Scientists find stem cell switch

July 2007

JIC scientists have discovered how plant stem cells in roots detect soil structure and whether it is favourable for growth.

Poor soil structure is a problem in tropical agriculture, where soil becomes compact as it dries out.

“We believe this is a first step towards understanding how plants respond to soil compaction. Armed with this understanding we can start to devise ways to tackle it”, said research leader Professor Liam Dolan, of the John Innes Centre in Norwich, UK.

The research team determined that the hormone ethylene regulates cell division in root stem cells. Ethylene is known to play a role in perceiving and communicating environmental cues.

“We predict that this is the mechanism plants use to detect how tough or soft the soil is around them”, said Professor Dolan.

As in humans, plant stem cells are the source of all growth. The defining characteristics of stem cells are that they are able to either regenerate themselves or produce other types of cells. The ultimate source of cells in the root is the ‘quiescent center’, a group of four stem cells that divides infrequently and can produce any type of cell in the root. This study proved that ethylene is the cue needed to promote cell division.

“Every spring, the growth in your garden is the result of the function of stem cells”, said Professor Dolan.

“Stem cells in buds are activated to divide and give rise to the growth for that season. In roots, we found that the division of stem cells is regulated by ethylene. We suggest that ethylene provides signals from the environment to activate cell division when the conditions are right”.

The research was carried out in the mustard-like plant Arabidopsis, but it is thought to apply to other plant species.

Notes for Editors

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John Innes Centre
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This research will appear in the 27 July, 2007, issue of the journal Science, published by the AAAS, the science society, the world's largest general scientific organization. See http://www.sciencemag.org and also http://www.aaas.org.

Ethylene Modulates Stem Cell Division in the Arabidopsis thaliana Root.
Olga Ortega-Martínez, Monica Pernas, Rachel Carol, Liam Dolan. Science Vol. 317. no. 5837, pp. 507 – 510 DOI: 10.1126/science.1143409

This work was funded by the BBSRC, the John Innes Foundation and the Spanish Ministerio de Educacion y Ciencia.

About the John Innes Centre

The JIC, Norwich, UK is an independent, world-leading research centre in plant and microbial sciences with over 800 staff. 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. http://www.jic.ac.uk

About BBSRC
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. For more information on BBSRC go to: www.bbsrc.ac.uk

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Scientists find stem cell switch