Molecular mechanisms that control plant growth plasticity

Supervisors: Professor Karen Halliday (see also here), Dr Ramon Grima

Project Description:

Plants are inherently plastic organisms. Their general body plan is genetically encoded, but plant architecture can be modified to adjust to the environment that surrounds it. In this sense, external cues, such as light and temperature, have a profound effect on the way a plant grows and develops, ultimately affecting a plant’s fitness, disease resistance and productivity1. Growth plasticity is particularly pronounced in leaves that are able to adapt to an extraordinary array of external conditions. This project will elucidate the light and temperature- activated molecular mechanisms that control cell proliferation, carbon partitioning and leaf architecture.
Results from this PhD project will be highly relevant for crop research. For instance, an expected outcome is the identification of molecular strategies to improve plant architecture in dense cropping environments (that normally reduce yield). The project will also have broad reach as it will deepen our understanding of environment-driven growth plasticity, a fundamental property that underlies the extraordinary evolutionary success of plants on earth.
Recent work from the Halliday lab has shown that alterations photoreceptor signalling lead to dramatic changes in metabolism, carbon resource partitioning and leaf biomass2.  This project will build on these findings new data form the Halliday lab that has identified molecular components that couple photoreceptor signalling to cell division. The aim will be to: i) elucidate the molecular connecting mechanism, ii) generate resources for molecular function analysis of key pathway components using cloning, gene editing and/or transgenic methods, iii) use our 3D imaging platform to quantify dynamic growth in photoreceptor / signalling pathway mutants, iv) quantify leaf photosynthesis and associated changes in carbon metabolism, v) conduct RNAseq and bioinformatics analysis that characterises the dynamical transciptome response through time, vi) work with theoretical scientists to model and predict the impacts of changing light and resource availability on growth: this will aid the development of strategies to improve plant growth and productivity in vegetation-rich field crop environments that exclude light.

References:
1. Ballaré CL, Pierik R. The shade-avoidance syndrome: multiple signals and ecological consequences. Plant Cell Environ. 2017 Review. PMID:  28102548
2. Yang D, Seaton DD, Krahmer J, Halliday KJ. Photoreceptor effects on plant biomass, resource allocation, and metabolic state. Proc Natl Acad Sci U S A. 5;113(27):7667-72. PMID:    27330114.

If you wish to apply for this project, please go to this link.

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