Phylogenetic analysis of <i>AGL6</i> lineages.

<p>A phylogenetic tree was built using the maximum-parsimony method through the program MEGA 7.0 based on the protein sequences of different species. <i>DGL14</i> and <i>GGM11</i> are used as outgroups. The percentage bootstrap values are indicated by numbers at the branch points.</p

Phylogenetic analysis of A-class genes.

<p>A phylogenetic tree was built using the maximum-parsimony method through the program MEGA 7.0 based on the protein sequences of different species. <i>GGM1</i> and <i>DAL1</i> are used as outgroups. The percentage bootstrap values are indicated by numbers at the branch points.</p

Phylogenetic analysis of B-class genes.

<p>A phylogenetic tree was built using the maximum-parsimony method through the program MEGA 7.0 based on the protein sequences of different species. PrDGL and GGM2 are used as outgroups. The percentage bootstrap values are indicated by numbers at the branch points.</p

Expression patterns of floral organ identity genes.

<p>Real time qPCR was performed showing expression in different organs. The <i>CejaActin</i> was used as an internal reference. Values represent the means ± standard error of triplicates.</p

Epidermal cells of leaves and floral parts of <i>Cercidiphyllum japonicum</i>.

<p>Since male and female flowers are the same besides floral organs, so just female ones were displayed. (A) Abaxial (bar = 50 μm) and amplified (inset; bar = 10 μm) epidermal cells of a outer scale at mature stage. (B) Adaxial (bar = 30 μm) epidermal cells of a outer a scale at mature stage. (C) Abaxial (bar = 25 μm) and adaxial (inset; bar = 20 μm) epidermal cells of a inner scale at mature stage, showing irregular striation. (D) Abaxial (bar = 30 μm) and adaxial (inset; bar = 10 μm) epidermal cells of a inner scale at mature stage. (E) Carpels from a mature flower (bar = 200 μm). (F) Epidermal cells of a stigma (left; bar = 15 μm) and back (right; bar = 5 μm) of carpel. (G) A stamen from a mature flower (bar = 200 μm). (H) Surface of anther (left; bar = 10 μm) and filament (right; bar = 20 μm). (I) Juvenile leaves (bar = 200 μm) and the abaxial and amplified epidermal cells (inset; bar = 15 μm). (J) Epidermal cells of glands (bar = 30 μm). (K) Surface of a stipule (bar = 500 μm), showing relatively regular sculpturing (insert; bar = 30 μm). (L) Bracts (bar = 300 μm), showing middle slotted or tee or cross grooves (bar = 20 μm).</p

All the MADS-box proteins in protein sequence comparisons and phylogenetic analysis.

<p>All the MADS-box proteins in protein sequence comparisons and phylogenetic analysis.</p

Phylogenetic analysis of C/D-class genes.

<p>A phylogenetic tree was built using the maximum-parsimony method through the program MEGA 7.0 based on the protein sequences of different species. <i>GGM3</i> and <i>DAL2</i> are used as outgroups. The percentage bootstrap values are indicated by numbers at the branch points.</p

A list of all primers used for gene cloning and qRT-PCR in this study.

<p>A list of all primers used for gene cloning and qRT-PCR in this study.</p

Representative predicted amino acid sequences of ABCD genes from <i>Cercidiphyllum japonicum</i> and selected taxa.

<p>Representative predicted amino acid sequences of ABCD genes from <i>Cercidiphyllum japonicum</i> and selected taxa.</p

Sequence information of the primers listed in Table 1.

<p>Sequence information of the primers listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0178382#pone.0178382.t001" target="_blank">Table 1</a>.</p