The role of metal ions in protein and fatty acids biosynthesis in soybean under micronutrients application to soil

Authors: GOLI, MUDLAGIRI - Mississippi Valley State University; MANJU, PANDE - Mississippi Valley State University; DANIEL, KIBET - Mississippi Valley State University; Bellaloui, Nacer; WRACHIEN, DANIELE - State University Of Milano

Submitted to: Agricultural Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/24/2018
Publication Date: 6/27/2018
Citation: Goli, M.B., Manju, P., Daniel, K., Bellaloui, N., Wrachien, D.D. 2018. The role of metal ions in protein and fatty acids biosynthesis in soybean under micronutrients application to soil. Agricultural Sciences. 9(6):741-749. https://doi.org/10.4236/as.2018.96052.
DOI: https://doi.org/10.4236/as.2018.96052

Interpretive Summary: Deficiencies of micro-nutrients (nutrients that are needed in small amounts by plants but are necessary for plant growth and development) in soil result in poor production and seed quality. Information about the effects of micro-nutrients on seed composition (protein, oil, and oleic and linoleic acids) is limited and what is available is still conflicting. The objective of this study was to investigate the effect of micro-nutrients manganese (Mn), copper (Cu), zinc (Zn), molybdenum (Mo), and boron (B) with and without citric acid (CA, thought to be an enhancer for micronutrient absorption) on seed composition. The compounds were applied to three-week-old ‘Bolivar’ soybean plants at vegetative and at beginning of seed-pod initiation stages. The plants were allowed to grow until maturity under greenhouse conditions. Results showed that Mn, Cu, and B treatments increased seed protein; however, Zn, Mo, Cu + CA, and B + CA treatments decreased the protein. Oil was increased by Zn, Mo, CA, Cu + CA, Zn + CA, Mo + CA, and B + CA treatments, but decreased with Mn and Cu treatments. One type of fatty acid, oleic acid, increased with Cu and B treatments, but decreased with Mn, Mo, CA, and Mn + CA, Cu + CA, Zn + CA, Mo + CA, and B + CA treatments. This research demonstrated that some micro-nutrients can increase protein and oleic acid, and others can increase oil, showing possible alteration of seed composition constituents by micronutrients. This information benefits growers for targeting specific desirable seed constituents (protein or oil).

Technical Abstract: The present study is part of our ongoing investigation to study the role of trace elements on soybean seed composition (protein, oil, and fatty acids). This study was conducted to study the effects of five trace elements (Mn, Cu, Zn, Mo, B). The treatments of Mn, Cu, Zn, Mo, and B were chlorides, except Mo as oxide, and B as boric acid. The treatments were Mn, Cu, Zn, Mo, and B alone and in combination with the chelating agent citric acid (CA), for example Mn + CA, Cu + CA, and Zn + CA. Soybean cultivar (Bolivar with maturity group V) was grown in a repeated greenhouse experiment in a randomized complete block design. The compounds were applied to three-week-old soy-bean plants at V3 (vegetative) and at R3 (beginning of seed-pod initiation) stages. The plants were allowed to grow until maturity under greenhouse conditions. The harvested seeds were analyzed for mineral, protein, and fatty acid contents. Results showed that Mn, Cu, and B treatments increased seed protein, while Zn, Mo, Cu + CA, and B + CA decreased the protein. Treatments of Zn, Mo, CA, Cu + CA, Zn + CA, Mo + CA, and B + CA increased the oil. Treatments of Mn and Cu decreased the oil. The Cu and B treatments in-creased oleic acid by 8.0% and 7.4%, respectively for Cu and B. Treatments of Mn, Mo, CA, and Mn + CA, Cu + CA, Zn + CA, Mo + CA, and B + CA de-creased oleic acid by 0.6% to 14.4%. Treatments of Cu, Zn, Mo, B, CA, Mn and their combination with CA increased linoleic acid by 1.3% to 6.5%. Our goal was to identify the trace elements that would make desirable alteration in the seed composition qualities.