Madhavi Latha Gandla1, Niklas Mähler2, Sacha Escamez2,3, Tomas Skotare1,4, Ogonna Obudulu3,5, Linus Möller6, Ilka N Abreu3, Joakim Bygdell1, Magnus Hertzberg6, Torgeir R Hvidsten2,7, Thomas Moritz3, Gunnar Wingsle3, Johan Trygg1,4, Hannele Tuominen8,9, Leif J Jönsson1. 1. Department of Chemistry, Umeå University, 901 87, Umeå, Sweden. 2. Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, 901 87, Umeå, Sweden. 3. Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 901 83, Umeå, Sweden. 4. Computational Life Science Cluster (CLiC), Department of Chemistry, Umeå University, Umeå, Sweden. 5. Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, 40530, Gothenburg, Sweden. 6. SweTree Technologies, PO Box 7981, 907 19, Umeå, Sweden. 7. Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, 1432, Ås, Norway. 8. Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, 901 87, Umeå, Sweden. hannele.tuominen@slu.se. 9. Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 901 83, Umeå, Sweden. hannele.tuominen@slu.se.
Abstract
BACKGROUND: Bioconversion of wood into bioproducts and biofuels is hindered by the recalcitrance of woody raw material to bioprocesses such as enzymatic saccharification. Targeted modification of the chemical composition of the feedstock can improve saccharification but this gain is often abrogated by concomitant reduction in tree growth. RESULTS: In this study, we report on transgenic hybrid aspen (Populus tremula × tremuloides) lines that showed potential to increase biomass production both in the greenhouse and after 5 years of growth in the field. The transgenic lines carried an overexpression construct for Populus tremula × tremuloides vesicle-associated membrane protein (VAMP)-associated protein PttVAP27-17 that was selected from a gene-mining program for novel regulators of wood formation. Analytical-scale enzymatic saccharification without any pretreatment revealed for all greenhouse-grown transgenic lines, compared to the wild type, a 20-44% increase in the glucose yield per dry weight after enzymatic saccharification, even though it was statistically significant only for one line. The glucose yield after enzymatic saccharification with a prior hydrothermal pretreatment step with sulfuric acid was not increased in the greenhouse-grown transgenic trees on a dry-weight basis, but increased by 26-50% when calculated on a whole biomass basis in comparison to the wild-type control. Tendencies to increased glucose yields by up to 24% were present on a whole tree biomass basis after acidic pretreatment and enzymatic saccharification also in the transgenic trees grown for 5 years on the field when compared to the wild-type control. CONCLUSIONS: The results demonstrate the usefulness of gene-mining programs to identify novel genes with the potential to improve biofuel production in tree biotechnology programs. Furthermore, multi-omic analyses, including transcriptomic, proteomic and metabolomic analyses, performed here provide a toolbox for future studies on the function of VAP27 proteins in plants.
BACKGROUND: Bioconversion of wood into bioproducts and biofuels is hindered by the recalcitrance of woody raw material to bioprocesses such as enzymatic saccharification. Targeted modification of the chemical composition of the feedstock can improve saccharification but this gain is often abrogated by concomitant reduction in tree growth. RESULTS: In this study, we report on transgenic hybrid aspen (Populus tremula × tremuloides) lines that showed potential to increase biomass production both in the greenhouse and after 5 years of growth in the field. The transgenic lines carried an overexpression construct for Populus tremula × tremuloides vesicle-associated membrane protein (VAMP)-associated protein PttVAP27-17 that was selected from a gene-mining program for novel regulators of wood formation. Analytical-scale enzymatic saccharification without any pretreatment revealed for all greenhouse-grown transgenic lines, compared to the wild type, a 20-44% increase in the glucose yield per dry weight after enzymatic saccharification, even though it was statistically significant only for one line. The glucose yield after enzymatic saccharification with a prior hydrothermal pretreatment step with sulfuric acid was not increased in the greenhouse-grown transgenic trees on a dry-weight basis, but increased by 26-50% when calculated on a whole biomass basis in comparison to the wild-type control. Tendencies to increased glucose yields by up to 24% were present on a whole tree biomass basis after acidic pretreatment and enzymatic saccharification also in the transgenic trees grown for 5 years on the field when compared to the wild-type control. CONCLUSIONS: The results demonstrate the usefulness of gene-mining programs to identify novel genes with the potential to improve biofuel production in tree biotechnology programs. Furthermore, multi-omic analyses, including transcriptomic, proteomic and metabolomic analyses, performed here provide a toolbox for future studies on the function of VAP27 proteins in plants.
Authors: G A Tuskan; S Difazio; S Jansson; J Bohlmann; I Grigoriev; U Hellsten; N Putnam; S Ralph; S Rombauts; A Salamov; J Schein; L Sterck; A Aerts; R R Bhalerao; R P Bhalerao; D Blaudez; W Boerjan; A Brun; A Brunner; V Busov; M Campbell; J Carlson; M Chalot; J Chapman; G-L Chen; D Cooper; P M Coutinho; J Couturier; S Covert; Q Cronk; R Cunningham; J Davis; S Degroeve; A Déjardin; C Depamphilis; J Detter; B Dirks; I Dubchak; S Duplessis; J Ehlting; B Ellis; K Gendler; D Goodstein; M Gribskov; J Grimwood; A Groover; L Gunter; B Hamberger; B Heinze; Y Helariutta; B Henrissat; D Holligan; R Holt; W Huang; N Islam-Faridi; S Jones; M Jones-Rhoades; R Jorgensen; C Joshi; J Kangasjärvi; J Karlsson; C Kelleher; R Kirkpatrick; M Kirst; A Kohler; U Kalluri; F Larimer; J Leebens-Mack; J-C Leplé; P Locascio; Y Lou; S Lucas; F Martin; B Montanini; C Napoli; D R Nelson; C Nelson; K Nieminen; O Nilsson; V Pereda; G Peter; R Philippe; G Pilate; A Poliakov; J Razumovskaya; P Richardson; C Rinaldi; K Ritland; P Rouzé; D Ryaboy; J Schmutz; J Schrader; B Segerman; H Shin; A Siddiqui; F Sterky; A Terry; C-J Tsai; E Uberbacher; P Unneberg; J Vahala; K Wall; S Wessler; G Yang; T Yin; C Douglas; M Marra; G Sandberg; Y Van de Peer; D Rokhsar Journal: Science Date: 2006-09-15 Impact factor: 47.728
Authors: C G Wilkerson; S D Mansfield; F Lu; S Withers; J-Y Park; S D Karlen; E Gonzales-Vigil; D Padmakshan; F Unda; J Rencoret; J Ralph Journal: Science Date: 2014-04-04 Impact factor: 47.728
Authors: Ajaya K Biswal; Melani A Atmodjo; Mi Li; Holly L Baxter; Chang Geun Yoo; Yunqiao Pu; Yi-Ching Lee; Mitra Mazarei; Ian M Black; Ji-Yi Zhang; Hema Ramanna; Adam L Bray; Zachary R King; Peter R LaFayette; Sivakumar Pattathil; Bryon S Donohoe; Sushree S Mohanty; David Ryno; Kelsey Yee; Olivia A Thompson; Miguel Rodriguez; Alexandru Dumitrache; Jace Natzke; Kim Winkeler; Cassandra Collins; Xiaohan Yang; Li Tan; Robert W Sykes; Erica L Gjersing; Angela Ziebell; Geoffrey B Turner; Stephen R Decker; Michael G Hahn; Brian H Davison; Michael K Udvardi; Jonathan R Mielenz; Mark F Davis; Richard S Nelson; Wayne A Parrott; Arthur J Ragauskas; C Neal Stewart; Debra Mohnen Journal: Nat Biotechnol Date: 2018-02-12 Impact factor: 54.908
Authors: Yao-Cheng Lin; Jing Wang; Nicolas Delhomme; Bastian Schiffthaler; Görel Sundström; Andrea Zuccolo; Björn Nystedt; Torgeir R Hvidsten; Amanda de la Torre; Rosa M Cossu; Marc P Hoeppner; Henrik Lantz; Douglas G Scofield; Neda Zamani; Anna Johansson; Chanaka Mannapperuma; Kathryn M Robinson; Niklas Mähler; Ilia J Leitch; Jaume Pellicer; Eung-Jun Park; Marc Van Montagu; Yves Van de Peer; Manfred Grabherr; Stefan Jansson; Pär K Ingvarsson; Nathaniel R Street Journal: Proc Natl Acad Sci U S A Date: 2018-10-29 Impact factor: 11.205