scholarly journals Impact of nitrogen and phosphorus fertilizers on Cry1Ac protein contents in transgenic cotton

2023 ◽  
Vol 83 ◽  
Author(s):  
S. U. Khan ◽  
S. Ali ◽  
S. H. Shah ◽  
M. A. Zia ◽  
S. Shoukat ◽  
...  
Keyword(s):  
Insect Pests ◽  
Standard Dose ◽  
Cross Resistance ◽  
Enzyme Linked Immunosorbent Assay ◽  
Bt Cotton ◽  
Nitrogen And Phosphorus ◽  
Cry Protein ◽  
Cry Toxin ◽  
Phosphorus Fertilizers ◽  
Cry1ac Protein

Abstract Application of different fertilizers to check the efficiency of expression of Bt (Bacillus thuringiensis) gene in one of the leading commercialized crops (cotton) against Lepidopteran species is of great concern. The expression of Cry protein level can be controlled by the improvement of nutrients levels. Therefore, the myth of response of Cry toxin to different combinations of NP fertilizers was explored in three Bt cotton cultivars. Combinations include three levels of nitrogen and three levels of phosphorus fertilizers. Immunostrips and Cry gene(s) specific primer based PCR (Polymerase Chain Reaction) analysis were used for the presence of Bt gene that unveiled the presence of Cry1Ac gene only. Further, the ELISA (enzyme-linked immunosorbent assay) kit was used to quantify the expression of Cry1Ac protein. Under various NP fertilizers rates, the level of toxin protein exhibited highly significant differences. The highest toxin level mean was found to be 2.3740 and 2.1732 µg/g under the treatment of N150P75 kg ha-1 combination while the lowest toxin level mean was found to be 0.9158 and 0.7641 µg/g at the N50P25 kg ha-1 level at 80 and 120 DAS (Days After Sowing), respectively. It was concluded from the research that the usage of NP fertilizers has a positive relation with the expression of Cry1Ac toxin in Bt cotton. We recommend using the N150P50 kg ha-1 level as the most economical and practicable fertilizer instead of the standard dose N100P50 kg ha-1 to get the desired level of Cry1Ac level for long lasting plant resistance (<1.5). The revised dose of fertilizer may help farmers to avoid the cross-resistance development in contradiction of insect pests.

scholarly journals Pink Bollworm Resistance to Bt Toxin Cry1Ac Associated with an Insertion in Cadherin Exon 20

Toxins ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 186 ◽  
Author(s):  
Ling Wang ◽  
Yuemin Ma ◽  
Xueqin Guo ◽  
Peng Wan ◽  
Kaiyu Liu ◽  
...  
Keyword(s):  
Insect Pests ◽  
Stop Codon ◽  
Premature Stop Codon ◽  
Pink Bollworm ◽  
Cross Resistance ◽  
Bt Cotton ◽  
Wild Type ◽  
Bt Toxin ◽  
Exon 20 ◽  
In Cells

Insecticidal proteins from Bacillus thuringiensis (Bt) are widely used to control insect pests, but their efficacy is reduced when pests evolve resistance. We report on a novel allele (r16) of the cadherin gene (PgCad1) in pink bollworm (Pectinophora gossypiella) associated with resistance to Bt toxin Cry1Ac, which is produced by transgenic cotton. The r16 allele isolated from a field population in China has 1545 base pairs of a degenerate transposon inserted in exon 20 of PgCad1, which generates a mis-spliced transcript containing a premature stop codon. A strain homozygous for r16 had 300-fold resistance to Cry1Ac, 2.6-fold cross-resistance to Cry2Ab, and completed its life cycle on transgenic Bt cotton producing Cry1Ac. Inheritance of Cry1Ac resistance was recessive and tightly linked with r16. Compared with transfected insect cells expressing wild-type PgCad1, cells expressing r16 were less susceptible to Cry1Ac. Recombinant cadherin protein was transported to the cell membrane in cells transfected with the wild-type PgCad1 allele, but not in cells transfected with r16. Cadherin occurred on brush border membrane vesicles (BBMVs) in the midgut of susceptible larvae, but not resistant larvae. These results imply that the r16 allele mediates Cry1Ac resistance in pink bollworm by interfering with the localization of cadherin.

scholarly journals A Strain of Bacillus thuringiensis Containing a Novel cry7Aa2 Gene that Is Toxic to Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae)

Insects ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 259 ◽  
Author(s):  
Mikel Domínguez-Arrizabalaga ◽  
Maite Villanueva ◽  
Ana Beatriz Fernandez ◽  
Primitivo Caballero
Keyword(s):  
Amino Acid ◽  
Bacillus Thuringiensis ◽  
Molecular Mass ◽  
Leptinotarsa Decemlineata ◽  
Insect Pests ◽  
Amino Acid Residues ◽  
Cry Protein ◽  
Lc50 Value ◽  
Leptinotarsa Decemlineata Say

The genome of the Bacillus thuringiensis BM311.1 strain was sequenced and assembled in 359 contigs containing a total of 6,390,221 bp. The plasmidic ORF of a putative cry gene from this strain was identified as a potential novel Cry protein of 1138 amino acid residues with a 98% identity compared to Cry7Aa1 and a predicted molecular mass of 129.4 kDa. The primary structure of Cry7Aa2, which had eight conserved blocks and the classical structure of three domains, differed in 28 amino acid residues from that of Cry7Aa1. The cry7Aa2 gene was amplified by PCR and then expressed in the acrystalliferous strain BMB171. SDS-PAGE analysis confirmed the predicted molecular mass for the Cry7Aa2 protein and revealed that after in vitro trypsin incubation, the protein was degraded to a toxin of 62 kDa. However, when treated with digestive fluids from Leptinotarsa decemlineata larvae, one major proteinase-resistant fragment of slightly smaller size was produced. The spore and crystal mixture produced by the wild-type BM311.1 strain against L. decemlineata neonate larvae resulted in a LC50 value of 18.8 μg/mL, which was statistically similar to the estimated LC50 of 20.8 μg/mL for the recombinant BMB17-Cry7Aa2 strain. In addition, when this novel toxin was activated in vitro with commercial trypsin, the LC50 value was reduced 3.8-fold to LC50 = 4.9 μg/mL. The potential advantages of Cry7Aa2 protoxin compared to Cry7Aa1 protoxin when used in the control of insect pests are discussed.

Isolating the ‘farmer’ effect as a component of the advantage of growing genetically modified varieties in developing countries: a Bt cotton case study from Jalgaon, India

2007 ◽  
Vol 145 (5) ◽  
pp. 491-500 ◽  
Author(s):  
S. MORSE ◽  
R. BENNETT ◽  
Y. ISMAEL
Keyword(s):  
Developing Countries ◽  
Insect Pests ◽  
Bt Cotton ◽  
Great Care ◽  
Land Area ◽  
Care Needs ◽  
Gross Margin ◽  
Depth Analysis ◽  
Per Se

SUMMARYThe present paper explores the ‘farmer’ effect in economic advantages often claimed for Bt cotton varieties (those with the endotoxin gene from Bacillus thuringiensis conferring resistance to some insect pests) compared to non-Bt varieties. Critics claim that much of the yield advantage of Bt cotton could be due to the fact that farmers adopting the technology are in a better position to provide inputs and management and so much of any claimed Bt advantage is an artefact rather than reflecting a real advantage of the variety per se. The present paper provides an in-depth analysis of 63 non-adopting and 94 adopting households of Bt cotton in Jalgaon, Maharashtra State, India, spanning the seasons 2002 and 2003. Results suggest that Bt adopters are indeed different from non-adopters in a number of ways. Adopters appear to specialize more on cotton (at least in terms of the land area they devote to the crop), spend more money on irrigation and grow well-performing non-Bt varieties of cotton (Bunny). Taking gross margin as the basis for comparison, Bt plots had 2·5 times the gross margin of non-Bt plots in both seasons. If only adopters are considered then the gross margin advantage of Bt plots reduces to 1·6 times that of non-Bt plots. This is still a significant advantage and could well explain the popularity of Bt in Maharashtra. However, it is clear that great care needs to be taken with such comparative studies.

Cyanide formation in Sorghum almum in relation to nitrogen and phosphorus nutrition

1964 ◽  
Vol 4 (12) ◽  
pp. 15 ◽  
Author(s):  
PE Kriedeman
Keyword(s):  
Phosphorus Uptake ◽  
Phosphorus Nutrition ◽  
Nitrogen And Phosphorus ◽  
Plant Yield ◽  
Phosphorus Fertilizers ◽  
Nitrogen And Phosphorus Uptake ◽  
Cyanide Content

The effects of nitrogen and phosphorus on the cyanide content of Sorghum almum Parodi, grown in the glasshouse on a phosphorus deficient soil, were investigated. Both nitrogen and phosphorus fertilizers increased the total cyanide content of plant tops; however, phosphorus dressings equivalent to 40 cwt superphosphate an acre depressed the percentage cyanide level. The effects of fertilization on cyanide production are discussed in terms of nitrogen and phosphorus uptake and plant yield.

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