Non-transgenic Parent Research Articles

Proteomic Analysis of Bt cry1Ac Transgenic Oilseed Rape (Brassica napus L.).

Oilseed rape (Brassica napus L.) is an important cash crop, but transgenic oilseed rape has not been grown on a commercial scale in China. It is necessary to analyze the characteristics of transgenic oilseed rape before commercial cultivation. In our study, differential expression of total protein from the leaves in two transgenic lines of oilseed rape expressing foreign Bt Cry1Ac insecticidal toxin and their non-transgenic parent plant was analyzed using a proteomic approach. Only shared changes in both of the two transgenic lines were calculated. Fourteen differential protein spots were analyzed and identified, namely, eleven upregulated expressed protein spots and three downregulated protein spots. These proteins are involved in photosynthesis, transporter function, metabolism, protein synthesis, and cell growth and differentiation. The changes of these protein spots in transgenic oilseed rape may be attributable to the insertion of the foreign transgenes. However, the transgenic manipulation might not necessarily cause significant change in proteomes of the oilseed rape.

Safety assessment of subchronic feeding of insect-resistant and herbicide-resistant transgenic soybeans to juvenile channel catfish (Ictalurus punctatus)

Transgenic soybean is one of the most planted crops for human food and animal feed. The channel catfish (Ictalurus punctatus) is an important aquatic organism cultured worldwide. In this study, the effect of six different soybean diets containing: two transgenic soybeans expressing different types of cp4-epsps, Vip3Aa and pat genes (DBN9004 and DBN8002), their non-transgenic parent JACK, and three conventional soybean varieties (Dongsheng3, Dongsheng7, and Dongsheng9) was investigated in juvenile channel catfish for eight weeks, and a safety assessment was performed. During the experiment, no difference in survival rate was observed in six groups. The hepatosomatic index (HSI) and condition factor (CF) showed no significant difference. Moreover, comparable feed conversion (FC), feeding rate (FR), and feed conversion ratio (FCR) were found between transgenic soybean and JACK groups. Assessment of growth performance showed that the weight gain rate (WGR) and specific growth rate (SGR) of channel catfish were consistent. In addition, there were no changes in enzyme activity indexes (lactate dehydrogenase (LDH), total antioxidant capacity (T-AOC), aspartate aminotransferase (AST) and alanine aminotransferase (ALT)) in channel catfish among treatments. The research provided an experimental basis for the aquaculture feed industry to employ transgenic soybean DBN9004 and DBN8002 for commercial purposes.

Compositional analysis of transgenic Bt-chickpea resistant to Helicoverpa armigera

ABSTRACT Transgenic chickpeas expressing high levels of a truncated version of the cry1Ac (trcry1Ac) gene conferred complete protection to Helicoverpa armigera in the greenhouse. Homozygous progeny of two lines, Cry1Ac.1 and Cry1Ac.2, had similar growth pattern and other morphological characteristics, including seed yield, compared to the non-transgenic counterpart; therefore, seed compositional analysis was carried out. These selected homozygous chickpea lines were selfed for ten generations along with the non-transgenic parent under contained conditions. A comparative seed composition assessment, seed storage proteins profiling, and in vitro protein digestibility were performed to confirm that these lines do not have significant alterations in seed composition compared to the parent. Our analyses showed no significant difference in primary nutritional composition between transgenic and non-transgenic chickpeas. In addition, the seed storage protein profile also showed no variation between the transgenic chickpea lines. Seed protein digestibility assays using simulated gastric fluid revealed a similar rate of digestion of proteins from the transgenic trcry1Ac lines compared to the non-transgenic line. Thus, our data suggest no unintended changes in the seed composition of transgenic chickpea expressing a trcry1Ac gene.

Field trial evidence of non-transgenic and transgenic Bt. rice genotypes in north of Iran

BackgroundField-testing genetically modified crops provides scientists with an opportunity to collect information on environmental interactions and agronomic performance, which is critical to a full environmental safety assessment as required by regulatory authorities. As a result, the goal of this research was field trial of transgenic and conventional rice genotypes. The experiment was carried out in a randomized complete blocks design (RCBD) with four replications and seven genotypes in three isolated regions under the biosafety standard protocol in north of Iran in 2016. In this study, four transgenic lines with an active cry1Ab gene in the vegetative stage and three conventional genotypes (control) as treatment were assessed. ResultsThe findings demonstrated that in all three regions, transgenic lines derived from Khazar cultivar, were similar to their parent(s) in terms of growth phenology, agronomical traits, grain amylose content, gel consistency, and gelatinization temperature. In all the three regions, the highest number of panicle per m2, number of filled spikelet per panicle, and filled spikelet percentage per panicle were obtained for transgenic lines. Khazar cultivar compared to the transgenic lines showed lower paddy yield. In all the three regions, transgenic lines had lower yield loss than their non-transgenic parent. The lowest number of white heads belonged to transgenic Tarom Molaii and transgenic lines. The most positive direct effect on paddy yield was related to the number of filled spikelet per panicle. Thus, this can be a good trait to achieve higher yield derived from reducing the negative indirect effect of dead heart and white heads. ConclusionIt can be concluded that by producing transgenic rice, which is resistant to stem borer with an active promoter in the reproductive stage, farmers can reduce significant part of yield loss resulting from dead heart and white heads directly correlating with the number of filled spikelet per panicle and paddy yield.

Food, Feed and Environmental Risk Assessment of Glufosinatetolerant Genetically Modified Oilseed Rape T45 for Food and Feed Uses, Import and Processing Under Regulation (EC) No 1829/2003 (Application EFSA/GMO/UK/2005/25)

Food, Feed and Environmental Risk Assessment of Glufosinatetolerant Genetically Modified Oilseed Rape T45 for Food and Feed Uses, Import and Processing Under Regulation (EC) No 1829/2003 (Application EFSA/GMO/UK/2005/25)

Embryogenic cell suspensions for high-capacity genetic transformation and regeneration of switchgrass (Panicum virgatum L.)

BackgroundSwitchgrass (Panicum virgatum L.), a North American prairie grassland species, is a potential lignocellulosic biofuel feedstock owing to its wide adaptability and biomass production. Production and genetic manipulation of switchgrass should be useful to improve its biomass composition and production for bioenergy applications. The goal of this project was to develop a high-throughput stable switchgrass transformation method using Agrobacterium tumefaciens with subsequent plant regeneration.ResultsRegenerable embryogenic cell suspension cultures were established from friable type II callus-derived inflorescences using two genotypes selected from the synthetic switchgrass variety ‘Performer’ tissue culture lines 32 and 605. The cell suspension cultures were composed of a heterogeneous fine mixture culture of single cells and aggregates. Agrobacterium tumefaciens strain GV3101 was optimum to transfer into cells the pANIC-10A vector with a hygromycin-selectable marker gene and a pporRFP orange fluorescent protein marker gene at an 85% transformation efficiency. Liquid cultures gave rise to embryogenic callus and then shoots, of which up to 94% formed roots. The resulting transgenic plants were phenotypically indistinguishable from the non-transgenic parent lines.ConclusionThe new cell suspension-based protocol enables high-throughput Agrobacterium-mediated transformation and regeneration of switchgrass in which plants are recovered within 6–7 months from culture establishment.

Abstract 1504: Characterization of a MC38 mouse syngeneic tumor model expressing human PD-L1 in the transgenic C57BL/6 mouse system expressing human PD-1 and PD-L1

Abstract The human checkpoint targets PD-1 and PDL-1 continue to demonstrate great promise in the clinic. With much of the current focus turning toward combination regiments, an animal model using the human clinical antibodies will be beneficial for evaluating new combination strategies. Here we continue characterization of a C57BL/6 transgenic mouse model expressing both the human PD-1 and PD-L1 combined with a modified murine MC38 colon tumor cell line expressing human PD-L1. Both PD-1 and PD-L1 expression of the transgenic mice were verified in ex vivo stimulated splenocytes by flow cytometry analysis. Expression of PD-L1 on the genetically modified MC38 cells was also demonstrated by flow cytometry. For in vivo efficacy evaluation, tumor-implanted mice were treated with the clinical agents nivolumab and pembrolizumab at 100 µg and atezolizumab at 1 mg on Days 3, 7, 10, and 14 post implant. Treatment with nivolumab and pembrolizumab initiated tumor regression by Day 17. Complete tumor regressions were seen at Day 28 in nivolumab, 62.5% complete regression, and pembrolizumab, 71.4% complete regression. Growth inhibition was 83.9%, 69.7%, and 95.0% on Day 28 for nivolumab, atezolizumab, and pembrolizumab, respectively, compared to the control animals. There was no significant body weight loss and no signs of toxicity in any of the treated animals. To compare the human anti-PD-1 and PD-L1 clinical agent specificity, the non-transgenic parent C57BL/6 mouse strain was implanted with the unmodified MC38 colon tumor cells. Treatment with pembrolizumab and atezolizumab was conducted as with the transgenic animals. Through 28 days no growth inhibition, tumor size 105.9% of control, was seen in the pembrolizumab treated group, demonstrating lack of cross reactivity of the human therapeutic in the standard mouse model. Atezolizumab did demonstrate a 56.9% growth inhibition compared to controls and is consistent with the known cross reactivity of atezolizumab between human and mouse. We have shown a genetically modified MC38 colon tumor expressing human PD-L1 in transgenic mice expressing both human PD-1 and PD-L1 to be a suitable model for checkpoint inhibitor evaluation of the human form of the particular checkpoint therapeutic. Further research will involve combining each of the checkpoint antibodies with various chemotherapeutic agents. Citation Format: Michael Koratich, Ted Green, Jie Liu, Charlotte Hammond, LaJuana Durbin, Jerry Zhou, Anna Chen, Murray Stackhouse. Characterization of a MC38 mouse syngeneic tumor model expressing human PD-L1 in the transgenic C57BL/6 mouse system expressing human PD-1 and PD-L1 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1504.

Effects of NaCl stress on the biochemical substances in Bt cotton as well as on the growth and development and adult oviposition selectivity of Helicoverpa armigera

BackgroundRecently, due to the development of food security strategies, cotton has been planted in inland saline-alkali dry soils or in coastal some saline-alkali soils in China. Under the condition, to comprehensively prevent and control Helicoverpa armigera in cotton fields with saline-alkali soils, it is important to study the larval growth and development of H. armigera and to study adult oviposition selectivity in H. armigera adults that feed on NaCl-stressed cotton plants.ResultsIn this study, Bt cotton GK19 was used for the experimental group and its nontransgenic parent Simian 3 was used for the control to study the effects of biochemical substances in cotton as well as larval growth and development and adult oviposition selectivity of H. armigera. The experiments were performed by growing cotton indoors under NaCl stress at concentrations of 0 mmol·L− 1, 75 mmol·L− 1 and 150 mmol·L− 1, respectively. The results showed that the expression of Bt protein was significantly inhibited for NaCl-stressed Bt cotton. The content of soluble protein and K+ in the leaves of cotton were decreased, while the content of gossypol and Na+ were increased. In addition, the 5th instar H. armigera larvae exhibited shorten the life span in a 13-day trial period. Under enclosure treatments and at different female densities, the adult oviposition of H. armigera decreased on high NaCl-stressed nontransgenic cotton, while the oviposition on Bt cotton tended to first increase but then decrease under low, moderate and high NaCl stress treatments.ConclusionsUnder certain content ranges of NaCl stress treatments, larval of H. armigera growth and development, and adult oviposition were no significant difference in the change for a certain period. However, under high NaCl stress, larval growth, development and adult oviposition were affected, which may provide insights for the prevention and control of H. armigera for Bt cotton in saline-alkali soils.

Rapid Identification of Genetically Modified Maize Using Laser-Induced Breakdown Spectroscopy

The safety of genetically modified (GM) food has attracted worldwide attention with a high-frequency appearance in people’s daily life. It is increasingly urgent to find a fast and efficient method to detect GM products to provide reference for safety evaluation. In the current study, we used laser-induced breakdown spectroscopy coupled with chemometrics methods to identify transgenic maize from their non-transgenic parent. One-hundred and twenty GM maize and 120 non-GM maize samples were firstly examined by laser-induced breakdown spectroscopy (LIBS) system. After obtaining the LIBS spectra, principal component analysis (PCA) was introduced to explore the separability of two kinds of samples, and 32 and 30 characteristic emission lines were selected using PCA loadings and weighted regression coefficients (BW), respectively. Classification models based on full spectra and characteristic emission lines were further built by applying partial least squares discrimination analysis (PLS-DA), soft independent modeling of class analogy (SIMCA), and extreme learning machine (ELM). The overall results demonstrated that all models achieved an excellent identification rate, especially the PCA loading-ELM model showed the best performance in the identification of GM maize, with 100% identification accuracy in both calibration and prediction sets. It can be concluded that LIBS combined with chemometrics methods provide a promising way for identification of transgenic maize.

Effect of NaCl-stressed Bacillus thuringiensis (Bt) cotton on the feeding behaviors and nutritional parameters of Helicoverpa armigera.

Saline-alkali soil is an arable land resource on which transgenic Bacillus thuringiensis (Bt) cotton has been planted on a large scale in accordance with food security strategies. There are, however, concerns about the insecticidal effects of Bt cotton on target insect pests. In this study, a Bt cotton variety, GK19, and its nontransgenic parent variety, Simian-3, were used as experimental models for investigating the effect of the expression of exogenous insecticidal proteins in Bt cotton under NaCl stress on the feeding behavior and nutritional parameters of Helicoverpa armigera. The results showed that the expression of exogenous insecticidal proteins in GK19 was significantly inhibited under NaCl stress. However, the feeding, crawling, resting and spinning down behavior of the 5th instar H. armigera larvae on GK19 Bt cotton, as well as the amount of food consumed and feces produced by these larvae, did not markedly differ under different NaCl concentrations. In contrast, the mean relative growth rate (MRGR), relative growth rate (RGR), approximate digestibility (AD), efficiency of conversion of ingested food (ECI) and efficiency of conversion of digested food (ECD) of the larvae markedly decreased in response to NaCl stress. Under the same concentration of NaCl, the nutritional parameters of the bollworm larvae on GK19 Bt cotton or Simian-3 nontransgenic cotton were different. However, the interaction between salt stress and cotton variety had no significant effect on the feeding behavior or nutritional parameters of H. armigera larvae. These results may provide a scientific basis for determining the effect of exogenous insecticidal protein expression in Bt cotton under NaCl stress on H. armigera and can therefore be useful for the effective application of Bt cotton in saline-alkali soils to prevent and control H. armigera.

Effects of glyphosate-resistant transgenic soybean on soil rhizospheric bacteria and rhizobia.

Transgenic soybean is the most widely grown genetically modified crop in the world, with herbicide resistance being the major modified trait. Microbial community is one of the most important indicators for soil quality. The effects of glyphosate-resistant transgenic soybean and glyphosate application on rhizospheric bacteria and rhizobia still remained unknown. In this study, with the non-transgenic parent Zhongdou 32 as control (CK), we investigated the effects of the G10-epsps transgenic glyphosate-resistance soybean SHZD32-01 without or with glyphosate application (abbreviated as GR and GR+G, respectively) on rhizospheric bacteria and rhizobia at different growth stages of soybean in field. Compared with CK, GR and GR+G had effects on soil pH, total organic carbon, total nitrogen and ammonium contents at the seedling and mature stages. GR significantly increased the abundance and diversity of soil rhizospheric bacterial community at the podding stage. GR+G significantly increased the abundance of soil rhizospheric bacterial community at the podding stage but decreased its diversity at the seeding and podding stages. GR and GR+G changed the relative abundance of dominant bacteria populations. Proteobacteria, Acidobacteria, Bacteroidetes, Chloroflexi, Planctomycetes and Actinobacteria were generally the dominant ones among the three treatments across all growth stages. Furthermore, GR and GR+G changed the relative abundance of rhizobia but did not change that of soybean-nodulating rhizobia, Bradyrhizobium and Sinorhizobium. The relative abundance of rhizobia in GR+G was decreased significantly at the podding stage. The abundance of actinobacteria and rhizobia was mainly affected by soil pH. Glyphosate-resistant transgenic soybean without or with glyphosate application altered soil rhizospheric bacteria and rhizobia at the podding stage, but the effects disappeared along with the growth of soybean.

Screening of transgenic maize using near infrared spectroscopy and chemometric techniques

The applicability of near infrared (NIR) spectroscopy combined with chemometrics was examined to develop fast, low-cost and non-destructive spectroscopic methods for classification of transgenic maize plants. The transgenic maize plants containing both cry1Ab/cry2Aj-G10evo proteins and their non-transgenic parent were measured in the NIR diffuse reflectance mode with the spectral range of 700–1900 nm. Three variable selection algorithms, including weighted regression coefficients, principal component analysis -loadings and second derivatives were used to extract sensitive wavelengths that contributed the most discrimination information for these genotypes. Five classification methods, including K-nearest neighbor, Soft Independent Modeling of Class Analogy, Naive Bayes Classifier, Extreme Learning Machine (ELM) and Radial Basis Function Neural Network were used to build discrimination models based on the preprocessed full spectra and sensitive wavelengths. The results demonstrated that ELM had the best performance of all methods, even though the model’s recognition ability decreased as the variables in the training of neural networks were reduced by using only the sensitive wavelengths. The ELM model calculated on the calibration set showed classification rates of 100% based on the full spectrum and 90.83% based on sensitive wavelengths. The NIR spectroscopy combined with chemometrics offers a powerful tool for evaluating large number of samples from maize hybrid performance trials and breeding programs.

Toxicologic evaluation of chronic feeding of glyphosate-resistant transgenic soybean GTS40-3-2 meal to rats

To assess the safety of glyphosate-resistant transgenic soybean, the transgenic soybean GTS40-3-2 meal and its non-transgenic counterpart parent A5403 were fed to first- and second-generation Sprague-Dawley (SD) rats (Rattus norvegicus) for 195 days. The soybean meal made up 20% of the total weight of the feed. Body weight, food consumption, hematology, blood biochemistry, and pathological observations were monitored weekly. The results showed that rats of each group experienced good growth and development, and although results of some organ weight ratios and serum biochemistry between the groups were significantly different (P<0.05), they were of no biological significance because the variations were within the normal range. These results indicate that glyphosate-resistant transgenic soybean GTS40-3-2 meal is as safe as its non-transgenic parent soybean A5403 in a long-term SD rat feeding study. The study provides experimental evidence for the safe usage of transgenic soybean GTS40-3-2.

Seed Metabolome Analysis of a Transgenic Rice Line Expressing Cholera Toxin B-subunit

Plant-based human vaccines have been actively developed in recent years, and rice (Oryza sativa L.) is one of the best candidate crops for their production and delivery. By expressing a modified cholera toxin B (CTB) subunit, we previously developed MucoRice-CTB, a rice-based vaccine against cholera, which is caused by infection of the intestine with the bacteria Vibrio cholerae. MucoRice-CTB lines have been extensively characterized by whole-genome sequencing and proteome analyses to evaluate the mutation profiles and proteome status, respectively. Here, we report non-targeted metabolomic profiling of the MucoRice-CTB transgenic rice line 51A (MR-CTB51A), MucoRice-RNAi (MR-RNAi), and their non-transgenic parent line by using gas chromatography–time-of-flight mass spectrometry. The levels of several amino acids, organic acids, carbohydrates, lipids, and secondary metabolites were significantly increased in MR-CTB51A compared with the non-transgenic parent line. These metabolomics results complement essential information obtained by genome sequencing and proteomics approaches, thereby contributing to comprehensive understanding of the properties of MucoRice-CTB as a plant-based vaccine.

Monitoring changes in the actinobacterial field communities present in the rhizosphere soil of a transgenic cotton producing Cry1Ab/Ac proteins

Abstract Transgenic cotton GK 12 producing Cry1Ab/Ac proteins can effectively control lepidopteran pests in agriculture. However, there are concerns that GK 12 has unintended side-effects on actinobacterial communities in the soil. Actinobacterial communities in the rhizosphere soil of cottons were analyzed by real-time PCR (qPCR) and denaturing gradient gel electrophoresis (DGGE) at different growth stages in three annual replications under field conditions. Population sizes and community structures of Actinobacteria were markedly affected by natural variations in years, growth stages and cultivars. No significant differences were found in population sizes (excepting at budding in 2009), community structures, and Shannon indices of Actinobacteria (excepting at budding in 2010) between the GK 12 and its non-transgenic parent Simian 3, although there were differences between the GK 12 and the conventional cotton DP 5415. Phylogenetic analysis of DGGE band sequences indicated that Cellulosimicrobium sp. and Rhodococcus sp. only occurred in the GK 12 and the Simian 3. The dominant Actinobacteria did not differ between the GK 12 and the Simian 3. In conclusion, the overall impacts of the GK 12 on actinobacterial communities in the rhizosphere soil, based on qPCR and DGGE, were not significant during three continuous years in northern China.

Metabolic responses of rice leaves and seeds under transgenic backcross breeding and pesticide stress by pseudotargeted metabolomics

Pesticide and anti-insect gene are two effective strategies to prevent insects from seriously influencing the growth and production of crops in agroecosystem. Few investigators have yet concerned the metabolic responses of different plant tissues to pesticide treatment and transgene with backcross breeding. In this study, the metabolic variations in samples of rice leaf and seed induced by transgenic backcross breeding and pesticide stress were investigated by a pseudotargeted metabolomics method based on gas chromatography–mass spectrometry. The results showed transgenic backcross breeding caused diverse metabolic changes for rice leaf and seed. Higher abundances of a wide range of carbohydrates, antioxidants and phenols were observed in transgenic backcross breeding leaves, while some amino acids and carbohydrates in rice seeds were down-regulated after transgenic backcross breeding. Moreover, the defense responses of rice leaves to pesticide stress were tightly associated with transgenic backcross breeding. Defense system accompanied with the accumulations of phenols and antioxidants was rapidly activated in non-transgenic parent compared to transgenic backcross breeding leaves under pesticide stress.

A 3-year field investigation of impacts of Monsanto’s transgenic Bt-cotton NC 33B on rhizosphere microbial communities in northern China

Monsanto’s Bt-cotton NC 33B, planted in northern China for more than one decade, effectively controls cotton bollworms and decreases the use of chemical insecticides. Because of the concern about undesirable ecological side-effects of transgenic Bt-cottons, it is important to assess Bt-cotton NC 33B’s effects on soil microorganisms in this zone. Microbial communities in the rhizosphere soil of Bt and non-Bt cottons were monitored under field conditions by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) fingerprints of eubacteria, fungi and actinomycetes at six growth stages after three-year cultivation. Results showed that the population sizes and community structures of eubacteria, fungi and actinomycetes in rhizosphere soil were markedly affected by natural variations in the environment related to cotton growth stages. However, there was no significant difference in eubacterial, fungal and actinomycete population size and community structures in rhizosphere soil between NC 33B and its non-transgenic parent. In general, Bt-cotton NC 33B did not show evident effects on microbial communities in the rhizosphere soil under field conditions after three-year cultivation. This study provides a theoretical basis for environmental impact monitoring of transgenic Bt cottons.

The effects of triazophos applied to transgenic Bt rice on the nutritional indexes, Nlvg expression, and population growth of Nilaparvata lugens Stål under elevated CO2

The brown planthopper, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), is a typical pest in which population resurgence can be induced by insecticides. Warmer global temperatures, associated with anthropogenic climate change, are likely to have marked ecological effects on terrestrial ecosystems. However, the effects of elevated CO2 (eCO2) concentrations on the resurgence of N. lugens that have been treated with pesticides used for transgenic Bt rice cultivation are not fully understood. The present study investigated changes in the protein content, soluble sugar content, free amino acid level, vitellogenin (Nlvg) mRNA expression, and the population growth of N. lugens on transgenic Bt rice (TT51) following triazaophos foliar spray under conditions of eCO2. The results showed that the protein content in the fat bodies and ovaries of N. lugens adult females in TT51 treated with 40 ppm triazophos under eCO2 was significantly higher than under ambient CO2 (aCO2) and was also higher than that in females feeding on the non-transgenic parent (MH63) under aCO2 at different days after emergence (DAEs). The soluble sugar content and free amino level of adult females in TT51 treated with 40 ppm triazophos under eCO2 was significantly higher than under aCO2 and was also higher than in MH63 under aCO2 at 1 and 3 DAE. The Nlvg mRNA expression level of N. lugens adult females in TT51 treated with 40 ppm triazophos under eCO2 was significantly higher than under aCO2 and was also higher than in MH63 under aCO2 at 1 and 3 DAE. The population number of N. lugens in TT51 treated with 40 ppm triazophos under eCO2 was significantly higher than under aCO2 and was also higher than in MH63 under aCO2. The present findings provide important information for integrated pest management with transgenic varieties and a better understanding of the resurgence mechanism of N. lugens under eCO2.

An Assessment of the Relative Influences of Genetic Background, Functional Diversity at Major Regulatory Genes, and Transgenic Constructs on the Tomato Fruit Metabolome

While the greatest strength of systems biology may be to measure tens of thousands of variables across different genotypes, this simultaneously presents an enormous challenge to statistical analysis that cannot be completely solved with conventional approaches that identify and rank differences. Here we examine a diverse panel of conventional and transgenic, field‐grown tomato fruits (Solanum lycopersicum L.) by liquid chromatography–mass spectrometry (LC‐MS) metabolic fingerprinting. We used a progression of statistics to examine phenotypic variation observed. While clear trends were found by principal component analysis (PCA) related to genetic background and ripeness, it could not detect differences between transgenic genotypes and their nontransgenic parent variety. Partial least squares discriminant analysis (PLS‐DA), a supervised method, identified 15 metabolic features of potential interest, but only five were significantly different between the transgenic lines and their nontransgenic parent. Weighted correlation network analysis (WGCNA) recognized relationships among these features and others, suggesting that a small suite of highly correlated compounds accumulated to significantly lower levels in the transgenic genotypes. We assert that metabolic fingerprinting with a series of statistical methods is an efficient and powerful approach to examine both large and small genetic effects on phenotypes of high value or interest.

Effects of triazophos on biochemical substances of transgenic Bt rice and its nontarget pest Nilaparvata lugens Stål under elevated CO2

The brown planthopper (BPH), Nilaparvata lugens Stål, is a serious rice pest throughout Asia. Recent outbreaks of N. lugens populations were mainly associated with the overuse of pesticides and resistance to insecticides. Warmer global temperatures that are associated with anthropogenic climate change are likely to have marked ecological effects on terrestrial ecosystems. However, the effects of elevated CO2 concentrations on the biochemical, physiological and nutrient quality of transgenic Bt rice that has been treated with pesticides and on the control efficacy of the pesticides are not understood. The present study investigated changes in soluble sugar content, free amino acid levels, oxalic acid levels, flavonoids levels, and triazophos residues in transgenic Bt rice (TT51) and the control efficacy of triazophos for N. lugens following triazophos foliar spray under conditions of elevated CO2 (eCO2). Our findings showed that the soluble sugar content of TT51 treated with triazophos under eCO2 was significantly higher than that under ambient CO2 (aCO2) and also higher than that of the non-transgenic parent (MH63) under aCO2. However, the results for free amino acid levels were the opposite of those for soluble sugar levels. The oxalic acid and flavonoid contents of rice plants significantly decreased with increases in triazophos concentration, CO2 concentration, and days after treatment (DAT). The oxalic acid and flavonoid contents of TT51 treated with triazophos under eCO2 were significantly lower than those under aCO2 and also lower than those of MH63 under aCO2. The residue concentration of triazophos varied with CO2 concentration, rice variety, and DAT. The residues in TT51 treated with 80ppm of trizaopos under eCO2 were significantly lower than those under aCO2 and those in MH63 under aCO2. The survival rate of nymphs N. lugens in TT51 under eCO2 was significantly higher than that under aCO2 and that in MH63 under aCO2 at 1 DAT or 15 DAT after the release of 2nd instars nymphs. These findings indicated that (1) for TT51, triazophos reduced the resistance of rice plants to N. lugens with an elevated CO2 concentration, as N. lugens consumed more phloem sap on TT51 plants; (2) triazophos dissipation in TT51 under eCO2 was significantly faster than that under aCO2 and that in MH63 under aCO2; (3) the control efficacy of triazophos for N. lugens significantly decreased under eCO2. The present findings provide important information for integrated pest management among transgenic varieties.