|SINGH, SHARDENDU - University Of Maryland Eastern Shore (UMES)|
|Sicher Jr, Richard|
Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/12/2016
Publication Date: 12/27/2016
Citation: Singh, S.K., Barnaby, J.Y., Reddy, V., Sicher Jr, R.C. 2016. Varying response of the concentration and content of soybean seed mineral elements, carbohydrates, organic acids, amino acids, protein, and oil to phosphorus starvation and CO2 enrichment. Frontiers in Plant Science. 7(1967):1-13. doi: 10.3389/fpls.2016-01967.
Interpretive Summary: A detailed investigation of the concentration (mg per gram dry seed) and content (total production per plant) of seed components such as, mineral elements, carbohydrates, organic acids, amino acids, protein, and oil in response to the combined impacts of phosphorus (P) deficiency and elevated atmospheric carbon dioxide (CO2) in soybean is limited. P deficiency and elevated CO2 often have opposite effects on plant growth and their interaction might alter the seed quality. To evaluate this, soybean was grown in a controlled environment at either sufficient or deficient levels of P under ambient and elevated CO2. Results showed that P deficiency primarily reduced concentrations of the oil and mineral elements, but enhanced a majority of other components. However, the content of seed components consistently declined under P starvation except for several amino acids. The elevated CO2 decreased the concentration but increased the total content of the majority of seed components in soybean plants, those grown near sufficient P nutrition. Results on the nutritional attributes of the phosphorus deficiency on soybean seeds will be useful to farmers and researchers to understand its nutritional impact and might offer a prospect for quality improvement.
Technical Abstract: A detailed investigation of the concentration (g-1 seed weight) and content (g plant-1) of seed mineral elements and metabolic profile under phosphorus (P) starvation at ambient (aCO2) and elevated carbon dioxide (eCO2) in soybean is limited. Soybean plants were grown in a controlled environment at either sufficient (0.50 mM P, control) or deficient (0.10 and 0.01 mM, P-stress) levels of P under aCO2 and eCO2 (400 and 800 µmol mol-1, respectively). Both the concentration and content of 36 out of 38 seed components responded to P treatment and on average 25 and 11 seed components increased and decreased, respectively, in response to P starvation. Concentrations of carbohydrates (e.g. glucose, sugar alcohols), organic acids (e.g. succinate, glycerate) and amino acids increased while oil and various mineral elements declined under P deficiency. However, the content of majority of seed components declined except several amino acids (e.g. phenylalanine, serine) under P deficiency. The concentration-based relationship between seed protein and oil was negative (r2 = 0.96), whereas content-based relationship was positive (r2 = 0.99) across treatments. The CO2 treatment also altered the concentration of 28 out of 38 seed components, of which 23 showed decreasing (e.g. sucrose, glucose, citrate, aconitate, several minerals and amino acids) while C, iron, Mn, glycerate, and oil showed increasing trends at eCO2. Despite a decreased concentration, the content of a majority of seed components were increased in response to eCO2, which was attributable to the increased seed yield. Thus, P deficiency primarily reduced the concentration of oil and mineral elements, but enhanced a majority of other components. However, the content of seed components consistently declined under P starvation except several amino acids. The eCO2 decreased the concentration but increased the content of the majority of seed components in soybean plants grown near sufficient P nutrition.