RNAi - Lite GM superweed control?

December 2015

In 2013, Monsanto succeeded in taking out a patent for the next trend in biotechnology.  This is based on interfering with gene expression rather than trying to put artificial genes into the plant.

The prime focus of the patent is a clever method for undoing all the problems caused Monsanto's herbicide-tolerant GM crops  in the first place.

High-tech gene interference will kill all the superweeds now plaguing GM growers after the overuse of blockbuster herbicide glyphosate (sold as 'Roundup' formula) and all the herbicide-tolerant volunteer crop plants that keep springing up in the years after planting a glyphosate-tolerant GM crop.  Monsanto's patent is very wide ranging: it includes the rights to liquid topical plant-coatings containing molecules of RNA (regulators of DNA) or DNA plus any other chemical adjuvants needed to get these into the plant cells, and the rights to apply the coatings in open fields or in greenhouses.

Twenty specific genes (including the artificial gene in herbicide-tolerant GM crops) may be interfered with by the technique and the gene-interference can be extended to invertebrate animal pests and viruses.

Also, the use of gene-interference for research is covered by the patent.

The only obvious limitation to the patent is that any artificial DNA involved will not become integrated into the cells' chromosomes, and will not, therefore, be a "genetic transformation" as previously understood.

Monsanto's chief technology officer and pioneer of GM seeds said the new venture would "open up a whole new way to use biotechnology" that "doesn't have the stigma, the same intensive regulatory studies and cost that we would normally associate with GMOs".

Fundamental concerns about this genre of gene modification have been flagged up before [1,2].  However, two new issues have emerged in relation to gene-interference.

One is that RNA and DNA molecules are vastly bigger than any chemical herbicide which has gone before.  The adjuvants present in the formulations applied must, therefore, be much more aggressively invasive than any predecessors.  This raises the spectres of co-lateral damage, toxic residues and enabling other environmental toxins into food.  Since adjuvants are classed by regulators as 'inert' solely because they're not herbicides, they are lightly- or un-regulated.

The second issue is environmental pollution. Monsanto is plugging RNA safety because "when the company doused dirt with RNA, it degraded and was undetectable after 48 hours".  Artificial RNA is much more stable than any natural version (which wouldn't last 48 hours), but a short-lived herbicide isn't much use.  Monsanto reportedly want to develop longer-lasting formulations especially for trees in which months-long persistence is needed.

Versions of gene interference which use DNA present a much bigger persistence problem: DNA can remain intact for thousands of years.

Independent scientists on an advisory panel convened by the US Environmental Protection Agency (EPA) noted "uncertainties in the potential mode of action in non-target species, potential for
chronic and sub lethal effects, and potential unintended consequences in the various life stages of non-target organisms."  As a result, they found "sufficient justification to question" whether the EPA's current methods of evaluating new pesticides, which were designed to vet chemicals, apply to these gene-altering treatments.  Before any such evaluations can be carried out, we need "a better understanding" of exactly how the technology works.

OUR COMMENT

There seems a huge potential in this to develop gene interference into terminator technology, and an equally huge potential for terminator RNA to get out of control.

In old-fashioned GMOs, the unpredictable effect of artificial genes on the function of the wider genome arises largely from the unpredictability of the regulatory RNA through which genes interact.  Artificial RNA is every bit as dangerous as all the genetic transformations which have gone before.

Make sure RNA interference technologies don't escape the stigma, and don't end up unregulated while the biotech industry pretends they're not GM.

See also RNAi: LITE-GM BUG BUSTERS coming shortly.

Background:

[1]  RNA MODIFIED FOOD - July 2013
[2]  RNAi IN GM FOOD CROPS - RISKS SUPPRESSED - June 2014

SOURCES:

• Tom Philpott, New Monsanto spray kills bugs by messing with their genes, Mother Jones, 19.08.15
• GMO lobby pushes new gene-silencing GMOs in spite of safety risks, GM Watch 18.08.15
• Paul Koberstein, A very different kind of GMO is headed to supermarket shelves, Earth Island Journal, 17.08.15
• Polynucleotide molecules for gene regulation in plants, Patent EP 2545182 A1, 16.01.2103