Plants intelligently adapt their water infrastructure in times of drought

About the episode

Almost all plants have a vascular system that pumps water and prevents dehydration. In extreme drought, the chain of water molecules along the way can break through the stem. This creates a gas bubble which prevents water from passing through. If this problem spreads through the factory, it’s game over.

Research now shows that the original shape of this vascular system – a cylinder in the center of the stem – becomes more susceptible to this spread as the size of the plant increases.

The first plants with a vascular system were only a few centimeters tall. They liked places with lots of water. In order to grow and live in other drier places, the vascular system first had to be modified. The larger the plant, the greater the challenge of creating a version that will thrive in drier conditions.

Fossils show that this vascular system evolved in different ways, in all forms. From cylinder to ovals, stars and rings. This observation had already been made in the 1920s, but it was not known why these complex structures appear in large factories.

Thanks to this new research, we now know that taller plants create a drought-resistant vascular system by limiting tissue width. The taller the plant, the thinner the tissue, the longer and more complex the shape of the vessels becomes. And this knowledge can be helpful in growing plants that can better withstand drought.

Read more: A century-old botanical riddle reveals key plant adaptations to drylands.