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Mothers In Science, produced by Professor Leyser as part of her Royal Society Rosalind Franklin Award, is now available for download from the link on the left

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Contact Details Department of Biology (Area 11) University of York PO Box 373 York YO10 5YW Tel: +44 (0)1904 328680 E-mail: hmol1@york.ac.uk Office: B/L212 Web Page: Mothers In Science pdf

Career Outline

1986	BA, Genetics	Cambridge University
1990	PhD, Genetics	Cambridge University
1990-1993	Post-doc	Bloomington Indiana, USA
1993-1994	Post-doc	Cambridge University
1994- 1999	Lecturer	Department of Biology, University of York
1999-2002	Reader	Department of Biology, University of York
2002-	Professor	Department of Biology, University of York
2002-2003	BBSRC Research Development Fellow	Department of Biology, University of York
2007	Elected Fellow of the Royal Society
2007	Elected Member of the European Molecular Biology Organisation

Research Interests

We are investigating the hormonal control of shoot branching in Arabidopsis, to understand better how plant hormones integrate environmental, developmental, and genetic inputs to regulate development. We are focusing on auxin, an inhibitor of shoot branching, which we have found operates through at least two distinct mechanisms (1). One is dependent on transcriptional regulation, and involves the AXR1 and TIR1 proteins. The second is dependent on auxin transport capacity in the main stem, which is modulated by the MAX pathway. In the MAX pathway, MAX1, MAX3, and MAX4 are required for the synthesis of a branch-inhibiting strigolactone, the perception of which requires MAX2 (2).

Discoveries
The MAX pathway reveals a signalling mechanism between the primary shoot apical meristem and axillary shoot apical meristems mediated by competition for auxin sink strength in the stem. An auxin sink is required to established canalised auxin export from auxin sources, such as axillary buds. This signalling system interacts with auxin and cytokinin signal transduction to integrate multiple inputs into shoot branching control.

Some Recent Publications

Bennett T, Sieberer T, Willett B, Booker J, Luschnig C and Leyser O (2006) The Arabidopsis MAX pathway controls shoot branching by regulating auxin transport. Current Biology 16: 553-563

Stirnberg P, Furner I and Leyser O (2007) MAX2 participates in an SCF complex which acts locally at the node to suppress shoot branching Plant Journal 50: 80-94

Current Research Projects

• Comparative Genomics of Shoot Branching (ERA-Net in Plant Genomics)
  Funding body: BBSRC
• Genome wide analysis of auxin-cytokinin interaction (ERA-Net in Plant Genomics)
  Funding body: BBSRC
• Accelerated breeding for biomass yield in short rotation coppice willow by exploiting knowledge of shoot development in Arabidopsis (Innovation in Crop Science Initiative)
  Funding body: BBSRC
• An Arabidopsis Pseudo-domestication experiment
  Funding body: Gatsby Foundation

Professional Activities

• Editorial Board: Annual Review of Plant Biology
• Editorial Board: Bioessays
• Editorial Board: Current Biology
• Editorial Board: F1000
• Chair, BBSRC Bioscience Skills and Careers Strategy Panel
• International Society for Plant Molecular Biology Board of Directors
• Co-Editor, The Arabidopsis Book
• Member, BBSRC Strategy Advisory Board

PhD Research Projects Available for 2010

Robustness and plasticity in shoot branching control (for 2010-11)
Plant development is notoriously plastic, with the environment having a profound effect on developmental outcomes. For example the degree of shoot branching is strongly influenced by nutrient availability. This response is encoded in a network of interacting long-range signals, including the strigolactone (or derivative), auxin and cytokinin signalling pathways. There are many ecotypes of Arabidopsis, which show substantial branching variation. This provides an exciting opportunity to determine the genetic basis for variation in the robustness and plasticity in shoot branching regulatory network. Various projects are available focusing on molecular aspects of these network properties, to their computational modelling.

Lab Members

Status	Name	Project
PA (Administrative) (40% FTE)	Rebecca Regan
Post doctoral fellow	Dörte Müller	Auxin cytokinin interactions in the control of shoot branching
Post doctoral fellow	Richard Challis	Comparative genomics of shoot branching
Post doctoral fellow (JSPS Post-doctoral Fe	Naoki Shinohara	Vascular development during axillary bud activation
Post doctoral fellow (40% FTE)	Anne Readshaw	An Arabidopsis Pseudo-domestication experiment
Post doctoral fellow (80% FT)	Sally Ward	Accelerated willow breeding for biomass
Post doctoral fellow (80% FT)	Petra Stirnberg	Proteomic and genetic analysis of SCFMAX2 and SCFTIR1
Post doctoral fellow (EU Marie Curie Fellow)	Malgorzata Domagalska	Characterisation of the ADVOLUTA gene, a novel shoot branching regulator
Post doctoral fellow (HFSP Research Fellow)	Céline Mouchel	Cross-species comparative analysis of the MAX pathway
Research Student	Philip Garnett	Integrative models for the hormonal control of shoot branching (Co-supervised by Susan Stepney, Computer Science)
Research Student	Scott Crawford	Analysis of the role of bud auxin export in Arabidopsis shoot branching
Research Student	Danielle Taylor	Characterisation of extragenic suppressors of the max1-1 shoot branching mutant
Research Student	Jo Hepworth	Comparative analysis of the MAX pathway
Research Student	Gilu George	Genotype by environment interaction in shoot branching
Research Student	David Newman	Using arabidopsis-derived tools to investigate shoot branching control in Brassicas
Technician	Lisa Williamson
Technician (40% FT)	Debbie Pears
Visitor	Jianli Liang	Chrysanthemum orthologues of the MAX genes (Joint Training PhD student, China Agricultural University)