CHEMICAL MAKERS INVEST IN SOLAR CAPACITY BOOST: New projects target raw materials and research
Polysilicon is used in the production of solar cells.
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HREE NEW SOLAR technology investments signal a rare bright spot of capital spending by the chemical industry. The projects will increase capacity and advance research for chemical components of both traditional polysilicon solar cells and newer thin-film modules. The two largest outlays involve Dow Corning and will increase manufacturing capacity for polysilicon and silane (SiH4); both raw materials have been in short supply in recent years. Hemlock Semiconductor—a joint venture involving Dow Corning, Shin-Etsu Handotai, and Mitsubishi Materials—will spend an initial $1.2 billion to build a polysilicon plant at a new site in Clarksville, Tenn. In addition, Hemlock plans a $1 billion expansion of its current location in Hemlock, Mich., to come on-line in 2011. Overall, the investments may total up to $3 billion and add 34,000 metric tons per year of capacity. Dow Corning’s second investment is in a silane plant to be located next to the Michigan facility. The com-
FUNGAL WARFARE The response of Arabidopsis plants to fungal infections (shown) involves metabolites of 4M-I3G.
PLANT CHEMISTRY: A molecule involved in plant defense could inspire design of new fungicides
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HEN PLANTS are being attacked by fungal pathogens, their only retaliation is an innate immune response that researchers are only beginning to pick apart. Now, teams in Germany and the U.S. are reporting a new molecule involved in this defense, one that could inspire the development of new antifungals for the agricultural industry. Working independently, both groups report that the new protagonist in the fight against fungi is 4-methoxyindol-3-ylmethylglucosinolate (4MI3G), yet “we have different takes on how the HO molecule acts in the plant,” Frederick M. O OH Ausubel, a plant scientist at Harvard S OH University, says. OH OCH3 Ausubel and his colleagues find that me– N OSO3 tabolites of 4M-I3G act as a signal in plants to activate the deposition of callose near N sites of fungal intrusion (Science, H DOI: 10.1126/science.1164627). 4-Methoxyindol-3-ylmethylglucosinolate Callose is a glucan polymer WWW.CEN-ONLI NE.ORG
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pany, which does not currently make silane, says it will spend “hundreds of millions” of dollars on the plant. Silane gas is used to deposit a thin layer of silicon in the manufacture of thin-film photovoltaics. Because they require less silicon, the cells are cheaper to produce, although they are not as efficient as traditional polysilicon solar panels. In a separate announcement, Konarka Technologies, a maker of flexible-film solar cells, says it has signed R&D agreements with the French oil and gas giant Total under which Total will get a nearly 20% stake in Konarka and provide the smaller firm with $45 million in funding. The partners will focus on new solar cell components, with Total providing expertise from chemical subsidiaries Atotech, Bostik, Hutchinson, Sartomer, and Total Petrochemicals. The news stands in contrast to recent spending cuts by chemical companies, but it does not surprise industry watchers. Georgina Benedetti, research analyst for Frost & Sullivan, says the projects were likely triggered by the extension of tax credits for the U.S. renewable energy sector (C&EN, Oct. 20, page 40). The eight-year extension “provides long-term market stability,” Benedetti says. “There was a lot of concern about incentives, and many companies were waiting to see what would happen.” Solar developers also expect President-Elect Barack Obama to call for increased spending in support of federal renewableenergy standards.—MELODY VOITH
that acts as a physical barrier against pathogens. At the same time, a team led by Paul Schulze-Lefert of the Max Planck Institute for Plant Breeding Research, in Cologne, Germany, and colleagues report (Science, DOI: 10.1126/science.1163732) that 4M-I3G metabolites have “direct antimicrobial activity” against fungi, similar to the antimicrobial peptides in mammalian innate immunity, Schulze-Lefert explains. The two different roles reported for 4M-I3G are not necessarily at odds, since “multifunctionality of small molecules [in plants] is the norm rather than an exception,” Schulze-Lefert explains. The combined work is “a big step forward for understanding what is stopping the plant pathogens,” says Jonathan Jones, a senior scientist at the Sainsbury Laboratory, in the U.K., who studies plant immunity. “We now have an additional component in fungal resistance that we did not know about before.” Both groups worked with the model plant Arabidopsis, and both believe that other plants in the same Brassinoid family, like rapeseed and cabbage, may also employ 4M-I3G. “The discoveries may open the field to the design of new fungicides,” Ausubel notes. Daniel J. Kliebenstein, a plant biologist at the University of California, Davis, says the work “shows great potential,” but he would like to see more proof that the results can be broadly applied to other plant families.— SARAH EVERTS
DECEM B ER 22, 2008
J UL I A P LOTN IKOV
D OW CO R NING
N EWS O F T H E W E E K
