Maize metabolomics in relation to cropping system and growing year impacts

Authors: Mattoo, Autar; Cavigelli, Michel; MISIC, DANIJELA - University Of Belgrade; GASIC, UROS - University Of Belgrade; MAKSIMOVIC, VUK - University Of Belgrade; KRAMER, MATTHEW - National Agricultural Statistical Service (NASS, USDA); KAUR, BHAVNEET - Former ARS Employee; MATEKALO, DRAGANA - University Of Belgrade; NESTOROVIC ZIVKOVIC, JASMINA - University Of Belgrade; Roberts, Daniel

Submitted to: Frontiers in Sustainable Food Systems
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/27/2023
Publication Date: 4/17/2023
Citation: Mattoo, A.K., Cavigelli, M.A., Misic, D., Gasic, U., Maksimovic, V., Kramer, M., Kaur, B., Matekalo, D., Nestorovic Zivkovic, J., Roberts, D.P. 2023. Maize metabolomics in relation to cropping system and growing year impacts. Frontiers in Sustainable Food Systems. https://doi.org/10.3389/fsufs.2023.113008910.3389/fsufs.2023.1130089.
DOI: https://doi.org/10.3389/fsufs.2023.113008910.3389/fsufs.2023.1130089

Interpretive Summary: Maize is important to global food security, being one of the predominant cereals in human and domesticated livestock diets worldwide. Due to the increasing human population, it will be important to not only design cropping systems to increase maize yield and sustainability but also to improve the nutritional quality of maize edible tissues. To determine cropping system impacts on maize grain nutritional content, metabolic fingerprinting of grain from conventional and organic maize varieties grown using five cropping systems was performed. Cropping systems were all at the same location within the Beltsville Agricultural Research Center in Beltsville, Maryland and were a three-year conventional no-till rotation, a three-year conventional chisel-till rotation, a two-year organic rotation, a three-year organic rotation, and a six-year organic rotation. Statistical analysis of maize grain nutrients determined that cropping system can significantly influence levels of certain metabolites. However, natural impacts were greater than cropping system impacts likely masking or over-riding some cropping system impacts on maize grain. Additionally, maize cultivar genetics had greater impact than cropping system on the maize grain metabolome and the greatest “managed” impact on the metabolite profiles. Results indicate that until natural environmental impacts on maize grain metabolite levels are understood and managed, the best approach to reliably increase maize grain nutritional quality is through development of maize cultivars with enhanced nutritional content that are robust to natural environmental influence. This information will be useful to scientist working to improve nutritional quality of plant foodstuffs.

Technical Abstract: Maize is important to global food security, being one of the predominant cereals in human and domesticated livestock diets worldwide. Due to the increasing human population, it will be important to not only design cropping systems to increase maize yield and sustainability but also to improve the nutritional quality of maize edible tissues. To determine cropping system impacts on maize grain nutritional content, metabolic fingerprinting of methanol extracts of grain from conventional and organic maize varieties grown for three growing seasons using five cropping systems was performed using ultra-high performance liquid chromatography (UHPLC) coupled with mass spectrometry (MS), adopting both non-targeted and targeted approaches. The cropping systems were all at the same location within the Beltsville Agricultural Research Center in Beltsville, Maryland and were a three-year conventional no-till rotation (NT), a three-year conventional chisel-till rotation (CT), a two-year organic rotation (Org2), a three-year organic rotation (Org3), and a six-year organic rotation (Org6). Each cropping system was employed at the same field site for at least a decade allowing specific cropping-system-induced alterations of soil edaphic and microbial properties. Nontargeted metabolic fingerprinting detected a total of 90 compounds, the majority of which were phenolics. An additional 7 carbohydrates and 7 organic acids in the maize grain were quantified. Statistical analysis of a subset of quantitative data for select phenolics, carbohydrates, and organic acids determined that cropping system can significantly influence levels of certain maize grain metabolites. However, natural impacts (growing year) were greater than cropping system impacts likely masking or over-riding some cropping system impacts on maize grain. Additionally, maize cultivar genetics had greater impact than cropping system on the maize grain metabolome and the greatest “managed” impact on the metabolite profiles. Results indicate that until natural environmental impacts on maize grain metabolite levels are understood and managed, the best approach to reliably increase maize grain nutritional quality is through development of maize cultivars with enhanced nutritional content that are robust to natural environmental influence.