|XU, GUANGLI - Sichuan Agricultural University|
|SINGH, SHARDENDU - University Of Maryland Eastern Shore (UMES)|
|Sicher Jr, Richard|
Submitted to: Plant Physiology and Biochemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/26/2016
Publication Date: 7/29/2016
Citation: Xu, G., Singh, S., Barnaby, J.Y., Buyer, J.S., Reddy, V., Sicher Jr, R.C. 2016. Effects of growth temperature and carbon dioxide enrichment on soybean seed components at different stages of development. Plant Physiology and Biochemistry. 108: 313-322.
Interpretive Summary: Climate change is predicted to have negative consequences for agriculture by decreasing seed yields of many crop species. However, carbon dioxide levels in the atmosphere are increasing and this may enhance crop yields. The current study examined the capacity of increasing amounts of carbon dioxide in the atmosphere to improve soybean seed development when plants were grown above or below the optimum temperature for yield. Various seed components were measured throughout seed formation using three growth temperatures and two carbon dioxide concentrations. We observed that carbon dioxide enrichment affected levels of various seed components early in development but this did not apply to mature seeds. This finding means that carbon dioxide enrichment can only reverse the effects of stressful growth temperatures during the onset of seed development and cannot influence the quality of mature soybean seeds. These findings should be of interest to soybean breeders and to government policymakers.
Technical Abstract: Soybean plants were grown to maturity in controlled environment chambers and at the onset of flowering three temperature treatments were imposed that provided optimum [28/24°C], low [22/18°C] or high [36/32°C] chamber air temperatures. In addition, plants were treated continuously with either 400 or 800 µmol mol-1 CO2. Seeds were harvested at 42 (R5), 53 (R6), 69 (R7) and 95 days after planting (i.e., final maturity). This study quantified 51 metabolites in developing soybean seeds, plus total lipids and proteins were measured at maturity. About 80% of measured soluble carbohydrates, amino acids and organic acids decreased to low levels in mature seeds, although important exceptions were raffinose, ribose/arabinose, citrate and all eight fatty acids. This suggested that the metabolism of young seeds likely supported subsequent lipid and protein synthesis. A total of 35 and 9 metabolites differed among temperature and CO2 treatments, respectively, and treatment effects were predominately observed on the first and second samplings. However, shikimate, pinitol and oleate were increased by high temperature treatments in mature seeds. The above results indicated that CO2 enrichment primarily altered metabolite levels during the initial stages of seed development and this was likely due to differing amounts of photosynthate formation in leaves.