Abstract
Seedlings of barley ( Hordeum vulgare L. cv. Agneta) were grown hydroponically under continuous light, constant temperature and relative humidity. During the first two weeks, the relative growth rate (RGR) was kept at 25% by limiting only the supply of nitrogen. The cultures were then transferred to nitrogen‐free media and the amounts of fructan, starch, sucrose, glucose and fructose in sink and source leaves were measured at 0, 12, 24, 48, 72, 120 and 156 h. The activities of two key enzymes in fructan metabolism, sucrose:sucrose fructosyltransferase (SST), fructan exohydrolase (FEH), as well as acid invertase were also measured in the two types of leaves. The fructan and starch levels in both sink and source leaves increased during nitrogen deficiency. The highest increase in starch was 200% of the control while for fmctans a 700% increase was recorded. The activity of SST increased parallel to fructan accumulation in sink leaves. However the FEH activity was constant and not affected by nitrogen deficiency. The invertase activity both in sink and source leaves was reduced by nitrogen deficiency. More fructans as well as sucrose and fructose accumulated in source leaves compared to sink leaves both before and after nitrogen starvation. The results show that fructan is the major carbohydrate reserve accumulating under nitrogen deficiency both in sink and source leaves in barley plants. The induction of fructan accumulation in sink leaves caused by nitrogen deficiency is intimately connected with the regulation of SST
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Claims 8
Claim · model-written summary
Nitrogen deficiency increased fructan in sink and source leaves by up to 700%.
- Taxon
- barley
.jpg?width=60)
Hordeum vulgaret0 - Organ / stage
- sink and source leavese0
- Treatment
- nitrogen deficiencye0
- Outcome
- fructane0
- Direction
- increasede0
- Value
- 700%e0
- Comparator
- controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“The fructan and starch levels in both sink and source leaves increased during nitrogen deficiency. The highest increase in starch was 200% of the control while for fmctans a 700% increase was recorded.”
t0“Effects of nitrogen deficiency on accumulation of fructan and fructan metabolizing enzyme activities in sink and source leaves of barley (Hordeum vulgare)”
t1“Effects of nitrogen deficiency on accumulation of fructan and fructan metabolizing enzyme activities in sink and source leaves of barley (Hordeum vulgare)”
Claim · model-written summary
Nitrogen deficiency increased leaf starch by up to 200% of control.
- Taxon
- barleyHordeum vulgaret0
- Organ / stage
- sink and source leavese0
- Treatment
- nitrogen deficiencye0
- Outcome
- starche0
- Direction
- increasede0
- Value
- 200%e0
- Comparator
- controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The fructan and starch levels in both sink and source leaves increased during nitrogen deficiency. The highest increase in starch was 200% of the control”
t0“Effects of nitrogen deficiency on accumulation of fructan and fructan metabolizing enzyme activities in sink and source leaves of barley (Hordeum vulgare)”
t1“Effects of nitrogen deficiency on accumulation of fructan and fructan metabolizing enzyme activities in sink and source leaves of barley (Hordeum vulgare)”
Claim · model-written summary
SST activity increased with fructan accumulation in sink leaves.
- Taxon
- barleyHordeum vulgaret0
- Organ / stage
- sink leavese0
- Gene
- SSTe0
- Outcome
- activity of SSTe0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The activity of SST increased parallel to fructan accumulation in sink leaves.”
t0“Effects of nitrogen deficiency on accumulation of fructan and fructan metabolizing enzyme activities in sink and source leaves of barley (Hordeum vulgare)”
t1“Effects of nitrogen deficiency on accumulation of fructan and fructan metabolizing enzyme activities in sink and source leaves of barley (Hordeum vulgare)”
Claim · model-written summary
FEH activity remained constant during nitrogen deficiency.
- Taxon
- barleyHordeum vulgaret0
- Treatment
- nitrogen deficiencye0
- Gene
- FEHe0
- Outcome
- FEH activitye0
- Direction
- constante0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the FEH activity was constant and not affected by nitrogen deficiency.”
t0“Effects of nitrogen deficiency on accumulation of fructan and fructan metabolizing enzyme activities in sink and source leaves of barley (Hordeum vulgare)”
t1“Effects of nitrogen deficiency on accumulation of fructan and fructan metabolizing enzyme activities in sink and source leaves of barley (Hordeum vulgare)”
Claim · model-written summary
Nitrogen deficiency reduced invertase activity in sink and source leaves.
- Taxon
- barleyHordeum vulgaret0
- Organ / stage
- sink and source leavese0
- Treatment
- nitrogen deficiencye0
- Outcome
- invertase activitye0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The invertase activity both in sink and source leaves was reduced by nitrogen deficiency.”
t0“Effects of nitrogen deficiency on accumulation of fructan and fructan metabolizing enzyme activities in sink and source leaves of barley (Hordeum vulgare)”
t1“Effects of nitrogen deficiency on accumulation of fructan and fructan metabolizing enzyme activities in sink and source leaves of barley (Hordeum vulgare)”
Claim · model-written summary
Source leaves accumulated more fructans, sucrose and fructose than sink leaves before and after nitrogen starvation.
- Taxon
- barleyHordeum vulgaret0
- Organ / stage
- source leavese0
- Outcome
- fructans as well as sucrose and fructosee0
- Direction
- Moree0
- Comparator
- sink leavese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“More fructans as well as sucrose and fructose accumulated in source leaves compared to sink leaves both before and after nitrogen starvation.”
t0“Effects of nitrogen deficiency on accumulation of fructan and fructan metabolizing enzyme activities in sink and source leaves of barley (Hordeum vulgare)”
t1“Effects of nitrogen deficiency on accumulation of fructan and fructan metabolizing enzyme activities in sink and source leaves of barley (Hordeum vulgare)”
Claim · model-written summary
The authors identify fructan as the main carbohydrate reserve during nitrogen deficiency.
- Taxon
- barleyHordeum vulgaree0
- Organ / stage
- sink and source leavese0
- Outcome
- fructan is the major carbohydrate reservee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“fructan is the major carbohydrate reserve accumulating under nitrogen deficiency both in sink and source leaves in barley plants.”
t0“Effects of nitrogen deficiency on accumulation of fructan and fructan metabolizing enzyme activities in sink and source leaves of barley (Hordeum vulgare)”
t1“Effects of nitrogen deficiency on accumulation of fructan and fructan metabolizing enzyme activities in sink and source leaves of barley (Hordeum vulgare)”
Claim · model-written summary
The authors link nitrogen-induced sink-leaf fructan accumulation to SST regulation.
- Taxon
- barleyHordeum vulgaret0
- Organ / stage
- sink leavese0
- Gene
- SSTe0
- Outcome
- fructan accumulatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The induction of fructan accumulation in sink leaves caused by nitrogen deficiency is intimately connected with the regulation of SST”
t0“Effects of nitrogen deficiency on accumulation of fructan and fructan metabolizing enzyme activities in sink and source leaves of barley (Hordeum vulgare)”
t1“Effects of nitrogen deficiency on accumulation of fructan and fructan metabolizing enzyme activities in sink and source leaves of barley (Hordeum vulgare)”
The same questions in other papers
nitrogen · quality: sugar starch · Hordeum vulgare (barley)Positive and negative results
2 papers in the same direction as this paper · 2 in the opposite direction
This paper is about lacking the nutrient, so it counts the other way round here.
- no effect
- positive
- positive
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See all 5 papers →nitrogen · molecular: metabolites · Hordeum vulgare (barley)Positive and negative results
15 papers in the same direction as this paper · 15 in the opposite direction
This paper is about lacking the nutrient, so it counts the other way round here.
- no effect
- positive
- positive
27 papers more in this group
See all 31 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.