As early as 2021, Bayer (previously Bayer-Monsanto) will release SmartStax Pro, the first federally-approved GMO to use RNA interference – a biological process that prevents cells from creating specific proteins – to defend plants against consumption by specific insect pests. Release of a GMO naturally corresponds with a reduction in biodiversity as the previous crops are outcompeted in the market, and SmartStax Pro illustrates the potential outcomes of this biodiversity loss and why a careful, informed approach to its implementation is crucial.
In recent years, environmentalists have become increasingly concerned about risks associated with biodiversity. For example, cultivation of organisms for their beneficial traits means replicating their negative traits as well. The Gros Michel banana was the dominant variety enjoyed in North America until Panama disease capitalized on the homogenous nature of the plants to spread unimpeded through plantations. The resistant Cavendish variety was selected as its successor, but scientists have predicted that it is only a matter of time until the disease evolves and spreads once more.
In the pest-control industry, the risks of heavy-handed insecticide use are clear. Random mutations that arise in pests may allow them to resist the effects of lethal compounds, and survivors live on to pass their traits to the next generation. Farmers are encouraged to leave patches of crops unprotected or rotate crops, strategies which ensure that enough non-resistant insects survive to pass on susceptible genes.
But in a world that values immediate economic benefit over long-term consequences, and a fast-growing population which requires farms to produce more than ever before, the concerns over human-induced resistance are already being realized. Bt toxins, derived from naturally-occurring bacteria, are the most abundantly used biological insecticide. In recent years, insect populations have been developing resistance to Bt toxin, due in part to the increased use of this compound. This could affect natural protection mechanisms that relied on these bacteria prior to their use in biotechnology.
With Bayer set to unveil the next development in their ‘arms race’ for supremacy against pests, long-term planning is crucial to avoid eventual disaster. The ways in which insects could become resistant to SmartStax Pro are already being anticipated.
To understand these possibilities, it is important to understand how RNA interference functions. The “central dogma” of life is the interaction between an organism’s innate cellular environment of DNA, RNA, and protein. DNA is the genetic blueprint while proteins perform work within cells. RNA acts as a messenger to control which proteins are made.
RNA interference operates at the messenger stage. Molecules called dsRNA use complementary structure to latch onto and prevent specific RNAs from relaying their signal. RNA interference is naturally used in, for example, virus resistance, but in the past 30 years this pathway has revolutionized biological research for its lab and field potential. As an agricultural tool, scientists create complementary dsRNA that bind to an RNA sequence that feeding insects use to create a vital protein. When insects eat the dsRNA, it enters their gut cells and prevents the corresponding protein from being made. Small genetic differences in RNA structure between species mean that scientists can create dsRNA that will kill one pest and be harmless to another. With SmartStax Pro, Bayer used genetic modification to create corn plants that express dsRNA within their cells and are lethal to their most notorious pest: the corn rootworm.
Insects could develop resistance in two ways. The first is by mutations that modify the structure of the insect’s RNA just enough that the dsRNA will be unable to bind. This is of little concern – there are many available targets, and plants can be created targeting another vital RNA instead.
The second possibility is more worrisome. With enough pressure and prolonged exposure, insects could stop responding to dsRNA entirely, either by developing a defense mechanism or losing the cellular pathway that leads to RNA interference. Scientists have already generated resistant insects for observation. Insects that lose this pathway could be susceptible to disease, threatening species’ survival if an opportunistic virus arises. It is also plausible that RNA interference plays a role in natural pest-plant interactions that is not yet understood, and the loss of the relationship could result in ecosystem imbalance.
As society leaps forward in developing agriculture, the value of sustainable approaches is more evident than ever. Indigenous Knowledge follows a pathway of respectful and harmonious human intervention in the ecosystem. This approach best guarantees biodiversity in food, and agricultural and environmental stewardship through sustainable practices. For example, crop rotation is an Indigenous tradition used since time immemorial, long before the scientific benefits of this practice became clear. Another strategy used by Indigenous communities was polyculture cropping, where many plant species were grown in a single area, which has been identified as improving soil quality.
Radical interventions with natural order fueled by biotechnology have not delivered on the promise of enhancing global food security. In fact, the measure or test of any knowledge system is the opportunity costs of its adoption. With the threat to global biodiversity, dangerous disruptions of the ecosystem, and other unknowns regarding GMOs, there is increased need for intensification of ethical and precautionary approaches to innovation. Given the stabilizing and sustainable tenor of Indigenous Knowledge, there is need for investment in empowering Indigenous Knowledge holders to support their contribution to sustainable agricultural and environmental endeavours. One way of providing such support is through the ABS process.
GMOs can be a source of economic potential, but their long-term effects remain unclear. Whether this trade-off is adequate must be closely examined. The natural order of ecosystems is undergoing a crucial turning point, where rapid developments in human practice are proceeding at unprecedented speeds. As the role of RNA interference in the wild is still not fully understood, Bayer will need to take special care to ensure that its potentially destabilizing effects are kept under wraps, and Indigenous Knowledge should be brought to the table when developing a sustainable approach.