Date of Award

Spring 4-1-2020

Semester of Degree


Document Type

Restricted Access Thesis

Degree Name

M.S. in Forest and Natural Resources Management


Forest and Natural Resources Management

Major Professor

John Drake

Steering Committee Member

Dr. William Powell

Steering Committee Member

Dr. Heather Coleman

Steering Committee Member

Dr. Julia Burton

Steering Committee Member

Dr. Neal Abrams


The American chestnut (Castanea dentata) was devastated in the early 20th century by chestnut blight (Cryphonectria parasitica). The American Chestnut Project at ESF has inserted an oxalate oxidase (OxO) gene to confer blight resistance in a restoration project. We hypothesized that transgene expression imposes a metabolic burden on transgenic plants that would give them higher rates of respiration and photosynthesis. We measured the physiology of transgenic, non- transgenic, and conventional hybrid chestnuts in 2018 and 2019. We found evidence of a stimulation of respiration in transgenic plants, but this was only present earlier in the season, and no consistent significant difference in photosynthesis between genotypes (Chapter 2). However, this respiratory stimulation in transgenic plants was not present in a larger sample of plants (Chapter 3). These results suggest that transgene expression modestly impacts chestnut physiology, and is not likely to significantly alter chestnut ecology in a field setting.