Abstract: Soil salinity (soil NaCl) can significantly reduce plant growth and yield; even moderate levels can reduce the grain yield of major cereal crops by 50%. In Australia, the estimated cost of salinity on agricultural productivity is valued at $1 billion per annum. Current efforts to improve crop salt tolerance have predominately focused on limiting the delivery of toxic sodium ions (Na⁺) to photosynthetic tissues. This has often been done by the manipulation of Na⁺ transporting High Affinity Potassium Transporter (HKT) proteins. This has had notable success, albeit with limited translation to major crops. Our recent research is seeking to challenge the paradigm of Na⁺ exclusion from vegetative tissues, and looking to redefine the role of sodium exclusion within salt tolerance. We (and other research groups) have identified bread wheat, barley and Arabidopsis accessions which can tolerate high leaf Na⁺ concentrations without penalty in shoot biomass of seed yield. We are seeking to understand how these plants tolerate significantly high levels of vegetative Na⁺, how they are able to maintain grain yield, and whether the accumulation of high levels of Na⁺ in their tissues is advantages in drought years in rainfed environments. This presentation will cover the identification and characterisation of “low leaf sodium” and “high leaf sodium” alleles of HKT1;5 in wheat and barley, their prevalence in current elite germplasm and opportunities for enhancing wheat and barley yield in rainfed environments.

Biography: A/Prof Stuart Roy is the Deputy Director (Industry) of the Australian Research Council (ARC) Industrial Transformation Training Centre (ITTC) for Accelerated Future Crops Development and the Associate Head of the School of Agriculture, Food and Wine (External Engagement & Outreach) at the University of Adelaide. His interests are in improving the abiotic stress tolerance of cereals crops and yield. For the last 14 years, he has been running Genetically Modified Organism and Gene Edited wheat and barley trials in South Australia, Western Australia and Victoria. These are proof of concept trials to determine the value of different genes of interest, with results of these trials are used to develop non-GMO alternatives for passing on to breeding programs.