Cloning and Functional Analysis of , the Key Genes for Grain Fatty Acid Synthesis in Bread Wheat

WRINKLED1 (WRI1), an (AP2) transcription factor (TF), critically regulates the processes related to fatty acid synthesis, storage oil accumulation, and seed development in plants. However, the genes remain unknown in allohexaploid bread wheat ( L.). In this study, based on the sequence of Arabidopsis , two genes of bread wheat, and , were cloned. was closely related to monocotyledons and clustered in one subgroup with , while was clustered in another subgroup with and . Both were expressed highly in the developmental grain, subcellular localized in the nucleus, and showed transcriptional activation activity. , rather than , promoted oil body accumulation and significantly increased triglyceride (TAG) content in tobacco leaves. Overexpression of compensated for the functional loss of in an Arabidopsis mutant and restored the wild-type phenotypes of seed shape, generation, and fatty acid synthesis and accumulation. Knockout of reduced grain size, 1000 grain weight, and grain fatty acid synthesis in bread wheat. Conclusively, , rather than , was the key transcriptional factor in the regulation of grain fatty acid synthesis in bread wheat. This study lays a foundation for gene regulation and genetic manipulation of fatty acid synthesis in wheat genetic breeding programs.