Scientists have found that plant roots adjust their shape to maximize water absorption. They stop branching when they lose contact with water and resume branching only after they reconnect with moisture, which helps the plant survive even in the driest conditions.
Plant scientists at the University of Nottingham have discovered a new water sensing mechanism they call "hydrosignaling". Phys.org portal. It shows how the movement of hormones is related to the flow of water. The results of the work of scientists were published in the journal Science.
Water is the molecule that limits the speed of life on earth. Climate change is causing rainfall patterns to become more erratic, affecting rainfed crops in particular.
Roots play a critical role in reducing the impact of water stress on plants by adapting their shape (for example, branching or deepening) to provide more water. Finding out how plant roots adapt to water stress is vital in helping crops increase their resilience to climate change.
Using X-ray micro-computed tomography, the researchers were able to reveal that the roots change their shape in response to the availability of external moisture, linking water movement to signals from plant hormones that control root branching.
The study provides important insights into key genes and processes that control root branching in response to limited water availability, helping scientists develop new approaches to control root architecture to improve water uptake and crop yields.
When roots come into contact with moisture, a key hormonal signal (auxin) enters with the water, causing new roots to form. root branches. However, when roots lose contact with moisture, they rely on internal water sources to mobilize another hormonal signal (ABA) outwards that blocks the branching signal from moving. This simple yet elegant mechanism allows plant roots to fine-tune their shape to local conditions and optimize moisture retrieval.
These new discoveries are only possible thanks to cutting-edge tools and the collaborative approach of an international team of scientists from the UK, Belgium, Sweden, the US and Israel.