Photorespiratory Bypass Increases Growth and Seed Yield in Camelina sativa

Camelina sativa, an oilseed crop is potential feedstock for biofuel. However, low yield makes its farming less profitable. Researchers form the North Carolina State University, led by Jyoti Dalal, aimed to increase camelina seed yield by reducing carbon loss from photorespiration.

Genes encoding enzymes of the Escherichia coli glycolate catabolic pathway, glycolate dehydrogenase (GDH), glyoxylate carboxyligase (GCL) and tartronic semialdehyde reductase (TSR), were introduced into camelina. Plants were transformed with either partial bypass (GDH) or full bypass (GDH, GCL and TSR) genes.

Both partial and full bypass transgenics exhibited reduced photorespiration and increased photosynthesis, with no loss in seed quality. The transgenics also showed increased vegetative biomass and faster development. However, the increase in growth of the transgenics was only observed under low CO₂ conditions.

Results suggest that photorespiratory bypass is effective in increasing photosynthetic productivity in camelina.