King Abdullah University of Science and Technology (KAUST)

Picture: The research team treated the plant Arabidopsis thaliana with a specially selected bacterial strain (as shown in the picture above) to promote their growth under stress conditions. The smaller plant on the left is the control, and the plant on the right is the plant that has been treated with bacteria. see more 

Bacteria living in the roots of some plants enable them to grow well under salty conditions. Their secret weapon is to trigger sulfur metabolism, and this discovery has helped develop new biotechnologies to promote the use of salt water to irrigate crops. This is an important prospect for countries like Saudi Arabia that rely on energy-intensive desalination of fresh water.

Certain types of beneficial bacteria interact with their plant hosts to help them thrive and also promote plant growth. In 2013, plant scientist Heribert Hirt founded the Darwin21 project at KAUST, which aims to use desert plant bacteria to improve agricultural sustainability in arid regions. This led to the isolation of a bacterium called Enterobacter. SA187, they found that it can make crops resistant to various stresses, including heat, drought and salt tolerance.

Hirt's team has now analyzed the genetic and metabolic changes that occur when SA187 and the model study plant Arabidopsis interact under salt-free and salt-stress conditions.

"We want to understand the molecular mechanism behind the salt tolerance produced by the interaction of plants with SA187," said Rewaa Jalal, a Ph.D. plant scientist. At KAUST, he is now an assistant professor at Jeddah University.

Generally, when plants are exposed to too much salt, their cells release reactive oxygen species, causing cell damage and reducing plant growth and crop yield. The researchers found that salt stress triggers the sulfur metabolism of the SA187 bacteria living in the roots of Arabidopsis thaliana. This in turn leads to the release of sulfur metabolites, which provide nutrients for sulfur metabolism in Arabidopsis plants, and produce a key antioxidant called glutathione, which can detoxify plants from salt-induced reactive oxygen species and make It can grow and thrive under pressure.

"Another important finding of our investigation is that we can directly add sulfur metabolites to replace the protective function of SA187 against plant salt stress damage, thus opening up the possibility of using probiotics in agriculture," Hirt said.

Hirt established a start-up company with molecular biologist Maged Saad and several current and former students, aiming to provide breakthrough technology that can use SA187 to treat seeds or crops, save money for Saudi farmers and make salt farming a reality .

"If such knowledge and appropriate tools are applied to arid and semi-arid regions, we can meet most of the global demand for food production," said Hanin Alzubaidy, a postdoctoral fellow.

Proceedings of the National Academy of Sciences

The coordinated metabolism of sulfur in bacteria and plants in the genus Enterobacter. SA187-induced plant salt stress tolerance

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Michael Cusack King Abdullah University of Science and Technology (KAUST) michael.cusack@kaust.edu.sa Office: 8083040

Heribert Hirt King Abdullah University of Science and Technology (KAUST) heribert.hirt@kaust.edu.sa

King Abdullah University of Science and Technology (KAUST)

Copyright © 2021 American Association for the Advancement of Science (AAAS)

Copyright © 2021 American Association for the Advancement of Science (AAAS)