YongQiang Wang, PhD
Personal Data:
Country of Origin: P. R. China
PhD period: June 2006 - May 2010
Title:
Reconstructing the interaction network of reproductive homeotic
proteins in a gymnosperm
Project Leader: Prof. Dr. Günter Theißen
Abstract:
In angiosperms (flowering plants), flower development is
controlled by hierarchically organized networks of genes, many
of which encode MIKC-type MADS-domain transcription factors.
Changes in these gene regulatory networks are underlying the
morphological evolution of flowers and hence the generation of
floral biodiversity. The interactions between floral
developmental control genes have so far mainly been defined
genetically. However, to better understand the molecular
evolutionary dynamics of the gene regulatory networks, its
“hard-wiring” has to be determined, i.e. the protein-protein and
protein-DNA interactions on which the network topology is based.
Of central interest are the floral homeotic proteins, which form
multimeric complexes (“floral quartets”) specifying angiosperm
floral organ identity. They do so by activating and repressing
appropriate target genes during the development of floral
organs. Some complexes composed of MIKC-type proteins are not
only required, but also sufficient to specify floral organ
identity.
Within the project, protein-protein and protein-DNA interactions
of gymnosperm MIKC-type proteins are studied. Extant gymnosperms
are probably the sister group of flowering plants (angiosperms)
and possess already putative orthologues of some angiosperm
floral homeotic genes. However, the reprocuctive organs of
gymnosperms lack typical and central features of angiosperm
flowers, like carpels, a perianth, and the bisexual organisation
of the flower. By examing the interaction network of gymnosperm
MIKC-type proteins and comparing it to the angiosperm network,
we hope to better understand the evolutionary origin of the
floral quartets. Eventually, this may also shed light on the
origin of the angiosperm flower. Major techniques being used
include yeast n-hybrid analyses (n = 2, 3, 4), gel retardation
assays, and co-immunoprecipitation assays. Plans for the future
include tests of protein-protein interactions in plants cells
employing bimolecular fluorescence complementation (BiFC).
Publications:
- Melzer R, Wang Y-Q, Theissen G (2010) The naked and the dead:
The ABCs of gymnosperm reproduction and the origin of the angiosperm flower. Semin Cell Dev Biol 21(1), 118-128.
- Wang, Y.‑Q., Melzer, R. und Theißen, G. (2010).
Molecular interactions of orthologues of floral homeotic
proteins from the gymnosperm Gnetum gnemon provide a
clue to the evolutionary origin of 'floral quartets'.
Plant J. 64, 177-190.
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