Scientists discover smart ‘switch’ in plants that allows them to redirect roots to find water

Scientists have discovered a rapid molecular switch in plant roots that allows them to detect dry soils and redirect root growth to find water. This discovery could help in developing drought-resilient crops and addressing future food security challenges.

Roots typically branch out in response to moisture in the soil, foraging for water and nutrients. However, when the growing root loses contact with moist soil, it temporarily halts the formation of lateral branches. This smart response helps plants redirect their root growth toward areas with higher water availability.

In this new study, led by scientists at the University of Nottingham in collaboration with Durham University has identified a rapid signalling mechanism that enables plant roots to detect and respond to dry soil conditions. The study, published in Science, reveals that this adaptive response is triggered by a rapid increase in reactive oxygen species (ROS) in root tips. ROS act as stress signals, indicating to the roots that it has entered a dry zone.

The team were able to reveal how the ROS interacts with a specific protein and hormone in the plant that regulates growth and development, and how this can be disrupted with the protein serving as a molecular switch, integrating environmental stress signals with hormonal control to shape root architecture.

Dr Poonam Mehra, BBSRC Discovery fellow from the University of Nottingham’s School of Biosciences led the research, she said: “This is a fast, efficient mechanism that allows plants to sense water stress and react almost immediately, allowing them to conserve resources and optimise root growth in response to their environment.”

Professor Malcolm Bennett from the University of Nottingham added, “This work shows how a single protein can act as a highly responsive sensor, linking the plant’s stress perception to growth decisions. It opens exciting possibilities for engineering crops that are better adapted to water-limited environments.”

This breakthrough is not only a step forward in basic plant science, but also holds important implications for global food security As drought becomes more frequent and severe due to climate change, understanding how roots respond to water stress is vital for developing crops that can survive in harsher environments.

This landmark study was conducted in partnership with seven additional institutions across the UK and Europe, combining expertise in molecular biology, structural biology, and advanced imaging technologies.

END