Growth under field conditions affects lignin content and productivity in transgenic Populus trichocarpa with altered lignin biosynthesis

• Published in: Biomass & bioenergy 2014-09, Vol.68 (C), p.228-239
• Main Authors: Stout, Anna T., Davis, Aletta A., Domec, Jean-Christophe, Yang, Chenmin, Shi, Rui, King, John S.
• Format: Article
• Language: English
• Subjects: aboveground biomass; Agricultural sciences; Bioenergy; Biological and medical sciences; biosynthesis; Biotechnology; coastal plains; coppicing; correlation; Energy; environmental factors; enzymatic hydrolysis; ethanol production; Field trial; Forestry; Fundamental and applied biological sciences. Psychology; Generalities. Production, biomass. Quality of wood and forest products. General forest ecology; Genetic engineering; Genetic technics; genetically modified organisms; Industrial applications and implications. Economical aspects; Life Sciences; Lignin; mass spectrometry; Methods. Procedures. Technologies; Miscellaneous; North Carolina; phenotype; piedmont; planting; Populus; Populus trichocarpa; Production. Biomass; tissue culture; Transgenic; Transgenic animals and transgenic plants; Transgenic plants; trees; Vegetal Biology
• ISSN: 0961-9534; 1873-2909
• DOI: 10.1016/j.biombioe.2014.06.008

This study evaluated the potential of transgenic Populus trichocarpa with antisense 4CL for reduced total lignin and sense Cald5H for increased S/G ratio in a short rotation woody cropping (SRWC) system for bioethanol production in the Southeast USA. Trees produced from tissue-culture were planted in the Coastal Plain, Piedmont, and Mountain regions of North Carolina, USA. Trees were observed for growth differences and biomass recorded for two coppices. Insoluble lignin and S/G ratio were determined by molecular beam mass spectroscopy after the second coppice. Survival, growth form, and biomass were very consistent within construct lines. Higher total lignin content and S/G ratio were positively correlated with total aboveground biomass. The low-lignin phenotype was not completely maintained in the field, with total lignin content increasing on average more than 30.0% at all sites by the second coppice The capacity to upregulate lignin in the event of environmental stress may have helped some low-lignin lines to survive. More research focused on promising construct lines in appropriate environmental conditions is needed to clarify if a significant reduction in lignin can be achieved on a plantation scale, and whether that reduction will translate into increased efficiency of enzymatic hydrolysis. •We evaluate growth of transgenic Populus in a short rotation system in Southeast USA.•Populus was transformed for reduced total lignin and increased S/G ratio.•Higher total lignin and S/G ratio were positively correlated with biomass.•Total lignin increased on average more than 30.0% at all sites by the second coppice.•Transgenics showed the capacity to upregulate lignin during environmental stress.