Journal Articles

Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915

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Subject: search.filters.subject.Evolution

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    Within and between whorls: Comparative transcriptional profiling of Aquilegia and Arabidopsis
    (Public Library of Science, 2010) Voelckel C; Borevitz J; Kramer E; Hodges S
    BACKGROUND: The genus Aquilegia is an emerging model system in plant evolutionary biology predominantly because of its wide variation in floral traits and associated floral ecology. The anatomy of the Aquilegia flower is also very distinct. There are two whorls of petaloid organs, the outer whorl of sepals and the second whorl of petals that form nectar spurs, as well as a recently evolved fifth whorl of staminodia inserted between stamens and carpels. METHODOLOGY/PRINCIPAL FINDINGS: We designed an oligonucleotide microarray based on EST sequences from a mixed tissue, normalized cDNA library of an A. formosa x A. pubescens F2 population representing 17,246 unigenes. We then used this array to analyze floral gene expression in late pre-anthesis stage floral organs from a natural A. formosa population. In particular, we tested for gene expression patterns specific to each floral whorl and to combinations of whorls that correspond to traditional and modified ABC model groupings. Similar analyses were performed on gene expression data of Arabidopsis thaliana whorls previously obtained using the Ath1 gene chips (data available through The Arabidopsis Information Resource). CONCLUSIONS/SIGNIFICANCE: Our comparative gene expression analyses suggest that 1) petaloid sepals and petals of A. formosa share gene expression patterns more than either have organ-specific patterns, 2) petals of A. formosa and A. thaliana may be independently derived, 3) staminodia express B and C genes similar to stamens but the staminodium genetic program has also converged on aspects of the carpel program and 4) staminodia have unique up-regulation of regulatory genes and genes that have been implicated with defense against microbial infection and herbivory. Our study also highlights the value of comparative gene expression profiling and the Aquilegia microarray in particular for the study of floral evolution and ecology.
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    Late miocene paleo-geomorphology of the bakony-balaton highland volcanic field (Hungary) using physical volcanology data
    (Gebruder Borntraeger, 1999) Nemeth K; Martin U
    A new view is presented of the Bakony-Balaton Highland Volcanic Field (BBHVF), Hungary, active in late Miocene and built up of ca. 100 mostly alkaline basaltic eruptive centers, scoria cones, tuff rings, maar volcanic complexes and shield volcanoes. A detailed map shows the physical volcanology of the monogenetic volcanic field. In areas where thick Pannonian Sandstone beds build up the pre-volcanic strata normal maar volcanic centers have formed with usually thick late magmatic infill in the maar basins. In areas, where relatively thin Pannonian Sandstone beds resting on thick Mesozoic or Paleozoic fracture-controlled, karstwater-bearing aquifer, large unusual maar volcanic sequences appear (Tihany type maar volcanoes). In the northern part of the field large former scoria cones and shield volcanoes give evidence for a smaller impact of the ground and surface water causing phreatomagmatic explosive activity. The Tihany type maar volcanic centers are usually filled by thick maar lake deposits, building up Gilbert type gravelly, scoria rich deltas in the northern side of the maar basins, suggesting a mostly north to south fluvial system in the pre-volcanic surface. Calculating paleosurface elevation for the eruptive centers, two paleo-geomorphology maps are drawn for a younger (4-2.8 Ma) and an older (7.54-4 Ma) scenario. The erosion rate of the volcanic field is estimated to vary between 96 m/Ma and 18 m/Ma. In the western site of BBHVF the erosion rate is higher (more than 60 m/Ma, Tapolca Basin), and an average 50 m/Ma in the center and eastern side.