Transgenic Grain Research Articles

Quantitative proteomic analysis of wheat grain proteins reveals differential effects of silencing of omega-5 gliadin genes in transgenic lines

Novel wheat lines with altered flour compositions can be used to decipher the roles of specific gluten proteins in flour quality. Grain proteins from transgenic wheat lines in which genes encoding the omega-5 gliadins were silenced by RNA interference (RNAi) were analyzed by quantitative 2-dimensional gel electrophoresis (2-DE). The precise effects of the genetic modifications on the proteome were assessed in four homozygous lines generated with the same RNAi construct. Two of the lines showed >80% decreases in omega-5 gliadins with only small changes in the levels of other gluten proteins. In the other two lines, omega-5 gliadins were not detectable by 2-DE. However, there were notable reductions in all omega-1,2 gliadins. Small decreases in several other gluten proteins were also detected in one of the lines. The other line showed notable decreases in three HMW-GS and an s-type LMW-GS, increases in two m-type LMW-GS and several alpha gliadins, as well as increases in both serpins and triticin. The study demonstrates that the same RNAi construct can have differential effects on the wheat grain proteome and highlights the importance of detailed proteomic analyses of transgenic grain prior to selecting lines for further assessment of flour quality and allergenic potential.

Purification of phosphinothricin acetyltransferase using Reactive brown 10 affinity in a single chromatography step

The expression of phosphinothricin N-acetyltransferase (PAT) protein in transgenic plants confers tolerance to the herbicide glufosinate. To enable the characterization of PAT protein expressed in plants, it is necessary to obtain high purity PAT protein from the transgenic grain. Because transgenically expressed proteins are typical present at very low levels (i.e. 0.1–50μg protein/g grain), a highly specific and efficient purification protocol is required to purify them. Based on the physicochemical properties of PAT, we developed a novel purification method that is simple, time-saving, inexpensive and reproducible. The novel method employs a single chromatography step using a reactive dye resin, Reactive brown 10-agarose. Reactive brown 10 preferentially binds the PAT protein, which can then be specifically released by one of its substrates, acetyl-CoA. Using Reactive brown 10-agarose, PAT protein was purified to homogeneity from cottonseed with high recovery efficiency. As expected, the Reactive brown 10-produced PAT was enzymatically active. Other applications of the method on protein expression and purification, and development of PAT enzymatic inhibitors were also discussed.

Iron and zinc complexation in wild-type and ferritin-expressing wheat grain: implications for mineral transport into developing grain

We have used synchrotron-based X-ray fluorescence and absorption techniques to establish both metal distribution and complexation in mature wheat grains. In planta, extended X-ray absorption fine structure (EXAFS) spectroscopy reveals iron phytate and zinc phytate structures in aleurone cells and in modified aleurone cells in the transfer region of the grain: iron is coordinated octahedrally by six oxygen atoms and fewer than two phosphorous atoms. Zinc is coordinated tetrahedrally by four oxygen atoms and approximately 1.5 phosphorus atoms in an asymmetric coordination shell. We also present evidence of modified complexation of both metals in transgenic grain overexpressing wheat ferritin. For zinc, there is a consistent doubling of the number of complexing phosphorus atoms. Although there is some EXAFS evidence for iron phytate in ferritin-expressing grain, there is also evidence of a structure lacking phosphorus. This change may lead to an excess of phosphorus within the storage regions of grain, and in turn to the demonstrated increased association of phosphorus with zinc in ferritin-expressing grains. Derivative X-ray absorption spectra also suggest that mineral complexation in the transfer region of ferritin-expressing grains is quite different from that in wild-type grain. This may explain why the raised levels of minerals transported to the developing grain accumulate within the crease region of the transgenic grain.

Functional analyses of TaHMA2, a P1B‐type ATPase in wheat

Currently, there are few studies concerning the function of heavy metal ATPase 2 (HMA2), particularly in monocotyledons, and the potential application of this protein in biofortification and phytoremediation. Thus, we isolated and characterized the TaHMA2 gene from wheat (Triticum aestivum L.). Our results indicate that TaHMA2 is localized to the plasma membrane and stably expressed, except in the nodes, which showed relatively high expression. Zinc/cadmium (Zn/Cd) resistance was observed in TaHMA2-transformed yeast. The over-expression of TaHMA2 increased the elongation and decreased the seed-setting rate in rice (Oryza sativa L.), but not Arabidopsis thaliana, tobacco (Nicotiana tabacum L.) or wheat. TaHMA2 over-expression also improved root-shoot Zn/Cd translocation, especially in rice. The seeds of transgenic rice and wheat, not tobacco, showed decreased Zn concentrations. The Zn concentration was decreased in all parts of the transgenic rice seeds, but was decreased only in the ventral endosperm of wheat, which showed an increased Zn concentration in the embryo and aleurone. The over-expression of TaHMA2 improved plant tolerance under moderate Zn stress and Zn deficiency, but Zn and Cd resistance decreased under high levels of Zn and Cd stress, respectively. The Cd concentration in transgenic rice seedlings was dramatically increased under Zn deficiency. Thus, over-expression of TaHMA2 showed a more obvious phenotype in monocotyledons than in dicotyledons. These findings provide important information for TaHMA2, and more efforts should be made in the future to characterize the reduced Zn concentration in TaHMA2 transgenic grains and the diversity of TaHMA2 substrate specificity.

Overview of genetically modified crops and their relevance for Nicaragua

The first transgenic plants were created in Europe about three decades ago. In Nicaragua, however, there is not commercial cultivation of transgenic crops allowed yet, and the only history of transgenic grain imports occurred in 2005, when the introduction of 15 events of GM maize was first authorized. The Law on Prevention of Risks from Living Modified Organisms by Means of Molecular Biotechnology was published in 2010, and more recently, in September 2012, the Law on Conservation and Sustainable Use of Biodiversity came into force. In line with the resulting requirements from these laws, the Ministry of Agriculture and Forestry (MAGFOR) currently works in coordination with the Molecular Biology Center at the University of Central America to ensure that grains imported in the country correspond to events legally authorized. This article begins by presenting an overview of transgenic crops (GMO), their history and their implications for the economy and human health. Next, we describe the current status of GMO in Nicaragua. We conclude that MAGFOR has been successful in fulfilling the law in regards to sampling of imports related to the introduction of GMO grains. It is recommended, however, that for better monitoring of compliance with these laws, it will be necessary to establish a systematic monitoring plan nationwide, aimed at the appropriate screening and detection of transgenic material both in crop seeds as well as in imported grains.

Transgenic rice grains expressing a heterologous ρ-hydroxyphenylpyruvate dioxygenase shift tocopherol synthesis from the γ to the α isoform without increasing absolute tocopherol levels

We generated transgenic rice plants overexpressing Arabidopsis thaliana ρ-hydroxyphenylpyruvate dioxygenase (HPPD), which catalyzes the first committed step in vitamin E biosynthesis. Transgenic grains accumulated marginally higher levels of total tocochromanols than controls, reflecting a small increase in absolute tocotrienol synthesis (but no change in the relative abundance of the α and γ isoforms). In contrast, there was no change in the absolute tocopherol level, but a significant shift from the γ to the α isoform. These data confirm HPPD is not rate limiting, and that increasing flux through the early pathway reveals downstream bottlenecks that act as metabolic tipping points.

Performance of broiler chickens fed diets containing DAS-68416-4 soybean meal

Broiler chickens are a fast growing monogastric animal commonly used to evaluate the equivalence between transgenic and non-transgenic grains as part of the human safety assessment process. While commonly viewed like other livestock feeding trials, such studies are performed with transgenic crops with input traits (that are not designed to improve nutrition) to aid regulatory authorities in evaluating safety. Studies of this type are actually more similar to toxicology studies in purpose, with sensitive endpoints like growth used to detect metabolic perturbations. DAS-68416-4 soybean expresses the aryloxyalkanoate dioxygenase-12 (AAD-12) enzyme which inactivates 2,4-diclorophenoxyacetic acid (2,4-D) and provides DAS-68416-4 soybeans tolerance to this herbicide. DAS-68416-4 also expresses the phosphinothricin acetyltransferase (PAT) enzyme from Streptomyces viridochromogenes which confers tolerance to glufosinate-ammonium herbicides. A 6-week broiler study was conducted with diets containing toasted DAS-68416-4 soybean meal (40, 36, and 32% in starter, grower and finisher diets, respectively) to evaluate nutritional wholesomeness and safety compared with conventional comparators. Toasting soybean meal is required to inactivate endogenous antinutrients making soybean suitable for consumption by monogastric animals like broiler chickens. Toasting was found to denature both the AAD-12 and PAT proteins rendering them non-detectable by enzyme linked immunosorbent assays. Broiler growth and performance parameters were measured over a 6-week period of exposure to diets containing different sources of toasted soybean meal, and results indicate that DAS-68416-4 soybean is nutritionally equivalent to non-transgenic soybean.

Efficacy of Bacillus thuringiensis Cry3Aa protoxin and protease inhibitors against coleopteran storage pests

Environmental impacts and resistance to insecticides pose serious challenges to stored-product insect and other types of pest control. Insect-resistant transgenic grain is a potential alternative to fumigants, but candidate control proteins are needed, especially for coleopterans. Therefore, we evaluated the efficacy of a coleopteran-active toxin, Bacillus thuringiensis Cry3Aa, with or without protease inhibitors, in laboratory feeding assays against coleopteran storage pests. In a comparison of the toxicity of Cry3Aa protoxin towards three species of coleopteran storage pests, Tenebrio molitor L. was found to be most sensitive, Tribolium castaneum (Herbst.) was most refractory and Rhyzopertha dominica F. displayed an intermediate response. For R. dominica, Cry3Aa combined with 3500 mg potato carboxypeptidase inhibitor or 5000 mg aprotinin kg(-1) diet resulted in both delayed development and increased mortality. Potato carboxypeptidase inhibitor and bovine aprotinin reduced the LC(50) of Cry3Aa for R. dominica two- and threefold respectively. Cry3Aa treatment resulted in fewer progeny from R. dominica, and progeny was further reduced when the protoxin was combined with potato carboxypeptidase inhibitor. These data support the hypothesis that a combination of Cry3Aa protoxin and protease inhibitors, particularly a potato carboxypeptidase inhibitor, may have applications in control strategies for preventing damage to stored products and grains by coleopteran pests.

Cloning and Characterization of Purple Acid Phosphatase Phytases from Wheat, Barley, Maize, and Rice

Barley (Hordeum vulgare) and wheat (Triticum aestivum) possess significant phytase activity in the mature grains. Maize (Zea mays) and rice (Oryza sativa) possess little or virtually no preformed phytase activity in the mature grain and depend fully on de novo synthesis during germination. Here, it is demonstrated that wheat, barley, maize, and rice all possess purple acid phosphatase (PAP) genes that, expressed in Pichia pastoris, give fully functional phytases (PAPhys) with very similar enzyme kinetics. Preformed wheat PAPhy was localized to the protein crystalloid of the aleurone vacuole. Phylogenetic analyses indicated that PAPhys possess four conserved domains unique to the PAPhys. In barley and wheat, the PAPhy genes can be grouped as PAPhy_a or PAPhy_b isogenes (barley, HvPAPhy_a, HvPAPhy_b1, and HvPAPhy_b2; wheat, TaPAPhy_a1, TaPAPhy_a2, TaPAPhy_b1, and TaPAPhy_b2). In rice and maize, only the b type (OsPAPhy_b and ZmPAPhy_b, respectively) were identified. HvPAPhy_a and HvPAPhy_b1/b2 share 86% and TaPAPhya1/a2 and TaPAPhyb1/b2 share up to 90% (TaPAPhy_a2 and TaPAPhy_b2) identical amino acid sequences. despite of this, PAPhy_a and PAPhy_b isogenes are differentially expressed during grain development and germination. In wheat, it was demonstrated that a and b isogene expression is driven by different promoters (approximately 31% identity). TaPAPhy_a/b promoter reporter gene expression in transgenic grains and peptide mapping of TaPAPhy purified from wheat bran and germinating grains confirmed that the PAPhy_a isogene set present in wheat/barley but not in rice/maize is the origin of high phytase activity in mature grains.

Utilizing Protein-Lean Coproducts from Corn Containing Recombinant Pharmaceutical Proteins for Ethanol Production

Protein-lean fractions of corn (maize) containing recombinant (r) pharmaceutical proteins were evaluated as a potential feedstock to produce fuel ethanol. The levels of residual r-proteins in the coproduct, distillers dry grains with solubles (DDGS), were determined. Transgenic corn lines containing recombinant green fluorescence protein (r-GFP) and a recombinant subunit vaccine of Escherichia coli enterotoxin (r-LTB), primarily expressed in endosperm, and another two corn lines containing recombinant human collagen (r-CIα1) and r-GFP, primarily expressed in germ, were used as model systems. The kernels were either ground and used for fermentation or dry fractionated to recover germ-rich fractions prior to grinding for fermentation. The finished beers of whole ground kernels and r-protein-spent endosperm solids contained 127-139 and 138-155 g/L ethanol concentrations, respectively. The ethanol levels did not differ among transgenic and normal corn feedstocks, indicating the residual r-proteins did not negatively affect ethanol production. r-Protein extraction and germ removal also did not negatively affect fermentation of the remaining mass. Most r-proteins were inactivated during the mashing process used to prepare corn for fermentation. No functionally active r-GFP or r-LTB proteins were found after fermentation of the r-protein-spent solids; however, a small quantity of residual r-CIα1 was detected in DDGS, indicating that the safety of DDGS produced from transgenic grain for r-protein production needs to be evaluated for each event. Protease treatment during fermentation completely hydrolyzed the residual r-CIα1, and no residual r-proteins were detectable in DDGS.

Generation of transgenic wheat (Triticum aestivum L.) accumulating heterologous endo‐xylanase or ferulic acid esterase in the endosperm

Endo-xylanase (from Bacillus subtilis) or ferulic acid esterase (from Aspergillus niger) were expressed in wheat under the control of the endosperm-specific 1DX5 glutenin promoter. Constructs both with and without the endoplasmic reticulum retention signal (Lys-Asp-Glu-Leu) KDEL were used. Transgenic plants were recovered in all four cases but no qualitative differences could be observed whether KDEL was added or not. Endo-xylanase activity in transgenic grains was increased between two and threefold relative to wild type. The grains were shrivelled and had a 25%-33% decrease in mass. Extensive analysis of the cell walls showed a 10%-15% increase in arabinose to xylose ratio, a 50% increase in the proportion of water-extractable arabinoxylan, and a shift in the MW of the water-extractable arabinoxylan from being mainly larger than 85 kD to being between 2 and 85 kD. Ferulic acid esterase-expressing grains were also shrivelled, and the seed weight was decreased by 20%-50%. No ferulic acid esterase activity could be detected in wild-type grains whereas ferulic acid esterase activity was detected in transgenic lines. The grain cell walls had 15%-40% increase in water-unextractable arabinoxylan and a decrease in monomeric ferulic acid between 13% and 34%. In all the plants, the observed changes are consistent with a plant response that serves to minimize the effect of the heterologously expressed enzymes by increasing arabinoxylan biosynthesis and cross-linking.

종자 특이 프로모터와 대두 Ferritin 유전자에 의한 벼 종실의 철분강화

The recombinant DNAs, pGBF, pGTF, and pZ4F, using soybean ferritin gene have constructed with the promoters derived from seed proteins, glutelin, globulin, and zein. The recombinant ferritin genes were transformed into rice plant by Agrobacterium-mediated transformation. Iron contents and agronomic traits have been evaluated in the transgenic progenies. The embryogenic calli survived from second selection medium were regenerated at the rates of 19.2% with pGBF, 15.0% with pGTF, and 18.4% with pZ4F in Donganbyeo and 6.7% with pGBF, 11.7% with pGTF, and 3.4% with pZ4F in Hwashinbyeo. The introduction of ferritin gene in putative transgenic rice plants was confirmed by PCR and Southern blot analysis and also the expression of ferritin gene was identified by Northern blot and Western blot analysis. The iron accumulation in transgenic rice grains of the transgenic rice plant, T1-2, with zein promoter and ferritin gene contained 171.4 ppm showing 6.4 times higher than 26.7 ppm of Hwashinbyeo seed as wild type rice, but the transgenic plants with globulin and glutelin showed a bit higher iron contents with a range from 2.1 to 3.0 times compare to wild type grain. The growth responses of transgenic plants showed the large variances in plant height and number of tillers. However, there were some transgenic plants having similar phenotype to wild type plants. In the T1 generation of transgenic plants, plant height, culm length, panicle length, and number of tillers were similar to those of wild type plants, but ripened grain ratio ranged from 53.3% to 82.2% with relatively high variation. The transgenic rice plants would be useful for developing rice varieties with high iron content in rice grains.

Metabolic profiling of transgenic rice with cryIAc and sck genes: An evaluation of unintended effects at metabolic level by using GC-FID and GC–MS

The cryIAc and sck genes were introduced to the rice for the purpose of improving the insect resistance. Metabolic profiles of wild and transgenic rice were compared to assess the unintended effects related to gene modification. Wild samples with different sowing dates or sites were also examined to determine the environmental effects on metabolites. The polar compounds of grains were extracted, trimethylsilylated and analyzed by gas chromatography-flame ionization detection (GC-FID). Partial least squares-discriminant analysis (PLS-DA) and principal component analysis (PCA) were applied to differentiate transgenic and wild rice grains. The significantly distinguishable metabolites were picked out, and then identified by gas chromatography–mass spectrometry (GC–MS). It was found that both the environment and gene manipulation had remarkable impacts on the contents of glycerol-3-phosphate, citric acid, linoleic acid, oleic acid, hexadecanoic acid, 2,3-dihydroxypropyl ester, sucrose, 9-octadecenoic acid (Z)-, 2,3-dihydroxypropyl ester and so on. Sucrose, mannitol and glutamic acid had a significant increase in transgenic grains in contrast to those in non-genetically modified (GM) rice.

Evaluation of corn grain with the genetically modified input trait DAS-59122-7 fed to growing-finishing pigs1

A growth performance experiment was conducted to assess the feeding value of a double-stacked transgenic corn grain for growing-finishing pigs. The genetically modified corn grain contained event DAS-59122-7, which expresses the Cry34/35Ab1 binary insecticidal protein for the control of corn rootworm. This modified transgenic grain is resistant to western corn rootworm and is also tolerant to herbicides containing the active ingredient glufosinate-ammonium. The modified grain (59122), a nontransgenic near-isoline grain (control corn), and a commercial corn (Pioneer brand hybrid 35P12) were grown in a 2005 production trial in individually isolated plots that were located 201 m apart. A total of 108 pigs were allotted to corn-soybean meal diets containing 1 of the 3 grains as the sole source of corn. There were 3 pigs per pen and 12 replicate pens per treatment. Pigs were fed grower diets from 37 to 60 kg, early finisher diets from 60 to 90 kg, and late finisher diets from 90 to 127 kg. Within each phase, data for ADG, ADFI, and G:F were calculated. At the conclusion of the experiment, pigs were slaughtered and data for carcass quality were collected. Differences between 59122 and the control corn were evaluated, with statistical significance at P<0.05. No differences in ADG, ADFI, or G:F between pigs fed the control corn and pigs fed the modified corn were observed during the grower, early finisher, or late finisher phases. For the entire experimental period, no difference between pigs fed the control and the 59122 corn were observed for final BW (128.9 vs. 127.1 kg), ADG (1.02 vs. 1.00 kg), ADFI (2.88 vs. 2.80 kg), or G:F (0.356 vs. 0.345 kg/kg). Likewise, no differences in dressing percentage (76.48 vs. 76.30%), LM area (49.8 vs. 50.4 cm(2)), 10th-rib back fat (2.20 vs. 2.12 cm), and carcass lean content (52.9 vs. 53.4%) were observed between pigs fed the control and the 59122 corn grain. It was concluded that the nutritional value of the modified transgenic corn grain containing event DAS-59122-7 was similar to that of the nontransgenic near-isoline control.

Evaluation of Nutritional Equivalency of Corn Grain from DAS-Ø15Ø7-1 (Herculex* I) in the Diets of Laying Hens

Grain from transgenic corn line TC1507 (Herculex* I) from Pioneer Hi-Bred International Inc. and Dow AgroSciences LLC, which expresses the Cry1F protein from Bacillus thuringiensis to provide protection from lepidopteran pests of corn, was compared with its isoline equivalent and 2 conventional corn strains in a 16-wk laying hen feeding trial. Egg production and production efficiency of hens fed the diet formulated with transgenic grain TC1507 were similar to those of hens fed diets formulated with isoline or nontransgenic conventional corns. Hens fed TC1507 had similar egg qualities as those fed nontransgenic grain diets. Diet × phase interactions were noted for Haugh unit and Roche color fan score. Hens fed conventional corn 2 had a poorer Haugh unit score compared with hens fed the other 3 diets. Conventional corn 1 had greater levels of xanthophylls compared with the other corn treatments, resulting in increased Roche color fan score for eggs produced by hens fed this diet. Overall, hens fed the transgenic Herculex* I corn grain containing the Cry1F protein performed as well as hens fed the isoline equivalent of Herculex* I and hens fed the conventional corn grains.

Oral administration of recombinant human granulocyte-macrophage colony stimulating factor expressed in rice endosperm can increase leukocytes in mice

Human granulocyte-macrophage colony stimulating factor (hGM-CSF) is used clinically to treat leucopenia typically caused by cancer chemotherapy or radiotherapy. This study used multiple strategies to obtain very high expression levels of OsrhGM-CSF (14 microg/seed) in rice endosperm. Electron micrographs of immunogold-labeled transgenic endosperm showed that rhGM-CSF was not only localized in protein bodies but was also distributed in the apoplast. A biological activity assay indicated that OsrhGM-CSF stimulated the growth of TF-1 cells in vitro. In addition, the transgene was used to effectively treat leucopenia by oral administration of the unprocessed transgenic grains. In cyclophosphamide-induced leucopenic mice, transgenic seeds produced a 27% (t=0.021) gain in leukocytes after 14 days feeding. Even in non-leucopenic mice, leukocyte gain was 37% (t=0.002) more than that of mice fed non-transgenic seeds. This study provides a novel approach to the use of oral unprocessed transgenic OsrhGM-CSF seeds to treat leucopenia.

Developing transgenic grains with improved oils, proteins and carbohydrates.

DuPont has developed cereals and oilseeds with improved proteins, carbohydrates, and oils for food, feed, and industrial applications. Products which have been or will be introduced include corn and soybeans with increased oil content, improved oil composition, increased amino acid content, altered protein content and functional qualities, altered starch composition, reduced oligosaccharide content, increased sucrose content, and combinations of these traits. These products have been developed using both mutation breeding and molecular biology-based transgenic approaches. We have also worked on improving the underlying technologies in order to accelerate product introductions. Gene discovery has been expedited through a genomics program that now has a database of more than two million sequences from a variety of plants, insects and microbes. Plant cell transformation for elite lines of crop species is being addressed through production laboratories with high throughput processes and through technology improvements. High-throughput, rapid and small-scale assays for biochemical parameters are used to identify plants carrying traits of interest. Small-scale functionality analyses, in which grains are broken down into their component parts and assayed for functional properties, indicate which seeds carry a trait of commercial value. Finally, a number of DNA marker systems are being used to accelerate trait introgression timelines.

Assessment of Real-time PCR Based Methods for Quantification of Pollen-mediated Gene Flow from GM to Conventional Maize in a Field Study

Maize is one of the main crops worldwide and an increasing number of genetically modified (GM) maize varieties are cultivated and commercialized in many countries in parallel to conventional crops. Given the labeling rules established e.g. in the European Union and the necessary coexistence between GM and non-GM crops, it is important to determine the extent of pollen dissemination from transgenic maize to other cultivars under field conditions. The most widely used methods for quantitative detection of GMO are based on real-time PCR, which implies the results are expressed in genome percentages (in contrast to seed or grain percentages). Our objective was to assess the accuracy of real-time PCR based assays to accurately quantify the contents of transgenic grains in non-GM fields in comparison with the real cross-fertilization rate as determined by phenotypical analysis. We performed this study in a region where both GM and conventional maize are normally cultivated and used the predominant transgenic maize Mon810 in combination with a conventional maize variety which displays the characteristic of white grains (therefore allowing cross-pollination quantification as percentage of yellow grains). Our results indicated an excellent correlation between real-time PCR results and number of cross-fertilized grains at Mon810 levels of 0.1-10%. In contrast, Mon810 percentage estimated by weight of grains produced less accurate results. Finally, we present and discuss the pattern of pollen-mediated gene flow from GM to conventional maize in an example case under field conditions.

Decreased accumulation of glutelin types in rice grains constitutively expressing a sunflower seed albumin gene

Previous studies have shown differential accumulation of sulfur rich glutelins and sulfur poor prolamins in transgenic rice seeds expressing a sunflower seed albumin gene [Hagan, N.D., Upadhyaya, N., Tabe, L.M., Higgins, T.J., 2003. The redistribution of protein sulfur in transgenic rice expressing a gene for a foreign, sulfur-rich protein. Plant J 34, 1–11]. Here, we show, by two-dimensional electrophoresis, differential accumulation of three classes of glutelin proteins – type I, II and III – and a globulin, not previously resolved, in transgenic seeds grown under low and high sulfur nutrition. Several glutelin polypeptides were resolved and four identified as a type I glutelin, two type II glutelins and a type III glutelin. Although sulfur nutrition did not affect the accumulation of sunflower seed albumin, the levels of all four identified glutelins and the globulin were lower in mature seeds derived from transgenic plants grown under sulfur-optimum or sulfur limited conditions compared to non-transgenic rice seeds. The reduction of all four glutelin polypeptides and the globulin varied from 21% to 68%. The re-allocation of sulfur reserves from endogenous proteins to the sulfur sink in transgenic grain is suggestive of a transcriptional control of sulfur mobilization in plants.

Cry 1Ab and Cry 9C Transgenic Corn Hybrid Effects on Laboratory Populations of Indianmeal Moth (Lepidoptera: Pyralidae) and Angoumois Grain Moth (Lepidoptera: Gelechiidae)

Several Bacillus thuringiensis Berliner (Bt) Cry proteins including Cry 1Ab, Cry 1Ac, and Cry 9C, have been observed at relatively high levels in Bt corn grain using the CaMV 35S promoter. Thus, a laboratory experiment was conducted to quantify the impact of DeKalb 679 BTY Cry 1 Ab (MON 810) and Garst 8600 BLT Cry 9C (CBH 351) transgenic grain on Indianmeal moth, Plodia interpunctella (Hübner), and Angoumois grain moth, Sitotroga cerealella (Olivier), survival, development and fecundity. Eggs of Indianmeal moth or Angoumois grain moth were added to cracked or whole kernel corn. Emergence and fecundity were recorded for 5 wks. Emergence and fecundity of both moth species was reduced on both Cry 1Ab and Cry 9C-transformed corn, but only Cry 1 Ab-transformed corn delayed development of Indianmeal moth. Results indicate that populations of these moths may be negatively impacted in grain bins by Bt corn hybrids and that lepidopteran populations should be monitored in field-scale assays to examine the effects of the presence of Bt corn hybrids on insects in storage environments.