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ARS Home » Midwest Area » Urbana, Illinois » Global Change and Photosynthesis Research » Research » Publications at this Location » Publication #337990
Title: Increasing sugar transport to improve soybean response to elevated [CO2]

Author
item LEMMONIER, PAULINE - Orise Fellow
item QUEBEDEAUX, JENNIFER - University Of Illinois
item BUSH, DANIEL - Colorado State University
item LEAKEY, ANDREW D B - University Of Illinois
item Ainsworth, Elizabeth - Lisa

Submitted to: American Society of Plant Biologists
Publication Type: Abstract Only
Publication Acceptance Date: 1/31/2017
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Elevated atmospheric [CO2] causes a direct increase in instantaneous photosynthesis and sugar production in C3 plants, leading to a yield increase which is promising to meet future food demand. However, previous studies have shown that soybean yield does not increase as much as predicted under elevated [CO2]. This is possibly the result of feedback inhibition of photosynthetic capacity by accumulated photoassimilates, suggesting insufficient sugar export capacity from the photosynthetic source to sink tissues. Increasing sugar export capacity through over-expressing proton/sucrose symporters involved in phloem loading has the potential to increase photosynthesis and yield under elevated [CO2]. In this study, soybean was transformed to overexpress the sucrose transporter AtSUC1H65K. Transgenic soybeans were grown at ambient (400 ppm) and elevated (600 ppm) [CO2] at the Soybean Free Air Concentration Enrichment facility during 2016. Instantaneous light-saturated photosynthesis and stomatal conductance were measured as well as the response of photosynthesis to intercellular [CO2]. Leaf and pod tissues were collected to confirm the expression of AtSUC1H65K, determine sucrose transport activity, and measure carbohydrate content. The effects of altered sucrose transport and elevated [CO2] on seed yield were measured at the end of the growing season.