RT Journal Article SR Electronic T1 An overexpressed Q allele leads to increased spike density and improved processing quality JF bioRxiv FD Cold Spring Harbor Laboratory SP 098558 DO 10.1101/098558 A1 Bin-Jie Xu A1 Qing Chen A1 Ting Zheng A1 Yun-Feng Jiang A1 Yuan-Yuan Qiao A1 Zhen-Ru Guo A1 Yong-Li Cao A1 Yan Wang A1 Ya-Zhou Zhang A1 Lu-Juan Zong A1 Jing Zhu A1 Cai-Hong Liu A1 Qian-Tao Jiang A1 Xiu-Jin Lan A1 Jian Ma A1 Ji-Rui Wang A1 You-Liang Zheng A1 Yu-Ming Wei A1 Peng-Fei Qi YR 2017 UL http://biorxiv.org/content/early/2017/01/05/098558.abstract AB Spike density and processing quality are important traits during the evolution of wheat, which is controlled by multiple gene loci. The associated gene loci have been heavily studied with slow progress. A common wheat mutant with extremely compact spikes and good processing quality was isolated. The gene (Qc1) responsible for the mutant phenotype was mapped and cloned, and the cellular mechanism for the mutant phenotype was investigated. Qc1 originated from a point mutation that interferes with the miR172-directed cleavage of the Q gene, leading to its overexpression. Qc1 reduces the longitudinal cell size of rachises, resulting in an increased spike density. Qc1 increases the number of vascular bundles, which suggests a higher efficiency in the transportation of assimilates in the spikes of the mutant than in the WT. This could account for the improved processing quality. The effects of Qc1 on spike density and wheat processing quality were confirmed by the identification of nine common wheat mutants having four different Qc alleles. These results deepen our understanding of the key role of Q gene, one of the most important domestication gene for wheat, and provide new insights for the potential application of Qc allele in wheat breeding.