Knockdown of PCBER1, a gene of neolignan biosynthesis, resulted in increased poplar growth
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Poplar trees displayed an increased plant height due to the transgenic knockdown of PCBER1, a gene of lignan biosynthesis. The wood composition was slightly altered in both overexpression and knockdown lines.
The gene PHENYLCOUMARAN BENZYLIC ETHER REDUCTASE1 (PCBER1) is well known as an important gene in the synthesis of lignans, a group of diverse phenylpropanoid derivatives. They are widely distributed in the plant kingdom and may have a role in both plant defense and growth regulation. To analyze its role in biomass formation and wood composition in poplar, both overexpression and knockdown approaches have been performed. Transgenic lines were analyzed on genetic and phenotypic levels, and partly in regard to their biomass composition. While the PCBER1 overexpression approach remained unremarkable concerning the plant height, biomass composition of obtained transgenic lines was modified. They had a significantly increased amount of ethanol extractives. The PCBER1 knockdown resulted in significantly deviating plants; after 17 months of greenhouse cultivation, transgenic plants were up to 38% higher compared to non-transgenic wild type. Most examined transgenic lines did not reveal a significantly enhanced stem diameter after three vegetation periods in the greenhouse. Significant changes were not obtained with regard to the three major wood components, lignin, cellulose and hemicelluloses. As a slight but not significant reduction in ethanol extractives was detected, the hypothesis arises that the lignan content could be influenced. Lignans become important in the pharmaceutical industry and clinical studies concerning cancer and other diseases, thus further investigations on lignan formation in poplar and its connection to biomass formation seem promising.
KeywordsBiomass Lignan synthesis Lignin Populus Transformation Vegetative growth
We are grateful to Guido Jach (Phytowelt, Cologne, Germany) for providing the amiRNA transformation vectors. Thanks to Susanne Jelkmann, Olaf Polak, Jonas Schönfeld, Jakob Fromme, Gundel Wiemann, Monika Spauszus, and Rainer Ebbinghaus for technical assistance. This work was part of the joint project “PopMass”, founded by the German Federal Ministry of Education and Research (BMBF) under the funding number 0315972A.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- ASTM E1690-08 (2016) Standard test method for determination of ethanol extractives in biomass. http://www.astm.org/cgi-bin/resolver.cgi?E1690-08. Accessed 30 May 2018
- Boerjan W, Polle A, Vander Mijnsbrugge K (2003a) Role in lignification and growth for plant phenylcoumaran benzylic ether reductase. US Patent Application No. 10/531,479, Publication US20060015967 A1Google Scholar
- Brügmann T (2016) Genetische Modifikation von SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1), FRUITFULL (FUL) und weiterer Kandidatengene in Pappelhybriden (Populus spec.). Dissertation, University of HamburgGoogle Scholar
- Fladung M, Ahuja MR (1995) “Sandwich” method for nonradioactive hybridization. Biotechniques 18(5):800–802Google Scholar
- FNR (2014) Basisdaten Bioenergie Deutschland 2014. Fachagentur Nachwachsende Rohstoffe, GülzowGoogle Scholar
- Gang DR, Kasahara H, Xia ZQ, Vander Mijnsbrugge K, Bauw G, Boerjan W, Van Montagu M, Davin LB, Lewis NG (1999) Evolution of plant defense mechanisms. Relationships of phenylcoumaran benzylic ether reductases to pinoresinol-lariciresinol and isoflavone reductases. J Biol Chem 274(11):7516–7527CrossRefGoogle Scholar
- Kauter D, Lewandowski I, Claupein W (2001) Pappeln in Kurzumtriebswirtschaft: Eigenschaften und Qualitätsmanagement bei der Festbrennstoffbereitstellung—Ein Überblick. Pflanzenbauwissenschaften 5(2):64–74Google Scholar
- Niculaes C, Morreel K, Kim H, Lu F, McKee LS, Ivens B, Haustraete J, Vanholme B, De Rycke R, Hertzberg M, Fromm J, Bulone V, Polle A, Ralph J, Boerjan W (2014) Phenylcoumaran benzylic ether reductase prevents accumulation of compounds formed under oxidative conditions in poplar xylem. Plant Cell 26(9):3775–3791CrossRefGoogle Scholar
- Pohjamo SP, Willför S, Reunanen M, Hemming J, Holmbom B (2002) Bioactive phenolic substances in fast-growing tree species. Report B1-02. Åbo Akademi University, Process Chemistry Group, ÅboGoogle Scholar
- Schirmer R (2009) Sortenprüfung von Pappelklonen-Voraussetzung für einen erfolgreichen Energieholzanbau. Holzproduktion auf forstgenetischer Grundlage im Hinblick auf Klimawandel und Rohstoffverknappung 28:123–129Google Scholar
- Umezawa T (1997) Lignans. In: Higuchi T (ed) Biochemistry and molecular biology of wood. Springer, Berlin, pp 181–194Google Scholar