Abstract
Light intensity and atmospheric CO2 partial pressure are two environmental signals known to regulate stomatal numbers. It has previously been shown that if a mature Arabidopsis leaf is supplied with either elevated CO2 (750 ppm instead of ambient at 370 ppm) or reduced light levels (50 micromol m-2 s-1 instead of 250 micromol m-2 s-1), the young, developing leaves that are not receiving the treatment grow with a stomatal density as if they were exposed to the treatment. But the signal(s) that it is believed is generated in the mature leaves and transmitted to developing leaves are largely unknown. Photosynthetic rates of treated, mature Arabidopsis leaves increased in elevated CO2 and decreased when shaded, as would be expected. Similarly, the levels of sugars (glucose, fructose, and sucrose) in the treated mature leaves increased in elevated CO2 and decreased with shade treatment. The levels of sugar in developing leaves were also measured and it was found that they mirrored this result even though they were not receiving the shade or elevated CO2 treatment. To investigate the effect of these treatments on global gene expression patterns, transcriptomics analysis was carried out using Affymetrix, 22K, and ATH1 arrays. Total RNA was extracted from the developing leaves after the mature leaves had received either the ambient control treatment, the elevated CO2 treatment, or the shade treatment, or both elevated CO2 and shade treatments for 2, 4, 12, 24, 48, or 96 h. The experiment was replicated four times. Two other experiments were also conducted, one to compare and contrast gene expression in response to plants grown at elevated CO2 and the other to look at the effect of these treatments on the mature leaf. The data were analysed and 915 genes from the untreated, signalled leaves were identified as having expression levels affected by the shade treatment. These genes were then compared with those whose transcript abundance was affected by the shade treatment in the mature treated leaves (1181 genes) and with 220 putative 'stomatal signalling' genes previously identified from studies of the yoda mutant. The results of these experiments and how they relate to environmental signalling are discussed, as well as possible mechanisms for systemic signalling.
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 7
Claim · model-written summary
Elevated CO2 increased photosynthesis in treated mature leaves.
- Taxon
- Arabidopsis
Arabidopsise0 - Organ / stage
- mature Arabidopsis leavese0
- Treatment
- elevated CO2e0
- Outcome
- Photosynthetic ratese0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Photosynthetic rates of treated, mature Arabidopsis leaves increased in elevated CO2”
Claim · model-written summary
Shade decreased photosynthesis in treated mature leaves.
- Taxon
- ArabidopsisArabidopsise0
- Organ / stage
- mature Arabidopsis leavese0
- Treatment
- shadede0
- Outcome
- Photosynthetic ratese0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Photosynthetic rates of treated, mature Arabidopsis leaves increased in elevated CO2 and decreased when shaded”
Claim · model-written summary
Elevated CO2 increased glucose, fructose and sucrose in mature leaves.
- Taxon
- ArabidopsisArabidopsist0
- Organ / stage
- mature leavese0
- Treatment
- elevated CO2e0
- Outcome
- levels of sugars (glucose, fructose, and sucrose)e0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the levels of sugars (glucose, fructose, and sucrose) in the treated mature leaves increased in elevated CO2”
t0“Arabidopsis leaves”
Claim · model-written summary
Shade decreased glucose, fructose and sucrose in mature leaves.
- Taxon
- ArabidopsisArabidopsist0
- Organ / stage
- mature leavese0
- Treatment
- shade treatmente0
- Outcome
- levels of sugars (glucose, fructose, and sucrose)e0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the levels of sugars (glucose, fructose, and sucrose) in the treated mature leaves increased in elevated CO2 and decreased with shade treatment”
t0“Arabidopsis leaves”
Claim · model-written summary
Developing leaf sugars mirrored mature-leaf sugar responses despite no direct treatment.
- Taxon
- ArabidopsisArabidopsist0
- Outcome
- levels of sugar in developing leavese0
- Direction
- mirrorede0
- Qualifier
- not receiving the shade or elevated CO2 treatmente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The levels of sugar in developing leaves were also measured and it was found that they mirrored this result even though they were not receiving the shade or elevated CO2 treatment.”
t0“Arabidopsis leaves”
Claim · model-written summary
Shade treatment affected expression of 915 genes in untreated developing leaves.
- Taxon
- ArabidopsisArabidopsist0
- Organ / stage
- untreated, signalled leavese0
- Treatment
- shade treatmente0
- Outcome
- expression levelse0
- Value
- 915 genese0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“915 genes from the untreated, signalled leaves were identified as having expression levels affected by the shade treatment.”
t0“Arabidopsis leaves”
Claim · model-written summary
Shade treatment affected transcript abundance of 1181 genes in mature treated leaves.
- Taxon
- ArabidopsisArabidopsist0
- Organ / stage
- mature treated leavese0
- Treatment
- shade treatmente0
- Outcome
- transcript abundancee0
- Value
- 1181 genese0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“transcript abundance was affected by the shade treatment in the mature treated leaves (1181 genes)”
t0“Arabidopsis leaves”
The same questions in other papers
co2 · physiology: photosynthesis · ArabidopsisPositive and negative results
3 papers in the same direction as this paper · 2 in the opposite direction
- negative
- negative
- positive
2 papers more in this group
See all 6 papers →co2 · molecular: metabolites · ArabidopsisResults agree
1 paper in the same direction as this paper
- positive
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.