Two separate pathways including SlCLV1, SlSTM and SlCUC that control carpel development in a bisexual mutant of Silene latifolia.
Carpel suppression is a trigger for sexual dimorphism in the dioecious plant Silene latifolia. To clarify what kind of genes are involved in carpel suppression in this species, we generated a bisexual mutant, R025, by C-ion beam irradiation. R025 produces bisexual flowers with a mature gynoecium and mature stamens. Genetic analysis of R025 attributed the bisexual trait to mutations on the Y chromosome. Scanning electron microscopy (SEM) analysis of early floral development revealed that the carpel size of R025 was different from that of wild-type males in spite of the male background in R025. We also identified an S. latifolia CLAVATA1-like gene (SlCLV1) as a candidate of the CLAVATA-WUSCHEL (CLV-WUS) pathway. Two separate pathways, the CLV-WUS pathway and the CUP-SHAPED COTYLEDON (CUC)-SHOOT MERISTEMLESS (STM) pathway, contribute to carpel development in the Arabidopsis floral meristem. SlSTM1 and SlSTM2 (orthologs of STM) and SlCUC (an ortholog of CUC1 and CUC2) have already been identified in S. latifolia. We therefore examined the expression patterns of SlCLV1, SlSTM (SlSTM1 and SlSTM2) and SlCUC in young flowers of R025 and wild-type males and females. The expression patterns of the three genes in the two pathways differ between the wild-type male and the bisexual mutant, and the differences in expression patterns of the three genes occur at the same stage. These results suggest that in addition to SlSTM1, SlSTM2 and SlCUC, SlCLV1 is also involved in carpel suppression in S. latifolia. They also suggest that a gynoecium-suppressing factor (GSF), which is lost in the R025 Y chromosome, acts on an upstream gene that is common to the two pathways, triggering sexual dimorphism in S. latifolia.
Koizumi
Ayako
A
Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, FSB-601, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8562 Japan.
Yamanaka
Kahori
K
Nishihara
Kiyoshi
K
Kazama
Yusuke
Y
Abe
Tomoko
T
Kawano
Shigeyuki
S
D000595:Amino Acid Sequence; D029681:Arabidopsis Proteins / Q000378:metabolism; D003001:Cloning, Molecular; D035264:Flowers / Q000254:growth & development*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018398:Homeodomain Proteins / Q000378:metabolism; D018519:Meristem / Q000235:genetics / Q000254:growth & development; D008969:Molecular Sequence Data; D009154:Mutation; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D018749:RNA, Plant / Q000235:genetics; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism; D016415:Sequence Alignment; D029751:Silene / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism
D029681:Arabidopsis Proteins; D018398:Homeodomain Proteins; D010940:Plant Proteins; D018749:RNA, Plant; C097496:STM protein, Arabidopsis; D020794:Receptor Protein-Tyrosine Kinases; C118166:CLV1 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases