A project undertaken at Western Sydney University, and supervised by Jayakumar Bose
Soil salinity is a major threat to food production throughout the world. The salinisation of agricultural lands is steadily increasing – every day an additional 2000–4000 ha of farmland is defined as saline. In Australia alone, salinity currently causes crop losses worth $1.3bn annually, and it is expected that salinity-affected arable land will triple by 2050. This jeopardises the increase in food production required to supply 9.3 billion people by 2050. Thus, improving salt tolerance is a top priority to ensure food security, but the narrow genetic variability for salt tolerance within crop plants limits the success of traditional breeding methods. This project will identify mechanisms that allow naturally salt-loving plants to maintain growth and yield in salty soils to create a fundamental breakthrough in our understanding of salt tolerance.
Figure 1.
The outcome generated in this project will help to formulate new strategies to introduce target genes that confer salt tolerance into salt-sensitive crops, thus improving the productivity of saline soils. The research will primarily focus on quinoa, a naturally salt-loving crop (halophyte) capable of growing in salty soils where most crops fail (Figure. 1). Interestingly, quinoa maintains or even enhances its ability to perform photosynthesis—the process through which plants convert sunlight into energy—under salt stress. This is in stark contrast to salt-sensitive crops like wheat and canola, which experience significant reductions in photosynthesis when exposed to salt. The presence of salt bladders (specialised cells) on the surface of the leaves has been implicated in storing excess salt and protecting the leaves from salt damage (Figure. 1). The overarching aim of this project is to understand how quinoa’s chloroplasts – organelles responsible for photosynthesis– function in saline conditions.
Figure 2.
This project will explore several key questions: How do quinoa’s chloroplasts adapt to salt stress? Why do salt bladders contain chloroplasts, and how do these chloroplasts function under high salt concentrations? How do these chloroplasts acquire the carbon dioxide needed for photosynthesis, given that salt bladders lack the pores (stomata) that typically facilitate gas exchange in leaves? To answer these questions, the project will utilise advanced techniques such as confocal microscopy, transmission electron microscopy, and transcriptome analysis to study changes in chloroplast structure, photosynthesis efficiency, and gene expression under salt stress.
The outcomes of this research could lead to significant breakthroughs in crop breeding. By identifying the genes and mechanisms that allow quinoa to thrive in saline soils, plant scientists could develop new strategies to introduce these traits into salt-sensitive crops. This advancement would enable farmers to cultivate crops on saline land, thereby increasing food production and mitigating the economic losses caused by soil salinity. Ultimately, this research could contribute to more sustainable agricultural practices, aiding in the effort to feed a growing global population while conserving natural resources and protecting the environment.