cry1ab protein
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2021 ◽  
pp. 1-10
Author(s):  
Bahador Hajimohammadi ◽  
Gilda Eslami ◽  
Elahe Loni ◽  
Mohammad Hassan Ehrampoush ◽  
Seyed Mohammad Moshtaghioun ◽  
...  

2021 ◽  
Author(s):  
Bo Lv ◽  
Yun-e Tang ◽  
Chao-min Li ◽  
Ou-lin Dai ◽  
Yong Peng ◽  
...  

Abstract Cry1Ab toxin has been effectively integrated into crops such as rice and cotton for pest control, and the safety evaluation of transgenic rice has attracted widespread attention. Nevertheless, the effects of transgenic rice straw on animal model are still unclear. Hence, the present study conducted an integrated analysis to evaluate the unintended effects of transgenic rice straw expressing Cry1Ab protein on the Institute of Cancer Research (ICR) mice under 90-day treatment. The results indicated that Cry1Ab rice straw had no significant effects on the behavior and body weight of mice. In addition, physiological indicators, including hemogram, blood biochemistry, apoptosis rate, and calcium ion concentration of the blood lymphocytes, displayed no alterations under Cry1Ab protein stress. Similarly, Cry1Ab rice straw had no adverse effects on several antioxidase activities (i.e., catalase, superoxide dismutase, peroxidase, glutathione peroxidase, and acetylcholine esterase). Moreover, we recorded that Cry1Ab stress did not adversely impact the sperm quality and follicular development of male and female ICR mice. Collectively, this integrated analysis indicates that Cry1Ab rice straw has no adverse or toxic effects on ICR mice after 90-day treatment and provides multi-level perspectives to assess the safety of genetically modified crops on non-target mammals.


2021 ◽  
Vol 33 (1) ◽  
Author(s):  
André Felipe Lohn ◽  
Miluse Trtikova ◽  
Ignacio Chapela ◽  
Rosa Binimelis ◽  
Angelika Hilbeck

Abstract Background In 2009, Spanish farmers reported a novel weed, now identified as a relative of maize’s ancestor, teosinte, in their maize fields. Introgression of the insect resistance transgene cry1Ab from genetically modified (GM) maize into populations of this weedy Spanish teosinte could endow it with additional defense mechanisms. The aims of this study were: (1) to test if hybridization between GM maize and weedy plants from Spain is possible; (2) to understand the relationship between transgene transcription activity, concentrations of the expected transgene product (Cry1Ab protein) and the bioactivity of the latter on target insect pests following transgene flow from GM maize into Spanish teosinte plants. Results We demonstrated that hybridization between GM maize and the weedy Spanish teosinte is possible, with no observable barrier to the formation of crop/weed hybrids when teosinte served as pollen donor. When GM maize plants were used as pollen donors, significant crossing incompatibility was observed: hybrid plants produced only few “normal” seeds. Nevertheless, viable F1 seeds from GM pollen crossed onto teosinte were indeed obtained. The cry1Ab transgene was stably expressed as mRNA in all crossings and backgrounds. Similarly, toxicity on neonate Ostrinia nubilalis, presumably due to Cry1Ab protein, was consistently expressed in teosinte hybrids, with mortality rates 95% or higher after only 4 days exposure, similar to rates on parental GM maize plants. Nevertheless, no strong correlations were observed between transgene transcription levels and Cry1Ab concentrations, nor between Cry1Ab concentrations and insect mortality rates across all of the different genetic backgrounds. Conclusions Our results establish fundamental parameters for environmental risk assessments in the European context: first, we show that crop/weed hybridization in fields where maize and teosinte exist sympatrically can lead to potentially catastrophic transfer of resistance traits into an already noxious weed; second, our results question the viability of using gene dosage to model and predict ecological performance in either the intended crop plant or the undesired teosinte weed. Significant questions remain that should be addressed in order to provide a scientific, sound approach to the management of this novel weed.


Toxins ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 335
Author(s):  
Su Mon Shwe ◽  
Sivaprasath Prabu ◽  
Yu Chen ◽  
Qincheng Li ◽  
Dapeng Jing ◽  
...  

Yellow Peach Moth (YPM), Conogethes punctiferalis (Guenée), is one of the most destructive maize pests in the Huang-Huai-Hai summer maize region of China. Transgenic Bacillus thuringiensis (Bt) maize provides an effective means to control this insect pest in field trials. However, the establishment of Bt resistance to target pests is endangering the continued success of Bt crops. To use Bt maize against YPM, the baseline susceptibility of the local populations in the targeted areas needs to be verified. Diet-overlay bioassay results showed that all the fourteen YPM populations in China are highly susceptible to Cry1Ab. The LC50 values ranged from 0.35 to 2.38 ng/cm2 over the two years of the collection, and the difference between the most susceptible and most tolerant populations was sevenfold. The upper limit of the LC99 estimates of six pooled populations produced >99% larval mortality for representative eight populations collected in 2020 and was designated as diagnostic concentrations for monitoring susceptibility in YPM populations in China. Hence, we evaluated the laboratory selection of resistance in YPM to Cry1Ab using the diet-overlay bioassay method. Although the resistant ratio was generally low, YPM potentially could evolve resistance to Cry1Ab. The potential developmentof resistance by target pests points out the necessity to implement resistance management strategies for delaying the establishment of pest resistance to Bt crops.


2021 ◽  
Vol 20 (3) ◽  
pp. 792-803 ◽  
Author(s):  
Jin-gang LIANG ◽  
Dan-dan ZHANG ◽  
Dong-yang LI ◽  
Sheng-yuan ZHAO ◽  
Chen-yao WANG ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bahador Hajimohammadi ◽  
Gilda Eslami ◽  
Hengameh Zandi ◽  
Mohammad Hassan Ehrampoush ◽  
Azar Naimi ◽  
...  

AbstractRice is considered one of the most important staple food crops. Genetically modified (GM) Bt rice, harbored cry1Ab gene expressing the insect-resistance protein has been developed to resistance to the insects. In this study, we assessed the safety of the GM Bt rice on Sprague–Dawley rats for 90 days. Totally, 120 rats in both sexes were used for three different diets, including 50% GM Bt rice, feeding with 50% rice, and standard feeding. Each 40 SD rats including 20 males and 20 females were considered as each diet. The clinical variables such as body weight and food consumption were measured and a range of clinical tests was examined, including hematology, serum chemistry parameters, urinalysis profile, thyroid, and sex hormone levels. Pathological assessments were also done. The results showed that the mean weekly feed utilization (%) had no significant difference among the studied groups. Also, blood biochemistry, hematological parameters, urine analysis, and hormonal levels had no significant differences among the groups. However, alanine aminotransferase was less in males versus female feeding with GM Bt rice. No histopathological changes were observed among the groups. In conclusion, this study demonstrated that GM Bt rice had no obvious adverse effects on rats' health.


2020 ◽  
Vol 113 (2) ◽  
pp. 974-979
Author(s):  
Prince C Addae ◽  
Mohammad F Ishiyaku ◽  
Jean-Batiste Tignegre ◽  
Malick N Ba ◽  
Joseph B Bationo ◽  
...  

Abstract Cowpea [Vigna unguiculata (L) Walp.] is an important staple legume in the diet of many households in sub-Saharan Africa. Its production, however, is negatively impacted by many insect pests including bean pod borer, Maruca vitrata F., which can cause 20–80% yield loss. Several genetically engineered cowpea events that contain a cry1Ab gene from Bacillus thuringiensis (Bt) for resistance against M. vitrata were evaluated in Nigeria, Burkina Faso, and Ghana (West Africa), where cowpea is commonly grown. As part of the regulatory safety package, these efficacy data were developed and evaluated by in-country scientists. The Bt-cowpea lines were planted in confined field trials under Insect-proof netting and artificially infested with up to 500 M. vitrata larvae per plant during bud formation and flowering periods. Bt-cowpea lines provided nearly complete pod and seed protection and in most cases resulted in significantly increased seed yield over non-Bt control lines. An integrated pest management strategy that includes use of Bt-cowpea augmented with minimal insecticide treatment for protection against other insects is recommended to control pod borer to enhance cowpea production. The insect resistance management plan is based on the high-dose refuge strategy where non-Bt-cowpea and natural refuges are expected to provide M. vitrata susceptible to Cry1Ab protein. In addition, there will be a limited release of this product until a two-toxin cowpea pyramid is released. Other than South African genetically engineered crops, Bt-cowpea is the first genetically engineered food crop developed by the public sector and approved for release in sub-Saharan Africa.


Water SA ◽  
2019 ◽  
Vol 45 (4 October) ◽  
Author(s):  
Amy Du Pisanie ◽  
Louis Du Preez ◽  
Johnnie Van den Berg ◽  
Rialet Pieters

Transgenic Bt maize plants are genetically modified to contain genes of Bacillus thuringiensis that encode for δ-endotoxins (Cry1Ab protein) that have insecticidal properties. These endotoxins target certain lepidopteran pests of maize. There are several entry routes by which Cry proteins enter the aquatic ecosystem in which aquatic organisms are exposed to these proteins. The main route is through plant debris such as leaves, stalks and postharvest detritus that are transported by means of run-off, rain and wind. While several studies have been conducted on the fate of Cry1Ab protein in terrestrial ecosystems, little is known of the release rates of Cry1Ab proteins from maize plant tissues that end up in aquatic ecosystems. In this study, leaves of Bt-maize and its isoline were submerged in containers filled with deionised or borehole water for a period of 16 days, and kept at 3 different temperatures (10±1, 21±1 and 30±1°C). Samples were collected at 1, 2, 4, 8, 16, 24, 48, 96, 192 and 384 h post submersion and analysed for Cry protein content using enzyme-linked immunosorbent assay (ELISA). The release of Cry protein from submerged maize leaves was influenced by temperature, and duration of immersion. An increase in Cry protein levels in the water was observed from the first hour onwards in both water types until the end of the experiment. The highest concentration of Cry protein was found at 30°C. This study showed that temperature and time period influence the release rate of Cry proteins from dried leaf matter into the aquatic environment.


PLoS ONE ◽  
2019 ◽  
Vol 14 (5) ◽  
pp. e0216481
Author(s):  
Arial J. Shogren ◽  
Jennifer L. Tank ◽  
Emma J. Rosi ◽  
Martha M. Dee ◽  
Shannon L. Speir ◽  
...  

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