cassons

Dr Stuart Casson

Room: E7b
0114 222 4235
s.casson@sheffield.ac.uk

General

Career History

  • August 2013: Lecturer; Dept. of Molecular Biology and Biotechnology, University of Sheffield
  • 2007 - 2013: Research Assistant; University of Bristol
  • 2000 - 2007: Research Assistant; Durham University
  • 1996 - 2000: PhD Student; Durham University

Honours and Distinctions

  • 2008 Federation of European Societies of Plant Biology (FESPB) young scientist award

Research Keywords

Plant development, stomata, light and CO2 regulation, photoreceptors

Research

My laboratory is interested in understanding the mechanisms that regulate plant development and in particular, how environmental signals regulate core developmental pathways. For this purpose I am using stomatal development as a model. Stomata are microscopic pores on the surface of leaves that regulate gas exchange between the plants and their environment, allowing the uptake of carbon dioxide for photosynthesis whilst restricting water loss. This ability to control their gas exchange has allowed plants to colonise a number of environments and was arguably a crucial evolutionary step in the colonization of the land by higher plants.

Stomata can regulate plant gas exchange through short term changes in stomatal aperture. However, my research is focused on a longer term mechanism whereby plants adapt to changes in their environment by regulating their stomatal development, resulting in new leaves with altered stomatal numbers. Light and CO2 are particularly important in regulating these changes in stomatal development and we are beginning to identify the key components that regulate stomatal development in response to these signals. Understanding how these environmental signals interact to regulate stomatal development is vital if we are to accurately model plant water use and performance in a changing environment

fig1

Figure 1: The epidermis of a developing leaf of the model plant Arabidopsis thaliana. Mature stomata (starred) consist of a pair of guard cells and arise from a series of stereotypical cell divisions.

fig2

Figure 2: The key stages in stomatal differentiation are regulated by three closely related transcription factors; SPEECHLESS, MUTE and FAMA. SPCH has been shown to be targeted by a MAP kinase signaling cascade, although there is evidence that this MAPK pathway can act at each stage of stomatal development and is not always inhibitory. A set of membrane bound receptors act upstream of this MAPK pathway and the receptors bind a series of EPIDERMAL PATTERNING FACTORS, which are small peptides. Some of these EPFs, such as EPF1 and EPF2, negatively regulate stomatal development whilst STOMAGEN acts as a positive regulator. A protease, SDD1, negatively regulates stomatal development although its target has yet to be identified.

fig3

Figure 3: Environmental control of stomatal development. Light quantity and CO2 regulate epidermal cell fates leading to either an increase (light) or decrease (CO2) in stomatal numbers. The HIGH CARBON DIOXIDE (HIC) gene regulates stomatal development in response to CO2, whilst the red light photoreceptor phytochrome B and the transcription factor PIF4 regulate stomatal development in response to light signals.

Teaching

Module Coordinator: MBB304 Plant Biotechnology

Level 3 Modules

Level 2 Modules

PhD Opportunities

I welcome applications from self-funded prospective home and international PhD students; see examples of possible projects below.

You can apply for a PhD position in MBB here.

Contact me at s.casson@sheffield.ac.uk for further information.



Photoreceptor regulation of plant development Plant growth and development is highly dependent on the light environment. Light provides energy to drive photosynthesis but light quality and quantity is also perceived by photoreceptors, which signal to regulate responses enabling plants to adapt to their environment. These light signalling pathways have been shown to interact with other signalling pathways that regulate plant responses to both biotic and abiotic stresses, such as pathogen attack and drought. Manipulating photoreceptor signalling therefore has the potential to improve plant resistance to both biotic and abiotic stress.








































Publications

Journal articles

Conference proceedings papers