背景回顾2：dlf1 (delayed flowering1) encodes a basic leucine zipper protein that interacts with the florigen ZCN8 to mediate floral induction in the shoot apex.

提出问题：However, the mechanism of how dlf1 promotes floral transition remains largely unknown. 

QTL：We demonstrate that dlf1 underlies qLB7‐1, a quantitative trait locus controlling leaf number and flowering time that was identified in a BC2S3 population derived from a cross between maize and its wild ancestor, teosinte (Zea mays ssp. parviglumis ).

组学：Transcriptome sequencing and chromatin immunoprecipitation sequencing demonstrated that DLF1 binds the core promoter of two AP1 /FUL subfamily MADS‐box genes, ZmMADS4 and ZmMADS67 , to activate their expression.

试验：Knocking out ZmMADS4 and ZmMADS67 both increased leaf number and delayed flowering, indicating that they promote the floral transition.

选择与适应：Nucleotide diversity analysis revealed that dlf1 and ZmMADS67 were targeted by selection, suggesting that they may have played important roles in maize flowering time adaptation.

结论：We show that dlf1 promotes maize floral transition by directly activating ZmMADS4 and ZmMADS67 in the shoot apex, providing novel insights into the mechanism of maize floral transition.