Engineered toxin-free cottonseed

“The world grows cotton for fibre not for seed,” said
Keerti Rathore, a researcher
at
Texas A&M University in College Station. For every kg of cotton fibre, the cotton
plant produces 1.65 kg of seeds that contain 21% oil and 23%
of a relatively good quality protein. But nutrient-rich cottonseeds are unfit for
human consumption because of a noxious chemical called gossypol. Currently cottonseeds are used
to make feed for cows, which can handle gossypol, thanks to special microbes in
their stomachs.
But now the research team has found a way to genetically
engineer cottonseeds that barely produce gossypol, possibly making the seeds fit
for human menus.

Genetics to reduce gossypol
The recent research used a technique called RNA
interference (RNAi) to suppress the biochemical
pathways that produce gossypol in cottonseed tissue. “The RNA mechanisms only
work on the seeds, so that the leaves still contain gossypol and discourage
insects from chewing them,” study co-author Rathore said. “If you knock it out
throughout the plant is more susceptible to diseases.”

Impact on food supply
The new
study could have a large impact on global food security if the technique can be
reproduced and cottonseeds are approved for (human) consumption.
Llewellyn,
the Australian cotton researcher, says
that developed countries will likely keep using
cottonseeds for animal feed and food oils. “But there will be some interesting
uses of the meal potentially as a substitute for soybeans,” he said.