ALI-1 , candidate gene of B1 locus, is associated with awn length and grain weight in common wheat

Awn plays a vital role in the photosynthesis, grain production and drought tolerance of common wheat; however, works on the systematic identification or cloning of genes controlling wheat awn length (AL) were seldom reported. Here, we conducted the Genome-wide association study (GWAS) in 364 wheat accessions and identified 25 loci involved in the AL, including dominant awn suppressors , and four homologs of awn controlling genes in rice and barley. Furthermore, the locus was mapped to a 125-kb physical interval harboring two genes on chromosome 5AL through map-based cloning. As the candidate gene for locus, a CH zinc finger gene () expressed predominantly in the developing spike of awnless individuals and suppresses downstream genes transcriptionally. reduces cytokinin content and simultaneously restrains cytokinin signal transduction, which leads to a stagnation of cell proliferation and reduction of cell number in awn. Noteworthily, was the first awn controlling locus that observed increasing grain length in wheat, which is a valuable supplemental attribution of awn on grain weight besides photosynthesis. Thus, pleiotropically regulates awn and grain development, and this work provides a strategy to achieve improved grain yield and address future extreme climate.