Centre for
PLANT SCIENCE

Eamens lab

Molecular characterisation of microRNA-directed responses to abiotic stress in plants

During the course of my PhD thesis research on plant molecular genetics at CSIRO Plant Industry Canberra, I became fascinated in the then emerging field of RNA silencing: an endogenous mechanism of gene expression regulation that occurs at the RNA level. In plants, RNA silencing is directed by various species of small RNA to regulate gene expression during all phases of vegetative and reproductive development. More recently, a specific species of small RNA, the microRNA (miRNA) species of small RNA, has been demonstrated across a wide range of evolutionary unrelated plant species, to direct a central role in altering the gene expression changes required for a plant to mount a defence response against an invading pathogen or to adapt to a changing environment.

At the University of Newcastle, we aim to identify the miRNAs responsible for driving the gene expression changes required by a plant to adapt to environmental stress, with a particular interest in the identification of miRNAs responsive to the abiotic stresses central to Australian cropping agriculture, drought stress, heat stress and salt stress. We initially base our studies in the genetic model plant species Arabidopsis thaliana (Arabidopsis). That is, we expose Arabidopsis to environmental stress to identify the stress responsive miRNAs of interest, and then via a molecular approach, we generate new Arabidopsis plant lines to determine if the introduced molecular modifications provide these plant lines with an added degree of tolerance to the applied stress. miRNAs, and the target genes under miRNA-directed expression regulation, have been highly conserved across plant evolution. Taking advantage of this, a future goal of the Eamens Lab is to translate the research findings made in Arabidopsis to agronomically important crop species.

In collaboration with the Grof Lab, we have also recently developed a transformation platform in the C4 monocot grass, Setaria viridis. Development of this platform, and of a suite of other S. viridis specific molecular tools, will allow for the molecular modification of this newly identified C4 model. C4 plants have a highly specialised leaf anatomy compared to that of C3 leaves, therefore; we aim to use S. viridis to molecularly characterise miRNA-directed adaptive responses to environmental stress in C4 plants, in parallel to those studies we currently undertake in Arabidopsis, a C3 plant.

If taking a molecular approach to functionally characterise miRNA-directed adaptation to environmental stress in plants sounds like an exciting research career direction to you, then please do not hesitate to contact me for further information.

Andrew Eamens: andy.eamens@newcastle.edu.au