Scientists have uncovered a new mechanism by which plants can regulate root architecture, a discovery that could lead to better ways of growing crops.
Adaptable roots are critical for plants to survive in changing environmental conditions, to anchor the plant to the ground and take up water and nutrients. One important aspect of root architecture is root branching, or lateral root development, a complex process involving plant hormones, environmental signals, and many genes and proteins.
Working on the plant species Arabidopsis, Biotechnology and Biological Sciences Research Council funded researchers from the universities of Birmingham and Nottingham discovered that a gene called AtMYB93 plays an important role in the regulation of root branching.
They found that plants where AtMYB93 was switched off had faster growing lateral roots and more of them, whereas the opposite was the case in plants where the gene was expressed at a higher level than usual.
They also discovered that the AtMYB93 gene was switched on in root cells by the presence of the plant hormone auxin, allowing the root branching process to be regulated by the hormone, and meaning that AtMYB93 may help the plant to 'decide' to grow lateral roots only when they are needed.
Dr Juliet Coates, from the University of Birmingham's School of Biosciences, said: "The AtMYB93 gene is exciting because of its specificity: it is only expressed in roots, and only in a few cells next to where the new root would form. This gene therefore represents a possible new target for specifically manipulating root branching in useful crop plants, to enhance their ability to grow and survive in a wider range of soils and environments, without affecting other important aspects of plant development such as shoot growth, flowering or seed yield."
Although the study, published in New Phytologist, took place in Arabidopsis plants, many other flowering plant species including plant crops such as barley, rice, millet, grape and oilseed rape all have similar genes to AtMYB93.
The paper "AtMYB93 is a novel negative regulator of lateral root development in Arabidopsis" by Gibbs et al. is published in New Phytologist and is available at http://onlinelibrary.wiley.com/doi/10.1111/nph.12879/full