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Across much of Africa’s arid regions, the distinct silhouettes of acacia trees define the skyline, standing as unobtrusive symbols of endurance in an environment where extreme temperatures and scarcity of water influence all living beings.

They maintain the soil, provide food for animals, offer shelter to wild creatures, and support the way of life for those who rely on pastures. However, as climate change leads to more severe droughts and heat, even these resilient trees are facing challenges.

Currently, new studies have revealed that two of Africa’s most famous acacia species, the flat-topped Vachellia tortilis and the tall Vachellia robusta, endure droughts using entirely different genetic approaches. One combats the situation. The other appears lifeless. Both demonstrate nature’s remarkable methods of surviving in a world with ever-decreasing water availability.

The research, conducted by the University of Würzburg and the Kenya Forestry Research Institute and featured in Nature Plants, provides more than just an insight into the molecular processes involved in drought resistance, but also presents a new approach for examining plant resilience under climate stress.

As per researchers, gaining insight into how trees adjust at a molecular level may assist in directing reforestation, carbon sequestration, and biodiversity initiatives in Africa’s arid regions, where acacias play a crucial role for both animals and the lives of herders.

Both acacia species are widespread throughout eastern and southern Africa, frequently found together, but they inhabit distinctly different ecological niches. The flat-topped acacia is prevalent in the most challenging environments across the continent, ranging from Turkana in Kenya to the deserts of Namibia. The splendid thorn acacia flourishes in more humid savannahs and along riverbanks.

To determine what makes their resilience unique, researchers headed by Maximilian Weinheimer cultivated young trees in a controlled greenhouse environment and subjected them to 43 days of simulated drought. They tracked how thousands of genes activated or deactivated—a molecular record of each tree’s internal reaction to stress.

The acacia with a flat top, a species less resistant to drought, initiated an active defense mechanism. It continued to operate its metabolic and photosynthesis genes, aiming to sustain growth and water equilibrium as soil moisture decreased. However, this effort had a price, as its energy supplies eventually declined.

Kenya’s northern drylands offer an unexpected abundance of wildlife, while the splendid thorn takes a slower, more measured approach. As the drought worsened, it did not resist but instead withdrew. The tree decreased its metabolic processes, saving energy and entering a controlled state of dormancy until conditions improved. “It’s almost counterintuitive,” says Weinheimer. “The species that lasts longer is the one that reacts less. It has learned to endure stress, rather than fight it.” To capture these subtle differences, the researchers created a new analytical tool known as Differential Gene Reaction (DGR) analysis. Unlike traditional “before and after” comparisons, DGR monitors how each gene’s activity changes over time, showing not only which genes respond, but also when and for how long.

This revelation indicates that both species utilize comparable physiological mechanisms, including the regulation of photosynthesis, water movement, and hormonal signaling, yet they activate these processes in distinct ways. The research implies that evolution has developed various genetic pathways for drought resistance even within one genus.

The results have significant consequences for Africa’s reforestation and climate adaptation initiatives. Numerous restoration efforts fall short as they neglect how species react to prolonged stress. Grasping genetic approaches such as these can assist in choosing trees that not only endure but also maintain carbon sequestration and biodiversity in more challenging climates.

The DGR method may also support the creation of crops that can withstand drought, as numerous stress-response mechanisms function similarly among different plant species. Provided by SyndiGate Media Inc. (Syndigate.info).