Improving Barley (Hordeum vulgare) Root Performance under Salinity through Beneficial Microbes

The close contact between roots and soil is vital for water and nutrient uptake but this also exposes roots to biotic and abiotic stress. Along with the roots and soil, the rhizosphere is densely populated with a variety of microorganisms. Interactions between roots, soil and rhizosphere community members are usually achieved by chemical communication. Root exudates present in the rhizosphere comprise a collection of primary and secondary metabolites that help in attracting belowground beneficial microbes, helping the plants to fight against biotic and abiotic stresses. Salinity in Australia causes one of the greatest impacts on agricultural production, leading to decreased plant performance and therefore yield. In 2001, over 5.7 million hectares, mostly agricultural land, were affected by salinity in Australia. Predictions indicate that, if effective solutions are not implemented, the area affected could increase to 17 million hectares by 2050. Understanding how plants, and particularly roots are affected is important to establish new avenues for improving performance and resistance to this detrimental soil-based stress. Barley is Australia`s second most important cereal crop. Here we propose that a comprehensive biochemical analysis of barley root exudates, beneficial rhizosphere communities and the rhizosphere itself is one of the approaches that can enhance our understanding of the chemical dialogue between these components. The aim of this project is to study the biochemical basis of the interactions between roots, microbes and soil using metabolomics tools so that a broader picture of how plants interact with belowground life to tolerate abiotic stress, particularly salinity, can be created. We believe answers to these questions will stimulate new ideas and spawn a new generation of strategies for enhancing crop production – the ultimate goal of agricultural industry as a grand challenge for science over the next 30 years is the provision of sufficient food, fibre and energy to support a global population of over 9 billion.