Copyright (c) 2009 All rights reserved. http://works.bepress.com/srobinson Recent documents in S. A. Robinson en-us Fri, 06 Nov 2009 23:23:04 PST 3600 http://works.bepress.com/srobinson/29 http://works.bepress.com/srobinson/29 Thu, 05 Nov 2009 20:14:22 PST Sharon Robinson was project initiator and curator of the Institute of Conservation Biology ICB University of Wollongong photograph competition in 2006 and subsequent calendars in 2007, 2009 and 2010. S. A. Robinson http://works.bepress.com/srobinson/28 http://works.bepress.com/srobinson/28 Thu, 05 Nov 2009 20:07:13 PST Photographing Cool Science was a photographic exhibition featuring the best of the Institute of Conservation Biology and Law photographic competition entries and Antarctic prints by Sharon Robinson. The exhibition was shown at Project Contemporary Art Space, Wollongong from 21st March- 1st April 2007 and in the Mackinnon Building, University of Wollongong, August 2007. The items are now on permanent exhibition in the University of Wollongong Library. S. A. Robinson http://works.bepress.com/srobinson/27 http://works.bepress.com/srobinson/27 Thu, 05 Nov 2009 19:59:05 PST Sharon Robinson was project initiator and curator of the Institute of Conservation Biology ICB University of Wollongong photograph competitions and calendars. S. A. Robinson http://works.bepress.com/srobinson/26 http://works.bepress.com/srobinson/26 Thu, 05 Nov 2009 19:50:43 PST Photographic exhibition of Antarctic prints. G. M.A. Netherwood http://works.bepress.com/srobinson/25 http://works.bepress.com/srobinson/25 Thu, 05 Nov 2009 19:39:58 PST Video and Chorotube prize winner on the subject of plants from the the Antarctic. S. A. Robinson http://works.bepress.com/srobinson/24 http://works.bepress.com/srobinson/24 Thu, 05 Nov 2009 18:52:11 PST "Fire, Water, Earth and Air - the elements of conservation", sums up the main research areas within the Institute for Conservation Biology ICB at the University of Wollongong, namely Fire Ecology, Marine Biology, Terrestrial Biology and Avian Biology. The exhibition shows a large selection of the entries from the 2006 and 2008 photocompetitions held by the ICB. S. A. Robinson http://works.bepress.com/srobinson/22 http://works.bepress.com/srobinson/22 Thu, 05 Nov 2009 18:16:03 PST We report a meta-analysis of data from 34 field studies into the effects of UV-B radiation on Arctic and Antarctic bryophytes and angiosperms. The studies measured plant responses to decreases in UV-B radiation under screens, natural fluctuations in UV-B irradiance, or increases in UV-B radiation applied from fluorescent UV lamps. Exposure to UV-B radiation was found to increase the concentrations of UV-B absorbing compounds in leaves or thalli by 7% and 25% (expressed on a mass or area basis, respectively). UV-B exposure also reduced aboveground biomass and plant height by 15% and 10%, respectively, and increased DNA damage by 90%. No effects of UV-B exposure were found on carotenoid or chlorophyll concentrations, net photosynthesis, Fv/Fm or ΦPSII, belowground or total biomass, leaf mass, leaf area or specific leaf area (SLA). The methodology adopted influenced the concentration of UV-B absorbing compounds, with screens and natural fluctuations promoting significant changes in the concentrations of these pigments, but lamps failing to elicit a response. Greater reductions in leaf area and SLA, and greater increases in concentrations of carotenoids, were found in experiments based in Antarctica than in those in the Arctic. Bryophytes typically responded in the same way as angiosperms to UV-B exposure. Regression analyses indicated that the percentage difference in UV-B dose between treatment and control plots was positively associated with concentrations of UV-B absorbing compounds and carotenoids, and negatively so with aboveground biomass and leaf area. We conclude that, despite being dominated by bryophytes, the vegetation of polar regions responds to UV-B exposure in a similar way to higher plant-dominated vegetation at lower latitudes. In broad terms, the exposure of plants in these regions to UV-B radiation elicits the synthesis of UV-B absorbing compounds, reduces aboveground biomass and height, and increases DNA damage. K. K. Newsham http://works.bepress.com/srobinson/23 http://works.bepress.com/srobinson/23 Thu, 05 Nov 2009 18:16:03 PST The receptacle of the sacred lotus is the main source of heat during the thermogenic stage of floral development. Following anthesis, it enlarges, greens and becomes a fully functional photosynthetic organ. We investigated development of photosynthetic traits during this unusual functional transition. There were two distinct phases of pigment accumulation in receptacles. Lutein and photoprotective xanthophyll cycle pigments accumulated first with 64% and 95% of the maximum, respectively, present prior to anthesis. Lutein epoxide comprised 32% of total carotenoids in yellow receptacles, but declined with development. By contrast, more than 85% of maximum total chlorophyll, β-carotene and Rubisco were produced after anthesis, and were associated with significant increases in maximum electron transport rates (ETR) and photochemical efficiency (Fv/Fm). Leaves and mature receptacles had similar Rubisco content and ETRs (>200 μmol m-2 s-1), although total chlorophyll and total carotenoid contents of leaves were significantly higher than those of green receptacles. Receptacle δ13C prior to anthesis was similar to that of leaves; consistent with leaf photosynthesis being the source of C for these tissues. In contrast, mature receptacles had significantly lower δ13C than leaves, suggesting that 14-24% of C in mature receptacles is the result of refixation of respired CO2. R. E. Miller http://works.bepress.com/srobinson/21 http://works.bepress.com/srobinson/21 Thu, 05 Nov 2009 18:16:02 PST The capacity of the polar flora to adapt is of increasing concern given current and predicted environmental change in these regions. Previous genetic studies of Antarctic mosses have been of limited value due to a lack of variation in the markers or non-specificity of the methods used. We examined the power of five microsatellite loci developed for the cosmopolitan moss Ceratodon purpureus to detect genetically distinct clones and infer the distribution of clones within and among populations from the Windmill Islands, East Antarctica. Our microsatellite data suggest extraordinarily high levels of variation reported in RAPD studies were artificially elevated by the presence of contaminants. We found surprisingly little contribution of asexual reproduction to the genetic structure of the Windmill Islands populations, but more loci are required to determine the distribution of individual clones within and among populations. It is apparent that Antarctic populations of C. purpureus possess less genetic diversity than temperate populations, and thus have less capacity for adaptive change in response to environmental variation, but more markers are needed to resolve the total genetic diversity in Antarctic C. purpureus and other mosses. L. J. Clarke http://works.bepress.com/srobinson/20 http://works.bepress.com/srobinson/20 Thu, 05 Nov 2009 18:16:01 PST Sacred lotus (Nelumbo nucifera) regulates temperature in its floral chamber to 32°C to 35°C across ambient temperatures of 8°C to 40°C with heating achieved through high alternative pathway fluxes. In most alternative oxidase (AOX) isoforms, two cysteine residues, Cys1 and Cys2, are highly conserved and play a role in posttranslational regulation of AOX. Further control occurs via interaction of reduced Cys1 with α-keto acids, such as pyruvate. Here, we report on the in vitro regulation of AOX isolated from thermogenic receptacle tissues of sacred lotus. AOX protein was mostly present in the reduced form, and only a small fraction could be oxidized with diamide. Cyanide-resistant respiration in isolated mitochondria was stimulated 4-fold by succinate but not pyruvate or glyoxylate. Insensitivity of the alternative pathway of respiration to pyruvate and the inability of AOX protein to be oxidized by diamide suggested that AOX in these tissues may lack Cys1. Subsequently, we isolated two novel cDNAs for AOX from thermogenic tissues of sacred lotus, designated as NnAOX1a and NnAOX1b. Deduced amino acid sequences of both confirmed that Cys1 had been replaced by serine; however, Cys2 was present. This contrasts with AOXs from thermogenic Aroids, which contain both Cys1 and Cys2. An additional cysteine was present at position 193 in NnAOX1b. The significance of the sequence data for regulation of the AOX protein in thermogenic sacred lotus is discussed and compared with AOXs from other thermogenic and nonthermogenic species. N M. Grant