A trial to develop drought-resistant acacia shrubs to combat desertification in Saudi Arabia has resulted in plants that can survive on as little as one liter of water a month.

 

The desert trial, which ended last month, showed that acacia plants treated with the plant hormone salicylic acid — a precursor of the drug aspirin — had a higher survival rate in arid conditions than conventional plants. Around 40 per cent of seedlings treated with the hormone survived on less than a liter of water a month, whereas only three per cent of untreated seedlings did.

 

The test took place in the arid Thumama Nature Park near Riyadh. The trial is part of a wider project that aims to address environmental degradation caused by overgrazing, while also exploring methods of growing plants in arid environments to reverse desertification, its partners say.

 

The team behind the work — representatives from Saudi Arabia’s ArRiyadh Development Authority and scientists from Kings Park, a city garden in Western Australia — are aiming to establish an area in Thumama Nature Park for producing seeds for distribution among local authorities.

 

To treat the plants, salicylic acid was coated on the seeds or sprayed onto the leaves of grown plants. The acid helps suppress a reactive form of oxygen molecule. Plants that do not get enough water overproduce these molecules, which damage cells and ultimately kill the plant. In addition, the chemical helps to shrink the stomata: the tiny leaf pores through which oxygen and carbon dioxide are exchanged and through which water vapor also inadvertently escapes.

 

By limiting water loss, or allowing the plants to become more water efficient, salicylic acid protects the plants under severe stress conditions.

 

 

PHOTO CREDIT: David Rose/Panos.