Btr1-A induces grain shattering and affects spike morphology and yield-related traits in wheat

Yue Zhao, Peng Xie, Panfeng Guan, Yongfa Wang, Yinghui Li, Kuohai Yu, Mingming Xin, Zhaorong Hu, Yingyin Yao, Zhongfu Ni, Qixin Sun, Chaojie Xie, Huiru Peng

Research output: Contribution to journalArticlepeer-review


Spike brittleness represents an important domestication trait in crops. Although the brittle rachis of wild wheat was cloned, however, the molecular mechanism underlying spike brittleness is yet to be elucidated. Here, we identified a single dominant brittle rachis gene Br-Ab on chromosome arm 3AbS using an F2 population of diploid wheat and designated Btr1-Ab. Sequence analysis of the Btr1-A gene in 40 diploid wheat accessions, 80 tetraploid wheat accessions and 38 hexaploid wheat accessions showed that two independent mutations (Ala119Thr for diploid and Gly97* for poly-ploids) in the Btr1-A coding region resulting in the nonbrittle rachis allele. Overexpression of Btr1-Ab in nonbrittle hexaploid wheat led to brittle rachis in transgenic plants. RNA-Seq analysis revealed that Btr1-A represses the expression of cell wall biosynthesis genes during wheat rachis development. In addition, we found that Btr1-A can modify spike morphology and reduce threshability, grain size and thousand grain weight in transgenic wheat. These results demonstrated that Btr1-A reduces cell wall synthesis in rachis nodes, resulting in natural spikelet shattering, and that the transition from Btr1-A to btr1-A during wheat domestication had profound effects on evolution of spike morphology and yield-related traits.

Original languageEnglish
Pages (from-to)1342-1353
Number of pages12
JournalPlant and Cell Physiology
Issue number6
StatePublished - 1 Jun 2019
Externally publishedYes

Bibliographical note

Publisher Copyright:
© The Author(s) 2019. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved.


  • Brittle rachis
  • Btr1-A
  • Domestication
  • RNA-Seq
  • Transgenic
  • Wheat.edited-statecorrected-proof

ASJC Scopus subject areas

  • Physiology
  • Plant Science
  • Cell Biology


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