by Helena Shilomboleni and Abdelbagi M. Ismail
The growing demand for rice in sub-Saharan Africa has seen an increase in policy initiatives aimed at developing domestic rice sectors through various measures, including the use of modern high-yielding varieties to help achieve self-sufficiency in rice. Considering Africa’s agriculture sectors’ extreme vulnerability to the impacts of climate change, including the acceleration of biotic and abiotic stresses, innovative breeding tools like gene editing have the potential to increase the genetic gain for rice and to improve the resilience of rice farming.
Over the past two decades, rice has become one of the most important staple food crops for sub-Saharan Africa (SSA) and plays a vital role in food and income security. The demand for rice has increased alongside rapid population growth, urbanization, and changing consumer behavior and diets on the continent. However, Africa’s rice imports exceeded USD 5.5 billion per year, an enormous economic burden that became particularly apparent during the 2007–2008 global food crisis.
Following this period, multiple African countries with assistance from various development partners established their National Rice Development Strategies (NRDS) to increase local production and to achieve rice self-sufficiency, assisted by the Coalition for African Rice Development (CARD) initiative.
Today, 32 African countries have NRDS in place devoted to developing their respective rice subsectors through a combination of measures. These include increased availability of climate-resilient, high-yielding varieties, with good grain quality and market value; improved access to modern production technologies and appropriate postharvest technologies, such as drying, storage and milling facilities, packaging, and market access; and enhanced capacity of key institutions and actors engaged in rice research, value chains, and development activities.
Various actors view advances in crop breeding, such as molecular markers and genome editing, as one of the most viable options to ensure sustained increases in productivity in the context of extreme climate vulnerability and acceleration in biotic and abiotic stresses.
Rice production is especially susceptible to such biotic and abiotic stresses, ranging from virulent pathogens that can wipe out 50%–80% of yields to extreme temperatures, submergence, drought, and salinity, which further threaten food production. Most currently used conventional and marker-assisted breeding approaches to developing high-yield rice varieties with tolerance to abiotic stresses and resistance to common diseases and pests have proved challenging, expensive, and time-consuming due to the complexity involved in dissecting the crop’s polygenic traits and their response mechanisms to multiple stresses.
In the last few years, breeders and biotechnologists initiated employing genome-editing approaches to generate rice varieties that synergistically improve grain yield potential and enhance resilience to maintain their performance despite the adversities of climate change.
Gene-editing technologies induce DNA modifications at targeted genomic locations to alter the biological activities of crops, through gene silencing (or knocking down of specific undesirable genes or traits), gene activation, or overexpression (to enhance stress-responsiveness) with or without the permanent insertion of any foreign DNA.
Among the tools that have been used to edit rice genes are the transcription-activator-like effector (TALE) nucleases and the clustered regularly interspaced short palindromic repeats (CRISPR/Cas) being used to address various stresses, such as host plant resistance. Zinc finger nucleases and meganucleases technologies have also been used in the breeding of various crops. Among these new tools, the CRISPR/Cas9 system is commonly used and is often presented as relatively more efficient and accessible.
Despite the lauded promise of genome editing to generate useful genetic traits to develop varieties more widely adapted to areas with less favorable climate and soil conditions, such as in SSA contexts, various critical scholars raise concerns over their use. It has been argued that gene-editing methods, much like genetic modification (GM) techniques, are prone to introducing unintended traits in crops, entailing statistically significant differences in genetic characteristics than the intended purpose, such as yield potential, seed germination, weed suppression ability, pest resistance, tolerance of abiotic stresses, and so on.
Critics also highlight that the same highly mutagenic techniques used in GM, such as agrobacterium infection or the gene gun to alter target genes, are utilized in gene editing. Accordingly, such techniques can create several unintended mutations throughout the genome, whose full implications on the performance of crops remain unknown.
However, recent research demonstrates that risks associated with gene editing are comparable to risks of conventional breeding methods currently in use. Moreover, meticulous gene editing, high-density sequencing, and extensive testing in target environments can help mitigate some risks while ensuring that new varieties proposed for release only carry targeted mutations.
An increasing number of African countries have shown policy interest in gene-editing technologies to address food security, reduce food imports, and increase the competitiveness of various products of the agricultural sector.
Like GM technologies, however, there are some sociopolitical challenges to fully embracing genome-edited innovations in Africa, and most African countries are only slowly progressing in implementing functional regulatory frameworks. Critical scholars and advocacy groups raise concerns about not only potential physical off-target hazards from gene editing such as genomic instability and cytotoxicity but a spectrum of socioeconomic issues including loss of food and seed sovereignty, entrenchment of intensive agriculture and corporate power through patent regimes, and little consideration for local farming practices and conditions.
This article contributes to the evolving literature and (contested) debates about genome-editing technologies in SSA by examining 3 key questions relevant to the development of rice subsectors on the continent.
These are as follows:
(1) What are some key activities currently underway in Africa to achieve rice self-sufficiency and what role can biotechnology play in these endeavors?
(2) What added value might genome-editing technologies offer to the genetic improvement of rice and Africa’s nascent research programs, and what challenges are they likely to face? and
(3) How might international partnerships advancing genome editing employ key principles from “responsible research and innovation” to achieve a more meaningful impact for Africa-specific contexts? This article argues that incorporating RRI or similar approaches in both national regulatory frameworks and crop improvement programs can help to achieve their potential while bringing about more inclusive and reflexive processes that strive to anticipate the benefits and limits associated with new biotechnologies as they relate to local contexts. Such an approach could create the necessary political space to test and assess the benefits (and risks) related to adopting gene-editing technologies in Africa’s rice subsector.
The growing demand for rice in SSA has seen an increase in policy initiatives aimed at developing domestic rice sectors through various measures, including the use of modern high-yielding varieties to help achieve self-sufficiency in rice. Considering Africa’s agriculture sectors’ extreme vulnerability to the impacts of climate change, including the acceleration of biotic and abiotic stresses, innovative breeding tools like gene editing have the potential to increase the genetic gain for rice and to improve the resilience of rice farming.
Rice is exceptionally suitable for improvement through genome editing, given the availability of genome sequences of numerous rice varieties at high density, an abundance of genomic resources, and the extensive knowledge being accumulated on traits and genes of agronomic and adaptive values as well as its economic and political importance.
Despite the promise of genome-editing technologies, their implementation to develop new varieties is likely to face sociopolitical challenges to transfer these scientific findings into feasible policy actions and eventual large-scale uptake by farmers. Concerns over gene editing range from potential physical off-target hazards, such as genomic instability and cytotoxicity, to farmers’ loss of food and seed sovereignty, to an entrenchment of intensive agriculture and corporate power through patent regimes.
One recommendation to increase the social acceptability of gene-editing technologies would be for national regulatory frameworks and crop improvement programs to consider adopting key principles from the International Rice Research Institute to help design such innovations in ways that are more conscious of and responsive to the needs, capacity, and values of target beneficiaries.
The literature on RRI and similar scholarship offer a road map that could help most gene-editing rice programs in Africa adopt some basic inclusion practices to at least achieve their potential of meeting farmer’s and market needs, as well as social acceptance.
Projects that seek to achieve meaningful impact at scale, both in terms of reaching large numbers of smallholder farmers and enhancing social acceptability, would have to adopt more ambitious steps in their level of inclusion for stakeholders and engagement with institutional structures.
More transparent and interactive processes could also help to open up political spaces to test and assess the benefits (and risks) related to adopting gene-editing technologies in Africa’s rice subsectors.
Read the study:
Shilomboleni H and Ismail AM (2023). Gene-editing technologies for developing climate resilient rice crops in sub-Saharan Africa: Political priorities and space for responsible innovation. Elementa: Science of the Anthropocene, 11(1).
