Date of Award

Summer 7-1-2022

Degree Type


Degree Name

Master of Science (MS)




Coleman, Heather


biofuel, hyperthermophilic endoglucanase, nutrient limitation, poplar, transgenic

Subject Categories

Biology | Life Sciences | Plant Sciences


The United States is currently reliant on other nations for energy and has been unable tomeet goals set for domestic production of 'green' energy such as second generation biofuel. Overcoming these challenges requires examination of transgenic biofuel feedstock plants, specifically in terms of their responses to two nutrient treatments. Here, we investigated the photosynthetic and growth impacts of expressing a hyperthermophilic endoglucanase in planta in a wildtype (WT) Populus alba × grandidentata background under 100% and 15% strength nutrient treatments. This gene was inserted for improvement of the pretreatment process and to limit inputs required during biofuel production. We characterized biomass allocation and photosynthetic limitations at three timepoints to determine differences in plant growth and development between the transgenic and WT plants. Some genotypic differences were found, particularly in terms of biomass accumulation and water transport, however the majority of changes were due to the level of nutrients received by the plants. The transgenic plants dedicated less biomass to roots and had decreased water use efficiency relative to the WT, but had slightly less xylem vulnerability to cavitation and similar net assimilation values. Our findings suggest the transgenic line can perform similarly to the WT and may be a suitable feedstock genotype to explore further for production of second generation biofuel.


Open Access



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