Science in Society Archive

SmartStax Maize a Medley of Transgenes with Problems

No case for releasing a poorly characterized GM crop with a medley of transgenes for which detrimental effects have been indicated in the limited cases where feeding trials have been carried out. Prof. Joe Cummins

This report has been submitted to US Environment Protection Agency on behalf of I-SIS.

SmartStax is a genetically modified (GM) maize that has eight GM traits combined or ‘stacked’ together, six for insect resistance (Bt) and two for herbicide tolerance. Current stacked GM trait crops on the market only have up to three traits each. SmartStax was created through collaboration between Monsanto and Dow AgroSciences [1] SmartStax Corn: Corporate War on Bees, SiS 46), allowing the two corporations to share GM traits. The traits are combined together using crosses between existing transgenic corn lines rather than using genetic transformation of a single maize strain. USDA/APHIS (United States Department of Agriculture/Animal and Plant Health Inspection Service) the usual regulator of GM crops approved the crops without an approval process, because the transgenic traits had been granted unregulated status previously, and those traits were combined using conventional breeding. Nevertheless, USEPA (United States Environment Protection Agency) were obligated to regulate the stacked crop varieties containing plant-incorporated protectants (PIPS). EPA invited public comment prior to registration of stacked varieties of corn but they approved SmartStax corn without allowing public comment prior to its registration.

SmartStax is seen as the answer to the recent meltdown of existing GM crops ravaged by superweeds and secondary pests [2] (GM Crops Facing Meltdown in the USA, SiS 46).

No regulation, nor public comment

Senior Regulatory Specialist of EPA Mike Mendelsohn commented [3]: “Section 3(c)(4) of the Federal Insecticide, Fungicide, and Rodenticide Act requires publication in the Federal Register of pesticide applications containing new active ingredients and/or changed use patterns.  SmartStax is a new product, but it contains already registered active ingredients and is for use on current use sites, therefore we did not publish a notice of receipt in the Federal Register.”

As insane as it may appear, EPA regards the health effects of transgenes stacked together and their impact on the environment as equivalent to a mixture of chemicals pesticides sprayed on a plant. They presume that there is no need for environmental assessment or toxicological evaluation of the mixed genes and their products within the crop plant, where many unintended effects in gene expression and metabolic profile can occur. The corporations appear to have been given carte blanche to load our food and feed with untested mixtures of old transgenes, with utter disregard of the interactions among the transgenes and gene products in food, feed and the environment.

An armoury of transgenes

SmartStax has been created by crossing four transgene varieties: MON89034 x 1507 x MON88017 x 59122 [4], which together provide eight traits. The eight traits are accompanied by an array of regulatory sequences derived from bacteria, plant viruses and other plants, are as follows, as far as one can tell, as SmartStax is very poorly characterised, and is in all probability a hybrid corn [5, 6].

Pat (events DAS-59122-7 and TC1507), phosphinothricin N-acetyltransferase  (from S.viridochromogenes) for glufosinate herbicide tolerance driven by  CaMV 35S promoter,  with CaMV 35S 3' polyadenylation signal as a transcription terminator; two copies of the pat gene and its promoter and terminator are present, one in each of  the  events DAS-59122-7  and TC1507.

CP4 epsps (event NK603), 5-enolpyruvylshikimate-3-phosphate synthase (Agrobacterium tumefaciens CP4) for glyphosate  herbicide tolerance , driven by  rice actin I promoter, with intron sequences, chloroplast transit peptide from A. thaliana  and A. tumefaciens nopaline synthase (nos) 3'-untranslated region terminator The genome has one copy of the NK603 event  containing 4  transgenes in one locus.

cry1A.105 (event MON 89034), a chimeric Cry1 delta endotoxin (Bacillus thuringiensis) for insect (Lepidopteron, moth) resistance, driven by CaMV 35S promoter, with 5'untranslated leader from wheat chlorophylla/b-binding protein, 3' untranslated region of wheat heat shock protein 17.3  as a transcription terminator. The genome has one copy of the event MON89034  containing 4  transgenes in one locus.

cry2Ab (event MON 89034), Cry2Ab delta endotoxin (Bacillus thuringiensis) for Lepidopteron (moth) resistance, driven by FMV35S promoter from figwort mosaic virus, with Hsp70 intron from maize heat shock protein gene, and .A. tumefaciens nopaline synthase (nos) 3'-untranslated region The genome has one copy of event 89034 containing 4 transgenes in the same locus.

cry3Bb1 (event MON 8801), Cry3Bb1 delta endotoxin (Bacillus thuringiensis subsp.kumamotoensis strain EG4691) for Coleopteran (corn rootworm)  resistance, driven by the   CaMV 35S promoter with duplicated enhancer region,  5' UTR from wheat chlorophyll a/b-binding protein, and  rice actin gene first intron; transcription is terminated by 3' UTR from wheat heat shock protein (tahsp17 3').  There is one copy of of event MON8801 in the genome, containing 6 transgenes.

cry1Fa2 (event TC1507), Cry1F delta endotoxin (Bacillus thuringiensis var.aizawai) for Lepidopteron (moth) resistance, driven by the ubiquitin (ubi) ZM (Zea mays) promoter and the first exon and intron; transcription is terminated by the 3' polyadenylation signal from ORF25 (Agrobacterium tumefaciens). There is one functional copy of the event containing 6 complete transgenes, and 2 partial copies of the event elsewhere in the genome.

cry35Ab1 (event DAS-59122-7), Cry35Ab1 delta endotoxin (Bacillus thuringiensis strain PS149B1) Insect  Coleopteran (corn rootworm) Resistance The toxin gene is driven by  the  Triticum aestivum peroxidase gene root-preferred promoter. The transcription is terminated by the  Solanum tuberosum proteinase inhibitor II (PINII) terminator. There is one copy of the  cry35Ab1 transgene in the genome.

cry34Ab1(event DAS-59122-7),  Cry34Ab1 delta endotoxin (Bacillus thuringiensis strain PS149B1) for Coleopteran (corn rootworm) resistance, driven by the  Zea mays ubiquitin gene promoter, intron and 5'UTR; transcription is terminated by the  Solanum tuberosum proteinase inhibitor II (PINII) terminator. There is one copy of cry34Ab1 transgene in the genome (note cry34Ab1 and cry 35Ab1 are combined in a single event DAS-59122-7).

The eight main traits in SmartStax corn include at least 34 transgenes. For the most part, the  transgenes were developed and patented during the mid 1980s  through to the mid 1990s. These old events were combined using traditional plant breeding techniques. The environmental and human safety of the transgenes have never been rigorously established while the regulatory agencies justify the safety of those many transgenes on the basis of the long time in which the transgenes have been used in GM food and feed in the Americas.  However, the modified foods were never labelled in the market, making epidemiological studies impossible.

Regulation permissive, detrimental effects ignored

Event DAS-59122-7, for example, was claimed substantially equivalent to non-transgenic corn based on measurements of a relatively few organic and inorganic nutrients [7]. A sub-chronic feeding study with stacked Lepidopteran and Coleopteran resistant traits (DAS-Ø15Ø7-1 x DAS-59122-7) maize grain in rats claimed to find no differences  in pathology between rats fed the stacked corn and those fed an isogenic corn.  Yet, statistically significant differences were observed in female rats: mean serum sodium concentration and mean serum chloride concentration were both lower (p < 0.05) in those consuming the transgenic corn diet compared with those consuming the control diet. A higher incidence of periductal brown pigment was observed in the pancreas of male rats consuming the transgenic diet (4/12) compared with animals consuming the control, but was not considered to be treatment-related [8].  In that way, all statistically significant differences were explained away, and the government regulators accepted that without question.  Earlier studies with DAS-59122 showed similar significant differences in nutrients between transgenic and non-transgenic lines that were equally dismissed.

Another sub-chronic feeding study of rats with 59122 grain compared with grain from a near-isogenic line for 90 days was carried out For the most part, the differences between 59122 and unmodified maize fed animals were not significantly different. However, levels of mean corpuscular haemoglobin, haemoglobin concentration, red cell width, reticulocyte count, and platelet count showed significant differences but these were not deemed significant enough for regulatory action [9] GM Maize 59122 Not Safe, SiS 34). Chickens fed grain from 59122 or from a near-isogenic maize were assessed after 42 days. The carcass and organ sizes were not significantly different, but the livers of female chickens fed transgenic maize were significantly enlarged, and again, not considered biologically significant by the company researchers.

A major caveat in earlier environmental safety studies was the use of bacterial protein surrogates for the proteins produced in the transgenic crops, which have genes adjusted in DNA sequence to optimize expression in plants and the resultant proteins differ substantially from those produced in bacteria both in amino acid sequences and in processing [9]

Recently, Giles-Eric Seralini and co-workers of independent scientists group Crigen in France found signs of hepato-renal toxicity in rats fed GM maize MON863 on re-analysis of raw data submitted by industry, and obtained through the courts [10]. Further analysis of data on glyphosate tolerant maize NK603 and Bt maizes MON810 and MON 863 revealed detrimental effects in the liver and kidney, as well heart, adrenal gland and hematopoietic system [11]. MON863 maize was found associated with signs of hormone dependent diseases [12].

Arpad Pusztai was commissioned by the German government to evaluate the Monsanto’s study on MON863. His report, also deemed confidential, was released after agreement was reached with all concerned parties. Pusztai's report stated, “..this imperfectly designed and executed study revealed a huge list of significant differences between the various biologically meaningful parameters of rats fed GM maize diets and the proper controls....the study strongly indicates that feeding rats on diets containing significant amounts of MON 863 corn can potentially be detrimental to the health of these animals and may cause major lesions in important organs (kidneys, liver, etc.), interfere with the function of their immune system (lymphocyte, WBC, granulocyte counts) and change their metabolism (glucose)…”

Pusztai summarized the differences between GM fed and control-fed rats, and their potential implications [13]: increased basophil count, which may indicate allergic reaction; increases in the number of lymphocytes and white blood cells, usually associated with infections, cancer, various toxins, and disease states; decreased reticulocyte count, indicative of anaemia; decreased kidney weight, pointing to blood pressure problems; and elevation in blood sugar levels, which cannot be dismissed as biologically insignificant, given the diabetes epidemic. There were also elevated levels of kidney inflammation, liver necrosis, and other changes. Pusztai added, “It is almost impossible to imagine that major lesions in important organs (kidneys, liver, etc) or changes in blood parameters (lymphocytes, granulocytes, glucose, etc.) that occurred in GM maize-fed rats, is incidental and due to simple biological variability.”

Another hazard that has been underestimated is the CaMV 35S promoter driving two of the traits, which we have warned against as a recombination hotspot that increases transgene instability. More seriously, it is a strong promoter promiscuously active in cells of practically all species including humans, and recent evidence indicates that it specifically induces transcription factors required for making CaMV, as well as HIV and other viruses associated with cancer [14, 15] (New Evidence Links CaMV 35S Promoter to HIV Transcription, SiS43).

There is no case for the commercialization of SmartStax, which is itself not assessed for safety, but consists of a medley of transgenes for which detrimental effects have been indicated in the limited cases where feeding trials have been carried out.

Article first published 12/04/10


  1. Cummins J. SmartStax Corn: Corporate War on Bees 2010
  2. Ho MW. GM crops facing meltdown in the USA. Science in Society 46 (to appear).
  3. E-mail communication from Mike Mendelsohn Senior Regulatory Specialist Office of Pesticide Programs/ Biopesticides and Pollution Prevention Division (7511P) U.S. Environmental Protection Agency 1200 Pennsylvania Avenue NW Washington DC 20460 to Mr. Arthur Tesla
  4. SmartStax in Europe, GMWatch, 4 August 2009,
  5. Agbios GM Database MON-89Ø34-3 x DAS- Ø15Ø7-1 x MON-88Ø17-3 x DAS-59122-7 (MON89034 x TC1507 x MON88017 x DAS-59122-7) SmartStax™ 2010
  6. United States Environmental Protection Agency Office of pesticides and Toxic substances Pesticide Fact Sheet Pesticide Name: MON 89034 x TC1507 x MON 88017 x DAS-59122-7 Date Registered: July 20, 2009  Registration Numbers: 524-581 & 68467-7
  7. Herman RA, Storer NP, Phillips AM, Prochaska LM, Windels P. Compositional assessment of event DAS-59122-7 maize using substantial equivalence.Regul Toxicol Pharmacol. 2007 Feb;47(1):37-47
  8. Appenzeller LM, Malley L, Mackenzie SA, Hoban D, Delaney B.Subchronic feeding study with genetically modified stacked trait lepidopteran and coleopteran resistant (DAS-Ø15Ø7-1xDAS-59122-7) maize grain in Sprague-Dawley rats. Food Chem Toxicol. 2009 Jul;47(7):1512-20
  9. Cummins J and Ho MW. GM Maize 59122 not safe. Science in Society 34, 27-28, 2007.
  10. Séralini GE, Cellier D, de Vendomois JS. New analysis of a rat feeding study with a genetically modified maize reveals signs of hepatorenal toxicity. Arch Environ Contam Toxicol. 2007, 52(4), 596-602.
  11. de Vendômois JS, Roullier F, Cellier D, Séralini GE.A comparison of the effects of three GM corn varieties on mammalian health. Int J Biol Sci. 2009, 5(7):706-26.
  12. Séralini GE, de Vendômois JS, Cellier D, Sultan C, Buiatti M, Gallagher L, Antoniou M, Dronamraju KR. How subchronic and chronic health effects can be neglected for GMOs, pesticides or chemicals. Int J Biol Sci.  2009, 5(5), 438-43.
  13. Puszta A. Evaluation of and Final Report on the summary report of the "13-Week Dietary Subchronic Comparison Study with MON 863 in Rats Preceded by a 1-Week Baseline Food Consumption Determination with PMI Certified Diet #5002(Report MSL-18175/Covance Study No. 6103-293)".
  14. Ho MW and Cummins J. New evidence links CaMV 35S promoter to HIV transcription. Microbial Ecology in Health and Disease 2009, 43, 1-3.
  15. Ho MW and Cummins J. New evidence links CaMV 35S promoter to HIV transcription. Science in Society 43, 26-27, 2009.

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There are 6 comments on this article so far. Add your comment above.

Kawai Genovia Comment left 28th April 2010 16:04:16
Hello Professor Joe Cummins of ISIS, my name is Kawai Genovia(its hawaiian) and i am currently working on an writing assignment on how GMO food and products have a wold-wide negative effect and are harmful and dangerous. So in this case i am in dire need for information that is backed by a significant scientific background. I ask for contact info or other sources that you would recommend to garner this information. I would hope to change others views on GMO and help them realize the current dangers that face us now. I view the monopolization of GMO crops as a global issue that should be confronted as soon as possible. The way i view the situation is "we may not have to worry about Global Warming killing us when we will willingly eat our-self to oblivion"

Douglas Hinds Comment left 13th April 2010 16:04:49
Joe, your article sheds light on the nature of GM Crops and makes the issue crystal clear: No one who reads the contents of your article could accept the presence of GM crops in the open environment and the international food supply, or fail to recognize the gross incompetence of those charged with preserving the environment and protecting the health of the USA's citizens. What does seem insane is the fact that people that useless could have been entrusted with positions of responsibility, which allowed them to put so much at risk. I quote you: "As insane as it may appear, EPA regards the health effects of transgenes stacked together and their impact on the environment as equivalent to a mixture of chemicals pesticides sprayed on a plant". "They presume that there is no need for environmental assessment or toxicological evaluation of the mixed genes and their products within the crop plant, where many unintended effects in gene expression and metabolic profile can occur". "The corporations appear to have been given carte blanche to load our food and feed with untested mixtures of old transgenes, with utter disregard of the interactions among the transgenes and gene products in food, feed and the environment". Nothing could be clearer than that! (And corroborated with data and references) Good work, Joe. Saludos (We did translate the GM Meltdown article into Spanish, which I'll send along shortly).

David Ryan Comment left 14th April 2010 00:12:46
Has Canada given regulatory approval? Do you know how many hectares are planned for cultivation in Canada, and where? Thanks, David

Joe Cummins Comment left 14th April 2010 13:01:22
Replying to Douglas Hinds, Thanks for the useful comments Douglas, Your work in Mexico is highly regarded around the world. The problems with SmartStax are great and the fact that old trans genes are slapped together after being exposed to pests ( some of which have mutated to resistance) along with their use having allowed invasion by pests that have natural resistance to the toxins.The parent transgenic maize plants will have been exposed to the pests and the invaders for many years Those farmers who pay handsomely for the use of the patented seeds have paid for a corn plant full of old trans genes that may soon succumb to pests and invaders. Of course, the seeds from the hybrid cannot be saved because of the lawyer pests and the fact that the insect and herbicide resistance traits will segregate in the second and later planting generations. Regards , joe

joe cummins Comment left 14th April 2010 13:01:18
Replying to David Ryan; My understanding is that Canada approved SmartStax maize January this year for a two year trial period. There was no public input into that decree, to my best knowledge. SmartStax seeds should be available this month. The food and feed corn will not be labelled as being SmartStax. The information on sale and planting of the seed s has not been disclosed but the planted fields may bear small SmartStax signs. I expect that the planting in Ontario and Quebec may be quite large. Thanks for the question. sincerely, joe

Dirkjan Comment left 20th August 2013 05:05:52
Thanks for sharing this. It will probably be admitted in September or October in Germany, according to this article: I will share this article on my FB for references to Smartstax, for those caring enough to read.