Gene stacking of multiple traits for high yield of fermentable sugars in plant biomass
Abstract Background Second-generation biofuels produced from biomass can help to decrease dependency on fossil fuels, bringing about many economic and environmental benefits. To make biomass more suitable for biorefinery use, we need a better understanding of plant cell wall biosynthesis. Increasing...
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| Format: | Article |
| Language: | English |
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BMC
2018-01-01
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| Series: | Biotechnology for Biofuels |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1186/s13068-017-1007-6 |
| _version_ | 1828802176121569280 |
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| author | Aude Aznar Camille Chalvin Patrick M. Shih Michael Maimann Berit Ebert Devon S. Birdseye Dominique Loqué Henrik V. Scheller |
| author_facet | Aude Aznar Camille Chalvin Patrick M. Shih Michael Maimann Berit Ebert Devon S. Birdseye Dominique Loqué Henrik V. Scheller |
| author_sort | Aude Aznar |
| collection | DOAJ |
| description | Abstract Background Second-generation biofuels produced from biomass can help to decrease dependency on fossil fuels, bringing about many economic and environmental benefits. To make biomass more suitable for biorefinery use, we need a better understanding of plant cell wall biosynthesis. Increasing the ratio of C6 to C5 sugars in the cell wall and decreasing the lignin content are two important targets in engineering of plants that are more suitable for downstream processing for second-generation biofuel production. Results We have studied the basic mechanisms of cell wall biosynthesis and identified genes involved in biosynthesis of pectic galactan, including the GALS1 galactan synthase and the UDP-galactose/UDP-rhamnose transporter URGT1. We have engineered plants with a more suitable biomass composition by applying these findings, in conjunction with synthetic biology and gene stacking tools. Plants were engineered to have up to fourfold more pectic galactan in stems by overexpressing GALS1, URGT1, and UGE2, a UDP-glucose epimerase. Furthermore, the increased galactan trait was engineered into plants that were already engineered to have low xylan content by restricting xylan biosynthesis to vessels where this polysaccharide is essential. Finally, the high galactan and low xylan traits were stacked with the low lignin trait obtained by expressing the QsuB gene encoding dehydroshikimate dehydratase in lignifying cells. Conclusion The results show that approaches to increasing C6 sugar content, decreasing xylan, and reducing lignin content can be combined in an additive manner. Thus, the engineered lines obtained by this trait-stacking approach have substantially improved properties from the perspective of biofuel production, and they do not show any obvious negative growth effects. The approach used in this study can be readily transferred to bioenergy crop plants. |
| first_indexed | 2024-12-12T06:59:24Z |
| format | Article |
| id | doaj.art-699655a689e544c3ab51116ae40baf0f |
| institution | Directory Open Access Journal |
| issn | 1754-6834 |
| language | English |
| last_indexed | 2024-12-12T06:59:24Z |
| publishDate | 2018-01-01 |
| publisher | BMC |
| record_format | Article |
| series | Biotechnology for Biofuels |
| spelling | doaj.art-699655a689e544c3ab51116ae40baf0f2022-12-22T00:33:52ZengBMCBiotechnology for Biofuels1754-68342018-01-0111111410.1186/s13068-017-1007-6Gene stacking of multiple traits for high yield of fermentable sugars in plant biomassAude Aznar0Camille Chalvin1Patrick M. Shih2Michael Maimann3Berit Ebert4Devon S. Birdseye5Dominique Loqué6Henrik V. Scheller7Feedstocks Division, Joint BioEnergy Institute, Lawrence Berkeley National LaboratoryFeedstocks Division, Joint BioEnergy Institute, Lawrence Berkeley National LaboratoryFeedstocks Division, Joint BioEnergy Institute, Lawrence Berkeley National LaboratoryFeedstocks Division, Joint BioEnergy Institute, Lawrence Berkeley National LaboratoryFeedstocks Division, Joint BioEnergy Institute, Lawrence Berkeley National LaboratoryFeedstocks Division, Joint BioEnergy Institute, Lawrence Berkeley National LaboratoryFeedstocks Division, Joint BioEnergy Institute, Lawrence Berkeley National LaboratoryFeedstocks Division, Joint BioEnergy Institute, Lawrence Berkeley National LaboratoryAbstract Background Second-generation biofuels produced from biomass can help to decrease dependency on fossil fuels, bringing about many economic and environmental benefits. To make biomass more suitable for biorefinery use, we need a better understanding of plant cell wall biosynthesis. Increasing the ratio of C6 to C5 sugars in the cell wall and decreasing the lignin content are two important targets in engineering of plants that are more suitable for downstream processing for second-generation biofuel production. Results We have studied the basic mechanisms of cell wall biosynthesis and identified genes involved in biosynthesis of pectic galactan, including the GALS1 galactan synthase and the UDP-galactose/UDP-rhamnose transporter URGT1. We have engineered plants with a more suitable biomass composition by applying these findings, in conjunction with synthetic biology and gene stacking tools. Plants were engineered to have up to fourfold more pectic galactan in stems by overexpressing GALS1, URGT1, and UGE2, a UDP-glucose epimerase. Furthermore, the increased galactan trait was engineered into plants that were already engineered to have low xylan content by restricting xylan biosynthesis to vessels where this polysaccharide is essential. Finally, the high galactan and low xylan traits were stacked with the low lignin trait obtained by expressing the QsuB gene encoding dehydroshikimate dehydratase in lignifying cells. Conclusion The results show that approaches to increasing C6 sugar content, decreasing xylan, and reducing lignin content can be combined in an additive manner. Thus, the engineered lines obtained by this trait-stacking approach have substantially improved properties from the perspective of biofuel production, and they do not show any obvious negative growth effects. The approach used in this study can be readily transferred to bioenergy crop plants.http://link.springer.com/article/10.1186/s13068-017-1007-6Plant cell wallGalactanArabidopsisPectinjStackXylan |
| spellingShingle | Aude Aznar Camille Chalvin Patrick M. Shih Michael Maimann Berit Ebert Devon S. Birdseye Dominique Loqué Henrik V. Scheller Gene stacking of multiple traits for high yield of fermentable sugars in plant biomass Biotechnology for Biofuels Plant cell wall Galactan Arabidopsis Pectin jStack Xylan |
| title | Gene stacking of multiple traits for high yield of fermentable sugars in plant biomass |
| title_full | Gene stacking of multiple traits for high yield of fermentable sugars in plant biomass |
| title_fullStr | Gene stacking of multiple traits for high yield of fermentable sugars in plant biomass |
| title_full_unstemmed | Gene stacking of multiple traits for high yield of fermentable sugars in plant biomass |
| title_short | Gene stacking of multiple traits for high yield of fermentable sugars in plant biomass |
| title_sort | gene stacking of multiple traits for high yield of fermentable sugars in plant biomass |
| topic | Plant cell wall Galactan Arabidopsis Pectin jStack Xylan |
| url | http://link.springer.com/article/10.1186/s13068-017-1007-6 |
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