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 (Triticum aestivum 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 TaPPDK1-1A.1 but activating TaPEPC3B and TaIDH6B transcriptional expression. Knockdown of TaDOF7.6 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.