Harvesting in Progress: The Crucial Role of Genetically Improved Crops in Latin America

Abstract

Crop genetic improvement in Latin America is necessary to address the region’s agricultural challenges and to enhance food security. The use of advanced biotechnological techniques, such as genetic engineering and molecular breeding, should enable the development of crops with improved traits tailored to the unique agroecological conditions prevalent in the region, similar to the observed impact of improved germplasm in leading countries using transgenic or edited plants. Research has focused on enhancing key agricultural traits, including tolerance to abiotic stresses, such as drought and salinity, resistance to pests, and herbicide resistance. However, other modifications designed to cope with emergent diseases and increase in nutritional content key nutrients such as vitamins and proteins should be addressed. Despite the benefits of genetic improvement, challenges, such as public perception, heavy regulatory frameworks, and a deficient communication on the benefits of these technologies, persist. Collaborative efforts among scientists, policymakers, and the public are essential to overcome these challenges. Through the application of innovative biotechnological tools, scientists are crafting crops with enhanced biotic and abiotic resistance, productivity, and nutritional value. As Latin America continues to grapple with the complexities of a changing climate and the imperative to feed a growing population, genetic improvement stands as a crucial ally in the pursuit of a sustainable and resilient agriculture.

1. Introduction

1.1 Agriculture in one of the most diverse regions on the planet

In 2022, the population in Latin America and the Caribbean reached 659,310,564 [1]. Globally, it is estimated that the population will reach 10 billion by 2050, with a demand for cereals of 1 billion tons and an additional 200 million tons of livestock products per year [2]. It is calculated that in the region, there are 576 million hectares of agricultural land, contributing 14% to the world’s agricultural production and accounting for 23% of net agricultural exports. Farmers number over 15 million, and sometimes whole families are involved in agricultural activities. The region has 23.4% of forested areas, including 31% of the planet’s freshwater. It is paramount to mention that 50% of the world’s biodiversity is present in the region [3]. The region is not immune to limitations in agricultural land; indeed, demographic pressure has caused the conversion of land to housing and has reduced cultivable land area, which is currently estimated at 11% of the Earth’s surface and utilizes 70% of freshwater from underground aquifers, rivers, and lakes. In addition to this problem, we must consider that climate change increases vulnerability to food security due to the emergence of new pests and diseases. According to National Aeronautics and Space Administration (NASA), the average surface temperature of the Earth in 2023 was the warmest ever recorded, 1.2 degrees Celsius above NASA’s reference period average (from 1951 to 1980) [4]. This extreme heat was associated with forest fires, rising sea levels, and the emergence of pathogens affecting plants, animals, and humans. In the same year, the climatic phenomenon ENSO (also known as El Niño) affected and continues into 2024, although in a neutral ENSO phase with a 79% probability in the second semester [5]. In a conservative risk analysis, considering that the population of Latin America supports its growth rate, food self-sufficiency is a challenge. Projections on global food supply assume that 60% of more production in 2050 will have to result from improved yields in agriculture by 90%, and only 10% from expansion of cultivated areas [6]. Therefore, improvements will have to come from the effective use of water, rational and efficient use of agrochemicals, the use of technologies to predict meteorological phenomena, and predominantly the use of genetically improved genotypes with greater genetic diversity, obtained through available biotechnological tools [7]. The region comprises 29 countries, which have diverse internal organizations, have faced climate challenges, suffer from high input and service costs, soil fertility loss, difficult access to credit, lack of training and technical assistance, and insufficient infrastructure for production, among several others. Political instability and penetration of organized crime are also widespread.

2. Challenges facing agricultural crops in the region

Food production is affected by factors that limit its production and yield; the main problems faced by producers in the region are described below.

2.1 Climate change

A change in climate is considered when it differs from the pattern recorded in a specific area [8, 9]. Erratic changes in temperature, precipitation, and increased carbon dioxide (CO₂) concentration are examples of climate changes that have a negative impact on agriculture. Therefore, plants tolerant to drought, cold, excessive heat, high irradiation, as well as those with the capacity to fix CO₂ more efficiently, are necessary to mitigate climate change. The strategy for their development and acquisition should include all available improvement tools to allow such plants to be grown on a commercial scale. Undoubtedly, modern biotechnology, including precision biotechnology or gene editing, will play a prominent role in the near future [10, 11].

2.2 Poor soils

The region’s soil presents problems due to being alkaline or acidic, high salinity, and low organic matter content. To counteract these problems, strategies to increase the availability of nutrients in these soils are necessary. Undoubtedly, the use of modern fertilizers, as well as the use of microbial bioinoculants, will improve the soil profiles that, currently, hinder optimal plant growth in the region [12].

2.3 Lack of modern fertilizers

In addition to the use of macro- and micronutrients, the use of growth regulators, such as auxins and cytokinins, which significantly increase the vegetative and reproductive growth of crops, is a biotechnological resource underutilized in the region. The production of endogenous beneficial microorganisms is necessary to provide plants with nutrients that impact plant health, as well as their safety by having fewer pesticides used for pest and disease control [13]. The production of organic vegetable crops is not only an important market niche for domestic consumption, but also as an opportunity to export products to high-demand countries, with a significant economic return for the producer [14].

2.4 Lack of pesticides and herbicides with lower residuality

Emerging pathogens have overcome the genetic resistance of current germplasms, and despite a long list of commercial agrochemicals that can potentially limit their spread, it is necessary to count with new active ingredients to address multidrug resistance, as well as compounds with lower residuality and toxicity that are thus environmentally friendly [15]. The use of germplasm resistant to insect pests based on Bacillus thuringiensis has allowed for a pause in the evolution of multiresistance to chemical pesticides, with the advantage of reduced use of these chemical agents in our food. Additionally, the use of plants resistant to herbicides with low residuality such as glyphosate is a technically desirable example, which despite its advantages, has been banned in countries like Mexico, although scientific evidence proves its safety. However, in addition to the ban on the use of these herbicides, the use of other agrochemicals with high toxicity and residuality is increasing; such is the case of the use of paraquat replacing the feared glyphosate in weed management tasks [16].

2.5 Drought

Drought is defined as a prolonged period of abnormally dry weather that directly influences human activities [17]. The United Nations Convention to Combat Desertification (UNCCD) classifies drylands according to their aridity index as arid, semiarid, and dry sub-humid. These areas, generically referred to as drylands, are characterized by climatic conditions, such as scarce and irregular precipitation, a significant difference between daytime and nighttime temperatures, soils with low organic matter and moisture, as well as high potential evapotranspiration [18]. According to the UNCCD, 12.1% of the Earth‘s land surface corresponds to arid zones; 17.7% to semiarid zones, and 9.9% to dry sub-humid zones [19]. Over two billion people live in these areas (approximately one in every three inhabitants of the planet), most of them in developing countries. In addition, dry areas host around 50% of livestock and 44% of the world’s agricultural land [20]. Latin America has a marked water deficit affecting its agricultural productivity; however, countries like Chile stand out, where 68% of its territory is classified as arid zone, and in the last decade has experienced the phenomenon of mega-drought, reducing up to 40% the expected average rainfall [21, 22]. Mexico is also suffering from several years of drought, and as of January 2024, 81.8% of its municipalities are under diverse degrees of water stress, of which 63% is moderate to exceptional [23]. Despite this, semi-arid regions of the region have greater technification and productivity, but the balance between production and sustainability is fragile [24]. The lack of comprehensive strategies for efficient water uses and low technification has caused not only social, but also environmental and economic problems. Plants with drought tolerance would be an advantage for producers.

2.6 Floods

Floods are defined as events that, due to precipitation, wave action, storm surge, or failure of a hydraulic structure, cause an increase in the level of the free water surface of rivers or the sea, generating invasion or penetration of water in places where it is not usually present, and generally causing damage to the population, agriculture, livestock, and infrastructure [25].

The record of floods has increased globally, with its main cause being considered the growth of human populations in proximity to local ecosystems with effluents, which exposes populations to the risk of flooding during rainy seasons [26]. The loss of flooded crops generally occurs due to root anoxia, as well as invasion by opportunistic microorganisms. In recent years, research has been conducted on the development of new GM crops of agricultural interest that are tolerant to periods of flooding and adverse environmental factors [27].

2.7 Pests

In Mexico, phytosanitary measures for the transport of plants and plant-derived goods are highly regulated to reduce the likelihood of introduction and spread of pests to the country and protect the phytosanitary condition of crops [28]. However, authorities in coordination with academic institutions must be prepared to identify and control the emergence of novel pests, pathogens, and associated diseases in a timely manner. The development of plants resistant to some pests is already a reality, and the benefits of this technology have been proved in various crops and in parts of the world [11]. Economically important crops such as cotton and maize have been genetically transformed by introducing genes encoding proteins with insecticidal action against the main pests of these crops [29]. The main source of insecticidal proteins comes from the bacterium B. thuringiensis, with demonstrated activity against pests of lepidoptera, coleoptera, or diptera. Other genes encoding insecticidal proteins such as vegetative insecticidal protein (VIP) from B. thuringiensis, lectins, and protease inhibitors have also been evaluated and demonstrated potential for pest control [30]. The application of Bacillus spp. and other plant-growth promoting bacteria is a novel strategy that may also be helpful for protecting plants against diverse pathogens.

3. Scenarios for increasing agricultural production

The increase in food production should be the consequence of expanding planting areas, as well as the use of cultural practices such as backyard planting for self-sufficiency, as proposed by various ideological trends. However, it is important to consider that the increase in food demand results not only from a growing population but also from an increase in the demand of specialty foods as well as for non-food products such as biofuels, coupled with the challenges posed by the emergence of novel pests and diseases, climate change, water deficit, decrease of arable land, and soil degradation in cultivated areas. Considering these limitations, there is a need for substantial acceleration in crop improvement and production [31]. Ideally, the increase in food production could come from expanding planting areas; however, arable land and water are two limiting resources not only in Latin America but worldwide. In fact, the conversion of agricultural areas to urban ones in major cities has been observed. Therefore, it is considered that increasing productivity in the field should be the result of a set of science and technology-based strategies that allow for the technification to optimize water, fertilizer, and pesticide use, as well as counting with germplasm displaying resistance or tolerance to biotic and abiotic stress through integrated crop management schemes [32]. Obtaining improved seeds selected from their centers of origin has the advantage of having germplasm with greater genetic diversity, desirable for resisting or mitigating pest or disease attacks, including emerging pathogens. These materials are a genetic source to identify new alleles for pest and disease resistance, as well as other traits for incorporation into cultivated plants and improving their health and safety [33].

3.1 Biotechnology as a tool to solve agricultural problems

Genetically modified plants, including those obtained through new precision technologies such as gene editing, are options that should be considered as part of an integrated strategy to address the agricultural problems of the region and ensure its food security. Considering that biotechnology has had a significant impact over the past 50 years in agriculture and has greatly expanded the objectives of plant breeding programs, there has been a substantial increase in the area of production of biotechnological crops since their first introduction in the 1990s, and it is expected to provide greater benefits with the introduction and commercialization of new germplasms [33]. Biotechnology has shown exceptional performance in weather prediction, early pest, and disease diagnosis, and of course, the generation of genetically improved plants. In the value chain of an agricultural product, it will also be especially important to consider its postharvest, labeling, and traceability of products to reach their consumer markets [34].

3.2 Use of improved plants in Latin America

The use of genetically improved plants is regulated in all countries, and there is no consensus on this issue. Almost all countries are signatories to the Cartagena Protocol and have developed biosafety legal frameworks, which have allowed them to authorize requests for planting genetically modified plants. However, only 58% of countries have an operational regulatory system [35, 36]. In fact, misinformation and commercial interests have fostered polarization in opinions about the use of these biotechnology products. On the other hand, due to the general interest in biotechnology applications, countries with regulatory systems have established a series of technical requirements to authorize their open-field testing in three scenarios: experimental planting, pilot planting, and commercial planting. According to a report from the Food and Agriculture Organization (FAO) Regional Office for Latin America and the Caribbean, in 2021, sustainable projects associated with the use of biotechnology were achieved, although there is substantial lag in the benefits of using biotechnology products [37].

The regulation of edited plants seems to foresee a niche of opportunity, since, if the product is regulated, the plants produced would only contain modifications consisting in one or few base substitutions or deletions, undistinguishable from those obtained through physical or chemical mutagenesis. Furthermore, the latter usually result in multiple changes throughout the genome, as is the case of most agronomically relevant crops obtained since the 1930s to the 1960s. For this reason, gene-edited plants resulting in discrete insertions or deletions would not be subject to the biosafety laws that regulate genetically modified organisms (GMOs). In contrast, if the editing considers insertion of DNA from another organism, it could be subject to the assumptions of the biosafety law. These scenarios have been discussed in various countries in the region, although in some, the issue has yet to be defined, as in the case of Mexico, which has not expressed its position on precision biotechnology products. The future is promising for this technique, which, if not overregulated, will help provide the desired improved plants for the region [36].

In the following section, we describe the production and consumption of GMOs in the countries of Latin America. In Mexico, maize production is a fundamental part of the Mexican diet; it is imperative to improve its productivity since Mexico has become the world’s leading importer of maize, increasing food dependency on the United States, from importing 396,000 tons in 1992 to 13.2 million tons in 2022. It is important to mention that Mexico is the main producer in the world of white maize, not so much yellow, which is mainly destined for livestock and industrial sectors. Indeed, the national production of yellow maize is deficient, and if the trend in the production and consumption of animal products, starches, and fructose continues, the shortfall could significantly increase in the short term [38]. Mexico only reports the planting of genetically modified (GM) canola and cotton, although the trend of not using GM plants is concerning, despite having signed trade treaties with Canada and the United States that include the use of genetically improved plants in the Biotechnology sector. However, Mexico has the infrastructure and human resources to produce genetically improved germplasm, including gene editing. Appropriate legislation would make developments evaluated under biosafety conditions to become commercially available for Mexican agriculture. Other technological applications related, but not restricted to agriculture, include the development of projects with efficient and low-emission technology, achieving 1842 agribusinesses to reduce greenhouse gas emissions (GHGs) by 6 million tons of CO₂, in addition to the production of electricity from biomass [39, 40].

An amendment introduced to the Constitution of Ecuador in 2008 has banned the cultivation of transgenic plants. However, a transgenic banana is being developed by researchers at an Ecuadorian university; this germplasm is intended to confer protection against one of the most devastating fungal diseases affecting this crop: Fusarium oxysporum f.sp. cubense tropical race 4. It will be interesting to see the use of this edited banana worldwide, which will positively impact the bioeconomy of countries where this fruit is considered a basic staple [41, 42]. Additionally, technology has been implemented in Ecuador that allows intelligent climate control directed to 800 farms with 1056 farmers, who have accordingly increased their production. Additionally, they have improved soil quality on 40 thousand hectares, thereby reducing emissions by 20% [39, 42].

Chile is one of the most accepting countries of innovative technologies, with three commercial events featuring Argentine herbicide-resistant canola and soybean, and maize resistant to lepidopteran pests. Chile adopted a regulatory approach for new plant breeding techniques. Parallel technological improvements have resulted in reduced energy usage, optimized pesticide application, and improved water and soil management by producers in the Maule region [43].

In Uruguay, GM maize and soybeans are actively cultivated, and researchers at universities are generating crops with novel traits, nurturing valuable human resources with the potential to produce new varieties for the region. Moreover, they have devised strategies for the effective and efficient use of herbicides in soybeans, resulting in net savings in crop production [39, 44].

Colombia is considered a megadiverse country that has been able to finalize agreements and progress in its public policies to reap the benefits of biotechnological applications, reflected in the commercial authorization of Argentine canola, carnation, cotton, flax, maize, rice, roses, soybeans, sugar beet, and wheat. Colombia has organized technical agroclimatic forums to help producers in predicting climate changes and reducing production costs [36, 40].

Brazil is an impressive example of technological advancements stemming from the Academia. The case of EMBRAPA (Brazilian Agricultural Research Corporation) producing common bean resistant to viruses has garnered global attention for successfully complying with over-regulated GMO legislation [45, 46]. Additionally, it has commercial authorizations for cotton, maize, soybeans, sugarcane, wheat, and eucalyptus. Brazil also stands out for generating new plant varieties obtained through gene editing, positioning it as a regional leader in this field [47].

Argentina is a regional benchmark and promoter of the safe use of genetically modified plants (and animals). The authorized commercial events include alfalfa, cotton, maize, potato, safflower, soybeans, sugarcane, and wheat. Its legislation is the result of consensuses that could serve as example for the development of similar laws in other countries in the region. In 2023, 24 million hectares were planted, representing 12–13% of the global transgenic surface area. Argentina is positioned as the third-largest producer of GM crops worldwide, behind the United States and Brazil. Argentina was the first to market drought-resistant GM wheat [48].

Costa Rica actively participates in regional initiatives on biotechnology and biosafety, and although it produces genetically modified cotton and soybean seeds, they are entirely for export to the country of origin as the seeds are not allowed for local consumption. Currently, about 1600 hectares of cotton and soybeans are planted for the purpose of seed multiplication for export to the United States. Despite this fact, research at public universities aims to obtain gene-edited rice with drought tolerance [49].

Cuba faces important deficits in food security, importing maize and soybeans for animal feed. Although they have produced GM plants, environmental debates have hindered significant plantings. However, they have the potential to produce modified plants, as they have the infrastructure and specialists to generate them [50].

Paraguay has authorized soybeans, maize, and cotton, showing a tendency toward increasing the area of GM crops to occupy significant positions in commercial planting. Paraguay has a planting area of 4 million hectares of GM plants [36].

Bolivia is also a major cultivator of herbicide-resistant soybeans. Legal discussions focus on the coexistence of GM maize with native varieties, considering the benefits in crop yield and production costs [51].

Honduras is the only country in Central America that allows commercial production and field trials of agricultural biotech crops, as it has allowed commercial planting of maize and rice. GM maize is sold for internal consumption and exported to Argentina, Colombia, and United States, while it imports yellow corn and soybean from the United States [52].

Panama has approved GM maize, although no data are available on the productivity of such commercial events [53].

3.3 Genetic improvement techniques

Genetically modified plants are species into which a gene encoding a novel trait has been introduced; this genetic modification aims to increase or decrease the expression of a gene or to introduce a gene encoding a novel trait. If the gene comes from the same plant, it is termed intragenic; if it comes from another plant, cisgenic; and if it comes from another species, transgenic [54, 55].

3.3.1 Process to obtain a genetically modified plant

Genetic modification conducted through genetic engineering differs from conventional plant breeding in precision and specificity. The process of generating a genetically modified crop can be divided into the following stages: 1. Identification and characterization of the gene of interest encoding a new trait. This step involves basic research showing the effectiveness and safety of the trait, such as drought tolerance or pest resistance. 2. Cloning of the gene into a vector with plant regulatory signals, typically using constitutive expression promoters in all plant tissues or differential expression promoters to ensure the trait is present where needed. 3. Genetic transformation and regeneration of the entire plant, involving the introduction of the gene of interest into plant explants through various methods, with the most used being Agrobacterium-mediated transformation and bioballistics. 4. Selection of plants encoding the gene of interest, characterizing the number of copies and insertion sites, transcriptional expression levels, and detection of the protein in tissues. 5. Efficacy assays under biosafety conditions and then in open-field trials. 6. Mass multiplication of the variety and/or sexual crosses with compatible elite germplasm for next field use (Figure 1) [54, 55].

Figure 1.

Process to obtain a genetically modified plant. 1. Identification and characterization of the gene of interest. 2. Cloning of the gene into a plant expression vector. 3. Genetic transformation and regeneration. 4. Selection of GM plants. 5. Efficacy assays and multiplication.

The bottleneck in genetic transformation is the introduction of the recombinant vector and the regeneration of transformed tissue. There are biological and physical methods for introducing genes from any donor species, thus expanding the possibility of transferring novel traits. Among the most used tools are the natural genetic engineer Agrobacterium, particle bombardment, protoplast transformation, and pollen magnetofection, among others [56]. Other transformation techniques have been described; however, the limiting factor is the regeneration of the complete and fertile plant. The biotechnologist selects the transformation tool based on the possibility of regenerating a complete plant from a transformed explant [55, 56].

3.3.2 How to edit a plant genome

In recent years, the generation of improved plants via genome editing, also known as New Breeding Techniques, has accelerated. The methodology involves the use of enzymes that allow cutting the gene to be modified and enabling natural repair mechanisms to result in discrete base insertions or deletions during the repair of the damaged chain. Different methods have been described, as zinc finger nucleases (ZFN), transcription activator-like effector nuclease (TALEN), Meganucleases, although the broadly used method is the CRISPR-Cas9 gene editing system, brilliantly developed by Doudna and Charpentier [57]. It is also possible to provide a healthy DNA template that serves as a reference for DNA repair and incorporates base changes into the target sequence. It is particularly interesting to note that plants produced with the generated mutations may be free of the editing tool used and be indistinguishable from plants obtained by conventional mutagenesis, a method employed to obtain a large portion of the plants we currently consume worldwide (Figure 2) [54].

Figure 2.

How to edit a plant gene. 1. Design of a gene editing strategy. 2. Introduction of the editing tool into the cell. 3. Recognition of the editing sequence. 4. Cleavage of target DNA. 5. 6. Repair of DNA by non-homologous end joining (NHEJ) or homologous recombination mechanisms. 7. Edited plant regeneration.

Among the available genome editing tools, the use of the CRISPR-Cas9 strategy has produced an impressive number of developments, stemming from both industry and academia. CRISPR-Cas9 stands for Clustered Regularly Interspaced Short Palindromic Repeats and the nuclease Cas9. Originally identified as part of a defense mechanism in some bacteria. The CRISPR-Cas9 system is a newly developed plant breeding method that uses site-specific nucleases to target DNA sequences [57]. This method allows modifications such as base insertion of deletions, provoking gene silencing or editing using DNA templates for repair via homologous recombination (HR), and even allows for transient gene silencing or transcriptional repression. Currently, there is a diversity of editing vectors that allow the design of ad hoc complexes, solely with the sequence of the gene of interest. Once the nuclease guided by the complementary RNA has cut the DNA sequence of interest, it must be repaired. If the break is repaired by the non-homologous end-joining [NHEJ) mechanisms, the DNA will likely encode inserted or deleted bases, resulting in permanent silencing of the target gene [54, 58]. Genome editing can be DNA-free if the protein and RNA complex are provided directly into the cells, thus eliminating the need to segregate the editing machinery in the next generation. It is also possible to insert a DNA sequence, also known as “Knock-ins.” For this purpose, a donor template encoding the new sequence must be provided, allowing homology-directed repair to incorporate the new sequence. New CRISPR-Cas variants are employed to regulate gene expression, epigenetic modifications, and chromatin interactions [59].

According to the International Service for the Acquisition of Agri-biotech Applications (ISAAA) reports in 2022, the market for plant breeding based on CRISPR in Latin America is projected to increase from 2021 to 2028, with a compound annual growth rate [CAGR) of 12.7% and is expected to reach USD 11.1 million by 2028 [40, 60]. Several international companies are expected to lead this regional development, although numerous public and private universities and research centers are already developing new genotypes, many of which contain insertions or deletions in target genes and are indistinguishable from those obtained by conventional mutagenesis techniques, which consumers are already used to acquiring as part of their diet.

3.4 Commercial developments of GM plants

Currently, the following genetically improved crops are commercially available and have various new characteristics, ranging from those desirable for producers such as resistance to biotic or abiotic stress, herbicides, to those attractive for consumers such as improved oleic profile, flavor, and color (Table 1). Alfalfa, apple, Argentine Canola, beans, carnation, chicory, cotton, cowpea, creeping bentgrass, eggplant, eucalyptus, flax, maize, melon, papaya, petunia, pineapple, plum, Polish canola, poplar, potato, rice, rose, safflower, soybean, squash, sugar beet, sugarcane, sweet pepper, tobacco, tomato, and wheat [61, 62].

Trait	Cultivar	Introduced gene
2,4-D herbicide resistance	Cotton, maize, safflower, soybean	aad-1 or aad-12
Altered lignin production	Alfalfa	ccomt (inverted repeat)
Anti-allergy	Rice	7crp
Coleopteran insect resistance	Maize, potato	Cry34Ab1, cry35Ab1, mcry3A, mcry3A, dvsnf7, cry3Bb1, ipd079Ea, cry3A
Delayed fruit softening	Tomato	Pg (sense, antisense)
Delayed ripening/senescence	Carnation, melon, pineapple	Sam-k, acc, accd or anti-efe
Dicamba herbicide resistance	Argentine canola, cotton, maize, soybean	dmo
Drought stress tolerance	Maize, soybean, sugarcane, wheat	cspB, Hahb-4, EcBetA, RmBetA
Enhanced photosynthesis/yield	Maize, soybean	Zmm28, bbx32
Enhanced Provitamin A content	Rice	Crt1, psy1
Fertility restoration	Argentine canola, maize	Bar star or ms45
Foliar late blight resistance	Potato	Rpi-vnt1
Glufosinate herbicide tolerance	Argentine canola, chicory, cotton, maize, Polish canola, rice, safflower, soybean, sugar beet	Bar, pat,
Glyphosate herbicide tolerance	Alfalfa, Argentine & Polish canola, cotton, bentgrass, maize, potato, soybean, sugar beet, sugarcane	cp4 epsps (aroA: CP4), gat4621, goxv247.
Hemipteran insect resistance	Cotton	mCry51Aa2
Imazamox herbicide tolerance	Argentine canola	AtAHAS
Increased ear biomass	Maize	Athb17
Isoxaflutole herbicide tolerance	Cotton, soybean	hppdPF W336
Late blight disease resistance	Potato	RB
Lepidopteran insect resistance	Cotton, cowpea, eggplant, maize, poplar, rice, soybean, sugar cane, tomato,	Cry1F, cry1Ac, cry1F, vip3A(a), cry2Ab2, cry1Ac, cry1Ab-Ac,
Low gossypol	Cotton	dCS
Lowered free asparagine	Potato	asn1
Lowered reducing sugars	Potato	PhL, R1, VInv
Male sterility	Argentine canola, chicory, maize	barnase
Mannose metabolism	Maize, rice	pmi
Mesotrione herbicide tolerance	Soybean	Avhppd-03
Modified alpha-amylase	Maize	Amy797E
Modified amino acid	Maize	cordapA
Modified flower color	Carnation, petunia, rose	Dfr, hfl (f3’5’h), bp40 (f3’5’h), dfr-diaca, cytb5, 5AT
Modified fruit color	Pineapple	b-Lyc, e-Lyc, Psy, acc
Modified oil/fatty acid	Argentine canola, safflower, soybean	Te, Lackl-delta12D, Micpu-delta-6D, Pavsa-delta-4D, Pavsa-delta5D, Picpaomega 3D, Pyrco-delta-5E, Pyrco-delta-6E, OtD5E, OtD6D, PirO3D, PlD4D, PpD6E, PsD12D, TcD4D, TcD5D, TpD6E, fad2.2, fatB, gm-fad2–1, D6D
Modified starch/carbohydrate	Potato	Gbss (AS)
Multiple insect resistance	Cotton, maize, poplar	CpTI, ecry3, IAb, API
Nematode resistance	Soybean	cry14Ab-1.b
Nicotine reduction	Tobacco	NtQPT1 (AS).
Non-browning	Apple	PGAS PPO suppression gene
Oxynil herbicide tolerance	Argentine canola, cotton, tobacco	bxn
Phytase production	Argentine canola	phyA, maize, phyA2, phy02
Reduced black spot	Potato	ppo5
Sulfonylurea herbicide tolerance	Carnation, cotton, flax, maize, soybean	surB, S4-HrA, als, zm-hra, csr1–2, gm-hra,
Tolerance to HPPD inhibiting herbicides	Soybean	hppdPf4Pa
Viral disease resistance	Bean, papaya, plum, potato, squash, sweet pepper, tomato	Ac1 (sense and antisense), prsv_cp, prsv_rep, ppv_cp, pvy_cp, plrv_orf1, plrv orf2, cmv_cp, wmv_cp, zymv_cp.
Volumetric wood increase	Eucalyptus	cel1

Table 1.

Expressed traits in genetically modified (GM) cultivars.

Modified from Ref. [61].

3.5 Plants obtained with edited genomes

Crops that have been genetically modified using nucleases for different purposes, such as increased resistance to pests, herbicides, improved nutritional profiles, and other desirable traits, are described below.

Soybean (Glycine max): Genes have been edited to confer resistance to pests, diseases, and herbicides, as well as to improve nutritional content and yield [63].

Maize (Zea mays): Edited genes provide resistance to pests, such as corn borers and corn rootworms, tolerance to herbicides, and enhanced nutritional quality [64].

Cotton (Gossypium hirsutum): Edited genes to increase fiber strength, as well as tolerance to herbicides [65, 66].

Canola (Brassica napus): Genes have been edited to confer resistance to herbicides and pests, along with modifications to improve oil content and quality [67].

Potato (Solanum tuberosum): Edited genes provide resistance to pests and diseases, such as late blight, as well as improved nutritional traits and reduced bruising [68].

Tomato (Solanum lycopersicum): Genes have been edited to enhance traits like shelf life, disease resistance, and nutritional content, including increased levels of antioxidants and vitamins [69].

Apple (Malus domestica): Edited genes are used to reduce browning after slicing and improve disease resistance [70].

Rice (Oryza sativa): Genes have been edited to enhance traits such as pest and disease resistance, tolerance to environmental stresses, and improved nutritional content [71, 72].

Wheat (Triticum aestivum): Edited genes provide resistance to pests and diseases, along with improved yield, nutritional quality, and tolerance to environmental stresses [73].

Common mushrooms (Agaricus bisporus) with browning prevention (not a plant) are commercially available [74].

4. Benefits of biotechnology products

Since their commercialization in 1996, the benefits related to increased plant productivity, environmental impact, health, and poverty reduction have been documented in countries that have adopted their cultivation. Over the period 1996 to 2020, the estimated economic income increased by $261.3 billion US dollars, considering the main crops (soybean, corn, cotton, and canola). This equates to an average farm income gain across all GM crops grown in this period of about $112/ha. In 2020, the farm income gains were $18.8 billion (average of $103/ha) [39]. The global adoption of GM cotton also displayed a positive impact, as farmers registered a gross farm income gain of about $134.8 million and in the 1997–2020 period [75]. Cost savings in Mexico represented a 29% increase in production compared to conventional varieties in the year 2000 [76]. In general terms, in 2008, the production of the four main crops in the world increased by 29.6 million metric tons (10.1 million tons of soybeans, 17.1 million tons of maize, 0.6 million tons of canola, and 1.8 million tons of cotton) thanks to the cultivation of GM crops [77]. Economic estimates in Argentina report revenues of $19.7 billion since the adoption of herbicide-tolerant soybeans (1996–2006); $482 million for B. thuringiensis (Bt) maize and $19.7 million for insect-resistant cotton in the period between 1998 and 2005, giving a total of $20.2 billion in gross revenues for these three crops in the country. Additionally, it is estimated that the adoption of herbicide-tolerant soybeans has contributed to the creation of around one million jobs, being a 36% increase in employment rates in the period 1996–2006 [78]. The first example of drought-tolerant wheat was developed in Argentina, and with the same technology, HB4 transgenic soybeans were already approved for use in the United States, Brazil, Paraguay, Canada, and China in 2022 [79]. Brookes (2022) analyzed for the Antama Foundation the agricultural environmental impact of GM crops in the period 1996–2020, concluding they have beneficially impacted global food, feed, and fiber production by almost one billion tons, with a reduction of its environmental footprint over 17%, calculated in a reduction of carbon emissions by 39,100 million kilograms, saving 14,700 million liters of fuel, similar to removing 25.9 million cars. From 1996 to 2020, the benefit of global net agricultural income was $ 288.54 USD billion, equivalent to an average increase in income of $ 123 USD per hectare. Globally, insect-resistant cotton and maize crops increased yields by an average of 17.7 and 14.5%, respectively, compared to conventional production of equivalent crops. Over 25 years of grown GM crops, global production has increased by 330 million tons of soybeans, 595 million tons of maize, 37 million tons of cotton fiber, 15.8 million tons of rapeseed, and 1.9 million tons of sugar beet. If transgenic crops had not been available to farmers in 2020, additional 11.6 million hectares of soybeans, 8.5 million hectares of maize, 2.8 million hectares of cotton, and 0.5 million hectares of rapeseed would have been needed. These crops have allowed 23.4 million hectares not to be dedicated to agriculture [39, 40].

5. Desirable examples of improved plants in Latin America

Several plant cultivars could benefit from improvement through gene editing or other breeding techniques to address specific challenges faced by farmers in the region. Cultivars that could be targeted for improvement include:

Maize is a staple crop in Latin American countries, improving traits, such as drought tolerance and resistance to may beetles (Phyllophaga spp.), could significantly benefit farmers. In addition, a desirable trait is the resistance to infestation by Aspergillus spp. in stored seeds, while the high accumulation of aflatoxins in stored maize is currently provoking health problems in consumers.

Soybean cultivation is widespread in Latin America, and enhancing traits, such as herbicide tolerance, reduction of infestation by white fly, and resistance to fungal pests, caused by Phakopsora pachyrhizi could lead to increased productivity and profitability for farmers.

Rice is an essential food crop in Latin America, improving its tolerance to flooding or drought could help ensure stable rice production in the region. Golden rice produced through genetic engineering to biosynthesize beta-carotene, a precursor of vitamin A, is a highly desirable development in the region, mainly for children, pregnant women, and elderly population. This crop started to be grown in 2021 in the Philippines, the first country in the world to approve Golden Rice for commercial propagation [80].

Beans are a valuable source of protein and nutrients in Latin American diets. Enhancing productivity could contribute to improving food security and nutrition for local communities. In addition, softer beans would be desirable, as they need to be cooked for longer times to be edible. The hardness of the seeds is discouraging the population from consuming beans, due to the time and energy spent to cook the seeds.

Potatoes are an important staple crop not only in countries like Peru and Bolivia, but are also highly consumed in the region. Improving traits, such as disease resistance, drought tolerance, resistance to nematode infestation, and yield potential, could help safeguard potato production and enhance farmer livelihoods.

Wheat cultivation is expanding in Latin America, improving traits such as yield, disease resistance, and tolerance to heat and drought could support sustainable production in the region. The International Maize and Wheat Improvement Center (CIMMYT) in Mexico is performing an impressive work in providing new genotypes of wheat, maize, and other cultivars adapted to the region [81].

Cotton cultivation is significant in Mexico, Brazil, and Argentina, enhancing traits such as lepidopteran pest resistance, fiber quality, and drought tolerance could support the textile industry, in which the postharvest technology is well established.

Sugarcane is an important crop for sugar production and biofuel, as proven by Brazil for many years, with positive impacts on economy and environment. Improving traits such as yield, disease resistance, and drought tolerance are desirable, as well as the adoption of ethanol and other more energetic alcohols in the region.

Coffee is a vital cash crop in many Latin American countries. Enhancing traits such as yield, disease resistance, coleopteran resistance, and tolerance to climate change could help coffee farmers adapt to changing environmental conditions and market demands. The infestation by nematodes is also a concern in coffee-growing areas.

Bananas are important food crops in Latin America. Improving fungal disease resistance is a key request in the region, currently threatened by Fusarium oxysporum f.sp. cubense tropical race 4. In addition, postharvest shelf life could help ensure stable production and supply during its value chain.

Pepper is an important crop in Mexico, but also appreciated worldwide nowadays. Insect pest resistance is the most urgent request, including resistance to viral infection, vectored by insects.

Cassava is a staple food around the world, adopted in Latin America, the culinary use of cassava roots and leaves is held back by the presence of cyanogenic glycoside compounds. Improved cassava with lower content of these harmful substances is in demand in the region.

6. Conclusions

Twenty-eight years after the appearance of genetically modified crops, a significant number of them have been released for commercial production with satisfactory results worldwide; proving their quality, safety, and absence of environmental effects. Latin America is a region with asymmetrical adoption of biotechnology products, although with specific demands due to preferences in its diet. Access to biotechnology products also needs to foster national research capacity to generate, evaluate, and adapt innovations according to local needs, support academic groups and public institutions in the country, have clear and appropriate regulations with reliable and transparent biosafety procedures, and have adequate intellectual property rights policies, as well as the integration of academic, industrial, and governmental actors in decision-making regarding the implementation, development, and commercialization of genetically improved crops.

Acknowledgments

We thank the members of our Cinvestav Applied Sciences group for their valuable opinions. Our research is supported by CONAHCYT CF-2023-G-731 to BXC.

Conflict of interest

The authors declare no conflict of interest.