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Updated: Oct 5, 2026

Transient Gene Expression in Tobacco using Gibson Assembly and the Gene Gun
Published on: April 18, 2014
Expression and chloroplast targeting of cholesterol oxidase in transgenic tobacco plants
D R Corbin1, R J Grebenok, T E Ohnmeiss
1Monsanto Company, Plant Protection Department, 700 Chesterfield Parkway North, St. Louis, Missouri 63198, USA. david.r.corbin@monsanto.com
Abstract:
Cholesterol oxidase represents a novel type of insecticidal protein with potent activity against the cotton boll weevil (Anthonomus grandis grandis Boheman). We transformed tobacco (Nicotiana tabacum) plants with the cholesterol oxidase choM gene and expressed cytosolic and chloroplast-targeted versions of the ChoM protein. Transgenic leaf tissues expressing cholesterol oxidase exerted insecticidal activity against boll weevil larvae. Our results indicate that cholesterol oxidase can metabolize phytosterols in vivo when produced cytosolically or when targeted to chloroplasts. The transgenic plants exhibiting cytosolic expression accumulated low levels of saturated sterols known as stanols, and displayed severe developmental aberrations. In contrast, the transgenic plants expressing chloroplast-targeted cholesterol oxidase maintained a greater accumulation of stanols, and appeared phenotypically and developmentally normal. These results are discussed within the context of plant sterol distribution and metabolism.
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