image: A root growing vertically, with a root hair cell emerging horizontally. view more
Credit: John Innes Center
Scientists at the John Innes Centre in Norwich have discovered how roots find their way past obstacles to grow through soil. The discovery, described in the forthcoming edition of Science, also explains how germinating seedlings penetrate the soil without pushing themselves out as they burrow.
“The key is in the fuzzy coat of hairs on the roots of plants” says Professor Liam Dolan. “We have identified a growth control mechanism that enables these hairs to find their way and to elongate when their path is clear”.
Root hairs explore the soil in much the same way as a person would feel their way in the dark. If they come across an obstacle, they feel their way around until they can continue growing in an opening. In the meantime, the plant is held in place as the hairs grip the soil.
This ability is governed by a self-reinforcing cycle. A protein at the tip of root hairs called RHD2 produces free radicals that stimulate the uptake of calcium from the soil. Calcium then stimulates the activity of RHD2, producing more free radicals and further uptake of calcium. When an obstacle blocks the hair’s path, the cycle is broken and growth starts in another location and direction.
“This remarkable system gives plants the flexibility to explore a complex environment and to colonise even the most unpromising soils”, says Professor Dolan.
“It also explains how seedlings are able to grow so quickly once they have established”.
In nutrient poor soils such as in parts of Australia and sub-Saharan Africa, plants have adapted by producing more root hairs. A better understanding of this adaptation will allow the development of crops able to grow in inhospitable environments.
This research was funded by the BBSRC, a Marie Curie International Incoming Fellowship and MEXT of Japan.
Contacts
For images and interviews with Professor Liam Dolan:
JIC Press Office
Zoe Dunford, Tel: 01603 255111, email: zoe.dunford@bbsrc.ac.uk
Andrew Chapple, Tel: 01603 251490, email: andrew.chapple@bbsrc.ac.uk
Notes to Editors
- The John Innes Centre, Norwich, UK is an independent, world-leading research centre in plant and microbial sciences with over 800 staff www.jic.ac.uk. JIC carries out high quality fundamental, strategic and applied research to understand how plants and microbes work at the molecular, cellular and genetic levels. The JIC also trains scientists and students, collaborates with many other research laboratories and communicates its science to end-users and the general public. The JIC is grant-aided by the Biotechnology and Biological Sciences Research Council.
- The Biotechnology and Biological Sciences Research Council (BBSRC) is the UK funding agency for research in the life sciences. Sponsored by Government, BBSRC annually invests around £380 million in a wide range of research that makes a significant contribution to the quality of life for UK citizens and supports a number of important industrial stakeholders including the agriculture, food, chemical, healthcare and pharmaceutical sectors. BBSRC carries out its mission by funding internationally competitive research, providing training in the biosciences, fostering opportunities for knowledge transfer and innovation and promoting interaction with the public and other stakeholders on issues of scientific interest.
- Marie Curie Fellowships provide European placements for pre and post-doctoral researchers http://cordis.europa.eu/improving/fellowships/home.htm
- MEXT is the Japanese Ministry of Education, Culture, Sports, Science and Technology http://www.mext.go.jp/english/
Journal
Science