Aussie Group Uses RNAi for High-Fiber Wheat

Scientists from Australia's Commonwealth Scientific and Industrial Research Organization and the French-based agricultural biotechnology company Biogemma UK are hoping to use the relatively new molecular-biology technique of RNA interference to develop a high-fiber wheat.

The researchers identified an enzyme that converts the amylose starch molecule to amylopection and then devised a silencing technology to stifle its production by inserting a fragment of DNA into the wheat to engage the process of RNA interference, according to a paper published this week in the Proceedings of the National Academy of Sciences.

Wheat higher in amylose is harder to digest, lowering the rate of blood sugar uptake and increasing the passage of fiber into the large bowel, which has beneficial health implications for humans [just read the fiber content on loaves of bread].

The knowledge gained through this research will be applied into a selective breeding program to produce a high-amylose wheat, rather than using genetic modification for commercialization, according to published reports.

RNA unterference is an emerging technology that is used to silence or turn off the production of protein in the DNA-to-protein biological process. Specifically, small RNAs are use to direct cellular RNAi mechanisms to degrate messenger RNA, silencing the expression of the gene by blocking production of the protein.

The technology is seen as being very specific and may hold great promise as a therapeutic. Still, it is very early in the game and there is much work to be done in understanding how this technology works in the human body and its long-term effects.

Andrew Fire and Craig Mello of Stanford and the University of Massachusetts, Worchester, respectively, coined the term “RNAi” after they injected double-stranded RNA into C. Elegans and noted the gene-silencing effect. Their research was printed in the journal Nature in 1998.

The first findings of this phenomenon date back to 1990 in plant research by scientists in the US and the Netherlands.

Australia's CSIRO has developed and is commercializing an RNAi “hairpin” technology.