Concerns of GM crop cultivation deliberate release of GMOs to the environment (i.e. not contained use in lab). related to the trait (e.g. effect of insect resistant GM crops on non-target organisms). related to the genetic insertion – outside the complex regulatory network that controls gene expression. – can interfere with normal plant function.
What we hear… 1)GE crops are widely grown 2) GE crops can contribute to food security (in the future) because they can deliver crops with… Increased yield Drought tolerance Nitrogen-fixing cereals Enhanced micronutrients (e.g. Golden Rice)
The Reality… From: Quist et al. 2013. Hungry for Innovation: pathways from GM crops to agroecology. In: European Environmental Agency (EEA) Late lessons from early warnings: science, precaution, innovation. Ch. 19. www.eea.europa.eu GM crops are grown on only 3 % of agricultural land globally. Virtually all these GM crops are either herbicide-tolerant, insect resistant or both.
No GM crops for increased yields. No evidence that current GM crops increase food security – designed for large scale commodity growers. GM crops are patented. Farmers face issues of contamination and liability. (see, e.g. IAASTD 2008, www.assessment.org, Quist et al. 2013 op cit.)www.assessment.org GM crops do not currently contribute to food security.
Current commercial GM crops – simple traits Current commercial GM crops contain relatively simple constructs that produce a non- metabolomic protein. E.g. Herbicide tolerance – production of protein conferring tolerance to a particular herbicide Insect resistance – production of protein toxic to a specific pest. Even for these relatively simple constructs, questions surround effects, safety is questioned.
Typical insert for a simple GM trait Genetic insert for Roundup Ready Soya
Complex traits Main focus of crop development is traits to cope with climate change (e.g. drought tolerance) or increased nutrition (e.g. enhanced vitamins). Most of these desirable traits are controlled by multiple genes. I.e. they are complex traits.
GM crops for complex traits At the R&D stage – not in commercial farming Most of the hopeful traits, e.g. nitrogen fixation, increased yield. Nature of the genetic engineering is complex. Often require several genes, including regulatory sequences (e.g. Golden Rice). OR over-expression of one inserted gene (e.g. Monsantos drought tolerance maize).
Example of complex genetic engineering Genetic insert for Golden rice
Problems with genetic engineering for complex traits Plant chemistry is complex. Metabolic pathways are not completely known or understood. High potential for unexpected and unpredictable effects with complex genetic engineering. May have human health implications, e.g. if a toxic product resulted from an unexpected pathway. May have environmental implications, e.g. if an unexpected product was toxic to wild animal species.
Genetic engineering for complex traits is very difficult Technically very difficult Assessment for food, feed and environmental safety very difficult. Genetic engineering is not suited to complex traits. Stuck in the pipeline?
Tolerance to new herbicides, e.g. 2,4-D, dicamba. Stacked traits herbicide tolerance with insect resistance multiple insect resistance multiple herbicide tolerance? Herbicide tolerance and insect resistance in new crops, e.g. eggplant. Whats really in the pipeline for GM crops?
New ways of inserting genetic material into plants. Some have more precise placement Some use genes from the same species (cisgenesis) Some dont produce a new protein, but maybe other risks (e.g. uptake of small RNAs affecting gene expression in humans – new science) But its the insertion of genetic material that gives rise to the concerns. New genetic engineering technologies
Science progresses: Junk DNA is no longer junk, but important in regulation Complexity of genetic regulation being realised. New theories on activation of duplicate genes in response to stress. Makes genetic engineering look very crude. Better understanding of genome function, more concern over GM crops
Biotechnology is not Genetic Engineering Often biotechnology is taken to be equivalent to genetic engineering But biotechnology is far broader. Biotechnologies encompass a wide array of plant breeding technologies, of which only one is genetic engineering.
The contribution of Marker Assisted Selection (MAS) Marker Assisted Selection (MAS) or smart breeding. Allows the identification of markers – segments of DNA located near the gene of interest. The presence of this marker in offspring indicates that the desired gene is present. It is smart conventional breeding – not genetic engineering.
1) Drought tolerant maize in Africa In the past 5 years, 34 drought tolerant varieties (hybrid and open-pollinated) have been released in 13 sub- Saharan African countries and are used by an estimated 2 million smallholder farmers. http://dtma.cimmyt.org/ http://dtma.cimmyt.org/ 2) Drought tolerant rice in Asia IRRI has developed drought-tolerant varieties which have been released in several countries including India, Philippines and Nepal. http://irri.org/ http://irri.org/ Examples
Drought tolerant wheat from CSIRO (Aus.) Submergence tolerant rice (IRRI). Bacterial blight resistant rice in Philippines, India and China. Nutrient enhanced crops: pro-vitamin A sweet potato and maize; iron and zinc rich bean and rice (Harvestplus and others). Yet more examples…
Further details of MAS in Greenpeace reports and technical briefings www.greenpeace.org
MAS has come of age The bottleneck to MAS is identification of markers, which is facilitated by sequencing of the genome. Several crop genomes have been made publically available in the last few years: – rice (2002), maize (2009), sorghum (2009), soy (2010), potato (2011), pigeon pea (2011), tomato (2012), chickpea (2013).
Conclusions GM crops are almost entirely herbicide tolerant or insect resistant – not likely to change in the future. Genetic engineering is not suited to complex traits – not appropriate technology for desired traits. Other modern breeding methods, such as Marker Assisted Selection (MAS) are producing varieties with desired traits – especially public funded efforts. BUT… its not only about crop varieties, its about how we farm.