Scientists identify the most heat-resistant plant ever discovered on Earth

In the heart of California's Death Valley, one of the most inhospitable places on the planet, where summer temperatures regularly exceed 49 degrees Celsius, life seems to have virtually no chance. And yet, it's precisely in this hell of sand and sun that a plant grows quietly and is able not only to survive, but to accelerate its growth when the heat becomes extreme. Its name is Tidestromia oblongifolia, also known as Arizona honeysweet, and it has just been officially recognised as the most heat-tolerant plant ever documented.

According to researchers, this desert species has developed a unique biological strategy: it has rethought the photosynthesis process from within, transforming temperatures lethal to most plants into a competitive advantage. The discovery could change the future of global agriculture, increasingly threatened by global warming.

The desert plant grows better when the heat exceeds 49°C.

The study began with a seemingly simple question: how can a plant stay green, productive and growing in conditions that kill off virtually all other plant life in just a few hours? Initial laboratory results were disappointing. Tidestromia oblongifolia seeds, grown under controlled conditions, struggled to develop, as if unsuited to life.

The problem, however, lay not with the plant, but with the context. Conventional laboratory conditions proved to be too 'mild' for Death Valley's brutal climate. Researchers therefore decided to artificially recreate the plant's natural environment, building special growth chambers capable of simulating intense sunlight, wide daily temperature ranges and extreme temperatures.

Once the context had been made more realistic, the true nature of the plant was forcefully revealed. In just ten days, the biomass of Tidestromia oblongifolia tripled, while other desert plants, already reputed to be heat-resistant, stopped growing altogether. The behaviour in question has never been observed with such intensity.

The secret of this extraordinary resistance lies in the plant's rapid adaptation of photosynthesis. After just two days' exposure to extreme temperatures, the plant continues to produce energy efficiently. After two weeks, the optimum temperature for photosynthesis reached 45 degrees Celsius, a value higher than that of any other known plant.

The implications of this study, published in the scientific journal Current Biology, go far beyond desert botany. With global temperatures estimated to rise by up to 5 degrees Celsius by the end of the century, heat stress is already reducing yields of key crops such as wheat, corn and rice.

Up until now, research has struggled to make crop plants more resistant to heat because studies have mainly focused on species that are easy to grow in the laboratory, and not very representative of extreme conditions. Tidestromia oblongifolia turns this perspective on its head, demonstrating that plants are capable of far more advanced adaptations than previously thought.

(MP/ ©Greenme.it/Translation and adaptation: The Global Nature/Pic: Unsplash)