Metabolic map of mature maize kernels

Metabolites in maize kernels are associated not only with nutritional value but also physiological properties such as maturation, desiccation, and germination. However, comprehensive information concerning the metabolome of maize kernels is limited. In this study, we identified 210 metabolites in mature kernels of 14 representative maize lines using a non-targeted metabolomic profiling approach. Further statistical analysis revealed that 75 metabolites were significantly variable among those tested lines, and certain metabolites out of the detected 210 metabolites played critical roles in distinguishing one line from another. Additionally, metabolite–metabolite correlation analysis dissected key regulatory elements or pathways involved in metabolism of lipids, amino acids and carbohydrates. Furthermore, an integrated metabolic map constructed with transcriptomic, proteomic and metabolic data uncovered characteristic regulatory mechanisms of maize kernel metabolism. Altogether, this work provides new insights into the maize kernel metabolome that would be useful for metabolic engineering and/or molecular breeding to improve maize kernel quality and yield.