Abstract
Plant allocation to defensive compounds in response to growth in elevated atmospheric CO(2) in combination with two levels of nitrogen was examined. The aim was to discover if allocation patterns of transgenic plants containing genes for defensive chemicals which had not evolved in the species would respond as predicted by the Carbon Nutrient Balance (CNB) hypothesis. Cotton plants (Gossypium hirsutum L.) were sown inside 12 environmental chambers. Six of them were maintained at an elevated CO(2) level of 900 micromol mol(-1) and the other six at the current level of approximately 370 micromol mol(-1). Half the plants in each chamber were from a transgenic line producing Bacillus thuringiensis (Bt) toxin and the others were from a near isogenic line without the Bt gene. The allocation to total phenolics, condensed tannins, and gossypol and related terpenoid aldehydes was measured. All the treatments were bioassayed against a non-target insect herbivore found on cotton, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae). Plants had lower N concentrations and higher C:N ratios when grown in elevated CO(2). Carbon defensive compounds increased in elevated CO(2), low N availability or both. The increase in these compounds in elevated CO(2) and low N, adversely affected growth and survival of S. exigua. The production of the nitrogen-based toxin was affected by an interaction between CO(2) and N; elevated CO(2) decreased N allocation to Bt, but the reduction was largely alleviated by the addition of nitrogen. The CNB hypothesis accurately predicted only some of the results, and may require revision. These data indicate that for the future expected elevated CO(2) concentrations, plant allocation to defensive compounds will be affected enough to impact plant-herbivore interactions.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 9
Claim · model-written summary
Elevated CO2 lowered cotton nitrogen concentration.
- Taxon
- cotton plants
Gossypium hirsutumt0 - Treatment
- elevated CO(2)e0
- Outcome
- N concentrationse0
- Direction
- lowere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Plants had lower N concentrations and higher C:N ratios when grown in elevated CO(2).”
t0“cotton plants”
Claim · model-written summary
Elevated CO2 raised the cotton carbon to nitrogen ratio.
- Taxon
- cotton plantsGossypium hirsutumt0
- Treatment
- elevated CO(2)e0
- Outcome
- C:N ratiose0
- Direction
- highere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Plants had lower N concentrations and higher C:N ratios when grown in elevated CO(2).”
t0“cotton plants”
Claim · model-written summary
Elevated CO2, low nitrogen, or both increased carbon defensive compounds in cotton.
- Taxon
- cotton plantsGossypium hirsutumt0
- Treatment
- elevated CO(2), low N availability or bothe0
- Outcome
- Carbon defensive compoundse0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Carbon defensive compounds increased in elevated CO(2), low N availability or both.”
t0“cotton plants”
Claim · model-written summary
Cotton defenses under elevated CO2 and low nitrogen adversely affected Spodoptera exigua growth.
- Taxon
- cotton plantsGossypium hirsutumt0
- Treatment
- elevated CO(2) and low Ne0
- Interactor
- Spodoptera exigua
Spodoptera exiguae1herbivore - Outcome
- growth and survival of S. exiguae0
- Direction
- adversely affectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The increase in these compounds in elevated CO(2) and low N, adversely affected growth and survival of S. exigua.”
e1“Spodoptera exigua (Hübner)”
t0“cotton plants”
Claim · model-written summary
Elevated CO2 decreased cotton nitrogen allocation to Bt toxin.
- Taxon
- cotton plantsGossypium hirsutumt0
- Treatment
- elevated CO(2)e0
- Outcome
- N allocation to Bte0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“elevated CO(2) decreased N allocation to Bt”
t0“cotton plants”
Claim · model-written summary
Added nitrogen largely alleviated the elevated CO2 reduction in cotton nitrogen allocation to Bt.
- Taxon
- cotton plantsGossypium hirsutumt0
- Treatment
- addition of nitrogene0
- Outcome
- N allocation to Bte1
- Direction
- alleviatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the reduction was largely alleviated by the addition of nitrogen”
e1“elevated CO(2) decreased N allocation to Bt”
t0“cotton plants”
Claim · model-written summary
The CNB hypothesis predicted only some cotton defense results.
- Taxon
- cotton plantsGossypium hirsutumt0
- Outcome
- accurately predicted only some of the resultse0
- Comparator
- CNB hypothesise0
Not reportedValue
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The CNB hypothesis accurately predicted only some of the results”
t0“cotton plants”
Claim · model-written summary
The authors suggest that the CNB hypothesis may require revision.
- Taxon
- cotton plantsGossypium hirsutumt0
- Outcome
- may require revisione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The CNB hypothesis accurately predicted only some of the results, and may require revision.”
t0“cotton plants”
Claim · model-written summary
The authors expect future elevated CO2 to affect cotton defensive allocation enough to affect plant herbivore interactions.
- Taxon
- cotton plantsGossypium hirsutumt0
- Treatment
- elevated CO(2) concentrationse0
- Outcome
- plant-herbivore interactionse0
- Qualifier
- future expectede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“for the future expected elevated CO(2) concentrations, plant allocation to defensive compounds will be affected enough to impact plant-herbivore interactions”
t0“cotton plants”
The same questions in other papers
co2 · Spodoptera exigua · Gossypium hirsutum (cotton)Positive and negative results
1 in the opposite direction
- negative
co2 · molecular: metabolites · Gossypium hirsutum (cotton)Positive and negative results
2 papers in the same direction as this paper · 1 in the opposite direction
- negative
- positive
- positive
nitrogen · molecular: metabolites · Gossypium hirsutum (cotton)Positive and negative results
1 paper in the same direction as this paper · 12 in the opposite direction
This paper is about lacking the nutrient, so it counts the other way round here.
- positive
- positive
- positive
10 papers more in this group
See all 14 papers →co2 · nutrient: content · Gossypium hirsutum (cotton)Positive and negative results
7 papers in the same direction as this paper · 6 in the opposite direction
- negative
- positive
- positive
10 papers more in this group
See all 14 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.