1
|
Robinson KM, Möller L, Bhalerao RP, Hertzberg M, Nilsson O, Jansson S. Variation in non-target traits in genetically modified hybrid aspens does not exceed natural variation. N Biotechnol 2021; 64:27-36. [PMID: 34048978 DOI: 10.1016/j.nbt.2021.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 05/20/2021] [Accepted: 05/22/2021] [Indexed: 11/18/2022]
Abstract
Genetically modified hybrid aspens (Populus tremula L. x P. tremuloides Michx.), selected for increased growth under controlled conditions, have been grown in highly replicated field trials to evaluate how the target trait (growth) translated to natural conditions. Moreover, the variation was compared among genotypes of ecologically important non-target traits: number of shoots, bud set, pathogen infection, amount of insect herbivory, composition of the insect herbivore community and flower bud induction. This variation was compared with the variation in a population of randomly selected natural accessions of P. tremula grown in common garden trials, to estimate how the "unintended variation" present in transgenic trees, which in the future may be commercialized, compares with natural variation. The natural variation in the traits was found to be typically significantly greater. The data suggest that when authorities evaluate the potential risks associated with a field experiment or commercial introduction of transgenic trees, risk evaluation should focus on target traits and that unintentional variation in non-target traits is of less concern.
Collapse
Affiliation(s)
- Kathryn M Robinson
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, 901 87, Umeå, Sweden.
| | - Linus Möller
- SweTree Technologies AB, P.O Box 4095, 904 03, Umeå, Sweden.
| | - Rishikesh P Bhalerao
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 901 83, Umeå, Sweden.
| | | | - Ove Nilsson
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 901 83, Umeå, Sweden.
| | - Stefan Jansson
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, 901 87, Umeå, Sweden.
| |
Collapse
|
2
|
Phytochemical Shift from Condensed Tannins to Flavonoids in Transgenic Betula pendula Decreases Consumption and Growth but Improves Growth Efficiency of Epirrita autumnata Larvae. J Chem Ecol 2019; 46:217-231. [PMID: 31879865 PMCID: PMC7056695 DOI: 10.1007/s10886-019-01134-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 10/31/2019] [Accepted: 12/09/2019] [Indexed: 11/16/2022]
Abstract
Despite active research, antiherbivore activity of specific plant phenolics remains largely unresolved. We constructed silver birch (Betula pendula) lines with modified phenolic metabolism to study the effects of foliar flavonoids and condensed tannins on consumption and growth of larvae of a generalist herbivore, the autumnal moth (Epirrita autumnata). We conducted a feeding experiment using birch lines in which expression of dihydroflavonol reductase (DFR), anthocyanidin synthase (ANS) or anthocyanidin reductase (ANR) had been decreased by RNA interference. Modification-specific effects on plant phenolics, nutrients and phenotype, and on larval consumption and growth were analyzed using uni- and multivariate methods. Inhibiting DFR expression increased the concentration of flavonoids at the expense of condensed tannins, and silencing DFR and ANR decreased leaf and plant size. E. autumnata larvae consumed on average 82% less of DFRi plants than of unmodified controls, suggesting that flavonoids or glandular trichomes deter larval feeding. However, larval growth efficiency was highest on low-tannin DFRi plants, indicating that condensed tannins (or their monomers) are physiologically more harmful than non-tannin flavonoids for E. autumnata larvae. Our results show that genetic manipulation of the flavonoid pathway in plants can effectively be used to produce altered phenolic profiles required for elucidating the roles of low-molecular weight phenolics and condensed tannins in plant–herbivore relationships, and suggest that phenolic secondary metabolites participate in regulation of plant growth.
Collapse
|
3
|
Chanoca A, de Vries L, Boerjan W. Lignin Engineering in Forest Trees. FRONTIERS IN PLANT SCIENCE 2019; 10:912. [PMID: 31404271 PMCID: PMC6671871 DOI: 10.3389/fpls.2019.00912] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 06/27/2019] [Indexed: 05/19/2023]
Abstract
Wood is a renewable resource that is mainly composed of lignin and cell wall polysaccharides. The polysaccharide fraction is valuable as it can be converted into pulp and paper, or into fermentable sugars. On the other hand, the lignin fraction is increasingly being considered a valuable source of aromatic building blocks for the chemical industry. The presence of lignin in wood is one of the major recalcitrance factors in woody biomass processing, necessitating the need for harsh chemical treatments to degrade and extract it prior to the valorization of the cell wall polysaccharides, cellulose and hemicellulose. Over the past years, large research efforts have been devoted to engineering lignin amount and composition to reduce biomass recalcitrance toward chemical processing. We review the efforts made in forest trees, and compare results from greenhouse and field trials. Furthermore, we address the value and potential of CRISPR-based gene editing in lignin engineering and its integration in tree breeding programs.
Collapse
Affiliation(s)
- Alexandra Chanoca
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Lisanne de Vries
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Wout Boerjan
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| |
Collapse
|
4
|
Venter HJ, Bøhn T. Interactions between Bt crops and aquatic ecosystems: A review. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2016; 35:2891-2902. [PMID: 27530353 DOI: 10.1002/etc.3583] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 05/13/2016] [Accepted: 08/11/2016] [Indexed: 06/06/2023]
Abstract
The term Bt crops collectively refers to crops that have been genetically modified to include a gene (or genes) sourced from Bacillus thuringiensis (Bt) bacteria. These genes confer the ability to produce proteins toxic to certain insect pests. The interaction between Bt crops and adjacent aquatic ecosystems has received limited attention in research and risk assessment, despite the fact that some Bt crops have been in commercial use for 20 yr. Reports of effects on aquatic organisms such as Daphnia magna, Elliptio complanata, and Chironomus dilutus suggest that some aquatic species may be negatively affected, whereas other reports suggest that the decreased use of insecticides precipitated by Bt crops may benefit aquatic communities. The present study reviews the literature regarding entry routes and exposure pathways by which aquatic organisms may be exposed to Bt crop material, as well as feeding trials and field surveys that have investigated the effects of Bt-expressing plant material on such organisms. The present review also discusses how Bt crop development has moved past single-gene events, toward multigene stacked varieties that often contain herbicide resistance genes in addition to multiple Bt genes, and how their use (in conjunction with co-technology such as glyphosate/Roundup) may impact and interact with aquatic ecosystems. Lastly, suggestions for further research in this field are provided. Environ Toxicol Chem 2016;35:2891-2902. © 2016 SETAC.
Collapse
Affiliation(s)
- Hermoine J Venter
- Unit for Environmental Sciences and Management, North-West University Potchefstroom Campus, North West Province, South Africa
| | - Thomas Bøhn
- GenØk-Center for Biosafety, Tromsø, Troms, Norway
| |
Collapse
|
5
|
Müller A, Kaling M, Faubert P, Gort G, Smid HM, Van Loon JJA, Dicke M, Kanawati B, Schmitt-Kopplin P, Polle A, Schnitzler JP, Rosenkranz M. Isoprene emission by poplar is not important for the feeding behaviour of poplar leaf beetles. BMC PLANT BIOLOGY 2015; 15:165. [PMID: 26122266 PMCID: PMC4486431 DOI: 10.1186/s12870-015-0542-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 06/05/2015] [Indexed: 05/07/2023]
Abstract
BACKGROUND Chrysomela populi (poplar leaf beetle) is a common herbivore in poplar plantations whose infestation causes major economic losses. Because plant volatiles act as infochemicals, we tested whether isoprene, the main volatile organic compound (VOC) produced by poplars (Populus x canescens), affects the performance of C. populi employing isoprene emitting (IE) and transgenic isoprene non-emitting (NE) plants. Our hypothesis was that isoprene is sensed and affects beetle orientation or that the lack of isoprene affects plant VOC profiles and metabolome with consequences for C. populi feeding. RESULTS Electroantennographic analysis revealed that C. populi can detect higher terpenes, but not isoprene. In accordance to the inability to detect isoprene, C. populi showed no clear preference for IE or NE poplar genotypes in the choice experiments, however, the beetles consumed a little bit less leaf mass and laid fewer eggs on NE poplar trees in field experiments. Slight differences in the profiles of volatile terpenoids between IE and NE genotypes were detected by gas chromatography - mass spectrometry. Non-targeted metabolomics analysis by Fourier Transform Ion Cyclotron Resonance Mass Spectrometer revealed genotype-, time- and herbivore feeding-dependent metabolic changes both in the infested and adjacent undamaged leaves under field conditions. CONCLUSIONS We show for the first time that C. populi is unable to sense isoprene. The detected minor differences in insect feeding in choice experiments and field bioassays may be related to the revealed changes in leaf volatile emission and metabolite composition between the IE and NE poplars. Overall our results indicate that lacking isoprene emission is of minor importance for C. populi herbivory under natural conditions, and that the lack of isoprene is not expected to change the economic losses in poplar plantations caused by C. populi infestation.
Collapse
Affiliation(s)
- Anna Müller
- Büsgen Institute, Forest Botany and Tree Physiology, University of Göttingen, Büsgenweg 2, 37077, Göttingen, Germany.
| | - Moritz Kaling
- Research Unit Environmental Simulation, Institute of Biochemical Plant Pathology, Helmholtz Zentrum München - German Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany.
- Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, D-85764, Neuherberg, Germany.
| | - Patrick Faubert
- Research Unit Environmental Simulation, Institute of Biochemical Plant Pathology, Helmholtz Zentrum München - German Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany.
- Département des Sciences Fondamentales, Chaire en éco-conseil, Université du Québec à Chicoutimi, 555, boul. de l'Université, Chicoutimi, Qc, G7H 2B1, Canada.
| | - Gerrit Gort
- Mathematical and Statistical Methods Group, Wageningen University, P.O. Box 100, 6700 AC, Wageningen, Netherlands.
| | - Hans M Smid
- Laboratory of Entomology, Wageningen University, P.O. Box 8031, NL-6700 EH, Wageningen, Netherlands.
| | - Joop J A Van Loon
- Laboratory of Entomology, Wageningen University, P.O. Box 8031, NL-6700 EH, Wageningen, Netherlands.
| | - Marcel Dicke
- Laboratory of Entomology, Wageningen University, P.O. Box 8031, NL-6700 EH, Wageningen, Netherlands.
| | - Basem Kanawati
- Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, D-85764, Neuherberg, Germany.
| | - Philippe Schmitt-Kopplin
- Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, D-85764, Neuherberg, Germany.
| | - Andrea Polle
- Büsgen Institute, Forest Botany and Tree Physiology, University of Göttingen, Büsgenweg 2, 37077, Göttingen, Germany.
| | - Jörg-Peter Schnitzler
- Research Unit Environmental Simulation, Institute of Biochemical Plant Pathology, Helmholtz Zentrum München - German Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany.
| | - Maaria Rosenkranz
- Research Unit Environmental Simulation, Institute of Biochemical Plant Pathology, Helmholtz Zentrum München - German Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany.
| |
Collapse
|
6
|
Hjältén J, Axelsson EP. GM trees with increased resistance to herbivores: trait efficiency and their potential to promote tree growth. FRONTIERS IN PLANT SCIENCE 2015; 6:279. [PMID: 25983736 PMCID: PMC4416443 DOI: 10.3389/fpls.2015.00279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 04/07/2015] [Indexed: 05/04/2023]
Abstract
Climate change, as well as a more intensive forestry, is expected to increase the risk of damage by pests and pathogens on trees, which can already be a severe problem in tree plantations. Recent development of biotechnology theoretically allows for resistance enhancement that could help reduce these risks but we still lack a comprehensive understanding of benefits and tradeoffs with pest resistant GM (genetically modified) trees. We synthesized the current knowledge on the effectiveness of GM forest trees with increased resistance to herbivores. There is ample evidence that induction of exogenous Bacillus thuringiensis genes reduce performance of target pests whereas upregulation of endogenous resistance traits e.g., phenolics, generates variable results. Our review identified very few studies estimating the realized benefits in tree growth of GM trees in the field. This is concerning as the realized benefit with insect resistant GM plants seems to be context-dependent and likely manifested only if herbivore pressure is sufficiently high. Future studies of secondary pest species and resistance evolution in pest to GM trees should be prioritized. But most importantly we need more long-term field tests to evaluate the benefits and risks with pest resistant GM trees.
Collapse
Affiliation(s)
- Joakim Hjältén
- Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural SciencesUmeå, Sweden
- *Correspondence: Joakim Hjältén, Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, Skogsmarksgränd 2, Umeå SE-90183, Sweden
| | - E. Petter Axelsson
- Department of Forest Ecology and Management, Swedish University of Agricultural SciencesUmeå, Sweden
| |
Collapse
|