Bt Cowpea May Present Hazards to Human and Environmental Health

TWN Info Service on Biosafety
26 May 2022
Third World Network
www.twn.my

Dear Friends and Colleagues

Bt Cowpea May Present Hazards to Human and Environmental Health

A recent scientific publication (Item 1) reports substantial deficiencies in the risk assessment of Bt cowpea approved for cultivation in Nigeria, genetically engineered to protect the plants from the larvae of Maruca vitrata, (pod borer). Cowpea is an indigenous African crop and major source of protein, consumed by around two hundred million people. It plays a crucial role in food and nutritional security, as well as providing an important source of income for farmers.

The Institute for Independent Impact Assessment of Biotechnology (Testbiotech) analysed the application for marketing and cultivation of this insect-resistant cowpea. It identified issues of concern regarding the safety of the Bt toxins produced in the plants. The main findings of its analyses are (Items 2 & 3):

(1) Outcrossing and hybridisation with traditional varieties and wild relatives of the cowpea are likely, and can lead to the spread of the transgenes in the environment.

(2) The potential adverse effects of the insecticidal toxin produced by the transgenic cowpea on biodiversity, insects and soil organisms were not empirically tested.

(3) Some specific findings indicate that cowpea may produce potential allergens. In addition, Bt proteins are thought to enhance or induce immune responses. The potential effects on health need to be assessed in regard to specific diets.

Testbiotech concludes that the identified hazards – on the environment and biodiversity, the cowpea gene pool, the livelihoods of farmers, as well as human and animal health – are serious. It recommends discontinuing the marketing of the plants as well as additional in-depth investigations. The identified reasons for concern can also be relevant to other countries where the Bt cowpea is approved, or where applications have been filed for release or marketing.

With best wishes,
Third World Network
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Item 1

DEFICIENCIES IN THE RISK ASSESSMENT OF GENETICALLY ENGINEERED BT COWPEA APPROVED FOR CULTIVATION IN NIGERIA: A CRITICAL REVIEW

Christoph Then *, Juliana Miyazaki and Andreas Bauer-Panskus
Plants 2022, 11(3), 380
https://doi.org/10.3390/plants11030380
https://www.mdpi.com/2223-7747/11/3/380/htm
29 Jan 2022

Abstract

We analyze the application filed for the marketing and cultivation of genetically engineered Bt cowpea (event AAT 709A) approved in Nigeria in 2019. Cowpea (Vigna ungiguiculata) is extensively grown throughout sub-Saharan Africa and consumed by around two hundred million people. The transgenic plants produce an insecticidal, recombinant Bt toxin meant to protect the plants against the larvae of Maruca vitrata, which feed on the plants and are also known as pod borer. Our analysis of the application reveals issues of concern regarding the safety of the Bt toxins produced in the plants. These concerns include stability of gene expression, impact on soil organisms, effects on non-target species and food safety. In addition, we show deficiencies in the risk assessment of potential gene flow and uncontrolled spread of the transgenes and cultivated varieties as well as the maintenance of seed collections. As far as information is publicly available, we analyze the application by referring to established standards of GMO risk assessment. We take the provisions of the Cartagena Protocol on Biosafety (CPB) into account, of which both Nigeria and the EU are parties. We also refer to the EU standards for GMO risk assessment, which are complementary to the provisions of the CPB.

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Item 2

PRESS RELEASE: TRANSGENIC COWPEA MAY IMPACT HEALTH AND THE ENVIRONMENT

Testbiotech
https://www.testbiotech.org/en/news/transgenic-cowpea-may-impact-health-and-environment
1 Feb 2022

Deficiencies in the risk assessment of Bt cowpea cultivated in Nigeria

A new scientific publication reports substantial deficiencies in the risk assessment of genetically engineered Bt cowpea approved for cultivation in Nigeria. The transgenic plants produce an insecticidal Bt toxin meant to protect the plants from the larvae of Maruca vitrata, which feed on the plants and are also known as pod borer. Testbiotech recommends discontinuing the marketing of the plants as well as additional in-depth investigations before planning any releases. The cultivation and consumption of the beans may otherwise negatively impact health and the environment.

The main findings of analyses of the publicly available data are:

(1) Outcrossing and hybridisation with traditional varieties and wild relatives of the cowpea are likely, and can lead to the spread of the transgenes in the environment. The long-term effects can neither be predicted nor controlled. Gene flow could become a threat to seed collections, seed saving and traditional farming, and thus endanger the unique common heritage of African farmers.

(2) The potential adverse effects of the insecticidal toxin produced by the transgenic cowpea on biodiversity, insects and soil organisms were not empirically tested. This is a major cause of concern, as cowpea naturally produce substances that are known to strongly increase the toxicity of the Bt proteins. Such synergistic effects may even impact food and feed safety. However, these hazards were neither considered nor examined.

(3) Some specific findings indicate that cowpea may produce potential allergens. In addition, Bt proteins are thought to enhance or induce immune responses. There are many traditional uses of cowpea in food and feed – this means that potential effects on health may vary and need to be assessed in regard to specific diets. However, no experimental data on food and feed safety are available.

Testbiotech concludes that the identified hazards are serious: the uncertainties and unknowns in regard to risk assessment are substantial. Therefore, without further in-depth investigation, release and cultivation of the Bt cowpea should not be allowed. The identified reasons for concern can also be relevant to other countries where the GE cowpea is approved, or where applications have been filed for release or marketing.

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Item 3

CULTIVATION OF BT COWPEA MAY IMPACT HEALTH AND THE ENVIRONMENT

Christoph Then, Juliana Miyazaki and Andreas Bauer-Panskus
Testbiotech
https://www.testbiotech.org/sites/default/files/Bt_Cowpea_risk%20assessment.pdf
Feb 2022

Summary

Testbiotech analysed the application for marketing and cultivation of insect-resistant cowpea – Event AAT709A (Ref.No. AAT/DPS-18VUIR-NG) – filed by the African Agricultural Technology Foundation and the Institute of Agricultural Research, Ahmadu Bello University Zaria (AATF, 2018) to the government of the Federal Republic of Nigeria in 2018 and the respective recommendation of the National Biosafety Committee (NBC) of Nigeria (NBMA, 2018) and the decision for approval (NBMA 2019). The transgenic cowpea (Vigna unguiculata) produces bacterial toxins originating form Bacillus thuringiensis (Bt toxin) classified as Cry1Ab. The toxins are meant to protect the cowpea against infestations with larvae of Maruca vitrata (pod borer).

The aim of the Testbiotech analysis was to come up with a reasoned opinion on whether the application and the recommendation can be regarded as adequate and sufficient to assess the risks of the genetically engineered cowpea, and justify approval for release, cultivation and consumption. Testbiotech identified and described potential hazards as well as resulting risks which should have been taken into account in the GE cowpea risk assessment. The identified risks were compared to the application and the assessment of the authorities in Nigeria. The issues as presented can also be relevant for other countries in which these GE cowpeas are approved or applied for release or marketing (such as Ghana).

The analysis focused on the following topics:

› stability in the expression of the inserted genes;

› gene flow to other cultivated varieties or wild relatives;

› impact on non-target organisms;

› impact on microbial communities;

› health risks at the stage of consumption. Specific causes for concern were identified from the available data:

› The expression of the Bt gene appears to lack sufficient stability; it is likely to be influenced by genetic backgrounds (of the specific varieties) and environmental conditions. One probable reason is the specific promoter used to enhance gene expression in the plants.

› Gene flow to regional varieties and wild relatives can be expected from the cultivation of the plants. If gene flow occurs, the GE plants can persist, propagate and generate viable offspring that cannot be controlled. This may trigger adverse effects caused by the spontaneous offspring that were not observed in the original GE cowpea. Long-term risk assessment of these next generation effects cannot be conducted in a sufficiently reliable way.

› The consequences of gene flow for seed collections, seed saving and traditional farming can be severe, putting at risk the common heritage of African farmers.

› The toxicity of Bt proteins (Cry1Ab) is increased by synergistic effects arising from the combination with the protease inhibitors (PI) produced by cowpea. The enhanced toxicity may also impact the selectivity of the toxin and susceptibility of non-target organisms.

› The synergistic effects arising from the combination of Bt toxins with the plant protease inhibitors (PI) may also enhance immune responses, including responses to allergens potentially produced in the cowpea.

› Bt toxins expressed in the plants may also affect their associated microbiome, including endophytes, mycorrhizae and other soil organisms. Negative effects on the microbial properties and the enzymatic activities in the rhizosphere cannot be excluded after long-term cultivation.

The concerns raised have a reasonable degree of probability and plausibility. Nevertheless, risk assessment failed to sufficiently address these issues. Moreover, it appears that the applicant does not acknowledge existing evidence such as:

› the expression of the Bt gene appears to lack sufficient stability;

› the high likelihood of gene flow to wild relatives and regional varieties; › the immune responses that can be enhanced by Bt toxins;

› synergistic effects between protease inhibitors (PI, as naturally produced in the cowpea) and Bt toxins can substantially increase the toxicity of the cowpeas and the products derived off;

› negative effects on the microbial properties and the enzymatic activities in the rhizosphere may occur after long-term cultivation. In conclusion, the Bt cowpea risk assessment is inadequate, unreliable and to some extent misleading.

The occurrence of adverse effects from the cultivation of the GE cowpea is not unlikely, including impacts on (i) the environment and biodiversity; (ii) the cowpea gene pool; (iii) the livelihoods of farmers as well as (iv) human and animal health. Since these causes for concern cannot be resolved or dispelled by the data presented for risk assessment, the cultivation of the transgenic cowpea in Nigeria should be discontinued.

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