Plant height is an essential characteristic of agronomic traits, and an ideal plant height is essential for achieving high crop yields.  Foxtail millet (Setaria italica) has become a novel diploid C₄ model crop.  The proteomic profiles of the internode, node, and leaf in two foxtail millet varieties with different heights, Ci846 and Yugu 18, were investigated at the jointing stage in this study.  There were different degrees of enrichment in various processes, such as plant hormone signal transduction, the MAPK signaling pathway, and others.  In particular, the proper content of auxin could activate downstream SiARFs-SiSAURs expression, which enhances the length of internodes.  Haplotype analysis of SiSAUR-like revealed two differential haplotypes of associated plant height, Hap1 and Hap2.  The molecular marker SiSAUR-like-FCM1-2 can effectively separate materials into Hap1 and Hap2.  Two additional genes, designated SiGH3 and SiTCH4, were found to be associated with plant height regulation.  In conclusion, this study not only uncovers the crucial role of auxin regulators in modulating plant height during the jointing stage but also provides molecular markers that will be invaluable for molecular breeding efforts.  The findings of this research help to elucidate the molecular mechanisms of plant height determination that can be used for crop variety innovation and breeding.

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.