Key points
- Proteomics is being used to investigate salinity tolerance in wheat
- Identifying proteins involved in salt tolerance using this technique should provide a step change for plant breeders
A keen interest in proteomics – the science enabling researchers to understand complex molecular mechanisms related to plant metabolic processes – underpins Bhagya Dissanayake’s grains PhD.
“I am studying how the metabolic machinery of wheat roots changes under salinity stress conditions,” she says.
Dryland salinity is a major environmental challenge for Western Australia, with the loss of agricultural productivity due to salinity damage estimated to be at least $519 million per year.
In 2018, Mrs Dissanayake was awarded a PhD scholarship supported by GRDC to undertake research in the Australian Research Council Centre of Excellence in Plant Energy Biology at the University of Western Australia, supervised by Professor Harvey Millar, Professor Rana Munns, Dr Christiana Staudinger and Dr Nicolas Taylor.
This followed completion of her honours degree in plant biotechnology in 2017 at the University of Sri Jayewardenepura, Sri Lanka. In her final year she conducted research to produce a polyclonal antiserum to detect a local virus strain that affects chilli plants in Asian countries.
New science informs approach
To improve salt tolerance in wheat, most strategies have focused on breeding for sodium transporters to keep the salt in the roots and thus protect the shoot. But this does not factor in how salt affects the roots themselves.
“This is striking, as the root is the first tissue that is in contact with salt and it’s the tissue responsible for nutrient uptake and ultimately driving plant growth.”
To further improve salt tolerance, Mrs Dissanayake is investigating new molecular markers associated with the complex traits governing root tolerance to salt.
“I have made detailed measurements of the temporal and physiological responses of wheat showing that the root responses are distinct from the shoot responses,” she says.
“I have built a detailed database using proteomics showing how hundreds of different proteins change within the roots of Australian commercial wheat varieties and other wheat genotypes with different levels of salt tolerance.”
This shows how the complex trait of salinity tolerance in wheat develops in the tissue that is first exposed to salt. With this information and her expertise, Mrs Dissanayake can now predict which genes would need to be altered to increase root salt tolerance.
“I have also built assays that can be used to analyse new wheat varieties to assess how well their roots are tolerating salinity, which is beneficial for Australian wheat growers.
Improvement of wheat root salt tolerance can complement existing work to exclude salt from shoots. The two traits can be stacked together to further reduce wheat yield losses in the future.
“We can then use marker-assisted conventional breeding – Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) – or other genetic methods to stack these traits together and then test the combined power of shoot exclusion and root tolerance in the field,” she says.
Mrs Dissanayake intends to build on her experience and work collaboratively with academics, industry and growers to produce better crops for the future.
More information: Mrs Bhagya Dissanayake, 0456 733 970, bhagya.dissanayake@research.uwa.edu.au