Discovery identifies plants that perform better in difficult conditions

Drought, salinity, flooding and extreme temperatures threaten many plants essential to humankind - and scientists at The University of Western Australia have discovered how they respond to these challenges.

Lead researcher Winthrop Professor Steven Smith, of the Australian Research Council Centre of Excellence in Plant Energy Biology based at UWA, said understanding how plants respond to these challenges was vital for food, fuel and fibre production.

“We found that when plants are stressed they respond by increasing their sensitivity to a steroid growth hormone called brassinosteroid. This provides a way for them to step up to the challenge of growth in harsh conditions,” Smith said.

“Our discovery - a great piece of scientific detective work - shows that a plant does not just succumb to whatever the weather serves up: it responds positively by putting energy into continued growth even under difficult circumstances. This finding opens a new door to find ways to identify or select plants that perform better in difficult conditions.”

Lead author Ping Che, Research Assistant Professor in UWA’s Centre of Excellence for Plant Metabolomics, said, “We linked two previously unconnected research fields. It was known that environmental stresses trigger a ‘quality control’ system in the internal membranes of plant cells but the targets of this QC system were unknown.

“We also had circumstantial evidence that brassinosteroids were involved in stress responses in plants. We discovered that the QC system directly activates brassinosteroid sensing, which in turn provides stress tolerance. Mutants defective in the QC system were sensitive to stress but this could be overcome by directly activating the steroid response system.”