A natural variation of TaERF-A1 encoding an AP2/ERF transcription factor confers semidwarf plant architecture and increased lodging resistance in wheat

The introduction of Reduced height (Rht) genes into wheat varieties results in semidwarf plant architecture with largely improved lodging resistance and harvest indices. Therefore, the exploration of new Rht gene resources to breed semidwarf wheat cultivars has been a major strategy for guaranteeing high and stable grain yields of wheat since the 1960s. In this study, we report the map-based cloning of TaERF-A1, which encodes an AP2/ERF transcription factor and acts as a positive regulator of wheat stem elongation, as a new gene for regulating plant height and spike length. The natural variant TaERF-A1 , characterized by a substitution from Phe (derived from Nongda3338) to Ser (derived from Jingdong6) at position 178, significantly weakened the stability of the TaERF-A1 protein. As a result, this substitution led to partly attenuated transcriptional activation of TaERF-A1-targeted downstream genes, including TaPIF4, resulting in the restriction of stem and spike elongation. Importantly, introgression of the semidwarfing-related allele TaERF-A1 in wheat materials significantly enhanced lodging resistance, especially in dense cropping systems. Therefore, our study reveals TaERF-A1 as a new Rht gene resource for breeding semidwarf wheat varieties with increased yield stability.