Auxin Holds the Key to More Efficient Crops

The phytohormone auxin might be considered as the master manipulator of plant development. It coordinates numerous growth and behavioral processes in the plant life cycle, including cell division and elongation, phloem and xylem differentiation, leaf senescence and fruit ripening. Auxin is required for the growth of root hairs, and it is commonly used in hormone rooting powders to encourage cuttings to root. However, little is known about auxin distribution in root hairs.

New research from the University of Bristol has shown how to increase the length of root hairs on plants, potentially improving crop yields, as plants with longer root hairs take up minerals and water more efficiently. Using a computer model built by scientists at Bard College, U.S.A., Angharad Jones and colleagues found that auxin is not delivered to root hair cells directly, but via the cells next door which act as canals through which the hormone is transported. During transport, some of the auxin leaks out, supplying hair cells with the signal to grow.

This new understanding will be crucial in helping farmers to produce food sustainably and to reduce fertilizer waste, which can cause severe damage to ecosystems.

The paper published by Nature Cell Biology is available at http://dx.doi.org/10.1038/ncb1815 Read the news release at http://www.bris.ac.uk/news/2008/6061.html