New research may reduce global need for nitrogen fertilizers
29th June 2006
Contact:
John Innes Centre Press Office:
Dr Vicky Just: +44 (0)1603 25511, email: victoria.just@bbsrc.ac.uk
and Out of hours: +44 (0)1603 450000
BBSRC Media Office
Matt Goode, Tel: (0)1793 413299, email: matt.goode@bbsrc.ac.uk
Tracey Jewitt, Tel: (0)1793 414694, email: tracey.jewitt@bbsrc.ac.uk
Research published today in the journal Nature reveals how
scientists at the John Innes Centre (JIC), Norwich and Washington State
University, USA have managed to trigger nodulation in legumes, a key
element of the nitrogen fixing process, without the bacteria normally
necessary. This is an important step towards transferring nodulation,
and possibly nitrogen fixation, to non-legume crops which could reduce
the need for inorganic fertilizers.
The researchers, funded by the Biotechnology and Biological Sciences
Research Council (BBSRC), the Royal Society and the US National Science
Foundation, have used a key gene that legumes require to establish the
interaction with the nitrogen-fixing bacteria to trigger the growth
of root nodules, even in the absence of the bacteria.
The fixation of nitrogen by some plants is critical to maintaining
the health of soil as it converts the inert atmospheric form of nitrogen
into compounds usable by plants. Legumes, as used in this study, are
an important group of plants as they have the ability to fix nitrogen
– which they owe to a symbiotic relationship with nitrogen-fixing bacteria
in root nodules. Legumes are often used as a rotation crop to naturally
enhance the nitrogen content of soils. Scientists have been working
for a number of years to understand the symbiosis between legumes and
rhizobial bacteria, with the hope that one day they can transfer this
trait to crop plants, the majority of which cannot fix nitrogen themselves.
Intensive crop agriculture depends heavily on inorganic fertilisers
that are often used to provide nutrients particularly nitrogen that
are critical for plant growth. The production of nitrogen fertilisers
requires a large amount of energy and is estimated to constitute approximately
50 per cent of the fossil fuel usage of the modern agricultural process.
Inorganic fertilizers also cause environmental problems associated with
leeching into our water systems.
Dr Giles Oldroyd is the research leader at JIC. He said: “We now have
a good understanding of the processes required to activate nodule development.
The nodule is an essential component of this nitrogen fixing interaction
as it provides the conditions required for the bacteria. Nodules are
normally only formed when the plant perceives the presence of the bacteria.
The fact that we can induce the formation of nodules in the plant in
the absence of the bacteria is an important first step in transferring
this process to non-legumes. If this could be achieved we could dramatically
reduce the need for inorganic nitrogen fertilizers, in turn reducing
environmental pollution and energy use. However, we still have a lot
of work before we can generate nodulation in non-legumes.”
Professor Julia Goodfellow, Chief Executive of BBSRC, commented: “BBSRC
is the principal funder of fundamental plant research in the UK and
commits millions of pounds a year to furthering our understanding of
basic plant biology. Such fundamental research may seem disconnected
from the every day world for many people but this project shows how
potentially important such science is. The findings have the potential
to lead to a practical application with substantial economic impact
for the UK.”
Images
The following images to accompany this story are available from the
JIC and BBSRC Media Offices
• White clover: Clover is a common legume of the UK and is often used
to naturally enrich agricultural soils for nitrogen.
• Pea nodules: Nodules occur on the roots of legumes, in this case pea.
The nitrogen fixing bacteria live inside the cells of the nodule.
• Clover pasture: Clovers form an essential component of the UK pastures,
which are used for cattle and sheep grazing. The clover provides a lot
of protein to grazing animals and also supports the nitrogen content
of the soil, reducing the need for fertiliser application to UK grasslands.
• Image of Dr Giles Oldroyd.
Notes to Editors
An ISDN studio is available for interviews at the John Innes Centre.
This research is published in Nature, June 29 2006, ‘Nodulation independent
of rhizobia induced by a calcium-activated kinase lacking autoinhibition’
This work was supported by the Biotechnology and Biological Sciences
Research Council and the Royal Society. Research at Washington State
University Agricultural Research Center was funded by the US National
Science Foundation.
Medicago truncatula (Barrel Medic or Barrel Medick) is a small legume
native to the Mediterranean region. It is a low-growing clover-like
plant 10-60 cm tall with trifoliate leaves, each leaflet rounded, 1-2
cm long, often with a dark spot in the in the centre. The flowers are
yellow, produced singly or in a small inflorescence of 2-5 together;
the fruit is a small spiny pod.
M. truncatula has been chosen as a model organism for legume biology.
It has a small diploid genome, is self-fertile, has a rapid generation
time and prolific seed production, it is also amenable to genetic transformation.
About BBSRC
The Biotechnology and Biological Sciences Research Council (BBSRC)
is the UK's principal public funder of basic and strategic research
across the biosciences. It is funded primarily by the Science Budget
through the Government's Office of Science and Innovation. BBSRC invests
over £350M pa in a wide range of research that makes a significant contribution
to the quality of life for UK citizens and supports advances in the
agriculture, food, chemical, healthcare and pharmaceutical sectors.
www.bbsrc.ac.uk
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