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Improvement of soybean productivity by enhancing photosynthetic capacity

Khang Hoang, University of Nebraska - Lincoln


Global demand for soybean is on the rise, which is reflected in harvest, which has increased by 25% from 253 million metric tons in 2011 to 315 million metric tons in 2015. ( Soybeans are utilized in many food, feed and industrial applications due to the value of seeds’ two primary co-products, protein and oil. To meet expected future demands for the crop, innovations around both agronomic inputs and genetics will be required. The expression of a cyanobacterial ictB (a putative inorganic carbon transporter B), a gene is involved in bicarbonate assimilation, and SBPase (sedoheptulose-1,7-biphosphatase) an enzyme catalyzes the hydrolysis of sedoheptulose-1,7-bisphosphate in the Calvin cycle, were explored in soybean plants as a means to enhance carbon assimilation in the crop. Expression cassettes carrying soybean codon optimized versions of ictB and the tomato SBPase, under the control of 35S CaMV and Rbcs promoters, respectively, were assembled in plasmids, alone or stacked. The ictB gene was either fused to the pea small subunit of Rubisco transit peptide (TP) to target protein to the plastid, or lacking transit peptide. The assembled expression cassettes were introduced into soybean via Agrobacterium-mediated transformation, and the derived transgenic events were characterized under both controlled and field environments. Photosynthesis data collected in both greenhouse and the field settings revealed transgenic soybeans events with improved photosynthetic rates, at late vegetative stage through early reproductive stage development, relative to wild type, control, plants. In addition, selected transgenic soybean events were evaluated under high CO2 level, under controlled environment. The information gathered from this program provide additional knowledge towards our understanding of the source/sink relationships in planta and insights into genetic strategies to further improve on the quality and quantity of soybean harvest.

Subject Area

Agronomy|Molecular biology|Plant sciences

Recommended Citation

Hoang, Khang, "Improvement of soybean productivity by enhancing photosynthetic capacity" (2016). ETD collection for University of Nebraska-Lincoln. AAI10250158.