Plant & zo
The science of plants and more
Excel through collaboration
Fungi, we see them mostly as the mushrooms that stick their heads above the ground in autumn. But underground there are whole networks of them. Plants make good use of those. They collaborate with Arbuscular mycorrhizal fungi. Exchanging sugars for nutrients. And are so able to excel during difficult times. Not only when there is a nutrient shortage, but also during a water shortage. For a long time, researchers thought this was a side effect. But now they show that these fungi actually provide extra water.
To us the ground appears to be impermeable, but in truth it is full of holes. Big holes, small holes, and miniscule holes. Water loves holes, as such it often can be found in them. A root that makes its way through the earth searchers water. Taking up the water out the big holes, and the small holes. But they can’t reach the water in the miniscule holes. The roots are too big for those. Fungal threads not, they can get into the miniscule holes and reach the water they are holding.
The fungal threads appear to transport the water to the plant
The American researchers used this fact. They grew plants in a pot with a barrier. Roots could not grow through this barrier, but fungal threads could. The researchers watered the plants with labelled water at the side of the barrier only fungi could access. Then they analysed the plants. Plants that collaborated with the fungi were sweating twice as much as plants without helping fungi. And two thirds of the collaborating plants sweat was labelled water. These plants were taking up water that they could only access with help of their fungal collaborators.
Subsequently they study how the fungi gets the water to the plant. The researchers dyed the water at the side of the barrier that only the fungi could access, using a dye that could not get through the cell membrane. They say the dye back in the roots. But also, at the outside of the fungal threads. It appears that the fungal threads hold on to the water at the outside. And in this way transport the water to the plant.
With the help of fungi, plants can get to the water in the miniscule holes. In this way fungi help plants in times of drought. When the extra water can be the difference between excelling or dying.
Kakouridis, A., Hagen, J.A., Kan, M.P., Mambelli, S., Feldman, L.J., Herman, D.J., Weber, P.K., Pett-Ridge, J. and Firestone, M.K. (2022), Routes to roots: direct evidence of water transport by arbuscular mycorrhizal fungi to host plants. New Phytol. https://doi.org/10.1111/nph.18281