The HOS1 protein is a key regulator of the plants response to cold stress and in Arabidopsis, hos1 mutant plants are better able to survive damaging periods of cold treatment. Engineering plants with altered HOS1 expression represents an important potential target for genetic modification to develop low temperature tolerant varieties of plants.
We have found that temperature is an important controlling input in the function of the circadian clock and that HOS1 gene expression is under circadian control. Furthermore it has recently been suggested that HOS1 is an ortholog of the vertebrate ELYS protein, which is a constituent part of the nuclear pore complex (NPC) in higher eukaryotes. The NPC is an enormous macromolecular complex responsible for controlling nucleocytoplasmic transport. The Parry lab has characterized Arabidopsis lines that have mutations within the plant nuclear pore complex and these mutant plants exhibit significant growth defects that are reminiscent of those observed in hos1.
This raises the intriguing hypothesis that the mechanism of HOS1 activity is linked to the circadian control of nuclear transport. We will investigated this relationship by testing the precise nuclear transport of key regulators of clock function, use of expression arrays to discover changes in gene expression associated with altered clock or NPC function and defining how the clock and NPC influences the plants response to environmental stress. This study represents a novel set of experiments of significance to all eukaryotes. Altering the rate of nuclear transport has significant potential as a target for genetic engineering. Mechanisms of nuclear transport and clock regulation are conserved throughout plant species so the information gathered using Arabidopsis is directly transferrable to crop plants. The chosen student will identify research directions to improve plant responses to environmental stresses with the ultimate goal of improving agricultural yield.
For further general information- http://www.geraintparry.weebly.com
Training:
The proposed project will allow the successful PGR to develop skills in the following experimental areas:
General molecular biology. Nucleic assay manipulation, gene cloning, protein analysis and microarrays. These are highly transferrable skills appropriate for a molecular biologist working in all experimental systems.
Plant Growth Techniques. The student will develop skills appropriate for work in any plant science laboratory including phytohormone assays, phenotypic assessments, transient and stable transformations and luciferase assays.
Bioinformatic analysis. The student will develop the skills to analyse microarray and RNAseq data from different mutant or transgenic lines. UoL has great strength in bioinformatics and these skills are critical for future studies that will focus on in silico analysis of large datasets.
Con-focal microscopy. The student will develop real-time imaging protocols to assess the nuclear transport of transcriptional regulators. Plants with defects in NPC function are expected to show relevant reproducible alterations in nuclear transport. Developing techniques for the precise real-time imaging of this movement in a variety of experimental settings will be highly informative and direct future studies.
Funding Notes:
We welcome applicants only with their own funding at the moment as all BBSRC funding has been allocated.
References:
Lee, H., Xiong, L., Gong, Z., Ishitani, M., Stevenson, B., and Zhu, J. (2001) The Arabidopsis HOS1 gene negatively regulates cold signal transduction and encodes a RING finger protein that displays cold-regulated nucleo-cytoplasmic partitioning. Genes Dev. 15. 912-924
Parry, G., Ward S., Cernac, A., Dharmasiri, S., and Estelle, M. (2006) The Arabidopsis SUPPRESSOR OF AUXIN RESISTANCE proteins are nucleoporins with an important role in hormone signaling and development. The Plant Cell 18. 1590-1603.
Gould, P., Locke, J., Larue, P., Southern, M., Davis, S., Hanano, S., Moyle, R., Milich, R., Putterill, J., Millar, A., Hall, A. (2006) The molecular basis of temperature compensation in the Arabidopsis circadian clock. Plant Cell 18. 1177-1187
Research Assessment Exercise (RAE) 2008 Results