M.R. Subramani

Chennai , July 20

COTTON is one plant that is sprayed with large amount of pesticides and insecticides. But a research of the plant in the US had led to discovery of a powerful compound that can help drive pests and diseases and, most probably, even treat cancer in humans.

The compound, gossypol, is found in almost all parts of the cotton plant but the focus is to extract the compound from its roots.

Ms Barbara Triplett, a plant physiologist with the Agricultural Research Service of the US Department of Agriculture (USDA), has found that the cotton plant could be made to produce clumps of prolific hairy roots that can be primed to produce gossypol.

Ms Triplett has found that injecting a bacterium (Rhizobium rhizogenes) in a cotton seedling's tender, new leaf using a toothpick will lead to stubs sprouting from the wound sites. In just a few weeks, these stubs will turn tendrils of fine, waving roots.

These roots can then be grown in the laboratory to produce valuable compounds throughout the year. The roots can originate from almost any plant, as long as a researcher can provide the exact environmental conditions — including temperature, pH, nutrients and hormones — needed to coax the fine tangles of roots into culture, according to the agricultural research arm of USDA.

The US scientists tried this method as other methods for extracting gossypol from other parts of the cotton plant had limitations.

Mr Michael Dowd, a chemical engineer with the research service, has found two valuable isomers from gossypol. One, a positive isomer, has been found to be less toxic but still it casts effects on microbes, insects and fungi. The other, which is negative, is currently of interest to those doing research on cancers.

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