Plant natriuretic peptides - novel protein signalling networks

Project Leader:   Dr Helen Irving

We have recently provided evidence for the presence and biological activity of a novel class of plant molecules that have the characteristics of a plant hormone with immunological similarity to vertebrate natriuretic peptides.  Using a reverse genomic approach, we identified this novel class of plant molecules – Plant Natriuretic Peptide (PNP) immunoanalogues – that affect several processes that are directly involved in the regulation of plant water and salt balance.  Since growth and survival of all living organisms, including plants, is critically dependent on this balance we predict that PNPs play a major, albeit unknown at the molecular level, role in plant responses to salinity and drought stresses.  In this project we set out to use molecular and genetic tools to investigate the functional biological role and mechanisms of action of PNPs and their protein signalling networks that interact with other classical hormones such as abscisic acid and biotic elicitors such as plant pathogens. This fundamental discovery research is undertaken with a long-term aim of harnessing this knowledge to improve salinity and drought resistance in commercially important crops.  

To reach this goal we have established a highly successful and multi-faceted international team (Prof Chris Gehring at the University of Western Cape, South Africa and Dr David Cahill at Deakin University, Geelong, Australia).  This team has played a key part in identifying the presence and unique importance of this novel plant hormone system.  Plant natriuretic peptides will be further characterised using an innovative combination of different fields and skills – Molecular Biology, (Analytical) Biochemistry, Bio-informatics, Biophysics, Genetics, Plant Physiology and Cell Biology – to bring the maximum breadth and depth to this focussed investigation into the nature of the novel PNP hormone system.  Moreover, we wish to determine if these plant compounds have any effect on animal tissues.  If such compounds are found to be active, they may form the basis of new classes of drugs.  Hence there are several PhD topics available for study within this project.

This project is funded in part by an Australian Research Council Discovery Grant.