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

Chapter 8
interaction patterns (within the species itself and even beyond the monocot class) and
differences in gene promoter activity of transcription factors. On the other hand,
molecular breeders can take advantage of the knowledge acquired on lily flower
genetics and attempt to manipulate its floral morphology and flowering time, in order
to generate novel and commercially interesting phenotypes.
B D
A C
E
Se Pe St Ca Ov
General Model
AP1+AP2
AP3+PI
AG
SEP3
Arabidopsis
AGL
11
Se Pe St Ca Ov
LMADS1 + ?
?
LLSEP3
LLAG1
LMADS
2
Te Te St Ca Ov
Lilium longiflorum
Figure 1. The ABCDE model for flower development. The current model states that five genetic
functions act in an overlapping fashion in order to trigger the development of floral organs. Genes of
each function were found in the model species Arabidopsis. In Lilium longiflorum, some of the ABCDE
functions were already characterized. This thesis presents the characterization of LLAG1 and LLSEP3
genes, showing C and E functions, respectively.
Heterologous system for functional characterisation of lily genes
Given the methodological difficulties encountered in lily to genetic studies of
flower morphology in a homologous system, such as its recalcitrance to genetic
transformation and a long vegetative phase, we approached the functional
characterisation of lily floral genes in a heterologous system, using the model species
Arabidopsis thaliana.
Despite the easy manipulation of this model species, we met some obstacles
during the characterization of LLAG1, which are described in the chapter four of this
thesis.
Notwithstanding, the use of Arabidopsis as a heterologous system in flower
development is not discouraged when the homologous system is not available or
presents inconveniences. Given the evolutionary conservation of the ABCDE model
and the extensive studies in flower development carried on in Arabidopsis, this species
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