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Theoretical and Applied Genetics
https://doi.org/10.1007/s00122-018-3119-1
ORIGINAL ARTICLE
Identication of candidate genes underlying genic male‑sterile msc‑1
locus via genome resequencing in Capsicum annuum L.
Qing Cheng
1
· Peng Wang
1
· Jinqiu Liu
1
· Lang Wu
1
· Zongpeng Zhang
1
· Tiantian Li
1
· Wenjiao Gao
1
· Wencai Yang
1
·
Liang Sun
1
· Huolin Shen
1
Received: 27 January 2018 / Accepted: 14 May 2018
© Springer-Verlag GmbH Germany, part of Springer Nature 2018
Abstract
Key message Based on genome resequencing, a strong candidate gene Capana02g002096 was identified in this study.
Capana02g002096 encodes a homolog of AtDYT1 which is a bHLH transcription factor and involves in the early
tapetal development.
Abstract Genic male-sterile line is an efficient tool for commercial hybrid seed production in pepper; however, so far, only
few genes controlling this trait have been cloned. A spontaneous genic male-sterile mutant, msc-1, had been identified and
widely used in China, of which the male-sterile trait was proved to be controlled by a single recessive locus. For cloning the
gene(s) underlying the msc-1 locus, genome resequencing and comparison analyses were performed between male-sterile and
male-fertile lines. According to the genomic variations and genes’ annotations, Capana02g002096 was selected as a candidate
gene underlying the msc-1 locus. Capana02g002096 encodes a homolog of AtDYT1, which is a bHLH transcription factor
and involves in the early tapetal development. Moreover, a 7-bp deletion was identified in the exon of Capana02g002096,
which led to a premature stop codon and may cause a loss-of-function mutation. Further genotyping in the 16C1369AB
population containing 1110 plants, a F
2
population consisting of 510 plants and 46 inbreed lines revealed that the male-sterile
phenotype was co-segregated with the 7-bp deletion. Additionally, real-time PCR analysis revealed that Capana02g002096
was an anther-specific gene and repression of the gene’s expression through VIGS led to male-sterile phenotype. Therefore,
based on the evidence at genetic, genomic, transcriptional and posttranscriptional levels, Capana02g002096 was considered
as a strong candidate gene underlying the msc-1 locus in pepper and was renamed Msc-1.
Introduction
Pepper (Capsicum annuum L.), due to its spicy flavor and
abundant nutrient, is loved by customers and has become one
of the most important horticultural crops grown worldwide
(Swamy et al. 2017; Liu et al. 2013). So far, hybrid F
1
seed,
due to its hybrid vigor, increased uniformity, better environ-
mental adaptability as well as capability of protecting the
intellectual property right, has been widely used in grain and
vegetative crop productions including pepper (Perez-Prat
and van Lookeren Campagne 2002; Kim and Zhang 2018).
However, with the increase in labor cost, especially in the
developing countries, such as China, the costing of hybrid
seed production now is increasing. One of the most intensive
labor costing steps during the hybrid seed production is the
emasculation, during which stamens need to be removed one
by one in each flower by hands. For overcoming this issue,
many efforts have been devoted to develop the male-sterile
lines in agricultural plants.
Based on the inheritance and molecular mechanism, male
sterility can be classified into two types: genic male sterility
(GMS) which is controlled by karyogene; cytoplasmic male
sterility (CMS) which is controlled by coaction of karyogene
and cytogene. Due to the 100% maintenance ability of the
Communicated by Michael J. Havey.
Electronic supplementary material The online version of this
article (https ://doi.org/10.1007/s0012 2-018-3119-1) contains
supplementary material, which is available to authorized users.
* Liang Sun
liang_sun@cau.edu.cn
* Huolin Shen
shl1606@cau.edu.cn
1
Beijing Key Laboratory of Growth and Developmental
Regulation for Protected Vegetable Crops, Department
of Vegetable Science, College of Horticulture, China
Agricultural University, Beijing 100193, China
@Phil_Robichaud
@deepthiw
@JoseServera