Botany Department Seminars

May 2012

Maximising the biodiversity value of urban trees: what birds really want

POSTPONED TILL FURTHER NOTICE
Ed Waite, PhD candidate, Department of Botany, University of Otago

Keeping it hot when it's cold outside: plant sex in the Arctic and Sub-Arctic

Lorna Little, PhD candidate, Department of Botany, University of Otago

Floral biology and genetic variation in Euphrasia dyeri.

Wednesday 16 May 2012 12 noon
Vicky McGimpsey, MSc candidate.

Are reproductive characteristics of Wahlenbergia albomarginata dependent on environment?

Wednesday 16 May 2012 12 noon
Olivia Sawrey, MSc candidate.

Beyond New Zealand: Global Biodiversity of Myxomycetes

Wednesday 23 May 2012 12 noon
Prof. Steven Stephenson, Department of Biological Sciences, University of Arkansas, Fayetteville, USA

April 2012

Evolution of chloroplasts and medieval manuscripts

Friday 13 April 1 pm
Union Street Lecture Theatre

Professor Chris Howe, Department of Biochemistry, University of Cambridge, United Kingdom

Evolutionary ecology in the alpine – insights from Fiordland

Wednesday 18 April 12
Dr Bill Lee, Landcare Research, Dunedin

March 2012

Three's a crowd: testing models for modification of breeding systems in a tristylous species

Wednesday 14 March
Prof's Stephen G. Weller and Ann K. Sakai, Department of Ecology and Evolutionary Biology, University of California Irvine, California, USA

Ever green but seeing red?  Deciphering the palette of New Zealand’s flora

Wednesday 14 March 5.30 pm – 6.30 pm
Commerce 2.22, Cnr Clyde Street  and Union Place East Leonard Cockayne Memorial Lecture

Professor Kevin S Gould, School of Biological Sciences, Victoria University of Wellington

February 2012

Deer herbivory as a driver of meta-community structure of forest floor vegetation in warm-temperate forests (the Boso peninsula, Japan).

Professor Zaal Kikvidze, Department of Natural Environment, Graduate School of Frontier Sciences, University of Tokyo

Wednesday 15 February at 12 noon
Phys Ed Seminar Room #213-4, 55 Union Street, Dunedin

ALSO:

Professor Zaal Kikvidze will be giving a talk to the Botanical Society of Otago on the evening of Wednesday 15 February at 5.20 pm in the Benham Seminar Room, Zoology Department, 346 Great King Street.

"Stucture of plant communities in edaphic and alpine deserts of the Japanese Archipelago"

Please be prompt as the door has to be held open.

The role of antisense RNAs in the lytic infection cycle of cyanophage P-SSP7 and its host Prochlorococcus MED4.

Tuesday 28 February 12 noon in Biochemistry Room 228

Dr Claudia Steglich
Experimental Bioinformatics and Genetics, University of Freiburg, Germany.

Several recent studies on whole-transcriptome expression analyses revealed that a significant portion of the transcriptome is expressed on the antisense strand, not only in eukaryotes, but also in bacteria and archaea, where data indicate that between 3% to more than half of all genes are associated with antisense RNAs (asRNAs). The first reported asRNA ever was cro asRNA of coliphage lambda in 1972. Surprisingly, only a handful phage asRNA have been found and characterized since then. Most of these asRNAs play important roles during phage development. The only known asRNA in a cyanophage is opposite of photosynthesis gene psbA encoding the D1 core protein of photosystem II and of the homing endonuclease (F-Cphl) in the cyanophage S-PM2. Transcripts of the asRNA as well as of psbA and F-Cphl are induced during the lytic infection cycle of S-PM2 in its host Synechococcus sp. WH7803.

In a recent study on whole-genome expression of the podovirus P-SSP7 and its cyanobacterial host Prochlorococcus MED4 it was shown that transcript abundance of 41 host genes, including Endoribonuclease E (RNase E), increased during lytic infection, while the vast majority of host mRNAs declined in abundance (1). It was suggested that the induction of the host RNase E transcript may help the phage by generating a source of nucleotides that (after nucleotide reduction by the phage-encoded ribonucleotide reductase) are utilized by the phage for its own replication (1). We found that the induction of the 41 host genes correlates with the presence of extraordinary long asRNAs, which protect these mRNAs from RNase E degradation (2). Intriguingly, the phage seems to protect its own RNAs from RNAse E cleavage by expressing long asRNAs that cover the complete transcriptome.

References
1. Lindell, D., Jaffe, J.D., Coleman, M.L., Futschik, M.E., Axmann, I.M., Rector, T., Kettler, G., Sullivan, M.B., Steen, R., Hess, W.R. et al. (2007) Genome-wide expression dynamics of a marine virus and host reveal features of co-evolution. Nature, 449, 83-86.
2. Stazic, D., Steglich, C. and Lindell, D. (2011) Antisense RNA protects mRNA from RNase E degradation by RNA–RNA duplex formation during phage infection. NAR, 39, 4890-4899

Transcriptomics and microarray-based RNA profiling reveals complex promoter architectures and novel regulators of photosynthesis and heterocyst differentiation in cyanobacteria

29 February 2012, 12 noon Union Street Lecture Theatre

Professor Wolfgang R. Hess
University of Freiburg, Faculty of Biology, 79104 Freiburg, Germany.

We have used extensive microarray-based RNA profiling and comparative RNAseq approaches to study the transcriptomes of simple unicellular cyanobacteria (1,2) as well as of complex species such as Anabaena sp. PCC7120 during the critical step to heterocyst cell differentiation and the switch to nitrogen fixation (3).

This work has redefined the regulons controlled by the transcription factors NtcA and HetR (3) and revealed specific functions of some of these non-coding RNAs in the control of stress responses, photosynthesis, outer cell membrane protein biosynthesis and the differentiation of cells. In Synechocystis PCC6803, the cis-antisense RNA IsrR controls accumulation of the light-harvesting protein IsiA under iron limited growth through a co-degradation mechanism with the isiA mRNA (4), whereas the now discovered trans-acting RNA SyR22 is required for a sustained high level translation. This same regulator is also involved in the control of Fe-S-cluster biogenesis and the expression of superoxide dismutase. Another conserved regulatory RNA, SyR1, is involved in the control of photosystem I gene expression. In Anabaena PCC7120, the expression of NsiR1 is one of the earliest known cell-type specific events in the differentiation of heterocysts (5) and the conservation of location, gene arrangement and sequence among heterocyst-forming cyanobacteria indicates a widely conserved identical and essential function in these species.

References
(1) Mitschke J., Georg J., Scholz I., Sharma C., Dienst, D., Bantscheff J., Steglich C., Voss B., Wilde, A., Vogel J., Hess W.R. (2011) An experimentally anchored map of transcriptional start sites in the model cyanobacterium Synechocystis sp. PCC 6803. Proc. Natl. Acad. Sci. USA 108, 2124-2129.
(2) Gierga G., Voss B., Hess W.R. (2012): Prediction and microarray based detection of non-coding RNAs in marine Synechococcus and their regulation under environmentally relevant stress conditions. ISME J. (Nature Publishing Group); doi:10.1038/ismej.2011.215 [Epub ahead of print].
(3) Mitschke J., Vioque A., Haas F., Hess W.R., Muro-Pastor A.M. (2011) Dynamics of transcriptional start site selection during nitrogen stress-induced cell differentiation in Anabaena sp. PCC7120. Proc. Natl. Acad. Sci. USA 108, 20130-20135.
(4) Dühring U., Axmann I.M., Hess W.R., Wilde A. (2006): An internal antisense RNA regulates expression of the photosynthesis gene isiA. Proc. Natl. Acad. Sci. USA, 103, 7054-7058
(5) Ionescu D., Voss B., Oren A., Hess W.R., Muro Pastor A. (2010) Heterocyst-specific transcription of a non-coding RNA encoded in a tandem array of direct repeats in cyanobacteria. J. Mol. Biol. 398, 177–188

December 2011

Invasive Species in Natural Ecosystems

Dr Margaret Stanley, School of Biological Sciences, University of Auckland.

Wednesday 21st December, 12 Noon.
Union St Lecture Theatre, Cnr Union St West & Great King St

All welcome!

November 2011

Ecosystems in waiting or a bright new future?

Dr John Ogden.

Wednesday 9 November 2011 12 noon
Student Learning Centre Seminar Room GW3, Information Services Building access via Cumberland or Albany Sts

Mixed plant and animal communities are now widely established in New Zealand. Will the forests of yesteryear eventually re-establish, or should we welcome a new species mixture dictated by a new disturbance regime? Work on the dynamics of the scrub communities on Great Barrier Island will be discussed.

Mountain earthquakes and their ecological effects: the case of the 2008 Sichuan earthquake.

Prof Qian Wang, Chengdu Institute of Biology, Chinese Academy of Sciences

Wednesday 16 November 12 noon
Union St Lecture Theatre, Cnr Union St West & Great King St

October 2011

Differential Susceptibility to Ocean Acidification.

Associate Professor Catriona Hurd, Department of Botany, University of Otago

Tuesday 4 October 2011  4pm
Marine Science Seminar room

My Place in the World: An Update on the Electron Microscopy Facilities at the University of Otago.

Allan Mitchell, Technical Manager, Otago Centre for Microscopy

Wednesday 5 October 2011 12 noon
Union St Lecture Theatre, Cnr Union St West & Great King St

Orokonui Landmark Lecture - The Meaning of Eco: Science or Brand?

Professor Kath Dickinson, Department of Botany, University of Otago

Wednesday 12 October 2011 7.30pm
St David’s Lecture Theatre

MSc proposals:

Aiko Lignon: MSc Plant Biotech proposal- genetic variation in Alfalfa mosaic virus
Max Corral: MSc Botany proposal- Can we use virus infection to manipulate secondary metabolites in economically important plants? 

Wednesday 19 October 2011 12 noon
Phys Ed Seminar Room #213-4, 55 Union St 

September 2011

Friendly Forest Fungi: mycorrhizae of NZ native forest trees

Wednesday 21th September 2011,12:00 PM - 12:50 PM
Union St Lecture Theatre

A talk by Dr David Orlovich in celebration of International Year of Forests 2011. I will discuss the importance of fungus-root symbioses in NZ forests and describe recent research on native mycorrhizal fungi. A Department of Botany Lunchtime Seminar. Note: Special time and Venue: Union St Lecture Theatre, Cnr Union St West & Great King St. Venue is subject to change, so please check back here for an update closer to the day.

10th Annual Geoff Baylis Lecture: Complex relationships with friends and foes: How native plants manage the risks

Wednesday 14th September 2011, 5:30 PM to 7:00 PM
Castle 1 Lecture theatre

Speaker Dr Bill Lee Landcare Research, Dunedin; Joint Graduate School of Biodiversity and Biosecurity, School of Biological Sciences, University of Auckland.

Plants share a world with many other organisms that represent both potential enemies and possible allies. For their enemies plants are a food source, but plants have developed numerous defences, including co-opting other animals, to protect vital organs. This involves strategic alliances, armed neutrality and active warfare. Plants also develop interdependencies with other biota for obtaining resources, assisting reproduction and dispersal, and limiting herbivory. The talk will explore what we know about these interactions in New Zealand, and discuss some of the extraordinary relationships amongst and between fungi, arthropods, birds, and plants. Emphasis will be on the strategies and tactics involved from the perspective of the plants, and how much plants are prepared to repel enemies and gain friends in natural ecosystems.

July 2011

Wednesday 17th August @ 12 noon, Union St Lecture Theatre

Induced mutations and biotechnology for horticultural crop improvement

Professor Shri Mohan Jain, Department of Agricultural Sciences University of Helsinki, Finland.

All welcome

John Smaillie Tennant Lecture. Thursday 21 July 2011 at 6.00 pm, St David Lecture Thearter.

How many species will survive the 21st century?

Peter H. Raven, President Emeritus, Missouri Botanical Garden

More on Peter's talk.

June 2011

Tuesday 7 June 1 pm in Benham Seminar Room, Zoology Department

Plant-environment interactions:  plant strategies and applications

Dr Rainer Hofmann, Senior Lecturer in Plant Biology, Faculty of Agriculture and Life Sciences Lincoln University

Plant-environment interactions: plant strategies and applications

In their natural environment, plants are exposed to a wide spectrum of environmental variables, including peak levels of ultraviolet (UV) radiation in summer, limited availability of water and nutrients, and many other abiotic and biotic factors. While the effects of these variables can impose considerable stress on plants, frequently they can also contribute to cross-tolerance. In many of these cases, flavonoids have been implicated as biochemical mediators. Our findings highlight the importance of UV radiation-mediated flavonoid production for preconditioning plants to better cope with other environmental variables such as drought. Our results are in line with plant strategy theory, indicating that investment into biochemical protection can come at a cost for primary productivity. The findings provide new avenues for plant improvement and crop production via the selection of productive germplasm that contains key protective metabolites to balance trade-offs between plant productivity and stress resistance. Applications of this knowledge in viticulture and oenology are also discussed.

May 2011

Wednesday 11 May 12 noon

Union St Lecture Theatre, Cnr Union St West & Great King St
12 noon : An investigation into the symbiosis of Pseudocyphellaria crocata
Jess Yardley (MSc final)

12.30 pm : Title:  to be advised
Emma Wallace (MSc proposal)

Wednesday 25 May 12 noon

Union St Lecture Theatre, Cnr Union St West & Great King St

Antioxidative strategies of intertidal macroalgae to radiation stress
Dr Ralf Rautenberger, DGF Postdoctoral Fellow, Botany Department)

April 2011

Wednesday 13 April 12 noon
Union Street Lecture Theatre, Cnr Union St West & Great King St

12 noon

Oxidative damage and antioxidant defences of the macroalgae Ulva pertusa and an associated grazing mollusk in response to fluoranthene contamination.
Nikita Engels, (MSc final), Department of Botany, University of Otago

12.30 pm

Plant strategies along small-scale snowmelt gradients in New Zealand.
Annika Korsten, (MSc final) Department of Botany, University of Otago

 

March 2011

Thursday 3rd March 5:30 PM

Archway 4 Lecture Theatre, access from Union Street East

• Mountain tops to ocean depths: my involvement with a range of ecological/environmental issues, mainly in the south

Wednesday 16 March 12 noon
Union Street Lecture Theatre, Cnr Union St West & Great King St

Hybrid fitness and ecological speciation in flowering plants

Professor Diane Campbell, University of California, Irvine and the Rocky Mountain Biological Laboratory

Wednesday 30 March 12 noon
Union Street Lecture Theatre, Cnr Union St West & Great King St

12 noon

Toxins, climate change and marine invertebrates.
Kathryn Lister, PhD Proposal, Department of Botany, University of Otago

12.30 pm

What is the role of facilitation in structuring alpine communities?
Britt Cranston, PhD Proposal, Department of Botany, University of Otago

 

January 2011

Union Street Lecture Theatre, 12 noon.

Amadou Camara, PhD Candidate, Department of Botany, University of Otago:

• The role of shrubs and rabbit herbivory in the ecological restoration of the drylands of south-central New Zealand.

Union St Lecture Theatre
Cnr Union St West & Great King St