everlasting? A study reveals the genetic secrets of the “non-dying” plant in the African desert

Willowicia plants have only two leaves that constantly elongate in a life cycle that scientists estimate to be up to 3,000 years. Her genes could help grow stronger crops in the context of global warming.

Willowicia, known as the “desert octopus,” is one of the oldest and most famous plants on the planet that lives in the arid Namib Desert, between Angola and Namibia. Its name in Afrikaans is “tweeblaarkanniedood”, which means “two leaves that never die”.

study published Recently in Nature Communications he reveals some of the genetic secrets of Welwitschia.

“This plant can live thousands of years and not stop growing. When it stops growing, it dies.” She said Andrew Leach, a plant geneticist at Queen Mary University of London and one of the study’s authors, told the New York Times.

“In fact, some of the largest specimens are thought to be over 3,000 years old,” he says.

The researchers, led by Tao Wan, a botanist at the Lake Ferry Botanical Garden in Shenzhen, China, analyzed the plant’s genome to understand its unique shape, extreme longevity and profound resilience.

They concluded that there Approximately 86 million years ago During a period of increased aridity and prolonged drought in the region, where the Namib Desert likely appeared – the entire genome of Weilwichia doubled after a cell division error, notes Wan, who showed that “extreme stress” is often associated with such events. .

Scientists say that much of the Willowicia genome is self-replicating “junk” DNA sequences, called retrotransposons, that experienced a “burst” of activity a million or two million years ago, possibly due to the increase in temperature.

To combat this, the Willowicia genome has undergone extensive genetic changes that silenced “junk” DNA through a process called DNA methylation.

This process, along with other selective forces, greatly reduced the size and Energy maintenance cost from Welwitschia’s refined DNA library, giving it “a very efficient, low-cost genome,” Wan notes.

Other genetic modifications

Also, as the middle leaf of the plant grows out from the tips or the ends of its stem and branches, the original tip of the wolfiechia eventually dies off. In this way, its new leaves emerge from a weak area in the plant’s anatomy called the basal meristem, which provides new cells for the developing plant, the specialist explains.

The large copy number or increased activity of some genes involved in efficient metabolism, cell growth and resistance in this region could help this region continue to grow under the intense environmental stress of the Sahara.

Genetic lessons from the Willwichia study can help people To grow crops that are more robust and require less water in the context of global warming.