Transgenic Soybean Research Articles

Compositional analysis of genetically modified soybeans placed on Taiwan market

Soybean is an important protein source for consumers in Taiwan. Soybean production in Taiwan is not self-sufficient. Taiwan imports 2.5 million tons of soybeans annually. More than 90% of the imported soybeans are genetically modified (GM). To provide an objective assessment on safety of GM soybean and for post-market monitoring, we conducted a comparative assessment on key component compositions between imported GM soybean and local non-GM soybean from Taiwan. All the soybean samples were purchased from the local market to simulate the status of Taiwanese consumers in purchasing soybeans. The GM soybean samples were herbicide-tolerant soybeans. The content of the proximate, the amino acid composition, the fatty acid composition, vitamins, minerals, antinutritional factors, and isoflavones of soybean samples were analyzed. Most contents of the key components of the GM soybean had no significant difference with those of the non-GM soybean. However, the contents of ash, crude protein, amino acids, myristic acid, behenic acid, phosphorus, iron and phytic acid were significantly lower in the GM soybean samples, and the contents of crude fat, margaric acid, and stearic acid were significantly higher in the GM soybean samples. But they were all within the range of reference values. A total of 314 pesticide residues in each of the samples were analyzed. Glyphosate residue was detected only in GM soybean samples, but it is well below the threshold prescribed by the government. In summary, the GM soybean samples purchased from Taiwan market were shown to be substantially equivalent to non-GM soybeans.

Compositional differences between conventional Chinese and genetically modified Roundup Ready soybeans

Glyphosate-tolerant genetically modified (GM) soybeans (Glycine max (L.) Merr.), known commercially as Roundup Ready soybeans, dominate oil consumption and are partly used for protein intake in China. Chemical composition of soybean seed determines its nutritional value, its processing suitability for various protein products, and market decisions. We conducted a compositional comparison of eight GM and 16 conventional Chinese representative soybean varieties. Crude protein, crude fat, moisture, ash, carbohydrate, crude fibre, amino acid and fatty acid contents of the different soybean genotypes were compared and analysed. The GM soybeans had the highest oil concentration but poorer quality, whereas conventional soybeans from the Huanghuaihai region of China showed significantly higher protein, total amino acid, essential amino acid and oleic acid contents, and lower n-6:n-3 ratio and carbohydrate content, which suggested superior nutritional value. Principal component analysis indicated that protein, carbohydrates and amino acids (except tryptophan, methionine, tyrosine, histidine and proline) contributed most to distinguishing GM soybeans from conventional Chinese soybeans. Differences among the GM and conventional soybeans collected from two major producing regions in China can help to guide manufacturing processes and market decisions with respect to soybeans. High protein and amino acid content in conventional Chinese soybeans mean the potential to expand and improve the International Life Sciences Institute Crop Composition Database used for safety assessment of GM soybean.

Residual herbicides in Roundup Ready soybean: A case study in multiple years and locations with Ipomoea triloba

ABSTRACT The evolution of glyphosate-resistant and -tolerant weeds has caused changes in weed management around the world. Residual herbicides are crucial tools for weed management, but the rate of adoption by soybean growers remains very low in Brazil. In this research, we used glyphosate tolerant Ipomoea triloba as a model weed species to evaluate the advantages of using residual herbicides on soybeans in multiple years and locations of transition and Cerrado regions of Brazil, rather than relying only on post-emergence control. Most residual herbicides provided enough residual activity to allow a longer application window in post-emergence. Treatments with residual herbicides increased overall weed control, preventing weed interference and increasing soybean yield. When two residual herbicides were used as opposed to only one, a better I. triloba control was achieved, reflecting in higher crop yield, especially in conditions of high weed infestation. The use of pre-emergence herbicides allows growers to have a longer application window for the post-emergence treatment, which is particularly important in Brazilian Cerrado large fields when logistic could be an issue.

Physiological quality and aflatoxins prevalence in conventional and transgenic soybeans during storage

Physiological quality and aflatoxins prevalence in conventional and transgenic soybeans during storage

Pea p68, a DEAD-box helicase, enhances salt tolerance in marker-free transgenic plants of soybean [Glycine max (L.) Merrill

Protein p68 is a prototype constituent of DEAD-box protein family, which is involved in RNA metabolism, induced during abiotic stress conditions. In order to address the salinity stress faced by economically important soybean crop, we have transformed soybean cv. PUSA 9712 via direct organogenesis with marker free construct of p68 gene by Agrobacterium-mediated genetic transformation. The putative transgenic plants were screened by Polymerase chain reaction (PCR), Dot blot analysis and Southern blot hybridization. Reverse transcriptase-PCR(RT-PCR) and Quantitative real-time PCR(qRT-PCR) established that the p68 gene expressed in three out of five southern positive (T1) plants. The transformed (T1) soybean plants survived irrigation upto 200mM of NaCl whereas the non-transformed (NT) plants could not survive even 150mM NaCl. The transgenic soybean (T1) plants showed a higher accumulation of chlorophyll, proline, CAT, APX, SOD, RWC, DHAR and MDHAR than the NT plants under salinity stress conditions. The transformed (T1) soybean plants also retained a higher net photosynthetic rate, stomatal conductance and CO2 assimilation as compared to NT plants. Further analysis revealed that (T1) soybean plants accumulated higher K+ and lower Na+ levels than NT plants. Yield performance of transformed soybean plants was estimated in the transgenic green house under salinity stress conditions. The transformed (T1) soybean plants expressing the p68 gene were morphologically similar to non-transformed plants and produced 22-24 soybean pods/plant containing 8-9g (dry weight) of seeds at 200mM NaCl concentration. The present investigation evidenced the role of the p68 gene against salinity, by enhancing the tolerance towards salinity stress in soybean plants.

Determination of Amino Acids and Nutritional Aspects in Transgenic Soybean Exposed to Glyphosate

With the increase of glyphosate tolerant transgenic soybean cultivation areas, this substance has become the main herbicide for this crop, its use may interfere with the metabolism and nutritional aspects of transgenic plants. In this scenario, the objective of this work was to verify the oil, protein, phytate and amino acid concentrations in glyphosate tolerant soybean cultivar. For this, a randomized block experiment with 6 treatments and 4 repetitions was performed. The analyzed cultivar was genetically modified soybean BRS Valiosa RR. The treatments consisted of glyphosate applied once, that is, respectively in the doses: 1,5 and 2,0 L ha-1 of the commercial product, glyphosate applied sequentially in the doses: 1,5 / 1,5; 2.0 / 1.5 and 2.0 / 1.5 / 1.5 L ha^-1 of commercial products, with intervals of 15 to 20 days between applications and control (clean) weeded (without glyphosate application)). Grains were harvested, macerated and 200 mg of each sample was used for extraction of soluble amino acids. After extraction, triplicate aliquots were analyzed to determine total soluble amino acids. For quantitative determination of free amino acids, reverse phase HPLC was used after derivatization with o-ophydialdehyde (OPA) on a Spherisorb ODS-2 (C18) column. OPA derivatives were detected by fluorescence and protein contents were determined by the Kjeldhal and Soxhlet method. The data obtained were submitted to analysis of variance and F test of the statistical program ASSISTAT version 7.7 beta. Significant analyzes were performed by comparing means by Tukey test at 5% probability. In conclusion, the data indicate that although the transgenic event affects some routes, amino acid synthesis was not affected nor in nutritional terms at the glyphosate doses studied.

Розробка імуноензимного діагностикуму для виявлення гліфосат-резистентної генетично модифікованої сої

The goal of research was development of competitive ELISA kit for detection of genetically modified plants resistant to glyphosate. As the source for gene isolation we have used leaves of GM soybean RoundUp Ready, line 40-3-2 (Monsanto). Using polymerase chain reaction the gene encoding the enzyme 5-enolpiruvilshykimat-3-phosphate synthase (CP4 EPSPS) was isolated, which provides resistance to the herbicide glyphosate. Isolated gene has been cloned into plasmid vector pET24(a), creating genetic construct pET-CP4EPSPS. E.coli (BL 21(DE3)) has been transformed by genetic construct and over expressed after induction by 0.5 mM IPTG. Recombinant enzyme CP4 EPSPS with molecular weight 45 kD was purified as inclusion bodies and used as antigen for 96-well polystyrene plates immobilization. Monoclonal antibodies CP4 EPSPS mAb3 (Artron BioResearch Inc., Canada) was used for synthesis of horseradish peroxidase conjugate and receiving diagnostic reagent. We have shown that in the competitive ELISA we can detect at least 0.1% of GM plants resistant to glyphosate, on the example of soybean (line RR 40-3-2), moreover we can also detect rapeseed (line GT73) and sugar beet (line H7-1).

Creation and analysis of marker free transgenic soybean germplasm with low phosphate tolerance transcription factor GmPTF1 based on Cre/ loxP system

Creation and analysis of marker free transgenic soybean germplasm with low phosphate tolerance transcription factor GmPTF1 based on Cre/ <i>loxP</i> system

Genome Editing in Soybean with CRISPR/Cas9.

CRISPR/Cas9 mediated genome editing technology has experienced rapid advances in recent years and has been applied to a wide variety of plant species, including soybean. Several platforms have been developed for designing and cloning of single CRISPR targets or multiple targets in a single destination vector. This chapter provides an updated working protocol for applying CRISPR/Cas9 technology to target a single gene or multiple genes simultaneously in soybean. We describe two platforms for cloning single CRISPR targets and multiplexing targets, respectively, and reagent delivery methodologies. The protocols address crucial limiting steps that can limit CRISPR editing in soybean hairy roots, composite plants, and tissue culture-based regenerated whole plants. To date, transgenic soybean plants with mutagenesis in up to three target genes have been obtained with this procedure.

DNA damage induced by exposure to pesticides in children of rural areas in Paraguay.

Background & objectives:Chronic exposure to pesticides can damage DNA and lead to cancer, diabetes, respiratory diseases and neurodegenerative and neurodevelopment disorders. The objective of this study was to determine the frequency of DNA damage through the comet assay and micronucleus (MN) test in two groups of children, under 10 yr of age living in rural Paraguay and in relation to pesticide exposure.Methods:Two groups of 5 to 10 yr old children were formed; the exposed group (group A, n=43), born and currently living in a community dedicated to family agriculture and surrounded by transgenic soybean crops, and the control group (group B, n=41), born and living in a community dedicated to family agriculture with biological control of pests. For each child, 2000 cells were studied for the MN test and 200 cells for the comet assay.Results:The comparison between exposed and control children revealed significant differences in biomarkers studied for the measurement of genetic damage (cell death and DNA damage). The median of MN was higher in the exposed group (6 vs. 1) (P<0.001). Binucleated cells (2.9 vs. 0.5, P<0.001); broken eggs (5.5 vs. 1.0, P<0.001); karyorrhexis (6.7 vs. 0.5, P<0.001); kariolysis (14.0 vs. 1.0, P<0.001); pyknosis (7.4 vs. 1.2, P<0.001) and condensed chromatin (25.5 vs. 7.0, P<0.001) were significantly higher in the exposed group. The values of tail length (59.1 vs 37.2 μm); tail moment (TM) (32.8 vs. 14.4 μm); TM olive (15.5 vs. 6); % DNA tail (45.2 vs. 27.6) and % DNA head (54.8 vs. 72.4), were significantly different between the two groups.Interpretations & conclusions:In children exposed to pesticides, a greater genotoxic and cytotoxic effect was observed compared to non-exposed children. Our findings suggest that monitoring of genetic toxicity in population exposed to pesticides and agrochemicals should be done.

Chemical Management of Broadleaf Buttonweed and Brazilian Pusley in Different Application Methods

ABSTRACT: Increased use of glyphosate in transgenic soybean areas has selected resistant and tolerant weed species. The aim of this study was to evaluate chemical management strategies for controlling Borreria latifolia and Richardia brasiliensis at pre-emergence (Pre), early post-emergence (Poste) and late post-emergence (Postl). Six experiments were carried out in a completely randomized design with four replicates per treatment in the Pre experiments and three in the Poste and Postl experiments, for each of the species. In the Pre experiments, tests were performed with herbicides imazethapyr, sulfentrazone, chlorimuron, diclosulam, S-metolachlor and saflufenacil. In the Poste experiments, seedlings were sprayed with herbicides bentazon, fomesafen, lactofen, flumioxazin and glyphosate. In Postl experiments, adult plants received glyphosate application associated with herbicides 2,4-D, carfentrazone, imazethapyr, flumiclorac, flumioxazin, sulfentrazone, chlorimuron, saflufenacil and glufosinate, plus three sequential applications with glyphosate only and paraquat/diuron. In the experiments, there was a control treatment without application of herbicides. In the Pre experiments, the plants established at 14 and 28 days after application (DAA) were evaluated. In the Poste and Postl experiments, shoot dry matter evaluation and visual control were performed at 14 and 28 DAA. The herbicides sulfentrazone, S-metolachlor and saflufenacil suppressed the emergence of both B. latifolia as R. brasiliensis; chlorimuron-ethyl and diclosulam were effective only on R. brasiliensis. In Poste, fomesafen, lactofen and flumioxazin reached levels of control over 90% of plants of both species. In Postl, glyphosate associated with carfentrazone, flumiclorac, flumioxazin, chlorimuron-ethyl, saflufenacil, glufosinate, and sequential applications of glyphosate/glyphosate, glyphosate/paraquat+diuron, glyphosate+2,4-D/paraquat+diuron reached levels control higher than 95%.

Вплив генетично модифікованої сої на постнатальний розвиток щурів третього покоління

Ukraine is one of European and world leaders in soybean cultivation. According to some estimations, 50% of the crops area is used currently for cultivation of the genetically modified varieties. As modified soybean areas are expanding, potential nutritional threats related to this product should be thoroughly assessed. There are still vivid discussions on possible threats and food safety of GMO. As seen from analysis of hundreds scientific papers dealing with this problem reviewed in Genetically Engineered Crops: Experiences and Prospects (2016), there is still no undoubtful evidence of distinct negative effects of GMO or GMO-containing food on human health. On the other hand, the idea of potential threat of genetically engineered products is also popular and has many supporters stating that these components should be considered as dangerous as long as no indisputable safety evidences are found. Moreover, some primary deviations were found in the viscera morphogenesis as a result of nutrition with GMO components. Chronic intoxications and some diseases have also been reported for next generations of the lab animals. That is why the discussion of possible food safety of GMO is still open and requires more data and evidences. This work deals with investigation of possible influence of nutrition with traditional and genetically modified soybeans in ration with content 35% protein on postnatal development in the third generation of rats. All experiments were carried from the third generation of the Wistar line rats. All rats were divided into three groups: one control and two experimental. All the groups were formed by random selection of the animals with the only account of the body weight. The control group animals were fed according to the standard vivarium ration. The second group animals were fed with the food containing 35 % protein of thermotreated soybeans. The third group animals were fed using the above procedure but with the genetically engineered soybean Roundup Ready, line GTS 40-3-2: 35% protein of their diet consisted of this GM material. Counted up the amount of living and dead rats, determined the average size of new-born, by sight fixed general physical state, shortchanged survivability, measured body mass of the rat in 2 months. It has been found that the pregnancy time was unchanged in both experimental groups comparing to the value of the control group. All baby rats were delivered after 21-23 days of pregnancy. An average offspring number was 7.3 ± 1.8 individuals in the control group; 7.1 ± 1.9 individuals – in the second group and 7.9 ± 1.9 individuals in the third group. No deviations were found in physical development of young rats from all the groups: the auricle opening time was 3-4 days; body hair erupted after 5-6 days; teething time was 9-10 days and eyes opening time was 15-16 days. No visible mutilations were registered. Death rate for the first five days was 5.2 % (control group), 8.8 % (second group) and 9.5 % (third group). Same rates for the next 25 days period were correspondingly 9.1 %, 9.6 % and 15.8 %. It is seen that postnatal death rate for the third group animals was somewhat higher than that in the second and control group. This effect can be caused by a long term influence of phytoestrogens and other bioactive compounds coming to the organism from GM soybeans. The researches results testify to absence of negative influence of the thermally treated genetically modified soybeans on the genesial functions of rats and posterity development third generation. Investigated comparison of postnatal posterity development in control and experimental the groups did not find out meaningful differences. The probed indexes were within the limits of physiology norms, characteristic for rats. Keywords : traditional soybean, genetically modified soybean, rat’s females, posterity, postnatal development, survivability, physical development

ASPECTOS LOGÍSTICOS E INSTITUCIONAIS QUE AFETAM A OFERTA DA SOJA LIVRE DE TRANSGÊNICOS

Este trabalho buscou identificar as mudanças ocorridas na Cadeia Logística da Soja bem como os impactos aos elos que a compõem (produtores, armazenadores/processadores, transportadores rodoviários, operadores ferroviários e portuários), em decorrência do advento e da difusão da soja transgênica, sob uma ótica sistêmica dos problemas que envolvem sua segregação. Para isso, foram identificados os pontos críticos e os cuidados e procedimentos necessários para a não contaminação da soja ao longo da Cadeia, garantindo assim a pureza do produto e o recebimento do prêmio pela segregação. O estudo foi de natureza exploratória, com abordagem qualitativa. Os resultados permitiram concluir que o elo armazenador/processador assume papel fundamental na coordenação de toda a logística da cadeia da soja, ampliando os seus limites no sentido “coaseano”, pagando os prêmios para os agentes que conseguem fazer a segregação, passando a ser visto com um coordenador de contratos.

Impact of co-expression of maize 11 and 18 kDa δ-zeins and 27 kDa γ-zein in transgenic soybeans on protein body structure and sulfur amino acid content

The methionine-rich seed storage proteins of maize have been expressed in transgenic plants as a means to improve the overall sulfur amino acid content of seed. Previous attempts to increase the sulfur amino acid content of soybean seeds by this approach has met with limited success. It has been shown co-expression of different class of zeins can result in their stable accumulation in transgenic plants. In this study, conventional crosses between transgenic plants individually expressing 11, 18 kDa δ-zeins and 27 kDa γ-zein were made to obtain plants that simultaneously express both the δ-zein and γ-zein. Transmission electron microscopic observation of thin-sections of transgenic soybean seeds revealed that the zeins accumulated in ER-derived protein bodies (PBs) which were found sparsely scattered in cytoplasm. The size of these PBs varied from 0.2 to 0.6 μm in soybean plants individually expressing 11, 18 kDa δ-zeins and 27 kDa γ-zein. In contrast, soybeans co-expressing the 18 kDa δ-zein and 27 kDa γ-zein the PBs was 3–4 times larger. Electron microscopic observation also revealed the sequestration of PBs inside the vacuoles where they could be subjected to degradation by vacuolar proteases. Amino acid analysis of transgenic soybean individually expressing 11, 18 kDa δ-zeins and 27 kDa γ-zein revealed only a minimal increase in the overall methionine content compared to the wild-type. In contrast, plants co-expressing 18 kDa δ-zein and 27 kDa γ-zein showed a significant increase (27%) in the methionine content compared to the control seeds.

The WRKY Transcription Factor GmWRKY12 Confers Drought and Salt Tolerance in Soybean.

WRKYs are important regulators in plant development and stress responses. However, knowledge of this superfamily in soybean is limited. In this study, we characterized the drought- and salt-induced gene GmWRKY12 based on RNA-Seq and qRT-PCR. GmWRKY12, which is 714 bp in length, encoded 237 amino acids and grouped into WRKY II. The promoter region of GmWRKY12 included ABER4, MYB, MYC, GT-1, W-box and DPBF cis-elements, which possibly participate in abscisic acid (ABA), drought and salt stress responses. GmWRKY12 was minimally expressed in different tissues under normal conditions but highly expressed under drought and salt treatments. As a nucleus protein, GmWRKY12 was responsive to drought, salt, ABA and salicylic acid (SA) stresses. Using a transgenic hairy root assay, we further characterized the roles of GmWRKY12 in abiotic stress tolerance. Compared with control (Williams 82), overexpression of GmWRKY12 enhanced drought and salt tolerance, increased proline (Pro) content and decreased malondialdehyde (MDA) content under drought and salt treatment in transgenic soybean seedlings. These results may provide a basis to understand the functions of GmWRKY12 in abiotic stress responses in soybean.

Allergenic extracts from natural and genetically modified soybean

Background. The wide spread of soybeans both natural and genetically modified (GM) in agriculture and food industry arises a question about the safety of its use, as soy is the most common food allergen among leguminous plants. Meanwhile, there are no registered domestic diagnostic allergens from soybeans in Russia. Objective. The aim of this study was to obtain allergenic extracts from natural and GM soybeans resistant to the herbicide «Roundup» and evaluate their biochemical and allergenic properties. Methods. Soybean extracts were obtained by the Evans-Kok method. The amount of protein nitrogen was determined by the Nessler method. The protein composition of the soybean was determined by the SDSPAGE. Specific activity was assessed in the reaction of NDTK. Allergenic activity was assessed in ELISA according to the sIgE levels to soy in the sera of patients with food allergy. Results. The protein fractions corresponding to known allergens weare revealed by SDS-PAGE in the samples of extracts: natural soybeans - Gly m 3, Gly m 5, and Gly m 6, while GM soybeans - Gly m Bd 30k. In addition to those proteins, in both extracts the 20 kD protein was clearly detected, which can correspond to the inhibitor of trypsin Kunitsa (Hor v 1, CMb, BDR). Allergenic soybean extracts bind sIgE and sIgG in the sera of patients with allergies. Conclusion. The obtained data confirm the high allergenic potential of extracts from natural soybeans, whereas the allergenic activity of GM soybeans extracts is reduced.

Effects of genetically modified and non‐genetically modified soybeans with different heat treatments on growth and health of Cyprinidae species with different feeding habits

An 8-week growth trial was conducted to investigate the effects of non-genetically modified (nGM) soybean (Youchun 06-1) and genetically modified (GM) soybean (Roundup Ready®) with and without a heat treatment on the growth and health of three Cyprinidae species with different feeding habits (grass carp Ctenopharyngodon idellus, gibel carp Carassius auratus gibelio, and black carp Mylopharyngodon piceus; body weight: 283.0 ± 2.0 g, 60.5 ± 0.7 g, and 261.4 ± 3.1 g). Five diets (FM, nGMS, hnGMS, GMS, and hGMS) were made with fishmeal and full-fat soybean (Youchun 06-1, heat-treated Youchun 06-1, Roundup Ready®, and heat-treated Roundup Ready®). The FM diet contained fishmeal as the sole protein source. The experimental diets contained full-fat soybean meal as 60% of dietary protein. Both temperature (60, 80, 100, and 120°C) and duration (1 and 2 hr) of heating influenced trypsin inhibitor activity (TIA) and protein solubility of nGM soybean and GM soybean. The TIA in GM soybean was higher than that in nGM soybean. After heating at 120°C for 2 hr, each amino acid of soybean treatment showed a slight decline. Neither source of soybean nor heat treatment affected the growth performance, feed utilization, chemical composition of the whole fish body and muscle, and lipase or amylase activity of the three Cyprinidae species (p > 0.05). Heat treatment of soybean meal slightly increased the plasma antioxidant capacity of the three fish and plasma cholecystokinin of black carp and grass carp. The unheated soybean treatment adversely affected the height and density of black carp intestinal villi, and all the soybean treatments caused disruption of the grass carp intestinal epithelium.

PHYSIOLOGICAL ANALYSES OF AN OVER-EXPRESSING CYTOKININ METABOLIC GENE GmIPT10 UNDER NORMAL AND DROUGHT CONDITIONS

Cytokinin (CK) is an important phytohormone, which not only plays significant role in plant development but also involves in mediating plant stress tolerance. Previous studies showed that the drought tolerance can be improved by stress-inducible overexpression of adenine isopentenyl transferase (IPT), which is a critical enzyme in CKs biosynthesis. To study the role of soybean GmIPT10 in regulating plant tolerance, we successfully generated GmIPT10-overexpressing transgenic soybean plants and screened a line carrying homozygous, single copy of transgene. Analyzing several physiological traits of this line demonstrated that it possessed stress tolerance characteristics, including increased primary root and shoot lengths, better production of shoot biomass, higher number of trifoliate leaves, and higher survival rate than the non-transgenic plants under drought condition. The net house experiments also showed that the GmIPT10-overexpressing transgenic soybean had a greater relative water content compared to the control genotype under applied drought condition. Therefore, this report indicated that plant drought tolerance might be enhanced via regulating expression of GmIPT10.

Increased multiple virus resistance in transgenic soybean overexpressing the double-strand RNA-specific ribonuclease gene PAC1.

Viruses constitute a major constraint to soybean production worldwide and are responsible for significant yield losses every year. Although varying degrees of resistance to specific viral strains has been identified in some soybean genetic sources, the high rate of mutation in viral genomes and mixed infections of different viruses or strains under field conditions usually hinder the effective control of viral diseases. In the present study, we generated transgenic soybean lines constitutively expressing the double-strand RNA specific ribonuclease gene PAC1 from Schizosaccharomyces pombe to evaluate their resistance responses to multiple soybean-infecting virus strains and isolates. Resistance evaluation over three consecutive years showed that the transgenic lines displayed significantly lower levels of disease severity in field conditions when challenged with soybean mosaic virus (SMV) SC3, a prevalent SMV strain in soybean-growing regions of China, compared to the non-transformed (NT) plants. After inoculation with four additional SMV strains (SC7, SC15, SC18, and SMV-R), and three isolates of bean common mosaic virus (BCMV), watermelon mosaic virus (WMV), and bean pod mottle virus (BPMV), the transgenic plants exhibited less severe symptoms and enhanced resistance to virus infections relative to NT plants. Consistent with these results, the accumulation of each virus isolate was significantly inhibited in transgenic plants as confirmed by quantitative real-time PCR and double antibody sandwich enzyme-linked immunosorbent assays. Collectively, our results showed that overexpression of PAC1 can increase multiple virus resistance in transgenic soybean, and thus provide an efficient control strategy against RNA viruses such as SMV, BCMV, WMV, and BPMV.

ITRAQ-based quantitative tissue proteomic analysis of differentially expressed proteins (DEPs) in non-transgenic and transgenic soybean seeds

The unintended effects of transgenesis have increased food safety concerns, meriting comprehensive evaluation. Proteomic profiling provides an approach to directly assess the unintended effects. Herein, the isobaric tags for relative and absolute quantitation (iTRAQ) comparative proteomic approach was employed to evaluate proteomic profile differences in seed cotyledons from 4 genetically modified (GM) and 3 natural genotypic soybean lines. Compared with their non-GM parents, there were 67, 61, 13 and 22 differentially expressed proteins (DEPs) in MON87705, MON87701 × MON89788, MON87708, and FG72. Overall, 170 DEPs were identified in the 3 GM soybean lines with the same parents, but 232 DEPs were identified in the 3 natural soybean lines. Thus, the differences in protein expression among the genotypic varieties were greater than those caused by GM. When considering ≥2 replicates, 4 common DEPs (cDEPs) were identified in the 3 different GM soybean lines with the same parents and 6 cDEPs were identified in the 3 natural varieties. However, when considering 3 replicates, no cDEPs were identified. Regardless of whether ≥2 or 3 replicates were considered, no cDEPs were identified among the 4 GM soybean lines. Therefore, no feedback due to GM was observed at the common protein level in this study.