A novel regulator of wheat tillering identified by using an upgraded BSA method, uni-BSA.

Unlabelled: Branching/tillering is a critical process for plant architecture and grain yield. However, Branching is intricately controlled by both endogenous and environmental factors. The underlying mechanisms of tillering in wheat remain poorly understood. In this study, we identified () as a novel regulator of wheat tillering using an enhanced bulked segregant analysis (BSA) method, uni-BSA. This method effectively reduces alignment noise caused by the high repetitive sequence content in the wheat genome. Loss-of-function of results in fewer tillers due to defects in axillary meristem initiation and bud outgrowth. We mapped to a 6 Mb region on the chromosome 2D short arm and validated a nucleotide-binding (NB) domain encoding gene as using CRISPR/Cas9. Furthermore, the lower sucrose concentration in the shoot bases of might result in inadequate bud outgrowth due to disturbances in the sucrose biosynthesis pathways. Co-expression analysis suggests that controls tillering by regulating , the ortholog of the tiller regulator () or the rice axillary meristem regulator (). This study not only offers a novel genetic resource for cultivating optimal plant architecture but also underscores the importance of our innovative BSA method. This uni-BSA method enables the swift and precise identification of pivotal genes associated with significant agronomic traits, thereby hastening gene cloning and crop breeding processes in wheat.

Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-024-01484-7.