Abstract
1. High- and low-nitrogen soybean plants grown in nutrient solutions were treated by introduction of sodium 2,4-dichlorophenoxyacetate (2,4-D) in the nutrient solutions at a concentration of 4 p.p.m. of the acid equivalent. After exposure to 2,4-D for 22-23 hours the plants were placed in newly prepared solutions similar to those used before the treatment. Harvests were made at the start of 2,4-D treatment and 1, 4, and 7 days later. Plants of each group were divided into leaf, stem and petiole, and root fractions, and fresh and dry weights of each fraction were taken. Analyses for total, soluble, amide, alpha-amino, ammonium, and nitrate nitrogen were made on the tissue of each fraction. Changes in distribution of the different forms of nitrogen in the organs following treatment were similar for both high-N and low-N plants. For brevity, the nitrogen analyses for the high-N plants only are reported. 2. Twisting of stem tips and epinasty of petioles, later followed by yellowing of leaves and swelling of stems and petiole bases, and ultimately by wilting and drying of leaves, were visible responses to 2,4-D treatment and appeared sooner in high-N than in low-N plants. 3. Neither high-N nor low-N plants showed any appreciable change in total dry weight after exposure to 2,4-D, in contrast with respective untreated control plants which continued to accumulate dry matter. 4. By the end of the 23-hour period following the start of exposure to 2,4-D, the percentage dry matter of leaves of treated plants was very significantly less than that of corresponding controls. Some days later, however, leaves of the treated plants wilted and showed a much higher percentage of dry matter. Possible factors affecting the water relations of the treated plants have been mentioned. 5. Treatment with 2,4-D apparently changed the absorbing capacity of roots as indicated by failure of treated plants to increase their content of total nitrogen, including nitrates, after exposure to 2,4-D. 6. Plants treated with 2,4-D showed a decrease in the percentage of protein nitrogen in the leaves and an increase in the concentration of this fraction in stems and roots as compared with untreated controls. At the same time, all organs of treated plants showed increases in soluble organic nitrogen fractions, particularly in undetermined forms classed as residual soluble organic nitrogen, over corresponding controls. Apparently some of the protein in the leaves of treated plants was hydrolyzed, and the products were translocated to the stems and roots where more protein was resynthesized. These results suggest that 2,4-D may affect proteolytic enzymes differently in leaves than in stems or roots.
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Claims 12
Claim · model-written summary
Nitrogen form redistribution after treatment was similar at high and low nitrogen.
- Taxon
- Soybean Plants
Glycine maxt0 - Outcome
- Changes in distribution of the different forms of nitrogene0
- Direction
- similare0
- Comparator
- high-N and low-N plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Changes in distribution of the different forms of nitrogen in the organs following treatment were similar for both high-N and low-N plants”
t0“Soybean Plants”
Claim · model-written summary
2,4-D caused sequential stem and petiole deformation, leaf yellowing and swelling, then wilting and drying.
- Taxon
- Soybean PlantsGlycine maxt0
- Treatment
- 2,4-D treatmente0
- Outcome
- Twisting of stem tips and epinasty of petioles, later followed by yellowing of leaves and swelling of stems and petiole bases, and ultimately by wilting and drying of leavese0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Twisting of stem tips and epinasty of petioles, later followed by yellowing of leaves and swelling of stems and petiole bases, and ultimately by wilting and drying of leaves, were visible responses to 2,4-D treatment and appeared sooner in high-N than in low-N plants.”
t0“Soybean Plants”
Claim · model-written summary
Visible responses to 2,4-D appeared sooner in high nitrogen plants.
- Taxon
- Soybean PlantsGlycine maxt0
- Material
- high-Ne0
- Outcome
- visible responsese0
- Direction
- soonere0
- Comparator
- low-N plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Twisting of stem tips and epinasty of petioles, later followed by yellowing of leaves and swelling of stems and petiole bases, and ultimately by wilting and drying of leaves, were visible responses to 2,4-D treatment and appeared sooner in high-N than in low-N plants.”
t0“Soybean Plants”
Claim · model-written summary
2,4-D-treated plants at both nitrogen levels did not appreciably gain dry weight, while controls accumulated dry matter.
- Taxon
- Soybean PlantsGlycine maxt0
- Treatment
- 2,4-De0
- Outcome
- total dry weighte0
- Direction
- Neither high-N nor low-N plants showed any appreciable changee0
- Comparator
- untreated control plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Neither high-N nor low-N plants showed any appreciable change in total dry weight after exposure to 2,4-D, in contrast with respective untreated control plants which continued to accumulate dry matter.”
t0“Soybean Plants”
Claim · model-written summary
Treated leaves had significantly less dry matter than controls after 23 hours.
- Taxon
- Soybean PlantsGlycine maxt0
- Organ / stage
- leavese0
- Treatment
- treated plantse0
- Outcome
- percentage dry mattere0
- Direction
- lesse0
- Comparator
- corresponding controlse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the percentage dry matter of leaves of treated plants was very significantly less than that of corresponding controls”
t0“Soybean Plants”
Claim · model-written summary
Treated leaves subsequently wilted and had a much higher dry matter percentage.
- Taxon
- Soybean PlantsGlycine maxt0
- Organ / stage
- leavese0
- Outcome
- percentage of dry mattere0
- Direction
- highere0
- Qualifier
- Some days latere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Some days later, however, leaves of the treated plants wilted and showed a much higher percentage of dry matter.”
t0“Soybean Plants”
Claim · model-written summary
2,4-D-treated plants failed to increase total nitrogen including nitrate, suggesting altered root absorption.
- Taxon
- Soybean PlantsGlycine maxt0
- Organ / stage
- rootse0
- Treatment
- 2,4-De0
- Outcome
- content of total nitrogen, including nitratese0
- Direction
- failure of treated plants to increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Treatment with 2,4-D apparently changed the absorbing capacity of roots as indicated by failure of treated plants to increase their content of total nitrogen, including nitrates, after exposure to 2,4-D.”
t0“Soybean Plants”
Claim · model-written summary
2,4-D caused a decrease in protein nitrogen in leaves versus controls.
- Taxon
- Soybean PlantsGlycine maxt0
- Organ / stage
- leavese0
- Treatment
- 2,4-De0
- Outcome
- protein nitrogene0
- Direction
- decreasee0
- Comparator
- untreated controlse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Plants treated with 2,4-D showed a decrease in the percentage of protein nitrogen in the leaves and an increase in the concentration of this fraction in stems and roots as compared with untreated controls.”
t0“Soybean Plants”
Claim · model-written summary
2,4-D caused a increase in protein nitrogen in stems and roots versus controls.
- Taxon
- Soybean PlantsGlycine maxt0
- Organ / stage
- stems and rootse0
- Treatment
- 2,4-De0
- Outcome
- protein nitrogene0
- Direction
- increasee0
- Comparator
- untreated controlse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Plants treated with 2,4-D showed a decrease in the percentage of protein nitrogen in the leaves and an increase in the concentration of this fraction in stems and roots as compared with untreated controls.”
t0“Soybean Plants”
Claim · model-written summary
2,4-D increased soluble organic nitrogen fractions in all organs relative to controls.
- Taxon
- Soybean PlantsGlycine maxt0
- Organ / stage
- all organse0
- Treatment
- treated plantse0
- Outcome
- soluble organic nitrogen fractionse0
- Direction
- increasese0
- Comparator
- corresponding controlse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“all organs of treated plants showed increases in soluble organic nitrogen fractions, particularly in undetermined forms classed as residual soluble organic nitrogen, over corresponding controls.”
t0“Soybean Plants”
Claim · model-written summary
The authors inferred leaf protein hydrolysis and translocation to stems and roots for protein resynthesis.
- Taxon
- Soybean PlantsGlycine maxt0
- Organ / stage
- leavese0
- Outcome
- proteine0
- Qualifier
- translocated to the stems and rootse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Apparently some of the protein in the leaves of treated plants was hydrolyzed, and the products were translocated to the stems and roots where more protein was resynthesized.”
t0“Soybean Plants”
Claim · model-written summary
2,4-D may act differently on proteolytic enzymes among leaves, stems and roots.
- Taxon
- Soybean PlantsGlycine maxt0
- Organ / stage
- leavese0
- Treatment
- 2,4-De0
- Gene
- proteolytic enzymese0
- Outcome
- proteolytic enzymese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“These results suggest that 2,4-D may affect proteolytic enzymes differently in leaves than in stems or roots.”
t0“Soybean Plants”
The same questions in other papers
2,4-D · growth · Glycine max (soybean)Results differ
14 papers in the same direction as this paper · 20 in the opposite direction
- positive
- positive
- positive
31 papers more in this group
See all 35 papers →2,4-D · disease · Glycine max (soybean)Positive and negative results
1 paper in the same direction as this paper · 2 in the opposite direction
- positive
- positive
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2,4-D · quality: protein · Glycine max (soybean)Results agree
1 paper in the same direction as this paper
- negative
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.