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lab profile
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 Sabine Zachgo
University of Osnabrueck
Barbarastr. 11
Osnabrueck, Lower Saxony 49076
Germany
zachgo@biologie.uni-osnabrueck.de
+49 541 969 2840
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| PI: |
YES |
| Taxa Studied: |
Plants |
| Techniques Employed: |
Quantitative PCR (qPCR), Microarrays, Sanger Sequencing, Bioinformatics/Sequence Analysis, In Situ Hybridization, RNA interference(RNAi), Sectioning for Histology, Scanning Electron Microscopy, Epifluoresence Microscopy, Confocal Microscopy, Transgenesis, Mutagenesis |
| Research Description: |
We are interested in the processes that led to the formation on the large floral diversity that we observe in extant angiosperms. Particularly angiosperm flowers exhibit a large diversity in petal number, size, shape and coloration that likely co-evolved with their pollinators. We analyze the molecular mechanisms controlling flower organ formation in model species such as Arabidopsis thaliana and Antirrhinum majus. The knowledge of basic conserved regulatory floral processes allows conducting comparative gene function approaches. By selecting non-model species that evolved morphological novelties such as petal monosymmetry, we aim to understand the molecular changes that contributed to the evolution of floral organ diversity. We analyze the Brassicaceae where more than 350 genera exhibit a polysymmetric corolla. However, in the genus Iberis, flowers with two differently sized petal pairs give rise to the formation of a monosymmetrical corolla. Analysis of the TCP1 transcriptions factor, known to control flower symmetry formation in Antirrhinum, showed that a heterochronic TCP1 expression change led to a differential control of cell divisions in the two petal pairs. In Arabidopsis, the formation of four petals requires the activity of ROXY1, a land-plant specific glutaredoxin. In roxy1 mutants, only 2,5 petals are formed. Surprisingly, GRXs have thus far only been associated with redox processes in stress regulation. Our data indicate that GRXs are also involved in flower regulation and raise the question, if and how a correlation between redox regulation and flower development exists. ROXYs interact with TGA transcription factors in the nucleus and likely modify TGA proteins posttranslationally and exert their reductive power by means of conserved cysteines in conserved short motifs. Only this land-plant specific ROXY-GRX subclass expanded strongly during the evolution of land plants. Analysis of ROXYs in basal land plants, such as the mosses Physcomitrella and Marchanita, will help to elucidate their ancestral function. |
| Lab Web Page: |
http://www.biologie.uni-osnabrueck.de/bogos/Zachgo/Zachgo.html |
| Willing to Host Undergraduates: |
YES |
| Actively Seeking Undergraduates: |
NO |
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