2026-01-01 PLANT PHYSIOLOGY AND BIOCHEMISTRY 2026 230(卷), null(期), (null页)
Setaria italica (foxtail millet), a globally important C4 model crop and climate-resilient cereal, sustains millions of people in arid/semi-arid regions. Enhancing its agronomic performance requires balancing biomass accumulation with the synthesis of storage compounds in leaves-processes which compete through interconnected chloroplast metabolic pathways governing photosynthesis and lipid biosynthesis. The RETICULATA-RELATED (RER) gene family, previously linked to chloroplast function regulation in Arabidopsis, is a critical leaf development regulator. Genome-wide analysis was used to identify nine non-redundant RER orthologs in S. italica, phylogenetically grouped into four evolutionarily distinct subclades. Tissue-specific profiling revealed leafpredominant expression of Seita.3G258000, and transgenic validation demonstrated that Seita.3G258000 overexpression in Arabidopsis accelerated flowering (24.3 % increase in leaf number) and activated vein patterning networks (2.1-3.3-fold upregulation of ERF1-2, PAP2.1, and NRT1.7). This comprehensive characterization of RER functions in a C4 crop system provides mechanistic insights into the coordination of chloroplast metabolic networks for crop improvement.