Assessing the natural variability in crop composition

Essential Oils as Antimicrobial Active Substances in Wound Dressings

Wound dressings for skin lesions, such as bedsores or pressure ulcers, are widely used for many patients, both during hospitalization and in subsequent treatment at home. To improve the treatment and shorten the healing time and, therefore, the cost, numerous types of wound dressings have been developed by manufacturers. Considering certain inconveniences related to the intolerance of some patients to antibiotics and the antimicrobial, antioxidant, and curative properties of certain essential oils, we conducted research by incorporating these oils, based on polyvinyl alcohol/ polyvinyl pyrrolidone (PVA/PVP) biopolymers, into dressings. The objective of this study was to study the potential of a polymeric matrix for wound healing, with polyvinyl alcohol as the main material and polyvinyl pyrrolidone and hydroxypropyl methylcellulose (HPMC) as secondary materials, together with additives (plasticizers poly(ethylene glycol) (PEG) and glycerol), stabilizers (Zn stearate), antioxidants (vitamin A and vitamin E), and four types of essential oils (fennel, peppermint, pine, and thyme essential oils). For all the studied samples, the combining compatibility, antimicrobial, and cytotoxicity properties were investigated. The obtained results demonstrated a uniform morphology for almost all the samples and adequate barrier properties for contact with suppurating wounds. The results show that the obtained samples containing essential oils have a good inhibitory effect on, or antimicrobial properties against, Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, and Candida albicans ATCC 10231. The MTT assay showed that the tested samples were not toxic and did not lead to cell death. The results showed that the essential oils used provide an effective solution as active substances in wound dressings.

Comparison of the seed nutritional composition between conventional varieties and transgenic soybean overexpressing Physaria FAD3-1

BACKGROUND

PfFAD3 transgenic soybean expressing omega-3 fatty acid desaturase 3 of Physaria produces increased level of α-linolenic acid in seed. Composition data of non-transgenic conventional varieties is important in the safety assessment of the genetically-modified (GM) crops in the context of the natural variation.

RESULTS

The natural variation was characterized in seed composition of 13 Korean soybean varieties grown in three locations in South Korea for 2 years. Univariate analysis of combined data showed significant differences by variety and cultivation environment for proximates, minerals, anti-nutrients, and fatty acids. Percent variability analysis demonstrated that genotype, environment and the interaction of environment with genotype contributed to soybean seed compositions. Principal component analysis and orthogonal projections to latent structure discriminant analysis indicated that significant variance in compositions was attributable to location and cultivation year. The composition of three PfFAD3 soybean lines for proximates, minerals, anti-nutrients, and fatty acids was compared to a non-transgenic commercial comparator (Kwangankong, KA), and three non-transgenic commercial varieties grown at two sites in South Korea. Only linoleic and linolenic acids significantly differed in PfFAD3-1 lines compared to KA, which were expected changes by the introduction of the PfFAD3-1 trait in KA.

CONCLUSION

Genotype, environment, and the interaction of environment with genotype contributed to compositional variability in soybean. PfFAD3-1 soybean is equivalent to the conventional varieties with respect to these components. © 2020 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Compositional equivalence assessment of insect-resistant genetically modified rice using multiple statistical analyses

The safety of transgenic Bt rice containing bacteria-derived mCry1Ac gene from Bacillus thuringiensis (Bt) was assessed by conducting field trials at two locations for two consecutive years in South Korea, using the near-isogenic line comparator rice cultivar ('Ilmi', non-Bt rice) and four commercial cultivars as references. Compositional analyses included measurement of proximates, minerals, amino acids, fatty acids, vitamins, and antinutrients. Significant differences between Bt rice and non-Bt rice were detected; however, all differences were within the reference range. The statistical analyses, including analysis of % variability, analysis of similarities (ANOISM), similarity percentage (SIMPER) analysis, and permutational multivariate analysis of variance (PERMANOVA) were performed to study factors contributing to compositional variability. The multivariate analyses revealed that environmental factors more influenced rice components' variability than by genetic factors. This approach was shown to be a powerful method to provide meaningful evaluations between Bt rice and its comparators. In this study, Bt rice was proved to be compositionally equivalent to conventional rice varieties through multiple statistical methods.

Hypothesis Testing of Inclusion of the Tolerance Interval for the Assessment of Food Safety

In the testing of food quality and safety, we contrast the contents of the newly proposed food (genetically modified food) against those of conventional foods. Because the contents vary largely between crop varieties and production environments, we propose a two-sample test of substantial equivalence that examines the inclusion of the tolerance intervals of the two populations, the population of the contents of the proposed food, which we call the target population, and the population of the contents of the conventional food, which we call the reference population. Rejection of the test hypothesis guarantees that the contents of the proposed foods essentially do not include outliers in the population of the contents of the conventional food. The existing tolerance interval (TI0) is constructed to have at least a pre-specified level of the coverage probability. Here, we newly introduce the complementary tolerance interval (TI1) that is guaranteed to have at most a pre-specified level of the coverage probability. By applying TI0 and TI1 to the samples from the target population and the reference population respectively, we construct a test statistic for testing inclusion of the two tolerance intervals. To examine the performance of the testing procedure, we conducted a simulation that reflects the effects of gene and environment, and residual from a crop experiment. As a case study, we applied the hypothesis testing to test if the distribution of the protein content of rice in Kyushu area is included in the distribution of the protein content in the other areas in Japan.

Safety assessment of foods from genetically modified crops in countries with developing economies

Population growth particularly in countries with developing economies will result in a need to increase food production by 70% by the year 2050. Biotechnology has been utilized to produce genetically modified (GM) crops for insect and weed control with benefits including increased crop yield and will also be used in emerging countries. A multicomponent safety assessment paradigm has been applied to individual GM crops to determine whether they as safe as foods from non-GM crops. This paper reviews methods to assess the safety of foods from GM crops for safe consumption from the first generation of GM crops. The methods can readily be applied to new products developed within country and this paper will emphasize the concept of data portability; that safety data produced in one geographic location is suitable for safety assessment regardless of where it is utilized.

Insect-protected event DAS-81419-2 soybean (Glycine max L.) grown in the United States and Brazil is compositionally equivalent to nontransgenic soybean

The transgenic soybean event DAS-81419-2 contains genes that encode the Cry1F, Cry1Ac, and PAT proteins. Cry1F and Cry1Ac provide protection against key lepidopteran insect pests, while PAT confers tolerance to the herbicide glufosinate. To satisfy regulatory requirements for the safety evaluation of transgenic crops, studies were conducted in the United States and Brazil to evaluate the nutrient and antinutrient composition of event DAS-81419-2 soybean. On the basis of the results of these studies, event DAS-81419-2 soybean is compositionally equivalent to nontransgenic soybean. This conclusion concurs with numerous other published studies in soybean and other crops where compositional equivalence between the transgenic crop and its nontransgenic comparator has been demonstrated.

Impacts on the metabolome of down-regulating polyphenol oxidase in potato tubers

Tubers of potato (Solanum tuberosum L. cv. Estima) genetically modified to reduce polyphenol oxidase (PPO) activity and enzymatic discolouration were assessed for changes in the metabolome using Liquid Chromatography-Mass Spectrometry (LC-MS) and Gas Chromatography (GC)-MS. Metabolome changes induced over a 48 hour (h) period by tuber wounding (sliced transverse sections) were also assessed using two PPO antisense lines (asPPO) and a wild-type (WT) control. Data were analysed using Principal Components Analysis and Analysis of Variance to assess differences between genotypes and temporal changes post-tuber wounding (by slicing). The levels of 15 metabolites (out of a total of 134 that were detected) differed between the WT and asPPO lines in mature tubers at harvest. A considerably higher number (63) of these metabolites changed significantly over a 48 h period following tuber wounding. For individual metabolites the magnitude of the differences between the WT and asPPO lines at harvest were small compared with the impacts of tuber wounding on metabolite levels. Some of the observed metabolite changes are explicable in terms of pathways known to be affected by wound responses. Whilst some statistically significant interactions (11 metabolites) were observed between line and time after wounding, very few profiles were consistent when comparing the WT with both asPPO lines, and the underlying metabolites appeared to be random in terms of the pathways they occupy. Overall, mechanical damage to tubers has a considerably greater impact on the metabolite profile than any potential unintended effects resulting from the down-regulation of PPO gene expression.

Measurement of endogenous allergens in genetically modified soybeans--short communication

The measurement of endogenous allergens is required by the European Commission (EC) as part of the compositional analysis for GM products from host plants that are common causes of food allergy, such as soybean (EC Implementing Regulation No. 503/2013). In each case, the EC Implementing Regulation indicates that analysis be conducted on identified allergens as specified in the Organization of Economic Cooperation and Development (OECD) consensus documents on compositional considerations for new plant varieties. This communication discusses the methods available to measure endogenous allergens as well as the endogenous soybean allergens that should be analyzed. It is suggested herein that in conjunction with the 2012 OECD consensus document on soybean, any list of soybean allergens should be based on clinically relevant data among publicly available allergen databases and peer-reviewed scientific publications, and the ability to measure the identified allergen. Based on a detailed analysis of the scientific literature, the following key points are recommended: (1) the acceptance of serum-free, quantitative analytical method data as an alternative to traditional IgE reactivity qualitative or semi-quantitative data for evaluation of endogenous soybean allergen content; (2) eight of the 15 potential allergens listed in the OECD soybean consensus document (Gly m 3, Gly m 4, Gly m Bd28K, Gly m Bd30K, Gly m 5, Gly m 6, Gly m 8, and Kunitz trypsin inhibitor) have both appropriate supporting clinical data and sufficient sequence information to be evaluated in comparative endogenous soybean allergen studies; and (3) the remaining seven proteins (Gly m 1, Gly m 2, unknown 50kDa protein, unknown 39kDa protein, P-22-25, lipoxygenase and lectin) lack sufficient data for clear classification as confirmed allergens and/or available sequence information and should not be currently included in the measurement of endogenous soybean allergens in the compositional analysis for the EU.

Analytical method evaluation and discovery of variation within maize varieties in the context of food safety: transcript profiling and metabolomics

Profiling techniques such as microarrays, proteomics, and metabolomics are used widely to assess the overall effects of genetic background, environmental stimuli, growth stage, or transgene expression in plants. To assess the potential regulatory use of these techniques in agricultural biotechnology, we carried out microarray and metabolomic studies of 3 different tissues from 11 conventional maize varieties. We measured technical variations for both microarrays and metabolomics, compared results from individual plants and corresponding pooled samples, and documented variations detected among different varieties with individual plants or pooled samples. Both microarray and metabolomic technologies are reproducible and can be used to detect plant-to-plant and variety-to-variety differences. A pooling strategy lowered sample variations for both microarray and metabolomics while capturing variety-to-variety variation. However, unknown genomic sequences differing between maize varieties might hinder the application of microarrays. High-throughput metabolomics could be useful as a tool for the characterization of transgenic crops. However, researchers will have to take into consideration the impact on the detection and quantitation of a wide range of metabolites on experimental design as well as validation and interpretation of results.

Unintended compositional changes in genetically modified (GM) crops: 20 years of research

The compositional equivalency between genetically modified (GM) crops and nontransgenic comparators has been a fundamental component of human health safety assessment for 20 years. During this time, a large amount of information has been amassed on the compositional changes that accompany both the transgenesis process and traditional breeding methods; additionally, the genetic mechanisms behind these changes have been elucidated. After two decades, scientists are encouraged to objectively assess this body of literature and determine if sufficient scientific uncertainty still exists to continue the general requirement for these studies to support the safety assessment of transgenic crops. It is concluded that suspect unintended compositional effects that could be caused by genetic modification have not materialized on the basis of this substantial literature. Hence, compositional equivalence studies uniquely required for GM crops may no longer be justified on the basis of scientific uncertainty.

Compositional equivalence of DAS-444Ø6-6 (AAD-12 + 2mEPSPS + PAT) herbicide-tolerant soybean and nontransgenic soybean

Soybeans from transgenic event DAS-444Ø6-6 are the first to express three proteins that provide tolerance to broad-spectrum herbicides. DAS-444Ø6-6 soybean expresses the aryloxyalkanoate dioxygenase-12 (AAD-12) enzyme from the soil bacterium Delftia acidovorans , which provides tolerance to the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D); the double-mutant 5-enolpyruvylshikimate-3-phosphate synthase (2mEPSPS) enzyme encoded by a modified version of the epsps gene from maize ( Zea mays ), which provides tolerance to the herbicide glyphosate; and the phosphinothricin acetyltransferase (PAT) enzyme from Streptomyces viridochromogenes , which provides tolerance to the herbicide glufosinate. The purpose of this study was to determine if the nutrient and antinutrient composition of forage and grain from DAS-444Ø6-6 soybean are similar to those of nontransgenic soybean. Forage was analyzed for proximates, fiber, and minerals; grain analyses further included vitamins, amino acid and fatty acid profiles, and antinutrients and bioactive components (lectin, phytic acid, raffinose, stachyose, trypsin inhibitor, and isoflavones). Results indicate that DAS-444Ø6-6 soybean is compositionally equivalent to nontransgenic soybean. Findings are consistent with similar studies for other input traits, as endogenous plant metabolic pathways that influence composition are expected to be less affected by transgenesis compared with traditional plant-breeding methods.

The use of whole food animal studies in the safety assessment of genetically modified crops: limitations and recommendations

There is disagreement internationally across major regulatory jurisdictions on the relevance and utility of whole food (WF) toxicity studies on GM crops, with no harmonization of data or regulatory requirements. The scientific value, and therefore animal ethics, of WF studies on GM crops is a matter addressable from the wealth of data available on commercialized GM crops and WF studies on irradiated foods. We reviewed available GM crop WF studies and considered the extent to which they add to the information from agronomic and compositional analyses. No WF toxicity study was identified that convincingly demonstrated toxicological concern or that called into question the adequacy, sufficiency, and reliability of safety assessments based on crop molecular characterization, transgene source, agronomic characteristics, and/or compositional analysis of the GM crop and its near-isogenic line. Predictions of safety based on crop genetics and compositional analyses have provided complete concordance with the results of well-conducted animal testing. However, this concordance is primarily due to the improbability of de novo generation of toxic substances in crop plants using genetic engineering practices and due to the weakness of WF toxicity studies in general. Thus, based on the comparative robustness and reliability of compositional and agronomic considerations and on the absence of any scientific basis for a significant potential for de novo generation of toxicologically significant compositional alterations as a sole result of transgene insertion, the conclusion of this review is that WF animal toxicity studies are unnecessary and scientifically unjustifiable.

Availability and utility of crop composition data

The safety assessment of genetically modified (GM) crops is mandatory in many countries. Although the most important factor to take into account in these safety assessments is the primary effects of artificially introduced transgene-derived traits, possible unintended effects attributed to the insertion of transgenes must be carefully examined in parallel. However, foods are complex mixtures of compounds characterized by wide variations in composition and nutritional values. Food components are significantly affected by various factors such as cultivars and the cultivation environment including storage conditions after harvest, and it can thus be very difficult to detect potential adverse effects caused by the introduction of a transgene. A comparative approach focusing on the identification of differences between GM foods and their conventional counterparts has been performed to reveal potential safety issues and is considered the most appropriate strategy for the safety assessment of GM foods. This concept is widely shared by authorities in many countries. For the efficient safety assessment of GM crops, an easily accessible and wide-ranging compilation of crop composition data is required for use by researchers and regulatory agencies. Thus, we developed an Internet-accessible food composition database comprising key nutrients, antinutrients, endogenous toxicants, and physiologically active substances of staple crops such as rice and soybeans. The International Life Sciences Institute has also been addressing the same matter and has provided the public a crop composition database of soybeans, maize, and cotton.

Safety of GM crops: compositional analysis

The compositional analysis of genetically modified (GM) crops has continued to be an important part of the overall evaluation in the safety assessment program for these materials. The variety and complexity of genetically engineered traits and modes of action that will be used in GM crops in the near future, as well as our expanded knowledge of compositional variability and factors that can affect composition, raise questions about compositional analysis and how it should be applied to evaluate the safety of traits. The International Life Sciences Institute (ILSI), a nonprofit foundation whose mission is to provide science that improves public health and well-being by fostering collaboration among experts from academia, government, and industry, convened a workshop in September 2012 to examine these and related questions, and a series of papers has been assembled to describe the outcomes of that meeting.

Metabolite profiling of maize kernels--genetic modification versus environmental influence

A metabolite profiling approach based on gas chromatography-mass spectrometry (GC-MS) was applied to investigate the metabolite profiles of genetically modified (GM) Bt-maize (DKC78-15B, TXP 138F) and Roundup Ready-maize (DKC78-35R). For the comparative investigation of the impact of genetic modification versus environmental influence on the metabolite profiles, GM maize was grown together with the non-GM near-isogenic comparators under different environmental conditions, including several growing locations and seasons in Germany and South Africa. Analyses of variance (ANOVA) revealed significant differences between GM and non-GM maize grown in Germany and South Africa. For the factor genotype, 4 and 3%, respectively, of the total number of peaks detected by GC-MS showed statistically significant differences (p < 0.01) in peak heights as compared to the respective isogenic lines. However, ANOVA for the factor environment (growing location, season) revealed higher numbers of significant differences (p < 0.01) between the GM and the non-GM maize grown in Germany (42%) and South Africa (10%), respectively. This indicates that the majority of differences observed are related to natural variability rather than to the genetic modifications. In addition, multivariate data assessment by means of principal component analysis revealed that environmental factors, that is, growing locations and seasons, were dominant parameters driving the variability of the maize metabolite profiles.