Multi-Omics Analyses Offer Novel Insights into the Selection of Sugar and Lipid Metabolism During Maize Domestication and Improvement.

Abstract

Over thousands of years of domestication, maize has undergone significant environmental changes. Understanding the genetic and metabolic trace during maize evolution can better contribute to molecular breeding and nutrition quality improvement. This study examines the metabolic profiles and transcriptomes of maize kernels from teosinte, landrace, and maize accessions at 15 days post-pollination. Differentially accumulated metabolites were enriched in sugar and lipid metabolism pathways. The metabolic selection profile exhibited four distinct patterns: continuous increases, constant decrease, initial decline or stability followed by an increase, and initial growth or stability followed by a subsequent decline. Sugars and JA were positive selection while LPCs/LPEs were negative selection during evolution. The expression level of genes related to sugar accumulation was significantly higher in maize, contrasting with enhanced glycolysis and lipid metabolism activity in teosinte. The correlation network highlighted distinct hormonal regulation of sugar and lipid metabolism. We identified 27 candidate genes associated with sugar, lipid, and JA that have undergone strong selection by population genomic regions. The positive selection of the PLD may explain the negative selection of LPCs/LPEs due to substrate competition. These findings enhance our understanding of the evolutionary trajectory of primary metabolism in maize and provide valuable resources for breeding and improvement.