An Overexpressed Q Allele Leads to Increased Spike Density and Improved Processing Quality in Common Wheat (Triticum aestivum)

G3: Genes, Genomes, Genetics

article

Bin-Jie Xu¹  Qing Chen¹  Ting Zheng¹  Yun-Feng Jiang¹  Yuan-Yuan Qiao¹  Zhen-Ru Guo¹  Yong-Li Cao¹  Yan Wang¹  Ya-Zhou Zhang¹  Lu-Juan Zong¹  Jing Zhu¹  Cai-Hong Liu¹  Qian-Tao Jiang¹  Xiu-Jin Lan¹  Jian Ma¹  Ji-Rui Wang¹  You-Liang Zheng¹  Yu-Ming Wei¹  Peng-Fei Qi¹ 

[1] Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan 611130, China

关键词: bread-making quality;    compact spike;    point mutation;    protein content;    wheat breeding;    mutant screen report;   

DOI  :  10.1534/g3.117.300562

学科分类：社会科学、人文和艺术（综合）

来源: Genetics Society of America

【 摘 要 】

Spike density and processing quality are important traits in modern wheat production and are controlled by multiple gene loci. The associated genes have been intensively studied and new discoveries have been constantly reported during the past few decades. However, no gene playing a significant role in the development of these two traits has been identified. In the current study, a common wheat mutant with extremely compact spikes and good processing quality was isolated and characterized. A new allele ( Q^c1 ) of the Q gene (an important domestication gene) responsible for the mutant phenotype was cloned, and the molecular mechanism for the mutant phenotype was studied. Results revealed that Q^c1 originated from a point mutation that interferes with the miRNA172-directed cleavage of Q transcripts, leading to its overexpression. It also reduces the longitudinal cell size of rachises, resulting in an increased spike density. Furthermore, Q^c1 increases the number of vascular bundles, which suggests a higher efficiency in the transportation of assimilates in the spikes of the mutant than that of wild type. This accounts for the improved processing quality. The effects of Q^c1 on spike density and wheat processing quality were confirmed by analyzing nine common wheat mutants possessing four different Q^c alleles. These results deepen our understanding of the key roles of Q gene, and provide new insights for the potential application of Q^c alleles in wheat quality breeding.

【 授权许可】

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