Scientists discover new plant protein - important applications in energy crops

Scientists at Michigan State University have identified a new protein necessary for chloroplast development, which might lead to a whole new class of energy crops. The discovery allows researchers to design crops that grow oil in their leaves, stems or roots, instead of only in their seeds. The first lab trials with such engineered crops are already under way: a type of cold-tolerant root-crop (rutabaga) has been modified to become 'oily', growing biomass with the consistency of an avocado, full of easily extractable oil.

Chloroplasts, which are specialized compartments in plant cells, convert sunlight, carbon dioxide and water into sugars and oxygen ("fuel" for the plant) during photosynthesis. The newly discovered protein, trigalactosyldiacylglycerol 4, or TGD4, offers insight into how the process works.

Nobody knew how this mechanism worked before we described this protein. This protein directly affects photosynthesis and how plants create biomass (stems, leaves and stalks) and oils. - Christoph Benning, MSU professor of biochemistry and molecular biology

Professor Benning, the lead scientist working on the new protein, is a member of the Great Lakes Bioenergy Research Center, a partnership between MSU and the University of Wisconsin-Madison funded by the U.S. Department of Energy to conduct basic research aimed at solving some of the most complex problems in converting natural materials to energy.

The research, published in the August 2008 issue of journal The Plant Cell, shows how TGD4 is essential for the plant to make chloroplasts. Plants that don't have the protein die before they can develop beyond the embryonic stage.

Understanding how TGD4 works may allow scientists to create plants that would be used exclusively to produce biofuels, possibly making the process more cost-effective. Most plants that are used to produce oils – corn, soybeans and canola, for example – accumulate the oil in their seeds.

But the scientists found that if the TGD4 protein is malfunctioning, the plant then accumulates oil in its leaves. If the plant is storing oil in its leaves, there could be more oil per plant, which could make production of biofuels such as biodiesel more efficient:
energy :: sustainability :: biomass :: bioenergy :: biofuels :: biodiesel :: vegetable oil :: chloroplast :: lipids :: biochemistry ::

Other members of the MSU research team are: Changcheng Xu, research assistant professor of biochemistry and molecular biology; Jilian Fan, research technician; and Adam Cornish, biochemistry undergraduate student at the time of the research and current graduate student. The research was funded by the Energy Department and the National Science Foundation. Professor Benning's research also is supported by the Michigan Agricultural Experiment Station.

Applying the knowledge
Professor Benning's team has started a project with genetically modified rutabagas, which should become squishy and oily. The scientists have inserted a gene called "wrinkled1" into the rutabagas that regulates the conversion of carbohydrates into oil.

The hope is that the gene will make the rutabagas produce oil rather than starch inside their bulbous roots, turning these cold-resistant root vegetables into a viable biofuel crop for Michigan. It will be at least six months before the scientists know whether the change works.

Plant oils are among the best potential sources of biofuel. They're rich in energy, easy to extract and convert. But they're inefficient in other ways. Most oilseed crops have relatively low yields per acre, and the seeds can be harvested only at certain times.

Benning hopes to produce better biofuel crops by developing plants that produce not only more oil, but oil that's more readily available.

We think we need to make oil in not just the seeds. If we could make it in the green tissues, like the leaves, stems or even underground tissues like roots or tubers, then we think we can make a lot more per land area. - Professor Christoph Benning

The newly discovered TGD4 protein helps the scientists in their research, as it plays a role in moving lipids, a group of organic compounds that includes fats and oils, around inside plant cells.

Lipids are the building blocks of the membranes surrounding and inside of chloroplasts, compartments inside the cell where plants convert solar energy into chemical energy - food, basically - during photosynthesis.

In this particular aspect of all of life - lipid synthesis of membranes - this is one of the biggest remaining questions. [Understanding the biochemical pathways that play a role in it] has implications for many, many aspects of practical plant biology, from increasing plant productivity to finding ways to generate new and useful products in plants. - John Browse, a professor of biochemistry and molecular plant sciences at Washington State University.

Benning and his colleagues hit on a promising side result, while researching the new protein. While plants will die without the TGD4 protein, a defective version of the protein will cause them to put lipids in the wrong places, causing plants to accumulate oil not only in their seeds, but in their leaves as well.

With current biofuel crops, corn and canola for example, "we have a very small portion of the biomass that goes to the seeds, and all the other stuff basically dries up, and nothing much happens with it". If plants could be made that produce oil throughout, "we could use that vegetative tissue, all that biomass that is going into making a plant", Benning said.

Schematic: chloroplast structure.

Picture: rutabaga, a cold-tolerant root crop.

References:
Changcheng Xu, Jilian Fan, Adam J. Cornish, and Christoph Benning, "Lipid Trafficking between the Endoplasmic Reticulum and the Plastid in Arabidopsis Requires the Extraplastidic TGD4 Protein", Plant Cell Advance Online Publication, Published on August 8, 2008; DOI: 10.1105/tpc.108.061176

MSU News: MSU’s discovery of plant protein holds promise for biofuel production - August 14, 2008.

Lansing State Journal: MSU biofuel research rooted in rutabagas - August 19, 2008.

Michigan State University: biofuel and bioenergy research.

Great Lakes Bioenergy Research Center.

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E.ON to invest £300 million into 150MW biomass power plant at Port of Bristol

E.ON, one of the UK's largest energy generators, has announced plans to invest around £300 million (€380/US$558 million) in a biomass power station at the Port of Bristol. It is the company's third large investment in biomass power in the UK, a country where bioenergy has the second largest potential amongst the renewables, after wind energy. E.ON has also been co-firing biomass in existing facilities.

At 150MW, the proposed Portbury Dock Renewable Energy Plant would generate enough power for more than 200,000 homes by burning wood that would largely be brought to the plant by boat. Transporing biomass fuels in bulk by boat is highly energy efficient.

This scheme would be one of the largest biomass power stations ever built in the UK and would make a considerable contribution to helping the Government meet its renewable energy targets. Schemes such as this, together with cleaner coal, gas and new nuclear, will help us to keep the UK's lights on, while also reducing carbon emissions and ensuring energy is as affordable as possible for our customers. - Dr Paul Golby, Chief Executive of E.ON UK

E.ON has issued a scoping statement to North Somerset Council, the Department for Business, Enterprise and Regulatory Reform (BERR) and other interested parties outlining the company's plans and hopes to submit a full application to BERR in the middle of next year.

If the project gets the green light, construction is expected to start in 2010, with the first power being produced in 2013 and full operation would be reached in 2014.

Portbury Dock is the third of E.ON's biomass developments in the UK. The company already operates Scotland's largest dedicated biomass power station at Steven's Croft near Lockerbie and, earlier this year, received permission for a 25MW biomass station in Sheffield (previous post):
energy :: sustainability :: biomass :: bioenergy :: biofuels :: co-firing :: renewables :: United Kingdom ::
As part of a multi-billion pound investment programme E.ON is:

• Currently building one of the world's largest gas-fired CHP power stations (1,275MW) at the Isle of Grain in Kent at a cost of around £500m;
• Working on the early stages of building the 1,200MW Drakelow CCGT in Derbyshire;
• Currently investing approximately £350m building the 180MW Robin Rigg offshore wind farm in the Solway Firth;
• Applying to build the 300MW Humber Gateway offshore wind farm with an investment cost of approximately £700M;
• Investigating two major marine projects, a wave power scheme off north Cornwall and a tidal stream project off Pembrokeshire;
• Partner in consortium looking to build the world's largest offshore wind farm, the 1,000MW London Array, in the Thames approaches;
• Looking at the possibility of building at least two nuclear power stations, and is working with AREVA and Siemens, and Westinghouse on designs;
• Investigating a green development portfolio that could supply around a million homes and displace the emission of two million tonnes of carbon dioxide a year.

However, despite these initiatives, environmentalists have been protesting against E.ON's plans to build a new coal power plant. The company has applied to build a 1,600MW 'cleaner' coal-fired power station at Kingsnorth in Kent at a cost of at least £1.5 billion. The company has also entered the project into the British government's carbon capture and storage competition.

References:
E.ON: E.ON announces plans to build one of UK’s largest biomass power stations at Port of Bristol - August 19, 2008.

Biopact: E.ON UK submits application for 25MW biomass plant - July 20, 2007

Biopact: UK's largest biomass plant approved, biomass task force created - June 16, 2007

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