Ongoing ecological and evolutionary consequences by the presence of transgenes in a wild cotton population

The Lithbea Domain

The tree of life is the evolutionary metaphor for the past and present connections of all cellular organisms. Today, to speak of biodiversity is not only to speak of archaea, bacteria, and eukaryotes, but they should also consider the "new biodiversity" that includes viruses and synthetic organisms, which represent the new forms of life created in laboratories. There is even a third group of artificial entities that, although not living systems, pretend to imitate the living. To embrace and organize all this new biodiversity, I propose the creation of a new domain, with the name Lithbea (from life-on-the-border entites) The criteria for inclusion as members of Lithbea are: i) the acellular nature of the living system, ii) its origin in laboratory manipulation, iii) showing new biological traits, iv) the presence of exogenous genetic elements, v) artificial or inorganic nature. Within Lithbea there are two subdomains: Virworld (from virus world) which includes all viruses, regarded as lifeless living systems, and classified according to the International Committee on Taxonomy of Viruses (ICTV), and ii) Humade (from human-made) which includes all synthetic organisms and artificial entities. The relationships of Lithbea members to the three classical woesian domains and their implications are briefly discussed.

Multiple domestication events explain the origin of Gossypium hirsutum landraces in Mexico

Several Mesoamerican crops constitute wild-to-domesticated complexes generated by multiple initial domestication events, and continuous gene flow among crop populations and between these populations and their wild relatives. It has been suggested that the domestication of cotton (Gossypium hirsutum) started in the northwest of the Yucatán Peninsula, from where it spread to other regions inside and outside of Mexico. We tested this hypothesis by assembling chloroplast genomes of 23 wild, landraces, and breeding lines (transgene-introgressed and conventional). The phylogenetic analysis showed that the evolutionary history of cotton in Mexico involves multiple events of introgression and genetic divergence. From this, we conclude that Mexican landraces arose from multiple wild populations. Our results also revealed that their structural and functional chloroplast organizations had been preserved. However, genetic diversity decreases as a consequence of domestication, mainly in transgene-introgressed (TI) individuals (π = 0.00020, 0.00001, 0.00016, 0, and 0, of wild, TI-wild, landraces, TI-landraces, and breeding lines, respectively). We identified homologous regions that differentiate wild from domesticated plants and indicate a relationship among the samples. A decrease in genetic diversity associated with transgene introgression in cotton was identified for the first time, and our outcomes are therefore relevant to both biosecurity and agrobiodiversity conservation.

Residual Effects of Transgenic Cotton on the Intestinal Microbiota of Dysdercus concinnus

The interaction among plants, insects, and microbes (PIM) is a determinant factor for the assembly and functioning of natural and anthropic ecosystems. In agroecosystems, the relationships among PIM are based on the interacting taxa, environmental conditions, and agricultural management, including genetically modified (GM) organisms. Although evidence for the unintended effects of GM plants on non-target insects is increasingly robust, our knowledge remains limited regarding their impact on gut microbes and their repercussions on the host's ecology, especially in the wild. In this study, we compared the gut microbial community of Dysdercus concinnus bugs collected on wild cotton (Gossypium hirsutum), with and without insecticidal transgenes (cry1ab/ac), in its center of origin and diversity. By sequencing the V4-V5 region of 16S rRNA, we show differences in the diversity, structure, and topology of D. concinnus gut microbial interactions between specimens foraging cotton plants with and without transgenes. Identifying unintended residual effects of genetic engineering in natural ecosystems will provide first-line knowledge for informed decision-making to manage genetic, ecological, and evolutionary resources. Thus, determining which organisms interact with GM plants and how is the first step toward conserving natural ecosystems with evidence of transgenic introgression.

Economic surplus implications of Mexico's decision to phaseout genetically modified maize imports

The Mexican government has decided to ban imports of genetically modified (GM) maize, to rely on agroecology for maize production to satisfy domestic yellow maize requirements. No economic impact assessment of this policy decision was made public, and the implications of this decision for users of yellow maize and consumers are significant. This article measures the economic surplus generated from Mexican GM yellow maize imports and domestic conventional yellow maize production over the last 20 years, and projects the economic surplus generated over five years from adopting agroecology for yellow maize production. We explore three likely scenarios and find that in all of them, yellow maize processors lose almost twice as much economic surplus as producers. In the most conservative loss estimate (Scenario 1), the surplus loss in five years is equivalent to 35% of the economic surplus generated over the last 21 years from GM maize imports and domestic Mexican conventional production. In all simulated Scenarios, between 2024 and 2025 the price of a metric ton of yellow maize will increase 81percent because of the change in production systems (from conventional to agroecology). These financial losses will ultimately factor into the prices consumers pay for poultry and red meat products, resulting in higher domestic retail food prices.

Transgene Flow: Challenges to the On-Farm Conservation of Maize Landraces in the Brazilian Semi-Arid Region

Brazil is one of the largest global producers of genetically modified crops and a center of origin and diversification of relevant species for agriculture and food. Transgenic monocultures occupy around 50 million hectares, whereas smallholder farmers, indigenous people, and traditional communities are responsible for in-situ/on-Farm conservation of local genetic resources. Based on 15 years of expertise in regulating GMOs and in cross-institutional agrobiodiversity conservation projects, this article discusses the challenges regarding the coexistence of these two agricultural models based on transgene flow detection in maize landraces. As part of a broad and unique participatory transgene-flow-monitoring process, 1098 samples of maize landraces were collected in the Brazilian Semi-arid Region between 2018 and 2021 and analyzed using immunochromatographic strips. The tests revealed 34% of samples with presence of GM proteins. It is concluded that the biosafety standards in force in Brazil do not allow the assurance of on-Farm conservation of maize. The sectors that contribute to agrobiodiversity conservation and do not benefit from using GM seeds are taking on the burden of this process. Transgene flow can be reduced by approving and enforcing more effective coexistence rules that consider maize landraces crop areas also as seed-producing areas added to full disclosure of commercial seeds origin.

Deficiencies in the Risk Assessment of Genetically Engineered Bt Cowpea Approved for Cultivation in Nigeria: A Critical Review

We analyze the application filed for the marketing and cultivation of genetically engineered Bt cowpea (event AAT 709A) approved in Nigeria in 2019. Cowpea (Vigna ungiguiculata) is extensively grown throughout sub-Saharan Africa and consumed by around two hundred million people. The transgenic plants produce an insecticidal, recombinant Bt toxin meant to protect the plants against the larvae of Maruca vitrata, which feed on the plants and are also known as pod borer. Our analysis of the application reveals issues of concern regarding the safety of the Bt toxins produced in the plants. These concerns include stability of gene expression, impact on soil organisms, effects on non-target species and food safety. In addition, we show deficiencies in the risk assessment of potential gene flow and uncontrolled spread of the transgenes and cultivated varieties as well as the maintenance of seed collections. As far as information is publicly available, we analyze the application by referring to established standards of GMO risk assessment. We take the provisions of the Cartagena Protocol on Biosafety (CPB) into account, of which both Nigeria and the EU are parties. We also refer to the EU standards for GMO risk assessment, which are complementary to the provisions of the CPB.

Eco-Geography of Feral Cotton: A Missing Piece in the Puzzle of Gene Flow Dynamics Among Members of Gossypium hirsutum Primary Gene Pool

Mexico is the center of origin and genetic diversity of upland cotton (Gossypium hirsutum L.), the most important source of natural fiber in the world. Currently, wild and domesticated populations (including genetically modified [GM] varieties) occur in this country and gene flow among them has shaped the species’ genetic diversity and structure, setting a complex and challenging scenario for its conservation. Moreover, recent gene flow from GM cultivars to wild Mexican cotton populations has been reported since 2011. In situ conservation of G. hirsutum requires knowledge about the extent of its geographic distribution, both wild and domesticated, as well as the possible routes and mechanisms that contribute to gene flow between the members of the species wild-to-domesticated continuum (i.e., the primary gene pool). However, little is known about the distribution of feral populations that could facilitate gene flow by acting as bridges. In this study, we analyzed the potential distribution of feral cotton based on an ecological niche modeling approach and discussed its implications in the light of the distribution of wild and domesticated cotton. Then, we examined the processes that could be leading to the escape of seeds from the cultivated fields. Our results indicate that the climatic suitability of feral plants in the environmental and geographic space is broad and overlaps with areas of wild cotton habitat and crop fields, suggesting a region that could bridge cultivated cotton and its wild relatives by allowing gene flow between them. This study provides information for management efforts focused on the conservation of wild populations, native landraces, and non-GM domesticated cotton at its center of origin and genetic diversity.