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

Ascribing genetic function from lily using heterologous system
type plants, Columbia (Col-0) ecotype, were also transformed by the same procedures
and followed up to the T2 generation. Figure 2 illustrates the transgenic Arabidopsis
phenotypes obtained with LLAG1 overexpression whereas Figure 3 shows their
Southern and northern analyses, confirming transgene integration and its active
transcription. The number of plants transformed, transformants recovered on selection
medium and their respective phenotypes in T1 generation are shown in Table 1.
A
B C D
Figure 2. Arabidopsis phenotypes. (A) Sibling plants with Col-0 background showing clear phenotypic
segregation of wild-type phenotype (left) and overexpressing LLAG1 (right) at 15 days after
germination. (B) Inflorescence with Col-0 wild-type flowers. (C) Flowers of an LLAG1 transgenic
Ler-0 plant showing a strong ap2-like phenotype. Note the homeotic changes of petals into stamen-
like organs (arrows). (D) A Col-0 x Ler-0 flower with an agamous-defective phenotype showing the
reiterated pattern (sepals-petals-petals)n.
Ectopic expression of AG (or its functional orthologues) in the outer whorls of a
flower induces homeotic changes of sepals into carpelloid organs and the petals into
stamens, giving an apetala2-like phenotype, as stated by the ABCDE model of flower
development, since AP2 and AG have antagonistic functions (Coen and Meyerowitz,
1991). AG expression with strong constitutive promoters, such as the CaMV35S, leads
to dwarf and weak plants, with few and curled leaves, early flowering, bumpy siliques,
few seeds, and the aforementioned floral homeotic changes (Li et al., 2002; Mizukami
and Ma, 1992; Rigola et al., 2001; Rutledge et al., 1998).
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