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Drought-tolerant transgenic [genetically modified (GM)] HB4® wheat carrying the drought-responsive sunflower gene Hahb4 was first developed in Argentina in 2019 and has already been approved for marketing and consumption as food/feed in at least ten countries. It has also been approved in Argentina and Brazil for commercial cultivation.

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The Environmental Risk Assessment (ERA) of genetically modified (GM) crops in Argentina is carried out by the National Advisory Commission on Agricultural Biotechnology (CONABIA) and the Innovation and Biotechnology Coordination (CIyB). Both have a large experience with this assessment, since 1991, when CONABIA was created. The continuous support to biotechnology as a state policy and as part of the decision to encourage developers in the regulatory process has helped make progress in the revision of the regulations. The experience gained during the last 30 years and the worldwide scientific advances supported the bases to update the regulatory framework. Focusing on the biosafety strengthening and the improvement of the applicant's experience in the GM crops evaluation process, during 2020 and 2021, the ERA went through a reviewing process. Some important modifications were made, such as (i) the assessment of stacked GM crops with focus on the possible interactions between transgenes and the expression products, (ii) the strengthening of the ERA taking into account the transportability of data and conclusions from the Confined Field Trials (CFTs), (iii) the adoption of Familiarity and History of Safe Use (HOSU) concepts on the risk assessment of the expression products, (iv) the special considerations for the unintended effects of insertional sites, and (v) as a post commercial release of GM crops, the Insect Resistance Management Plan (IRMP) was reformulated. These novel approaches enhance the ERA; they make it more efficient by applying the science criteria and the accumulated experience and scientific bibliography on the topic.

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Recent studies predict that global food demand of major grain crops will not be accompanied by the required increase in yield (Hall and Richards, 2013). Additionally, current figures estimate that the impact of climate change on agriculture will yield losses of 8-43%, mainly due to abiotic stresses. A second generation of transgenic crops (SGTC) was projected to mitigate these constraints worldwide. However, SGTC remain unavailable as market products. Here, we present our viewpoints about current limitations and future perspectives.

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The use of genetically modified (GM) plants has increased in recent decades, but there are uncertainties about their effects on soil microbial communities. Aiming to quantify root colonization and characterize arbuscular mycorrhizal fungi (AMF) communities associated with roots and rhizosphere soil of different maize genotypes, a field trial was carried out in Southern Brazil with three maize genotypes as follows: a GM hybrid (DKB 240 VTPRO), its non-modified isoline (DKB 240), and a landrace (Pixurum). Soil samples were collected to evaluate the occurrence of AMF during the growth of corn genotypes at sowing and V3 (vegetative), R1 (flowering), and R3 (grain formation) stages of the crop. The occurrence of AMF was determined by the morphological identification of spores, and by analyzing AMF community composition in soil and roots of maize, using PCR-DGGE. The GM genotype of maize promoted lower mycorrhizal colonization in the vegetative stage and had lower sporulation at grain development than the conventional hybrid and the landrace maize. Twenty AMF morphotypes were identified and 13 were associated with all maize genotypes. The genera Acaulospora, Glomus, and Dentiscutata had the largest numbers of species. There were no differences in AMF community composition due to maize genotypes or genetic modification, but crop phenological stages affected AMF communities associated with maize roots.

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This study assesses the economic and environmental impacts that have arisen from the adoption and use of genetically modified (GM) cotton and maize in Colombia in the fifteen years since GM cotton was first planted in Colombia in 2003. A total of 1.07 million hectares have been planted to cotton and maize containing GM traits since 2003, with farmers benefiting from an increase in income of US $301.7 million. For every extra US $1 spent on this seed relative to conventional seed, farmers have gained an additional US $3.09 in extra income from growing GM cotton and an extra US $5.25 in extra income from growing GM maize. These income gains have mostly arisen from higher yields (+30.2% from using stacked (herbicide tolerant and insect resistant cotton and +17.4% from using stacked maize). The cotton and maize seed technology have reduced insecticide and herbicide spraying by 779,400 kg of active ingredient (-19%) and, as a result, decreased the environmental impact associated with herbicide and insecticide use on these crops (as measured by the indicator, the Environmental Impact Quotient (EIQ)) by 26%. The technology has also facilitated cuts in fuel use, resulting in a reduction in the release of greenhouse gas emissions from the GM cotton and maize cropping area and contributed to saving scarce land resources.

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This study investigates the dynamics of glyphosate and AMPA in the soil surface layer of two fields growing glyphosate-resistant crops in the loess Pampas of Córdoba Province, Argentina. Glyphosate decay and AMPA formation/decay were studied after a single application, using decay kinetic models. Furthermore, glyphosate and AMPA concentrations were investigated in runoff to evaluate their off-site risk. During a 2.5-month study, cultivations of glyphosate-resistant soybean and maize received an application of 1.0 and 0.81 kg a.e. ha-1, respectively, of Roundup UltraMax©. Topsoil samples (0-1, 1-2 cm) were collected weekly (including before application) and analysed for glyphosate, AMPA and soil moisture (SM) contents. Runoff was collected from runoff plots (3 m2) and weirs after 2 erosive rainfall events, and analysed for glyphosate and AMPA contents (water, eroded-sediment). Under both cultivations, background residues in soil before application were 0.27-0.42 mg kg-1 for glyphosate and 1.3-1.7 mg kg-1 for AMPA. In the soybean area, the single-first-order (SFO) model performed best for glyphosate decay. In the maize area, the bi-phasic Hockey-Stick (HS) model performed best for glyphosate decay, due to an abrupt change in SM regimes after high rainfall. Glyphosate half-life and DT90 were 6.0 and 19.8 days, respectively, in the soybean area, and 11.1 and 15.4 days, respectively, in the maize area. In the soybean area, 24% of the glyphosate was degraded to AMPA. In the maize area, it was only 5%. AMPA half-life and DT90 were 54.7 and 182 days, respectively, in the soybean area, and 71.0 and 236 days, respectively, in the maize area. Glyphosate and AMPA contents were 1.1-17.5 times higher in water-eroded sediment than in soil. We conclude that AMPA persists and may accumulate in soil, whereas both glyphosate and AMPA are prone to off-site transport with water erosion, representing a contamination risk for surface waters and adjacent fields.

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Forage seasonality makes farmers use conservation practices. Mixing corn silage and legumes can enhance silage quality and hence animal productivity. Therefore, this study aimed to evaluate yield and quality of silages from intercropping between genetically modified corn and soybean for glyphosate tolerance (RR - Roundup Ready) as a function of plant spatial arrangement, soybean variety, and sowing fertilization methods. Two intercropping arrangements of RR corn and RR soybeans were tested: alternate single rows of corn and soybeans and double corn rows for each soybean row. Treatments were randomized blocks with four replications, arranged in a 2x2+1 factorial scheme. The first factor was sowing fertilization method (2): only in corn rows or in total area. The second factor was soybean variety (2): medium- and late-cycle genotypes, and an additional treatment of corn monoculture. After harvest, forage material was analyzed for agronomic characteristics and then ensiled for 60 days. Thereafter, bromatological composition, fermentation profile, and losses were analyzed during silage fermentation process. No differences were observed among treatments for total silage production. Overall, silage from intercropping treatments showed higher levels of hemicellulose, total digestible nutrients, crude protein, and ether extract, thus improving silage quality. However, lower contents of dry matter, acid detergent fiber, and cellulose were also observed in silage from intercropped treatments. In short, adding soybeans to silage can improve final roughage, reducing costs of protein and energy supplements.

A sazonalidade na produção das plantas forrageiras impõe aos produtores o uso de práticas de conservação de forragem. A silagem de milho com leguminosas pode aumentar a qualidade e resultar em maior produtividade animal. Portanto, objetivou-se avaliar a produtividade e a qualidade da silagem do consórcio entre as culturas de milho e soja geneticamente modificadas para tolerância ao herbicida glifosato (RR - Roundup Ready) em função do arranjo espacial das plantas, variedades de soja e adubação de semeadura. Foram realizados dois ensaios com consórcio entre milho RR e soja RR, sendo em arranjo simples (uma linha de milho alternada com uma linha de soja) e outro em arranjo duplo (duas linhas de milho alternada com uma linha de soja). Os tratamentos foram delineados em blocos ao acaso em esquema fatorial 2x2+1, com quatro repetições. O primeiro fator foi constituído de duas modalidades de adubação de semeadura na linha: somente no milho, omitindo a soja; e em área total; o segundo fator a duas variedades de soja: de ciclo médio e tardio. O tratamento adicional correspondeu ao monocultivo de milho. Após colheita do material foi analisado suas características agronômicas, depois o material foi ensilado por 60 dias e realizadas as análises bromatológicas, fermentativas e de perdas durante o processo de fermentação da silagem. Não foram observadas diferenças entre tratamentos para a produção total de silagem. De forma geral, a silagem oriunda dos consórcios apresentou maiores valores para os teores de hemicelulose, nutrientes digestíveis totais, proteína bruta e extrato etéreo beneficiando a qualidade da silagem produzida. Por outro lado, foram observados menores valores percentuais de matéria seca, de fibra em detergente ácido e celulose. Em síntese, a soja pode auxiliar no resultado final do volumoso, diminuindo gastos com suplementação proteica ou uso de suplementos energéticos.

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Forage seasonality makes farmers use conservation practices. Mixing corn silage and legumes can enhance silage quality and hence animal productivity. Therefore, this study aimed to evaluate yield and quality of silages from intercropping between genetically modified corn and soybean for glyphosate tolerance (RR - Roundup Ready) as a function of plant spatial arrangement, soybean variety, and sowing fertilization methods. Two intercropping arrangements of RR corn and RR soybeans were tested: alternate single rows of corn and soybeans and double corn rows for each soybean row. Treatments were randomized blocks with four replications, arranged in a 2x2+1 factorial scheme. The first factor was sowing fertilization method (2): only in corn rows or in total area. The second factor was soybean variety (2): medium- and late-cycle genotypes, and an additional treatment of corn monoculture. After harvest, forage material was analyzed for agronomic characteristics and then ensiled for 60 days. Thereafter, bromatological composition, fermentation profile, and losses were analyzed during silage fermentation process. No differences were observed among treatments for total silage production. Overall, silage from intercropping treatments showed higher levels of hemicellulose, total digestible nutrients, crude protein, and ether extract, thus improving silage quality. However, lower contents of dry matter, acid detergent fiber, and cellulose were also observed in silage from intercropped treatments. In short, adding soybeans to silage can improve final roughage, reducing costs of protein and energy supplements.(AU)

A sazonalidade na produção das plantas forrageiras impõe aos produtores o uso de práticas de conservação de forragem. A silagem de milho com leguminosas pode aumentar a qualidade e resultar em maior produtividade animal. Portanto, objetivou-se avaliar a produtividade e a qualidade da silagem do consórcio entre as culturas de milho e soja geneticamente modificadas para tolerância ao herbicida glifosato (RR - Roundup Ready) em função do arranjo espacial das plantas, variedades de soja e adubação de semeadura. Foram realizados dois ensaios com consórcio entre milho RR e soja RR, sendo em arranjo simples (uma linha de milho alternada com uma linha de soja) e outro em arranjo duplo (duas linhas de milho alternada com uma linha de soja). Os tratamentos foram delineados em blocos ao acaso em esquema fatorial 2x2+1, com quatro repetições. O primeiro fator foi constituído de duas modalidades de adubação de semeadura na linha: somente no milho, omitindo a soja; e em área total; o segundo fator a duas variedades de soja: de ciclo médio e tardio. O tratamento adicional correspondeu ao monocultivo de milho. Após colheita do material foi analisado suas características agronômicas, depois o material foi ensilado por 60 dias e realizadas as análises bromatológicas, fermentativas e de perdas durante o processo de fermentação da silagem. Não foram observadas diferenças entre tratamentos para a produção total de silagem. De forma geral, a silagem oriunda dos consórcios apresentou maiores valores para os teores de hemicelulose, nutrientes digestíveis totais, proteína bruta e extrato etéreo beneficiando a qualidade da silagem produzida. Por outro lado, foram observados menores valores percentuais de matéria seca, de fibra em detergente ácido e celulose. Em síntese, a soja pode auxiliar no resultado final do volumoso, diminuindo gastos com suplementação proteica ou uso de suplementos energéticos.(AU)

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La tolerancia a herbicidas es una de las características más usadas en los cultivos GM, con resultados positivos para los agricultores y el ambiente. El punto de partida, es el desarrollo de casetes de expresión que expresen la característica de interés, inicialmente construidos mediante técnicas de biología molecular convencionales. Actualmente, con herramientas de bioinformática y biología sintética, es posible diseñar y probar el constructo in silico, para luego contratar su síntesis. Esta aproximación, permite optimizar la expresión mediante la modificación del uso codónico. En este trabajo se diseñaron y evaluaron en Nicotiana benthamiana versiones semisintéticas de genes que confieren tolerancia al herbicida fosfinotricina. Se realizó un análisis de libertad de operación, con el fin de asegurar que los constructos diseñados no violen derechos de propiedad intelectual en Colombia. Se obtuvieron dos casetes de expresión con libertad de operación, que expresan versiones del gen bar.

Herbicide tolerance is one of the features most used in GM crops, which has shown positive results for farmers and the environment. The starting point is the development of expression cassettes that express the characteristic of interest, they are initially constructed by standard molecular biology techniques. Currently, by bioinformatics and synthetic biology tools, it is possible to design and test the construct in silico, and then hire their synthesis. This approach allows optimizing expression by modifying the codon usage. In this work there were designed and evaluated semi-synthetic versions of genes in Nicotiana benthamiana, these genes confer tolerance to the herbicide phosphinothricin. It was made an analysis of freedom to operate in order to ensure that the designed constructs not violate intellectual property in Colombia. There were obtained two expression cassettes with freedom to operate, which express versions of the bar gene.

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Agricultural biotechnology and genetically modified (GM) crops are effective tools to substantially increase productivity, quality, and environmental sustainability in agricultural farming. Furthermore, they may contribute to improving the nutritional content of crops, addressing needs related to public health. Chile has become one of the most important global players for GM seed production for counter-season markets and research purposes. It has a comprehensive regulatory framework to carry out this activity, while at the same time there are numerous regulations from different agencies addressing several aspects related to GM crops. Despite imports of GM food/feed or ingredients for the food industry being allowed without restrictions, Chilean farmers are not using GM seeds for farming purposes because of a lack of clear guidelines. Chile is in a rather contradictory situation about GM crops. The country has invested considerable resources to fund research and development on GM crops, but the lack of clarity in the current regulatory situation precludes the use of such research to develop new products for Chilean farmers. Meanwhile, a larger scientific capacity regarding GM crop research continues to build up in the country. The present study maps and analyses the current regulatory environment for research and production of GM crops in Chile, providing an updated overview of the current status of GM seeds production, research and regulatory issues.

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