Overexpression of ZmNAC118 significantly reduced the auricle region and leaf angle in leaves above the ear in maize. ZmNAC118 affects leaf angle development by regulating the expression of CYP450 family genes. Leaf angle critically influences maize canopy structure and yield. NAC transcription factors regulate various developmental processes, yet their role in maize leaf angle remains poorly understood. In this study, we demonstrate that modulating the expression level of ZmNF-YC13 significantly alters the expression of ZmNAC118 , suggesting that these two genes likely function within a common regulatory pathway. ZmNAC118 shows preferential expression in leaf tissues and encodes a nuclear-localized protein capable of transcriptional activation. Phenotypic analyses demonstrated that overexpression of ZmNAC118 leads to a pronounced reduction in auricle size and leaf angle. Transcriptomic profiling further revealed that ZmNAC118 modulates the expression of CYP450 genes associated with brassinosteroid (BR) and auxin (IAA) metabolic pathways. These CYP450 genes clustered into hormone-related phylogenetic clades, with a subset overlapping targets of ZmNF-YC13, indicating co-regulation within a shared pathway. Our study identifies ZmNAC118 as a key regulator of leaf angle and a promising candidate for maize architectural improvement.
Yang et al. (2026) studied this question.