Control of petal shape and floral zygomorphy in Lotus japonicus.
Zygomorphic flowers, with bilateral (dorsoventral) symmetry, are considered to have evolved several times independently in flowering plants. In Antirrhinum majus, floral dorsoventral symmetry depends on the activity of two TCP-box genes, CYCLOIDEA (CYC) and DICHOTOMA (DICH). To examine whether the same molecular mechanism of floral asymmetry operates in the distantly related Rosid clade of eudicots, in which asymmetric flowers are thought to have evolved independently, we investigated the function of a CYC homologue LjCYC2 in a papilionoid legume, Lotus japonicus. We showed a role for LjCYC2 in establishing dorsal identity by altering its expression in transgenic plants and analyzing its mutant allele squared standard 1 (squ1). Furthermore, we identified a lateralizing factor, Keeled wings in Lotus 1 (Kew1), which plays a key role in the control of lateral petal identity, and found LjCYC2 interacted with Kew1, resulting in a double mutant that bore all petals with ventralized identity to some extents. Thus, we demonstrate that CYC homologues have been independently recruited as determinants of petal identities along the dorsoventral axis in two distant lineages of flowering plants, suggesting a common molecular origin for the mechanisms controlling floral zygomorphy.
National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
Xianzhong
X
Feng
Zhong
Z
Zhao
Zhaoxia
Z
Tian
Shilei
S
Xu
Yonghai
Y
Luo
Zhigang
Z
Cai
Yumei
Y
Wang
Jun
J
Yang
Zheng
Z
Wang
Lin
L
Weng
Jianghua
J
Chen
Leiying
L
Zheng
Xizhi
X
Guo
Jianghong
J
Luo
Shusei
S
Sato
Satoshi
S
Tabata
Wei
W
Ma
Xiangling
X
Cao
Xiaohe
X
Hu
Chongrong
C
Sun
Da
D
Luo
D000483:Alleles; D000595:Amino Acid Sequence; D017124:Conserved Sequence; D035264:Flowers / Q000033:anatomy & histology* / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D000070116:Lotus / Q000033:anatomy & histology* / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D016415:Sequence Alignment
D010940:Plant Proteins