Cutting Edge Seminar

Speaker
Julia Bailey-Serres
University of California, Riverside

Title:
Waterproofing plants: Sensing, signaling and response mechanisms


Host Johannes Hanson

Room KB3A9

Abstract

The development of crops that can survive extreme weather conditions is imperative due to climate change and population growth. Improving plant yields when there is too little or two much water is especially important. Flooding stress, including soil waterlogging and partial to complete submergence, reduces oxygen availability for ATP production, triggering alterations in gene transcription, mRNA translation and energy metabolism. The plant-specific Group VII Ethylene Response Factor (ERF-VII) transcription factors have emerged as pivotal regulators of flooding and low oxygen responses in plants. In rice (Oryza sativa), ERF-VIIs SUB1A and SNORKEL1/2 enable survival or escape of submergence, respectively. In Arabidopsis thaliana, there are five ERF-VIIs, which are unstable under oxygen-replete conditions due to turnover via the N-end rule of targeted proteolysis. As oxygen levels fall, the ERF-VIIs are stabilized and direct the upregulation of genes associated with anaerobic metabolism. Along with transcriptional regulation in oxygen-deprived cells, there is significant post-transcriptional control. As an energy conserving mechanism, mRNA translation is largely repressed by the sequestration of approximately 90% of the cellular transcripts in large cytosolic granular complexes. We recently reported dynamics in the movement of ribosomes along mRNAs and RNA binding protein that binds many cellular mRNAs that are sequestered during hypoxia. This protein-mRNA association is rapidly reversed upon reoxygenation, allowing stored mRNAs to resume translation. Our efforts to understand low oxygen sensing, signaling and response mechanisms are motivated by the ecological and agronomic relevance of flooding biology in light of the challenges of the 21^st century.

Mustroph, A., Zanetti, M.E., Jang, C.J., Holtan, H.E., Repetti, P.P., Galbraith, D.W., Girke, T. and Bailey-Serres, J. (2009) Profiling the Arabidopsis translatome in discrete cell types resolves altered cell-specific priorities in response to hypoxia. Proceedings of the National Academy of Sciences, USA. 106(44):18843-18848.

Gibbs, D.J., Lee, S.C., Isa, N.M.,Gramuglia, S., Fukao, T., Bassel, G.W., Correia, C.S, Corbineau, F., Theodoulou, F.L., Bailey-Serres, J. and Holdsworth, M.J. (2011) Homeostatic response to hypoxia is regulated by the N-end rule pathway in plants. Nature 479(7373):415-418.

Fukao, T., Yeung, E. and Bailey-Serres, J. (2012) The submergence tolerance gene, SUB1A, delays leaf senescence under prolonged darkness through hormonal regulation in rice. Plant Physiology. 160:1795–1807.

Juntawong, P., Girke, T., Bazin, J. and Bailey-Serres, J. (2014) Translational dynamics revealed by genome-wide profiling of ribosome footprints in Arabidopsis Proceedings of the National Academy of Sciences, USA. 111(1):E203-12.

Sorenson, R. and Bailey-Serres, J. (2014) Selective mRNA sequestration by OLIGOURIDYLATE BINDING PROTEIN 1 contributes to translational control during hypoxia in Arabidopsis. Proceedings of the National Academy of Sciences, USA. 111(6):2373-2378.

Cutting Edge Steve McKeand

NOTE Change of Time and Lecture room!!!

KB3B1
Host: Harry Wu

Title: Characterization of new players in planar polarity establishment in Arabidopsis.

Stefano Pietra, Department of Plant Physiology, Umeå university

Place: KB3B1, KBC

Opponent: Dr. Niko Geldner, Associate Professor, Department of Plant Molecular Biology, University of Lausanne.

UPSC Seminars 2014 NOTE  Change of TIME!
Half-time seminar

Daniel Decker

Title:
UDP-sugar-utilizing pyrophosphorylases in plants

Host: Leszek Kleczkowski

UPRA Meeting Montpellier

UPSC Seminars 2014

Half-time Seminar

Speaker:
Chen Zhi-qiang

Title:
Quantitative genetics of wood quality traits in Norway spruce

Speaker
Dr. Andrew J. Tanentzap
Dept. Of Plant Sciences, Cambridge University (http://www.plantsci.cam.ac.uk/research/andrewtanentzap)

Title:
Titel: ECOSYSTEM ECOLOGY NEEDS MORE EVOLUTION

Host: Maria Eriksson
Room: Lilla hörsalen, KB3A9

Abstract: Disturbances associated with global change are degrading natural ecosystems.  But policy-makers and managers need predictions of how ecosystem functioning and patterns of biodiversity might respond to disturbances in order to intervene.  My research group is addressing these needs by tackling problems around water security.  We are focusing on how alterations to vegetation associated with land-use change and water extraction are, respectively, reducing the productivity of food webs in boreal lakes and persistence of biodiversity hotspots in dryland landscapes.  We are finding that the local outcomes of global change may ultimately be driven by the evolutionary history of traits determining species' responses to disturbance and their competitive abilities. 

Older lineages that have had longer to diversify within niche space may lose their ecological advantages as disturbance intensifies.  We are now interested in testing these ideas over much larger macro-ecological scales and linking evolution in the expression of response traits to underlying genetic processes.

UPSC Seminars 2014

Half-time Seminar

Speaker:
Kristoffer Jonsson


Room: KB3B1