In response to water-scarce conditions, plant roots can adapt their shape, branching when moist and rooting deeper without branching when dry, to maximize the amount of water available in the soil.
Understanding how this works may help future plants adapt to increasingly harsh climates.
A recent study published in Science reveals how plants can do just that.
Using micro-CT imaging, the researchers found that when roots come into contact with water in the soil, a key hormonal signal moves with the water to the inside of the root system, stimulating root branching.
When the soil environment is dry, water inside the root system moves outward along with another hormone, ABA, preventing the branching signal from moving inward.
This mechanism allows the root system to adjust its shape to the environment and maximize water uptake.