Abstract

Hybrids between divergent populations commonly show hybrid sterility; this reproductive barrier hinders hybrid breeding of the japonica and indica rice (Oryza sativa L.) subspecies. Here we show that structural changes and copy number variation at the Sc locus confer japonica–indica hybrid male sterility. The japonica allele, Sc-j, contains a pollen-essential gene encoding a DUF1618-domain protein; the indica allele, Sc-i, contains two or three tandem-duplicated ~ 28-kb segments, each carrying an Sc-j-homolog with a distinct promoter. In Sc-j/Sc-i hybrids, the high-expression of Sc-i in sporophytic cells causes suppression of Sc-j expression in pollen and selective abortion of Sc-j-pollen, leading to transmission ratio distortion. Knocking out one or two of the three Sc-i copies by CRISPR/Cas9 rescues Sc-j expression and male fertility. Our results reveal the gene dosage-dependent allelic suppression as a mechanism of hybrid incompatibility, and provide an effective approach to overcome the reproductive barrier for hybrid breeding.

Details

Title
Genomic structural variation-mediated allelic suppression causes hybrid male sterility in rice
Author
Shen, Rongxin 1 ; Wang, Lan 2 ; Liu, Xupeng 1 ; Wu, Jiang 1 ; Jin, Weiwei 3 ; Zhao, Xiucai 1 ; Xie, Xianrong 1 ; Zhu, Qinlong 1 ; Tang, Huiwu 1 ; Li, Qing 1 ; Chen, Letian 1 ; Yao-Guang Liu 1 

 State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangzhou, China; Key Laboratory of Plant Functional Genomics and Biotechnology of Guangdong Provincial Higher Education Institutions, Guangzhou, China; College of Life Sciences, South China Agricultural University, Guangzhou, China 
 Key Laboratory of Plant Functional Genomics and Biotechnology of Guangdong Provincial Higher Education Institutions, Guangzhou, China; College of Life Sciences, South China Agricultural University, Guangzhou, China 
 National Maize Improvement Center of China, Key Laboratory of Crop Genetic Improvement and Genome of Ministry of Agriculture, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, China 
Pages
1-10
Publication year
2017
Publication date
Nov 2017
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
1960496157
Copyright
© 2017. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.