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    Mongabay, a leading resource for news and perspectives on environmental and conservation issues related to the tropics, has launched Tropical Conservation Science - a new, open access academic e-journal. It will cover a wide variety of scientific and social studies on tropical ecosystems, their biodiversity and the threats posed to them. Tropical Conservation Science - March 8, 2008.

    At the 148th Meeting of the OPEC Conference, the oil exporting cartel decided to leave its production level unchanged, sending crude prices spiralling to new records (above $104). OPEC "observed that the market is well-supplied, with current commercial oil stocks standing above their five-year average. The Conference further noted, with concern, that the current price environment does not reflect market fundamentals, as crude oil prices are being strongly influenced by the weakness in the US dollar, rising inflation and significant flow of funds into the commodities market." OPEC - March 5, 2008.

    Kyushu University (Japan) is establishing what it says will be the world’s first graduate program in hydrogen energy technologies. The new master’s program for hydrogen engineering is to be offered at the university’s new Ito campus in Fukuoka Prefecture. Lectures will cover such topics as hydrogen energy and developing the fuel cells needed to convert hydrogen into heat or electricity. Of all the renewable pathways to produce hydrogen, bio-hydrogen based on the gasification of biomass is by far both the most efficient, cost-effective and cleanest. Fuel Cell Works - March 3, 2008.

    An entrepreneur in Ivory Coast has developed a project to establish a network of Miscanthus giganteus farms aimed at producing biomass for use in power generation. In a first phase, the goal is to grow the crop on 200 hectares, after which expansion will start. The project is in an advanced stage, but the entrepreneur still seeks partners and investors. The plantation is to be located in an agro-ecological zone qualified as highly suitable for the grass species. Contact us - March 3, 2008.

    A 7.1MW biomass power plant to be built on the Haiwaiian island of Kaua‘i has received approval from the local Planning Commission. The plant, owned and operated by Green Energy Hawaii, will use albizia trees, a hardy species that grows in poor soil on rainfall alone. The renewable power plant will meet 10 percent of the island's energy needs. Kauai World - February 27, 2008.

    Tasmania's first specialty biodiesel plant has been approved, to start operating as early as July. The Macquarie Oil Company will spend half a million dollars on a specially designed facility in Cressy, in Tasmania's Northern Midlands. The plant will produce more than five million litres of fuel each year for the transport and marine industries. A unique blend of feed stock, including poppy seed, is expected to make it more viable than most operations. ABC Rural - February 25, 2008.

    The 16th European Biomass Conference & Exhibition - From Research to Industry and Markets - will be held from 2nd to 6th June 2008, at the Convention and Exhibition Centre of FeriaValencia, Spain. Early bird fee registration ends 18th April 2008. European Biomass Conference & Exhibition - February 22, 2008.

    'Obesity Facts' – a new multidisciplinary journal for research and therapy published by Karger – was launched today as the official journal of the European Association for the Study of Obesity. The journal publishes articles covering all aspects of obesity, in particular epidemiology, etiology and pathogenesis, treatment, and the prevention of adiposity. As obesity is related to many disease processes, the journal is also dedicated to all topics pertaining to comorbidity and covers psychological and sociocultural aspects as well as influences of nutrition and exercise on body weight. Obesity is one of the world's most pressing health issues, expected to affect 700 million people by 2015. AlphaGalileo - February 21, 2008.

    A bioethanol plant with a capacity of 150 thousand tons per annum is to be constructed in Kuybishev, in the Novosibirsk region. Construction is to begin in 2009 with investments into the project estimated at €200 million. A 'wet' method of production will be used to make, in addition to bioethanol, gluten, fodder yeast and carbon dioxide for industrial use. The complex was developed by the Solev consulting company. FIS: Siberia - February 19, 2008.

    Sarnia-Lambton lands a $15million federal grant for biofuel innovation at the Western Ontario Research and Development Park. The funds come on top of a $10 million provincial grant. The "Bioindustrial Innovation Centre" project competed successfully against 110 other proposals for new research money. London Free Press - February 18, 2008.

    An organisation that has established a large Pongamia pinnata plantation on barren land owned by small & marginal farmers in Andhra Pradesh, India is looking for a biogas and CHP consultant to help research the use of de-oiled cake for the production of biogas. The organisation plans to set up a biogas plant of 20,000 cubic meter capacity and wants to use it for power generation. Contact us - February 15, 2008.

    The Andersons, Inc. and Marathon Oil Corporation today jointly announced ethanol production has begun at their 110-million gallon ethanol plant located in Greenville, Ohio. Along with the 110 million gallons of ethanol, the plant annually will produce 350,000 tons of distillers dried grains, an animal feed ingredient. Marathon Oil - February 14, 2008.

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Saturday, March 08, 2008

Scientists discover genetics of nitrogen fixation in plants - potential implications for future agriculture

Some plants have the capacity to grow well in nutrient poor soils without additional fertilizers. This is the result of a very efficient symbiosis between either nitrogen fixing bacteria that interact with the plant's roots, or between these roots and mycorrhizal fungi. These symbioses allow plants to strongly improve their uptake of nitrogen, phosphorus and water. Now a team of French and German scientists has discovered [*.pdf French/Spanish] the common genetic mechanism at work that allows the elements of the symbiosis to interact.

Their findings might make it possible to transfer the nitrogen fixing capacity of legumes to a wide range of crops that do not have this ability, including maize and rice. Ultimately, this could lead to a massive reduction of inorganic fertilizer consumption. The discovery is reported in the early edition of the Proceedings of the National Academy of Sciences.

The team of researchers from the Institut de Recherche pour le Développement (IRD) and the University of Munich have been collaborating for years on the project. They found that one of the genetic elements of nitrogen fixing plants called SymRK (Symbiosis Receptor Kinase), used by leguminous plants (pea, alfalfa...) to join Rhizobia bacteria and mycorrhizal fungi, is also essential for the establishment of the symbiosis between the tropical tree Casuarina - an actinorhizal plant that thrives in poor sandy soils - and nitrogen fixing bacteria belonging to the genus Frankia. This new understanding unlocks the keys to the genetics of the nitrogen fixing capacity of plants, and could make it possible to apply the mechanism to the development of crops that massively cut back on fertilizers.

Inorganic fertilizers are an essential but expensive input for farmers. World wide consumption of nitrogen fertilizers was around 130 million tonnes in 2007. Phosphate demand stood at around 37 million ton. Prices are rising steadily because of high oil and gas prices. Some crops like maize require large applications that have to be repeated each growing seaon. Particular cropping systems - such as growing nitrogen-fixing crops after other crops - can limit the need for fertilizers marginally and temporarily.

But what if crops like maize and rice could be designed in such a way that they do not require any additional inorganic fertilizers? That would revolutionise agriculture on a global scale and would greatly limit the different types of pollution and ecosystem damage caused by artificial fertilizers. The discovery of the genetic basis for the efficient N2-fixing capacity in plants might make the development of such crops possible.

The association between mycorrhizal fungi and plants is estimated to be more than 400 million years old. It helped plants colonize the land. Today, the symbiosis can be found in more than 80% of the all plant species. More recently, approximately 60 million years ago, a new symbiosis developed between soil bacteria known as rhizobia, and leguminous plants, which granted them the unique capacity to nourish themselves by extracting nitrogen from the air to use it as a nutrient.

Rhizobia establish themselves inside the root nodules of legumes, where they transform nitrogen into ammonium that can be directly taken up by the plant. In return, the plant provides to the micro-organisms with nutrients in the form of complex glucides:
:: :: :: :: :: :: :: :: :: :: :: ::

Unlocking the mechanism
For several years, scientists have tried to unlock the genetic mechanisms responsible for these mutually beneficial relations between plants and bacteria on the one hand, and bacteria and fungi on the other.

Already in 2000, IRD researchers discovered a genetic signaling mechanism common to the way in which legumes interact with rhizobia and to the way in which mycorrhizae work. The symbioses use a common genetic element baptized SymRK. This gene intervenes in recognizing Nod factors - the signaling molecules that are crucial for the rhizobia to establish themselves in root nodules.

So-called actinorhizal plants have formed a second group of plants that have acquired the capacity to benefit from a symbiosis with another type of nitrogen-fixing bacteria called Frankia. The genetic mechanisms of these plants' relationship with their symbiont has not been studied in-depth so far.

The actinorhizal plants can be found in disturbed environments, such as volcanic soils or mining terrain and in soils starved of nitrogen, such as sandy moraines.

There are approximately 260 species of actinorhizal plants distributed over 24 genera and 8 families of flowering plants. To study the symbiosis, the French and German researchers were particularly interested in the tropical Casuarina tree, better known under the name filao. Casuarinas thrive at tropical beaches, in poor sandy soils.

Using techniques from molecular biology, the scientists looked for the sequence coding the SymRK gene within the Casuarina genome. Once they identified the gene, they wanted to find out whether it is again responsible for the establishment of the symbiosis between filao and the Frankia bacteria.

To find out, they developed transgenic plants in which the expression of the SymRK gene was strongly reduced. They then compared the capacity of these plants to form symbiotic nodules on their roots with that of wild plants. According to these analyses, the plants whose SymRK gene's potency was reduced, produced half the number of root nodules compared with the control plants. The formation of mycorrhizae also strongly decreased compared with the wild Casuarina trees.

These results indicate that the reduction of the expression of the SymRK gene, in filao, causes a major reduction in its capacity to fix atmospheric nitrogen as well as a reduction of its aptitude to form mycorrhizae. More generally, these conclusions highlight the fact that there is a common genetic element at work in nitrogen fixing plants that seems essential for the installation of the three types of symbiotic associations utilizing bacteria (Rhizobium and Frankia) or mycorrhizal fungi.

A better comprehension of these genetic mechanisms could contribute, in the years to come, to the development of techniques to transfer the genetic material necessary for the nitrogen fixing capacity to crops that are unable to perform this task, such as cereals like maize and rice.

Whereas rice does establish a symbiotic relation with a mycorrhizal fungus, it is indeed inapt to develop nitrogen fixing nodules. However, by modifying its genome in such a way that rice plants too are capable of feeding off the atmospheric nutrient, it would become possible to significantly limit the nitrogen fertilizer needs in rice cultivation. This would have major economic and environmental effects: reduced production costs for farmers world wide and less pollution from nitrogen runoff.

If the N2-fixing capacity is transferred to all the major grain crops currently produced, world agriculture would be transformed forever.

Translated for Biopact by Laurens Rademakers.

Image: Frankia is genus of nitrogen-fixing bacteria that live in the soil and have a symbiotic relationship with many plants. By focusing on the genome of Frankia, French and German scientists discovered a genetic mechanism responsible for root-fungal and root-bacterial symbioses. Credit: MicrobeWiki.

Hassen Gherbi, Katharina Markmann, Sergio Svistoonoff, Joan Estevan, Daphné Autran, Gabor Giczey, Florence Auguy, Benjamin Péret, Laurent Laplaze, Claudine Franche, Martin Parniske, and Didier Bogusz, "SymRK defines a common genetic basis for plant root endosymbioses with arbuscular mycorrhiza fungi, rhizobia, and Frankia bacteria", Published online on March 3, 2008, Proc. Natl. Acad. Sci. USA, DOI: 10.1073/pnas.0710618105,

IRD: Un mécanisme génétique universel découvert chez les plantes fixatrices d’azote [*.pdf] - Fiche n°288 - Février 2008

AlphaGalileo: Un mecanismo genético universal descubierto en las plantas fijadoras de nitrógeno - March 7, 2008.


Blogger MichaelW said...

See book by D Blume "Alcohol Can Be a Gas!" for material on symbiotic relationship between mycorrhizal fungi and plants.

less inorganic fertilizers..... what a concept.

Every time I see studies like this, I marvel at how ahead of them D Blume is. As it says," If the N2-fixing capacity is transferred to all the major grain crops currently produced, world agriculture would be transformed forever."
Let's all get together and promote this!

3:02 PM  

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