Suppression of the Transcription Factor TaDOF7.6 Enhances Photosynthesis and Energy Metabolism to Boost Wheat Yield

Yield improvement is a key breeding objective for wheat (<i>Triticum aestivum</i> L.) to ensure food security. DNA-binding with one finger (DOF) transcription factors regulate primary metabolism and abiotic stress responses; however, their role in yield-related traits in wheat remains unexplored. Here, we characterized a nuclear-localized DOF family transcription factor, TaDOF7.6, which negatively regulates grain dimensions and weights, with the RNAi-knockdown and CRISPR-knockout wheat plants exhibiting enhanced plant growth and superior grain-filling capacity. TaDOF7.6 has transcriptional activation activity and it can bind to the promoters of three key genes involved in photosynthesis and energy metabolism with suppressing <i>TaPPDK1-1A.1</i> but activating <i>TaPEPC3B</i> and <i>TaIDH6B</i> transcriptional expression. Knockdown of <i>TaDOF7.6</i> significantly promoted photosynthesis and energy-related metabolism, affecting the balance between the TCA cycle, glycolysis pathways, and amino acid metabolisms during wheat grain filling. All these results suggest that TaDOF7.6 is a critical regulator in wheat growth regulation and yield production. Suppression of TaDOF7.6 led to a significant reprogramming of matter and energy metabolism pathways, thereby greatly promoting plant growth and grain filling in wheat.