Abstract
Indole-3-acetic acid was observed to bring about a prompt and marked increase in the amount of 14C accumulated by segments of sunflower hypocotyl from solutions of labelled glutamic acid, glycine, and lysine. The curve relating magnitude of effect to indole-3-acetic acid concentration followed the comparable curves for water uptake and extension growth. The accumulation of 14C was related to the external concentration of glutamic acid by a curve which departed only slightly from linearity. The percentage increase in 14C accumulation brought about by auxin did not decline to any appreciable extent with increasing external concentration of glutamic acid. Under nitrogen the amount of 14C taken up from solutions of labelled glutamic acid in 1·75 hour was cut down by approximately one-third, and the auxin effect was abolished. The Q10 for 14C accumulation between 16° C. and 26° C. was 1·2 in the absence of indole-3-acetic acid, and was 1·3 in its presence. When net water uptake was eliminated by the addition of mannitol to the external solution, 14C accumulation in auxin-free media was not depressed. The percentage increase in 14C accumulation brought about by auxin, however, was markedly reduced. The fate of the 14C accumulated was investigated by means of chromatography on resin columns and on filter paper. About 30–40 percent, of the 14C was in the form of glutamic acid after approximately a hours' treatment. No marked difference in the level of glutamic acid was observed between auxin-treated and control segments. The effect of auxin was more evident on the amounts of other radioactive derivatives, as yet unidentified. It was observed that, not only was the amount of CO2 evolved in respiration higher in the presence of indole-3-acetic acid, but that this CO2 was richer in 14C, i.e. in auxin-treated tissue glutamic acid formed a larger proportion of the substrate respired. The possible implications of these observations are discussed. It is pointed out that indole-3-acetic acid may have achieved its effect by stimulating a transfer process, by lessening a diffusion resistance, or by promoting a process or processes which, by removing free amino-acids within the cell, maintain an inward diffusion gradient.
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Claims 16
Claim · model-written summary
Indole-3-acetic acid promptly increased 14C accumulation from labeled amino-acid solutions.
- Taxon
- sunflower
Helianthus annuuse0 - Organ / stage
- hypocotyle0
- Treatment
- Indole-3-acetic acide0
- Outcome
- amount of 14C accumulatede0
- Direction
- increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Indole-3-acetic acid was observed to bring about a prompt and marked increase in the amount of 14C accumulated by segments of sunflower hypocotyl from solutions of labelled glutamic acid, glycine, and lysine.”
Claim · model-written summary
The concentration-response curve for auxin effect followed those for water uptake and extension growth.
- Taxon
- Helianthus annuusHelianthus annuust0
- Treatment
- indole-3-acetic acide0
- Outcome
- curve relating magnitude of effecte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The curve relating magnitude of effect to indole-3-acetic acid concentration followed the comparable curves for water uptake and extension growth.”
t0“Helianthus annuus”
Claim · model-written summary
14C accumulation rose nearly linearly with external glutamic-acid concentration.
- Taxon
- Helianthus annuusHelianthus annuust0
- Compound
- glutamic acide0
- Outcome
- accumulation of 14Ce0
- Direction
- relatede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The accumulation of 14C was related to the external concentration of glutamic acid by a curve which departed only slightly from linearity.”
t0“Helianthus annuus”
Claim · model-written summary
The auxin-induced percentage increase in accumulation did not appreciably decline as external glutamic acid increased.
- Taxon
- Helianthus annuusHelianthus annuust0
- Compound
- glutamic acide0
- Outcome
- percentage increase in 14C accumulatione0
- Direction
- did not declinee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The percentage increase in 14C accumulation brought about by auxin did not decline to any appreciable extent with increasing external concentration of glutamic acid.”
t0“Helianthus annuus”
Claim · model-written summary
Nitrogen reduced labeled glutamic-acid uptake by about one-third in 1.75 hours.
- Taxon
- Helianthus annuusHelianthus annuust0
- Treatment
- nitrogene0
- Outcome
- amount of 14C taken upe0
- Direction
- cut downe0
- Value
- approximately one-thirde0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under nitrogen the amount of 14C taken up from solutions of labelled glutamic acid in 1·75 hour was cut down by approximately one-third, and the auxin effect was abolished.”
t0“Helianthus annuus”
Claim · model-written summary
Nitrogen abolished the auxin effect on uptake.
- Taxon
- Helianthus annuusHelianthus annuust0
- Treatment
- nitrogene0
- Outcome
- auxin effecte0
- Direction
- abolishede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under nitrogen the amount of 14C taken up from solutions of labelled glutamic acid in 1·75 hour was cut down by approximately one-third, and the auxin effect was abolished.”
t0“Helianthus annuus”
Claim · model-written summary
The Q10 of accumulation was 1.2 without auxin.
- Taxon
- Helianthus annuusHelianthus annuust0
- Outcome
- Q10 for 14C accumulatione0
- Value
- 1·2e0
- Qualifier
- in the absence of indole-3-acetic acide0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The Q10 for 14C accumulation between 16° C. and 26° C. was 1·2 in the absence of indole-3-acetic acid, and was 1·3 in its presence.”
t0“Helianthus annuus”
Claim · model-written summary
The Q10 of accumulation was 1.3 with auxin.
- Taxon
- Helianthus annuusHelianthus annuust0
- Outcome
- Q10 for 14C accumulatione0
- Value
- 1·3e0
- Qualifier
- in its presencee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The Q10 for 14C accumulation between 16° C. and 26° C. was 1·2 in the absence of indole-3-acetic acid, and was 1·3 in its presence.”
t0“Helianthus annuus”
Claim · model-written summary
Mannitol elimination of net water uptake did not depress accumulation without auxin.
- Taxon
- Helianthus annuusHelianthus annuust0
- Treatment
- addition of mannitole0
- Outcome
- 14C accumulatione0
- Direction
- not depressede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“When net water uptake was eliminated by the addition of mannitol to the external solution, 14C accumulation in auxin-free media was not depressed.”
t0“Helianthus annuus”
Claim · model-written summary
Mannitol markedly reduced the auxin-induced increase in accumulation.
- Taxon
- Helianthus annuusHelianthus annuust0
- Outcome
- percentage increase in 14C accumulatione0
- Direction
- reducede0
Not reportedTreatmentComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The percentage increase in 14C accumulation brought about by auxin, however, was markedly reduced.”
t0“Helianthus annuus”
Claim · model-written summary
About 30–40 percent of accumulated label was glutamic acid after treatment.
- Taxon
- Helianthus annuusHelianthus annuust0
- Outcome
- 14C was in the form of glutamic acide0
- Value
- 30–40 percente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“About 30–40 percent, of the 14C was in the form of glutamic acid after approximately a hours' treatment.”
t0“Helianthus annuus”
Claim · model-written summary
Glutamic-acid level showed no marked difference between auxin-treated and controls.
- Taxon
- Helianthus annuusHelianthus annuust0
- Treatment
- auxin-treatede0
- Outcome
- level of glutamic acide0
- Direction
- No marked differencee0
- Comparator
- control segmentse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“No marked difference in the level of glutamic acid was observed between auxin-treated and control segments.”
t0“Helianthus annuus”
Claim · model-written summary
Auxin affected amounts of other unidentified radioactive derivatives more evidently.
- Taxon
- Helianthus annuusHelianthus annuust0
- Treatment
- auxine0
- Outcome
- amounts of other radioactive derivativese0
- Direction
- more evidente0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The effect of auxin was more evident on the amounts of other radioactive derivatives, as yet unidentified.”
t0“Helianthus annuus”
Claim · model-written summary
Auxin increased respiratory CO2 evolution.
- Taxon
- Helianthus annuusHelianthus annuust0
- Treatment
- indole-3-acetic acide0
- Outcome
- amount of CO2 evolved in respiratione0
- Direction
- highere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the amount of CO2 evolved in respiration higher in the presence of indole-3-acetic acid”
t0“Helianthus annuus”
Claim · model-written summary
Respiratory CO2 was richer in 14C with auxin.
- Taxon
- Helianthus annuusHelianthus annuust0
- Treatment
- auxin-treatede0
- Outcome
- CO2 was richer in 14Ce0
- Direction
- richere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“this CO2 was richer in 14C, i.e. in auxin-treated tissue glutamic acid formed a larger proportion of the substrate respired.”
t0“Helianthus annuus”
Claim · model-written summary
The authors propose transport or diffusion mechanisms for the auxin effect.
- Taxon
- Helianthus annuusHelianthus annuust0
- Treatment
- indole-3-acetic acide0
- Outcome
- its effecte0
- Qualifier
- stimulating a transfer processe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“indole-3-acetic acid may have achieved its effect by stimulating a transfer process, by lessening a diffusion resistance, or by promoting a process or processes which, by removing free amino-acids within the cell, maintain an inward diffusion gradient.”
t0“Helianthus annuus”
The same questions in other papers
nitrogen · physiology: hormones · Helianthus annuus (common sunflower)Positive and negative results
3 in the opposite direction
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class · molecular: metabolites · Helianthus annuus (common sunflower)Positive and negative results
4 in the opposite direction
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1 paper more in this group
See all 5 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.