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Salazar R, Pollmann S, Morales-Quintana L, Herrera R, Caparrós-Ruiz D, Ramos P. In seedlings of Pinus radiata, jasmonic acid and auxin are differentially distributed on opposite sides of tilted stems affecting lignin monomer biosynthesis and composition. Plant Physiol Biochem 2019; 135:215-223. [PMID: 30576980 DOI: 10.1016/j.plaphy.2018.12.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [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: 10/19/2018] [Revised: 12/05/2018] [Accepted: 12/12/2018] [Indexed: 05/25/2023]
Abstract
Plants respond to the loss of vertical growth re-orientating their affected organs. In trees, this phenomenon has received the scientific attention due to its importance for the forestry industry. Nowadays it is accepted that auxin distribution is involved in the modulation of the tilting response, but how this distribution is controlled is not fully clear. Auxin transporters that determine the spatio-temporal auxin distribution in radiate pine seedlings exposed to 45° of tilting were identified. Additionally, based on indications for an intimate plant hormone crosstalk in this process, IAA and JA contents were evaluated. The experiments revealed that expression of the auxin transporters was down-regulated in the upper half of the tilted stem, while being induced in the lower half. Moreover, transporter-coding genes were first induced at the apical zone of the stem. IAA was consistently redistributed toward the lower half, which is in accordance with the expression profile of the auxin transporters. In contrast, JA was mainly accumulated in the upper half of tilted stems. Finally, lignin content and monomeric composition were analyzed in both sides of stem and along the time course of tilting. As expected, lignin accumulation was higher at the lower half of stem at longer times of tilting. However, the most marked difference was the accumulation of the H-lignin monomer in the lower half, while the G-lignin unit was more dominant in the upper half. Here, we provide detailed insight in the distribution of IAA and JA, affecting the lignin composition during the tilting response in Pinus radiata seedlings.
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Affiliation(s)
- Romina Salazar
- Instituto de Ciencias Biológicas, Campus Talca, Universidad de Talca, Avda. Lircay s/, Talca, Chile
| | - Stephan Pollmann
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Pozuelo de Alarcón, Spain
| | - Luis Morales-Quintana
- Multidisciplinary Agroindustry Research Laboratory, Universidad Autónoma de Chile, Chile
| | - Raul Herrera
- Instituto de Ciencias Biológicas, Campus Talca, Universidad de Talca, Avda. Lircay s/, Talca, Chile
| | - David Caparrós-Ruiz
- Centre for Research in Agricultural Genomics (CRAG) Consorci CSIC-IRTA-UAB-UB Edifici CRAG Campus de Bellaterra de la UAB, 08193, Cerdanyola del Valles, Barcelona, Spain
| | - Patricio Ramos
- Instituto de Ciencias Biológicas, Campus Talca, Universidad de Talca, Avda. Lircay s/, Talca, Chile.
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Özparpucu M, Gierlinger N, Burgert I, Van Acker R, Vanholme R, Boerjan W, Pilate G, Déjardin A, Rüggeberg M. The effect of altered lignin composition on mechanical properties of CINNAMYL ALCOHOL DEHYDROGENASE (CAD) deficient poplars. Planta 2018; 247:887-897. [PMID: 29270675 DOI: 10.1007/s00425-017-2828-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 12/08/2017] [Indexed: 05/08/2023]
Abstract
CAD-deficient poplars enabled studying the influence of altered lignin composition on mechanical properties. Severe alterations in lignin composition did not influence the mechanical properties. Wood represents a hierarchical fiber-composite material with excellent mechanical properties. Despite its wide use and versatility, its mechanical behavior has not been entirely understood. It has especially been challenging to unravel the mechanical function of the cell wall matrix. Lignin engineering has been a useful tool to increase the knowledge on the mechanical function of lignin as it allows for modifications of lignin content and composition and the subsequent studying of the mechanical properties of these transgenics. Hereby, in most cases, both lignin composition and content are altered and the specific influence of lignin composition has hardly been revealed. Here, we have performed a comprehensive micromechanical, structural, and spectroscopic analysis on xylem strips of transgenic poplar plants, which are downregulated for cinnamyl alcohol dehydrogenase (CAD) by a hairpin-RNA-mediated silencing approach. All parameters were evaluated on the same samples. Raman microscopy revealed that the lignin of the hpCAD poplars was significantly enriched in aldehydes and reduced in the (relative) amount of G-units. FTIR spectra indicated pronounced changes in lignin composition, whereas lignin content was not significantly changed between WT and the hpCAD poplars. Microfibril angles were in the range of 18°-24° and were not significantly different between WT and transgenics. No significant changes were observed in mechanical properties, such as tensile stiffness, ultimate stress, and yield stress. The specific findings on hpCAD poplar allowed studying the specific influence of lignin composition on mechanics. It can be concluded that the changes in lignin composition in hpCAD poplars did not affect the micromechanical tensile properties.
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Affiliation(s)
- Merve Özparpucu
- Institute for Building Materials (IfB), ETH Zurich, 8093, Zurich, Switzerland
| | - Notburga Gierlinger
- Institute for Biophysics, University of Natural Resources and Life Sciences Vienna, 1190, Vienna, Austria
| | - Ingo Burgert
- Institute for Building Materials (IfB), ETH Zurich, 8093, Zurich, Switzerland
- Laboratory of Applied Wood Materials, EMPA, 8600, Dübendorf, Switzerland
| | - Rebecca Van Acker
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, 9052, Ghent, Belgium
| | - Ruben Vanholme
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, 9052, Ghent, Belgium
| | - Wout Boerjan
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, 9052, Ghent, Belgium
| | | | | | - Markus Rüggeberg
- Institute for Building Materials (IfB), ETH Zurich, 8093, Zurich, Switzerland.
- Laboratory of Applied Wood Materials, EMPA, 8600, Dübendorf, Switzerland.
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Abstract
The lignin structural ramifications of coumarate 3-hydroxylase (C3H) downregulation have not been addressed in hardwoods. Such information is required to accompany an assessment of the digestibility and bioenergy performance characteristics of poplar, in particular. Structurally rich 2D NMR methods were applied to the entire lignin fraction to delineate lignin p-hydroxyphenyl:guaiacyl:syringyl (H:G:S) levels and linkage distribution changes (and to compare with traditional degradative analyses). C3H downregulation reduced lignin levels by half and markedly increased the proportion of H units relative to the normally dominant G and S units. Relative stem H unit levels were up by ∼ 100-fold to ∼ 31 %, almost totally at the expense of G units; differences in the lignin interunit linkage distributions were more subtle. The H level in the most drastically C3H-downregulated transgenic poplar falls well beyond the H:G:S compositional bounds of normal angiosperms. The response observed here, in poplar, differs markedly from that reported for alfalfa where the S:G ratio remained almost constant even at substantial H levels, highlighting the often differing responses among plant species.
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Affiliation(s)
- John Ralph
- Department of Biochemistry, Enzyme Institute, University of Wisconsin-Madison, 1710 University Avenue, Madison, WI 53726 USA
- Department of Biological Systems Engineering, University of Wisconsin-Madison, 460 Henry Mall, Madison, WI 53706 USA
- DOE Great Lakes Bioenergy Research Center, and Wisconsin Bioenergy Initiative, University of Wisconsin-Madison, Madison, WI 53706 USA
| | - Takuya Akiyama
- Wood Chemistry Laboratory, Department of Biomaterial Sciences, the University of Tokyo, Bunkyo-ku Tokyo, 113-8657 Japan
| | - Heather D. Coleman
- Department of Biology, Syracuse University, 460 Life Sciences Complex, 107 College Place, Syracuse, NY 13244 USA
| | - Shawn D. Mansfield
- Department of Wood Science, University of British Columbia, Vancouver, BC V6T 1Z4 Canada
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