DAVIS, Calif. -- A bay-tree gene transferred into a rapeseedplant could lead to improved soaps, shampoos and detergents.

That's the view here at Calgene Inc., where plant moleculargeneticists are focused on the gene that encodes a protein thatmakes the seeds of undomesticated California bay(Umbellularia californica) produce and store small quantities oflaurate. Laureate is a scarce and valuable oil.

As reported in the July 3 edition of Science magazine, Calgeneresearchers first switched this DNA sequence into a commonlaboratory testing plant, the mouse-ear cress (Arabidopsisthaliana), which promptly churned out large quantities oflaurate, a fatty acid it never made before. They then put theirgene into rapeseed (Brassica napus), which normally producescanola, an important industrial oil. Calgene is conducting trialsto see if rapeseed can switch on laurate production in the field.

"Laurate is a crucial ingredient in soap and detergentmanufacture because it is soluble in oil and water alike," saidplant biochemist John B. Ohlrogge of Michigan State University.The U.S. imports nearly 1 million tons of laurate a year, most ofit from Southeast Asia, where it's extracted from coconuts andpalm kernels. The food industry uses it for the chocolatecoating on ice cream bars.

Calgene figures it's one to two years ahead of its closestcompetitors, thought to be Du Pont and Unilever, in developingthis potential new source of laurate, Ohlrogge said.

What makes laurate such a special fatty acid is its chemicalstructure: a chain of 12 carbon atoms lined up in a row. Canola,corn oil and other vegetable oils consist of 18 carbon atoms.

A specific enzyme, fatty acid synthase, elongates the carbonchain, two atoms at a time, said Vic Knauf, Calgene's vicepresident of research. In most crops, it stops at 18, but in thevariant, thioesterase (TE), that encodes elongation in the baytree, as in tropical palm trees, the enzyme switches off at 12carbons.

Proctor & Gamble Co., Cincinatti is interested in the results ofthe ongoing transgenic rapeseed field trial of the same 12-carbon TE gene is. P&G "has been funding Calgene's research inthis area since 1985, by some $600,000 to $1 million a year,"Knauf said. In return, P&G acquired an exclusive option to buythe product from Calgene.

"If the rapeseed trials turn out as good in the field as they didin the lab, given the current price of coconuts, we can make alot of money!"

-- David N. Leff Science Editor

(c) 1997 American Health Consultants. All rights reserved.

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