Abstract
Abstract According to Thornley, J.H.M. (Nature, 227, 304-305, 1970) and McCree, K.J. (Crop Sci., 14, 509-514, 1974), respiratory substances are used only for maintenance respiration when plants are exposed to the dark conditions for a long period of time (more than 2 d). The maintenance respiration is also affected by the nitrogen status in plant, because protein turnover is one of the major energy consumption sources under maintenance process. Therefore, to determine whether respiratory substances are used only for maintenance, 14C- [U] -sucrose or a mixture of 14C- [U] -amino acids was introduced to rice and soybean plants from the tip of leaf. Plants were grown under natural light conditions and under dark conditions for 4 d with 2 nitrogen levels (0.2 and 0.02 g N L-1 soil). After the introduction of the 14C-compounds, the 14CO2 respiratory rate was monitored during 24 h, then the 14C distribution to organic acids, free amino acids, proteins, sugars, and polysaccharides was analyzed. Following results were obtained. 1. When 14C-[U]-sucrose or a mixture of 14C-[U]-amino acids was introduced to the leaf of rice and soybean plants, the 14C release rate by respiration was not affected by the nitrogen and light treatments except when 14C-sucrose was introduced to soybean in the low N plot. The 14C release rate from the 14C-compounds introduced into leaf in the low N plot of soybean was higher in the dark treatment than in the natural light treatment.2. 14C-distribution ratio after introduction of 14C-sucrose and a mixture of 14C-amino acids to the leaf was not significantly affected by the nitrogen treatment. When 14C-sucrose was introduced to rice leaf, the 14C-distribution ratio to sugars and proteins was higher and that to polysaccharides was lower in the natural light treatment than in the dark treatment. The 14C-distribution ratio was less aifected by the light or nitrogen treatment in case of soybean leaf.3. Although it was assumed that maintenance metabolism was dominant in the lower leaf (counted from the bottom), the 14C-distribution ratio was similar to that of upper leaf.4. Nitrogen content of leaf was not different between rice and soybean in the high N treatment, unlike the 14C-distribution ratio. In rice, the nitrogen content of leaf was about twice as high in the high N treatment compared with the low N treatment, while the 14C-distribution ratio in leaf was stable regardless of nitrogen treatment. Based on the above results, it is suggested that since the 14C-distribution ratio into each chemical component did not change regardless of light treatment, nitrogen treatment, or leaf age, It was impossible to separate respiration into two components, such as growth and maintenance respiration. The results also indicated that current photosynthates and storage substances were not used only for growth and maintenance, respectively.
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Claims 12
Claim · model-written summary
Nitrogen and light generally did not affect tracer respiratory release in rice and soybean.
- Taxon
- rice and soybean plants
Glycine max
Oryza sativae1 - Treatment
- nitrogen and light treatmentse0
- Outcome
- 14C release rate by respiratione0
- Direction
- not affectede0
- Qualifier
- except when 14C-sucrose was introduced to soybean in the low N plote0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the 14C release rate by respiration was not affected by the nitrogen and light treatments except when 14C-sucrose was introduced to soybean in the low N plot.”
e1“introduced to rice and soybean plants from the tip of leaf”
Claim · model-written summary
Soybean low-N tracer release was higher in darkness than natural light.
- Taxon
- soybeanGlycine maxe0
- Treatment
- dark treatmente0
- Outcome
- 14C release ratee0
- Direction
- highere0
- Qualifier
- low N plote0
- Comparator
- natural light treatmente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The 14C release rate from the 14C-compounds introduced into leaf in the low N plot of soybean was higher in the dark treatment than in the natural light treatment.”
Claim · model-written summary
Nitrogen treatment did not significantly affect tracer distribution.
- Taxon
- rice and soybean plantsGlycine maxOryza sativae1
- Treatment
- nitrogen treatmente0
- Outcome
- 14C-distribution ratioe0
- Direction
- not significantly affectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“14C-distribution ratio after introduction of 14C-sucrose and a mixture of 14C-amino acids to the leaf was not significantly affected by the nitrogen treatment.”
e1“introduced to rice and soybean plants from the tip of leaf”
Claim · model-written summary
In rice, natural light raised tracer allocation to sugars and proteins relative to darkness.
- Taxon
- riceOryza sativae0
- Treatment
- natural light treatmente0
- Outcome
- 14C-distribution ratio to sugars and proteinse0
- Direction
- highere0
- Comparator
- dark treatmente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“When 14C-sucrose was introduced to rice leaf, the 14C-distribution ratio to sugars and proteins was higher and that to polysaccharides was lower in the natural light treatment than in the dark treatment.”
Claim · model-written summary
In rice, natural light lowered tracer allocation to polysaccharides relative to darkness.
- Taxon
- riceOryza sativae0
- Treatment
- natural light treatmente0
- Outcome
- that to polysaccharidese0
- Direction
- lowere0
- Comparator
- dark treatmente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“When 14C-sucrose was introduced to rice leaf, the 14C-distribution ratio to sugars and proteins was higher and that to polysaccharides was lower in the natural light treatment than in the dark treatment.”
Claim · model-written summary
Soybean tracer distribution was less affected by light or nitrogen.
- Taxon
- soybeanGlycine maxe0
- Treatment
- light or nitrogen treatmente0
- Outcome
- 14C-distribution ratioe0
- Direction
- less aifectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The 14C-distribution ratio was less aifected by the light or nitrogen treatment in case of soybean leaf.”
Claim · model-written summary
Lower and upper leaves had similar tracer distribution.
- Taxon
- rice and soybean plantsGlycine maxOryza sativae2
- Organ / stage
- lower leafe1
- Outcome
- 14C-distribution ratioe0
- Direction
- similare0
- Comparator
- upper leafe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the 14C-distribution ratio was similar to that of upper leaf.”
e1“maintenance metabolism was dominant in the lower leaf”
e2“introduced to rice and soybean plants from the tip of leaf”
Claim · model-written summary
At high nitrogen, rice and soybean leaves did not differ in nitrogen content.
- Taxon
- rice and soybeanGlycine maxOryza sativae0
- Outcome
- Nitrogen content of leafe0
- Direction
- not differente0
- Qualifier
- high N treatmente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nitrogen content of leaf was not different between rice and soybean in the high N treatment”
Claim · model-written summary
Rice leaf nitrogen content was about twice as high at high versus low nitrogen.
- Taxon
- riceOryza sativae0
- Treatment
- high N treatmente0
- Outcome
- nitrogen content of leafe0
- Direction
- as highe0
- Value
- about twicee0
- Comparator
- low N treatmente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In rice, the nitrogen content of leaf was about twice as high in the high N treatment compared with the low N treatment”
Claim · model-written summary
Rice leaf tracer distribution remained stable across nitrogen treatments.
- Taxon
- riceOryza sativae1
- Treatment
- nitrogen treatmente0
- Outcome
- 14C-distribution ratio in leafe0
- Direction
- stablee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the 14C-distribution ratio in leaf was stable regardless of nitrogen treatment.”
e1“In rice, the nitrogen content of leaf”
Claim · model-written summary
Authors concluded growth and maintenance respiration could not be separated using tracer allocation.
- Taxon
- rice and soybean plantsGlycine maxOryza sativae1
- Outcome
- impossible to separate respiration into two componentse0
- Qualifier
- 14C-distribution ratio into each chemical component did not changee2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“It was impossible to separate respiration into two components, such as growth and maintenance respiration.”
e1“introduced to rice and soybean plants from the tip of leaf”
e2“14C-distribution ratio into each chemical component did not change regardless of light treatment, nitrogen treatment, or leaf age”
Claim · model-written summary
Current photosynthates and storage substances were not restricted to growth and maintenance, respectively.
- Taxon
- rice and soybean plantsGlycine maxOryza sativae1
- Outcome
- current photosynthates and storage substances were not used only for growth and maintenance, respectivelye0
- Qualifier
- growth and maintenancee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“current photosynthates and storage substances were not used only for growth and maintenance, respectively.”
e1“introduced to rice and soybean plants from the tip of leaf”
The same questions in other papers
light · physiology: respiration · Oryza sativa (rice)Positive and negative results
1 paper in the same direction as this paper · 1 in the opposite direction
- positive
- negative
light · physiology: respiration · Glycine max (soybean)Positive and negative results
2 papers in the same direction as this paper · 1 in the opposite direction
- positive
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- no effect
nitrogen · physiology: respiration · Glycine max (soybean)Positive and negative results
2 papers in the same direction as this paper · 1 in the opposite direction
- positive
- negative
- negative
nitrogen · physiology: respiration · Oryza sativa (rice)Positive and negative results
4 papers in the same direction as this paper · 2 in the opposite direction
- positive
- positive
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3 papers more in this group
See all 7 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.