Abstract
A protective antigen (PA) gene from Bacillus anthracis Cohn has been inserted into tobacco ( Nicotiana tabacum L.) chloroplasts to produce an anthrax vaccine. The PA protein is the primary immunogen of human vaccines for anthrax disease. The objective of this study was to determine the optimum soil water content for producing antigen vaccine in tobacco leaves. High leaf antigen concentration is important in vaccine manufacturing. Protective antigen tobacco, transformed from ‘Petite Havana SR1’, was transplanted to native soil (fine‐loamy, mixed, thermic Typic Argiudolls) in a greenhouse floor. Treatments consisted of soil water potential (Φ) irrigation thresholds (−20, −34, −48, and −62 kPa) based on sensors buried 10 cm in soil. Since plant growth is normally stimulated when soil moisture is readily available, we hypothesized that soil moisture might dilute leaf PA content. Results showed that increasing biomass with optimum irrigation did not dilute PA in leaves. Using ELISA quantification, −34 kPa irrigation threshold averaged 529 μg PA kg −1 leaf fresh weight for two ratoon harvests. Leaves from drier irrigation treatments did not have significantly higher PA content or biomass. Tobacco grown with more frequent irrigations using −20 kPa Φ threshold averaged less biomass and produced leaves with significantly lower antigen. In a separate experiment, gravimetric soil water use was compared between nontransgenic Petite Havana and PA plants at button growth stage. Genetic engineering tobacco for PA caused reduced leaf area in plants. Transpiration was significantly higher with nontransgenic plants, indicating that lower irrigation rates may be needed for antigen tobacco.
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Claims 8
Claim · model-written summary
The −34 kPa irrigation threshold gave an average of 529 μg PA per kg leaf fresh weight over two ratoon harvests.
- Taxon
- tobacco
Nicotiana tabacumt0 - Treatment
- −34 kPa irrigation thresholde1
- Outcome
- PAe1
- Value
- 529 μg PA kg −1 leaf fresh weighte1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Genetically Modified Tobacco”
e1“−34 kPa irrigation threshold averaged 529 μg PA kg −1 leaf fresh weight for two ratoon harvests”
Claim · model-written summary
Leaves from drier irrigation treatments did not have significantly higher PA content or biomass.
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- drier irrigation treatmentse2
- Outcome
- PA content or biomasse2
- Direction
- highere2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Genetically Modified Tobacco”
e2“Leaves from drier irrigation treatments did not have significantly higher PA content or biomass”
Claim · model-written summary
Optimum irrigation, which increased biomass, did not dilute PA in leaves.
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- optimum irrigatione3
- Outcome
- PA in leavese3
- Direction
- did not dilutee3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Genetically Modified Tobacco”
e3“Results showed that increasing biomass with optimum irrigation did not dilute PA in leaves”
Claim · model-written summary
More frequent irrigation at the −20 kPa threshold gave less biomass.
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- more frequent irrigations using −20 kPa Φ thresholde4
- Outcome
- biomasse4
- Direction
- lesse4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Genetically Modified Tobacco”
e4“Tobacco grown with more frequent irrigations using −20 kPa Φ threshold averaged less biomass and produced leaves with significantly lower antigen”
Claim · model-written summary
More frequent irrigation at the −20 kPa threshold gave significantly lower leaf antigen.
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- more frequent irrigations using −20 kPa Φ thresholde4
- Outcome
- antigene4
- Direction
- significantly lowere4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Genetically Modified Tobacco”
e4“Tobacco grown with more frequent irrigations using −20 kPa Φ threshold averaged less biomass and produced leaves with significantly lower antigen”
Claim · model-written summary
Genetic engineering for PA reduced leaf area in tobacco plants.
- Taxon
- tobaccoNicotiana tabacumt0
- Organ / stage
- button growth stagee6
- Treatment
- Genetic engineering tobacco for PAe5
- Outcome
- leaf areae5
- Direction
- reducede5
- Comparator
- nontransgenic Petite Havanae6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Genetically Modified Tobacco”
e5“Genetic engineering tobacco for PA caused reduced leaf area in plants”
e6“gravimetric soil water use was compared between nontransgenic Petite Havana and PA plants at button growth stage”
Claim · model-written summary
Transpiration was significantly higher in nontransgenic plants.
- Taxon
- tobaccoNicotiana tabacumt0
- Material
- nontransgenic plantse7
- Outcome
- Transpiratione7
- Direction
- highere7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Genetically Modified Tobacco”
e7“Transpiration was significantly higher with nontransgenic plants”
Claim · model-written summary
The authors suggest that lower irrigation rates may be needed for antigen tobacco.
- Taxon
- tobaccoNicotiana tabacumt0
- Outcome
- lower irrigation ratese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Genetically Modified Tobacco”
e0“indicating that lower irrigation rates may be needed for antigen tobacco”
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See all 21 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.