title: Hybrid male sterility in rice controlled by interaction between divergent alleles of two adjacent genes.
abstract: Sterility is common in hybrids between divergent populations, such as the indica and japonica subspecies of Asian cultivated rice (Oryza sativa). Although multiple loci for plant hybrid sterility have been identified, it remains unknown how alleles of the loci interact at the molecular level. Here we show that a locus for indica-japonica hybrid male sterility, Sa, comprises two adjacent genes, SaM and SaF, encoding a small ubiquitin-like modifier E3 ligase-like protein and an F-box protein, respectively. Most indica cultivars contain a haplotype SaM(+)SaF(+), whereas all japonica cultivars have SaM(-)SaF(-) that diverged by nucleotide variations in wild rice. Male semi-sterility in this heterozygous complex locus is caused by abortion of pollen carrying SaM(-). This allele-specific gamete elimination results from a selective interaction of SaF(+) with SaM(-), a truncated protein, but not with SaM(+) because of the presence of an inhibitory domain, although SaM(+) is required for this male sterility. Lack of any one of the three alleles in recombinant plants does not produce male sterility. We propose a two-gene/three-component interaction model for this hybrid male sterility system. The findings have implications for overcoming male sterility in inter-subspecific hybrid rice breeding.
authors.affiliation: Key Laboratory of Plant Functional Genomics and Biotechnology of Guangdong Province, College of Life Sciences, South China Agricultural University, Wushan, Guangzhou 510642, China.
authors.forename: Yunming
authors.initials: Y
authors.lastname: Long
authors.forename: Lifeng
authors.initials: L
authors.lastname: Zhao
authors.forename: Baixiao
authors.initials: B
authors.lastname: Niu
authors.forename: Jing
authors.initials: J
authors.lastname: Su
authors.forename: Hao
authors.initials: H
authors.lastname: Wu
authors.forename: Yuanling
authors.initials: Y
authors.lastname: Chen
authors.forename: Qunyu
authors.initials: Q
authors.lastname: Zhang
authors.forename: Jingxin
authors.initials: J
authors.lastname: Guo
authors.forename: Chuxiong
authors.initials: C
authors.lastname: Zhuang
authors.forename: Mantong
authors.initials: M
authors.lastname: Mei
authors.forename: Jixing
authors.initials: J
authors.lastname: Xia
authors.forename: Lan
authors.initials: L
authors.lastname: Wang
authors.forename: Haibin
authors.initials: H
authors.lastname: Wu
authors.forename: Yao-Guang
authors.initials: YG
authors.lastname: Liu
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D001947:Breeding; D002678:Chimera / Q000235:genetics*; D017343:Genes, Plant; D005838:Genotype; D006239:Haplotypes; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics*; D010641:Phenotype; D051479:Plant Infertility / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011058:Pollen / Q000235:genetics / Q000648:ultrastructure; D016415:Sequence Alignment; D020798:Two-Hybrid System Techniques
chemical_list: D010940:Plant Proteins