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.
Feng
Xianzhong
X
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.
Zhao
Zhong
Z
Tian
Zhaoxia
Z
Xu
Shilei
S
Luo
Yonghai
Y
Cai
Zhigang
Z
Wang
Yumei
Y
Yang
Jun
J
Wang
Zheng
Z
Weng
Lin
L
Chen
Jianghua
J
Zheng
Leiying
L
Guo
Xizhi
X
Luo
Jianghong
J
Sato
Shusei
S
Tabata
Satoshi
S
Ma
Wei
W
Cao
Xiangling
X
Hu
Xiaohe
X
Sun
Chongrong
C
Luo
Da
D
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