The breathtaking dance of plants
The way in which plants space out the pores through which they breathe depends on keeping a protein active during stem cell growth, according to John Innes Centre scientists.
Plant pores, called stomata, are essential for life. When they evolved about 400 million years ago, they helped plants conquer the land. Plants absorb carbon dioxide through stomata and release oxygen and water vapour as part of the Earth’s carbon and water cycles.
Stomata need to be evenly spaced to maximise breathing capacity. But how they establish an even spatial pattern during plant growth has been a mystery.
In a paper to be published in Science, the JIC scientists show that the ability of cells to divide and form stomata is retained in only one of the two daughter cells generated by each division. This pattern, known as stem cell behaviour, is also found in certain animal cells, like those that form skin or bone.
In the case of stomata, the stem cell property depends on a protein called SPEECHLESS (SPCH) being kept active in a single daughter cell. The daughter cell is kept at the centre of her cellular relatives through a sort of molecular dance through which the polarity of cells switches at each division. The daughter eventually forms a stoma, surrounded by non-stomatal relatives, ensuring that the stomatal pores are spaced out.
“Unravelling this mechanism was only possible because of advances in live imaging and computational modelling,” said Professor Enrico Coen from JIC, the plant science centre strategically funded by the Biotechnology and Biological Sciences Research Council (BBSRC).
The computer modelling predicted rules that the scientists were able to validate experimentally in the plant Arabidopsis. They tracked various markers such as a fluorescent protein to see the patterns that formed in growing leaves.
The research could help scientists to tailor the number and arrangement of stomata to different environments. This could regulate the efficiency at which plants absorb carbon dioxide or diffuse water vapour.
The work was funded by BBSRC, the Natural Sciences and Engineering Research Council of Canada and the US National Institutes of Health.
Reference: Generation of Spatial Patterns Through Cell Polarity Switching , Robinson, S. et al Science 333 (6048) 1436-1440 doi: science.1202185 This research will appear in the 9 September, 2011, issue of the journal Science, published by the AAAS, the science society, the world’s largest general scientific organization. Seehttp://www.sciencemag.org, and also http://www.aaas.org.
About the John Innes Centre:
The John Innes Centre, www.jic.ac.uk, is a world-leading research centre based on the Norwich Research Park www.nrp.org.uk. The JIC’s mission is to generate knowledge of plants and microbes through innovative research, to train scientists for the future, and to apply its knowledge to benefit agriculture, human health and well-being, and the environment. JIC delivers world class bioscience outcomes leading to wealth and job creation, and generating high returns for the UK economy. JICis one of eight institutes that receive strategic funding from the Biotechnology and Biological Sciences Research Council and received a total of £28.4M investment in 2010-11.
BBSRC invests in world-class bioscience research and training on behalf of the UK public. Our aim is to further scientific knowledge to promote economic growth, wealth and job creation and to improve quality of life in the UK and beyond.
Funded by Government, and with an annual budget of around £445M, we support research and training in universities and strategically funded institutes. BBSRC research and the people we fund are helping society to meet major challenges, including food security, green energy and healthier, longer lives. Our investments underpin important UK economic sectors, such as farming, food, industrial biotechnology and pharmaceuticals.
For more information about BBSRC, our science and our impact see:http://www.bbsrc.ac.uk
For more information about BBSRC strategically funded institutes see:http://www.bbsrc.ac.uk/institutes