Researchers develop plants with enhanced drought resistance

Researchers have developed plants with increased drought resistance by modifying the signaling of the plant steroid hormones, known as brassinosteroids. The study, published in the journal Nature Communications, is the first to find a strategy to increase hydric stress resistance without affecting overall plant growth.

Ana Caño-Delgado, a researcher at the Center for Research in Agricultural Genomics (CRAG), has been studying how brassinosteroids regulate plant development and growth in the model plant Arabidopsis thaliana for more than 15 years. In the current work the researchers have studied drought resistance and growth in Arabidopsis thaliana plants with mutations in different brassinosteroid receptors. They found that the plants that overexpress the BRL3 brassinosteroid receptor in the vascular tissue are more resistant to the lack of water than control plants and that, unlike the other mutants, they do not present defects in their development and growth. “We have discovered that modifying brassinosteroid signaling only locally in the vascular system, we are able to obtain drought resistant plants without affecting their growth,” explained Caño-Delgado.

CRAG researchers in collaboration with researchers from Europe, the United States, and Japan analyzed the metabolites in the genetically modified plants and demonstrated that arabidopsis plants overexpressing the BRL3 receptor produce more osmeoprotective metabolites (sugars and proline) in the aerial parts and in the roots under normal irrigation conditions. When these plants were exposed to drought conditions, these protective metabolites quickly accumulated in the roots, protecting them from drying out. Hence, the BRL3 overexpression prepares the plant to respond to the situation of water scarcity, a mechanism known as priming.

Now, the researchers are working on applying this strategy in plants of agronomic interest, especially in cereals. “Drought is one of the most important problems in today’s agriculture. So far, the biotechnological efforts that have been made to produce plants more resistant to drought have not been very successful because as a counterpart to an enhanced drought resistance there was always a decrease in plant growth and productivity. It seems that we have finally found a strategy that could be applied, and we want to continue exploring it,” concluded Caño-Delgado.

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