Populus deltoides Bartr.), representing an ontogenetic series from leaf plastochron index (LPI) 3.0 to 8.0, were fed (14)CO2 and harvested after 2-24 h. Importing leaves from LPI-1.0 through 8.0 on each plant were sectioned into 9 parts, and each part was quantitatively assayed for (14)C activity. The highest level of (14)C import was by leaves from LPI 1.0 to 3.0, irrespective of source-leaf age. (14)C was translocated preferentially to either the right or left lamina-half depending on the position of the importing leaf in the phyllotactic sequence and its stage of development. For example, import was high when the importing leaf and the source leaf had two vascular bundles in common, moderately high with one bundle in common, and low with no bundles in common. The distribution of (14)C within young importing leaves was highest in the lamina tip and decreased toward the base. With increasing leaf age, incorporation declined in the lamina tip and increased in the base.It may be concluded that each cottonwood leaf progresses through a continuum of importing and exporting stages as its lamina expands. The photosynthate imported by a given leaf is compartmentalized, with different exporting leaves supplying photosynthate to rather restricted regions of the lamina. Such localization within the importing leaf depends on its vascular connections with each of the exporting leaves, and these are predictable from a knowledge of the phyllotaxy.
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Affiliation(s)
- P R Larson
- North Central Forest Experiment Station, U.S. Department of Agriculture, Forest Service, Star Route No. 2, 54501, Rhinelander, Wisconsin, USA
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Larson PR, Isebrands JG, Dickson RE. Fixation patterns of (14)C within developing leaves of eastern cottonwood. Planta 1972; 107:301-314. [PMID: 24477480 DOI: 10.1007/bf00386392] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/1972] [Indexed: 06/03/2023]
Abstract
Individual leaves of eastern cottonwood (Populus deltoides), representing an ontogenetic series from leaf plastochron index 0.0 to 8.0, were fed (14)CO2 photosynthetically and then harvested at times ranging from 15 to 1440 min. The lamina of each fed leaf was sectioned from tip to base into 5 parts, and each part was quantitatively assayed for (14)C activity. In young leaves, the percentage of the total (14)C fixed (expressed in dpm/mg of dry leaf tissue) was high in the lamina tip and decreased almost linearly toward the base. With increasing leaf age, the percentage of (14)C fixed decreased in the lamina tip and increased in the base. The relative activity in mature leaves was almost uniform throughout the lamina. No differences were detected in the (14)C distribution patterns within leaves over the time series.On the basis of the data presented and of anatomical observations of developing cottonwood leaves, the hypothesis that the precociously mature lamina tip may provide photosynthates to the still-expanding lamina base was shown to be invalid. It is concluded that bidirectional transport in a developing cottonwood leaf results from simultaneous import to the immature basal region and export from the mature tip.
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Affiliation(s)
- P R Larson
- North Central Forest Experiment Station, USDA Forest Service, Rhinelander, Wisconsin, USA
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Gordon JC, Larson PR. Seasonal Course of Photosynthesis, Respiration, and Distribution of C in Young Pinus resinosa Trees as Related to Wood Formation. Plant Physiol 1968; 43:1617-24. [PMID: 16656946 PMCID: PMC1087050 DOI: 10.1104/pp.43.10.1617] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Rates of net photosynthesis and dark respiration, and distribution of (14)C were determined for new (current season's) and old (previous season's) needles at 10 times during the seasonal development of young Pinus resinosa Ait. trees. The seasonal changes in these factors associated with the development of the new shoot were related to known seasonal patterns of wood formation.Net photosynthesis per gram of needle dry weight (photosynthetic efficiency) was maximum in the old needles at the time of first new needle elongation; at the same time translocation of (14)C from old to new needles was greatest. Photosynthetic efficiency of new needles was maximum at the end of the period of rapid new needle elongation, when the new needles also began exporting much greater quantities of (14)C to other plant parts. In particular, the amount translocated from the new needles to the stem was greatly increased. At this time thick-walled xylem cells were first observed in the stem.These results, together with those of previous studies, indicate that the production of thick-walled xylem tracheids normally associated with latewood is physiologically correlated with maturation of the current season's needles. Because there is a lesser demand for photosynthate in the new shoot and a high rate of photosynthesis in the whole plant at the time of new needle maturity, a sharply increased amount of photosynthate becomes available for wall synthesis by cambial derivatives.
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Affiliation(s)
- J C Gordon
- North Central Forest Experiment Station, Forest Service, United States Department of Agriculture, Rhinelander, Wisconsin
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