Abstract
Spinach plants (Spinacia oleracea L.) were grown in hydroponic culture in a glasshouse under full sunlight. They were supplied with different concentrations of nitrate nitrogen in solution, ranging from 1 to 12 mM, in order to produce leaves with different nitrogen contents. Oxygen evolution at CO2 saturation was measured as a function of absorbed irradiance in leaf discs with an oxygen electrode. Electron transport activities, reaction centre densities, cytochrome f and plastoquinone contents, RuP2 carboxylase and coupling factor activities and soluble protein content were measured in similar material. Although nitrogen and chlorophyll contents per unit leaf area were reduced by 60% by nitrogen deficiency, when expressed on a chlorophyll basis, thylakoid components, electron transport activities and the rate of oxygen evolution at CO2 saturation were similar between nitrogen treatments. In contrast, the content of soluble protein and RuP2 carboxylase expressed on a chlorophyll basis was greater the greater the nitrogen content per unit leaf area. Therefore the ratio of RuP2 carboxylase activity to electron transport activity increased in leaves having greater nitrogen content.
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Claims 4
Claim · model-written summary
Nitrogen deficiency reduced nitrogen and chlorophyll contents per leaf area by 60%.
- Taxon
- Spinach
Spinacia oleraceat0 - Treatment
- nitrogen deficiencye0
- Outcome
- nitrogen and chlorophyll contents per unit leaf areae0
- Direction
- reducede0
- Value
- 60%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Although nitrogen and chlorophyll contents per unit leaf area were reduced by 60% by nitrogen deficiency”
t0“Spinach”
Claim · model-written summary
On a chlorophyll basis, thylakoid components, electron transport activities and CO2-saturated oxygen evolution were similar across nitrogen treatments.
- Taxon
- SpinachSpinacia oleraceat0
- Treatment
- nitrogen treatmentse0
- Outcome
- thylakoid components, electron transport activities and the rate of oxygen evolutione0
- Direction
- similare0
- Qualifier
- on a chlorophyll basise0
- Comparator
- nitrogen treatmentse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“when expressed on a chlorophyll basis, thylakoid components, electron transport activities and the rate of oxygen evolution at CO2 saturation were similar between nitrogen treatments.”
t0“Spinach”
Claim · model-written summary
Soluble protein and RuP2 carboxylase content per chlorophyll were greater with greater leaf nitrogen content.
- Taxon
- SpinachSpinacia oleraceat0
- Compound
- nitrogene0
- Outcome
- content of soluble protein and RuP2 carboxylasee0
- Direction
- greatere0
- Qualifier
- on a chlorophyll basise0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the content of soluble protein and RuP2 carboxylase expressed on a chlorophyll basis was greater the greater the nitrogen content per unit leaf area.”
t0“Spinach”
Claim · model-written summary
The ratio of RuP2 carboxylase to electron transport activity increased in leaves with greater nitrogen content.
- Taxon
- SpinachSpinacia oleraceat0
- Compound
- nitrogene0
- Outcome
- ratio of RuP2 carboxylase activity to electron transport activitye0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Therefore the ratio of RuP2 carboxylase activity to electron transport activity increased in leaves having greater nitrogen content.”
t0“Spinach”
The same questions in other papers
nitrogen · physiology: pigments · Spinacia oleracea (spinach)Results differ
15 papers in the same direction as this paper · 3 in the opposite direction
This paper is about lacking the nutrient, so it counts the other way round here.
- no effect
- negative
- negative
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See all 19 papers →nitrogen · physiology: photosynthesis · Spinacia oleracea (spinach)Positive and negative results
4 papers in the same direction as this paper · 6 reporting no difference from an alternative
- negative
- positive
- positive
7 papers more in this group
See all 11 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.