New research has discovered how plant roots sense the availability of moisture in soil and then adapt their shape to optimise acquisition of water.
The discovery could enable crops to be bred which are more adaptive to changes in climate conditions, such as water scarcity, and help ensure food security in the future, according to researchers at the universities of Nottingham and Durham.
These findings, published in the journal ‘Science’, describe a new molecular mechanism discovered by collaborating teams from the above universities, primarily funded by a joint award from the Biotechnology and Biological Sciences Research Council (BBSRC).
Plants are able to adapt to different soil moisture conditions by altering their root architecture, but up until now, it was not understood how this is done, according to the researchers.
Root branches only form when in direct contact with soil moisture using an adaptive response termed hydropatterning. Professor Malcolm Bennett of the University of Nottingham, and Professor Ari Sadanandom from the Department of Biosciences at Durham University, discovered that hydropatterning is controlled by a branching master gene called ARF7.
Their teams observed plant roots lacking ARF7 were no longer able to hydropattern. The researchers concluded that when roots are exposed to moisture ARF7 remains active and promotes root branching, but when exposed to air, ARF7 is modified and inactivated, blocking root branching.
Professor Sadanandom says: “Plants are relatively immobile and therefore their growth and development is very much dependent on their environment. Our research has identified the particular protein which can modify, and even inactivate root branching, therefore limiting plant growth and development.
“This is hugely exciting as it opens up the possibility for us to adapt this protein interaction and potentially develop plants that could continue to branch roots even in challenging conditions such as water scarcity.”
Professor Bennett concluded: "Water is critical for plant growth, development and, ultimately, their survival. Surprisingly, understanding how plants sense water availability has eluded scientists until now. By studying how plant roots modify their branching in response to water availability, we have uncovered a novel molecular mechanism. This represents a major step forward and opens the way for breeders to develop new crops better adapted to climate change and helping deliver global food security.”