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Department of Horticulture and Crop Science


​HCS Colloquium - Kyle Benzle

Nov 13, 2015, 11:30am - 12:45pm

​HCS Colloquium Announcement for November 13, 2015
11:30 AM in 121 Fisher (Wooster) video-linked to 244 Kottman (Columbus)

Presenter: Kyle Benzle

Advisor: Katrina Cornish

SAC members: Clay Sneller, John Cardina (HCS), Ana Alonso & Robert Tabita (Mol. Gen.)

Proposal Type: PhD Proposal

Title of Presentation: Enhanced photosynthesis in plants through expression of a deinhibited Rubisco


The efficiency at which a plant assimilates carbon from atmospheric CO2 is a key rate-limiting step in crop productivity. In all photosynthetic organisms, the rate of CO2 uptake is reduced as O2 builds up in active tissues and inhibits the enzyme responsible for carbon capture, Rubisco (Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase). We aim to reduce O2 inhibition of carbon capture inTaraxacum kok-saghyz (TK) by testing the hypothesis that flux through the common rate-liming step of CO2 assimilation by photosynthetic organisms may generally be increased by expressing certain mutated native versions of the gene coding for the large subunit of Rubisco, rbcL. These amino acid changes were found to decrease oxygenase activity in the Rubisco of the photosynthetically active microorganism, Rhodobacter sp. TK holds commercial interest as it produces a high quality (high molecular weight) rubber in its roots, reproduces quickly via root regeneration and offers an environmentally friendly alternative to petroleum derived synthetic rubber. A TK line expressing a deinhibited Rubisco and an herbicide resistance gene is likely to not only increase understanding of how these modifications function but lead to a viable commercial crop. Additional assimilate may lead to large plants and/or a higher rubber content as rubber is a sink for excess assimilate.