Flower development of Lilium longiflorum - The Lilium information ...

Isolation and Characterisation of LLSEP3
Figure 2. Phylogenetic analysis of MADS-box genes. The tree was generated by the ClustalX version
1.8 program (Thompson et al., 1997) using a Phylip distance matrix with 1,000 bootstrap trials.
Graphic representation was produced by the TreeView software (Page, 1996). LLSEP3 is indicated
in bold. The species of origin are given after the respective gene names. Bars represent 10% amino
acid substitution per site along the 185 domain.
An explanation of why SEP3 induces early flower phenotype cannot be easily
given up till now. This phenomenon may be due to its intrinsic and uncharacterised
role during floral meristem identity or even with functional mimicry of a floral
meristem gene, such as AP1. Segregation of early flowering and twisted leaves was
followed up and confirmed until the T2 generation. T1 generation plants were assessed
for RNA expression, showing active transcription of LLSEP3 and the selection NPTII
gene (Figure 5).
A B
flower bud length (cm)
1.5 2.0 2.5 3.0 3.5 L T S C
LLSEP3
GAPDH
Figure 3. Expression profile analysis of LLSEP3. A. LLSEP3 transcripts are present in developing floral
buds (1.5 to 3.5 cm lengths). B. LLSEP3 is expressed in mature floral organs (T, tepals; S, stamens;
C, carpels) and not detected in leaves (L). Ten micrograms of total RNA were loaded in each lane.
Loading control is given by hybridisation with a lily GAPDH probe in the lower panels.
Whereas antisense expression of SEP3 in Arabidopsis led to phenotypes similar
to intermediate alleles of the flower meristem identity and homeotic gene ap1 (Pelaz et
al., 2001a), antisense expression of LLSEP3 in Arabidopsis did not show any visible
phenotypic alteration, presumably because its sequence already diverges too much to
promote gene silencing of SEP3 by antisense RNA.
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