Abstract
Limitations of carbon fixation within spinach leaves due to light and CO2 were investigated. Under equivalent photon fluxes, carbon fixation was higher when leaves were irradiated adaxially compared to abaxially. Maximal carbon fixation occurred in the middle of the palisade mesophyll under adaxial illumination, whereas, maximal carbon fixation occurred in the spongy mesophyll under abaxial illumination. Total carbon fixation and the pattern of carbon fixation across leaves were similar, when leaves were irradiated with 800 micromol quanta m(-2) s(-1) either adaxially alone or adaxially plus abaxially (1,600 micromol quanta m(-2) s(-1)). In contrast, when both leaf surfaces were irradiated simultaneously with 200 micromol quanta m(-2) s(-1), total carbon fixation increased and carbon fixation in the middle of the leaf was higher compared to leaves irradiated unilaterally with the low light. Feeding 14CO2 through either the adaxial or abaxial leaf surface did not change the pattern of carbon fixation across the leaf. Increasing 14CO2 pulse-feeding times from 5 s to 60 s allowed more 14CO2 to be fixed but did not change the pattern of 14CO2 fixation across the leaf. We concluded that in spinach, the distribution of both light and Rubisco activity within leaves has significant effects on the patterns of carbon fixation across leaves; whereas CO2 diffusion does not appear to affect the carbon fixation pattern within spinach leaves.
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Claims 11
Claim · model-written summary
Under equal photon flux, carbon fixation in spinach leaves was higher with adaxial than with abaxial irradiation.
- Taxon
- spinach
Spinacia oleraceae0 - Treatment
- irradiated adaxiallye1
- Outcome
- carbon fixatione1
- Direction
- highere1
- Qualifier
- Under equivalent photon fluxese1
- Comparator
- abaxiallye1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Limitations of carbon fixation within spinach leaves due to light and CO2”
e1“Under equivalent photon fluxes, carbon fixation was higher when leaves were irradiated adaxially compared to abaxially”
Claim · model-written summary
Maximal carbon fixation under adaxial illumination occurred in the middle of the palisade mesophyll.
- Taxon
- spinachSpinacia oleraceae0
- Organ / stage
- middle of the palisade mesophylle2
- Treatment
- adaxial illuminatione2
- Outcome
- Maximal carbon fixatione2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Limitations of carbon fixation within spinach leaves due to light and CO2”
e2“Maximal carbon fixation occurred in the middle of the palisade mesophyll under adaxial illumination, whereas, maximal carbon fixation occurred in the spongy mesophyll under abaxial illumination”
Claim · model-written summary
Maximal carbon fixation under abaxial illumination occurred in the spongy mesophyll.
- Taxon
- spinachSpinacia oleraceae0
- Organ / stage
- spongy mesophylle2
- Treatment
- abaxial illuminatione2
- Outcome
- Maximal carbon fixatione2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Limitations of carbon fixation within spinach leaves due to light and CO2”
e2“Maximal carbon fixation occurred in the middle of the palisade mesophyll under adaxial illumination, whereas, maximal carbon fixation occurred in the spongy mesophyll under abaxial illumination”
Claim · model-written summary
Total carbon fixation and its pattern across leaves were similar under adaxial-only and combined adaxial-plus-abaxial irradiation at 800 micromol quanta m(-2) s(-1).
- Taxon
- spinachSpinacia oleraceae0
- Treatment
- irradiated with 800 micromol quanta m(-2) s(-1) either adaxially alonee3
- Outcome
- Total carbon fixation and the pattern of carbon fixation across leavese3
- Direction
- similare3
- Comparator
- adaxially plus abaxiallye3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Limitations of carbon fixation within spinach leaves due to light and CO2”
e3“Total carbon fixation and the pattern of carbon fixation across leaves were similar, when leaves were irradiated with 800 micromol quanta m(-2) s(-1) either adaxially alone or adaxially plus abaxially (1,600 micromol quanta m(-2) s(-1))”
Claim · model-written summary
Simultaneous low-light irradiation of both leaf surfaces increased total carbon fixation compared with unilateral low light.
- Taxon
- spinachSpinacia oleraceae0
- Treatment
- both leaf surfaces were irradiated simultaneously with 200 micromol quanta m(-2) s(-1)e4
- Outcome
- total carbon fixatione4
- Direction
- increasede4
- Comparator
- leaves irradiated unilaterally with the low lighte4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Limitations of carbon fixation within spinach leaves due to light and CO2”
e4“when both leaf surfaces were irradiated simultaneously with 200 micromol quanta m(-2) s(-1), total carbon fixation increased and carbon fixation in the middle of the leaf was higher compared to leaves irradiated unilaterally with the low light”
Claim · model-written summary
Simultaneous low-light irradiation of both leaf surfaces raised carbon fixation in the middle of the leaf compared with unilateral low light.
- Taxon
- spinachSpinacia oleraceae0
- Treatment
- both leaf surfaces were irradiated simultaneously with 200 micromol quanta m(-2) s(-1)e4
- Outcome
- carbon fixation in the middle of the leafe4
- Direction
- highere4
- Comparator
- leaves irradiated unilaterally with the low lighte4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Limitations of carbon fixation within spinach leaves due to light and CO2”
e4“when both leaf surfaces were irradiated simultaneously with 200 micromol quanta m(-2) s(-1), total carbon fixation increased and carbon fixation in the middle of the leaf was higher compared to leaves irradiated unilaterally with the low light”
Claim · model-written summary
Feeding 14CO2 through either leaf surface did not change the pattern of carbon fixation across the leaf.
- Taxon
- spinachSpinacia oleraceae0
- Treatment
- Feeding 14CO2 through either the adaxial or abaxial leaf surfacee5
- Outcome
- pattern of carbon fixation across the leafe5
- Direction
- did not changee5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Limitations of carbon fixation within spinach leaves due to light and CO2”
e5“Feeding 14CO2 through either the adaxial or abaxial leaf surface did not change the pattern of carbon fixation across the leaf”
Claim · model-written summary
Longer 14CO2 pulse-feeding (5 s to 60 s) allowed more 14CO2 to be fixed in spinach leaves.
- Taxon
- spinachSpinacia oleraceae0
- Treatment
- pulse-feeding times from 5 s to 60 se6
- Outcome
- 14CO2 to be fixede6
- Direction
- moree6
- Comparator
- 5 se6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Limitations of carbon fixation within spinach leaves due to light and CO2”
e6“Increasing 14CO2 pulse-feeding times from 5 s to 60 s allowed more 14CO2 to be fixed but did not change the pattern of 14CO2 fixation across the leaf”
Claim · model-written summary
Longer 14CO2 pulse-feeding did not change the pattern of 14CO2 fixation across the spinach leaf.
- Taxon
- spinachSpinacia oleraceae0
- Treatment
- pulse-feeding times from 5 s to 60 se6
- Outcome
- pattern of 14CO2 fixation across the leafe6
- Direction
- did not changee6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Limitations of carbon fixation within spinach leaves due to light and CO2”
e6“Increasing 14CO2 pulse-feeding times from 5 s to 60 s allowed more 14CO2 to be fixed but did not change the pattern of 14CO2 fixation across the leaf”
Claim · model-written summary
The distribution of both light and Rubisco activity within spinach leaves has significant effects on the pattern of carbon fixation across leaves.
- Taxon
- spinachSpinacia oleraceae0
- Outcome
- patterns of carbon fixation across leavese7
- Qualifier
- distribution of both light and Rubisco activity within leavese7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Limitations of carbon fixation within spinach leaves due to light and CO2”
e7“the distribution of both light and Rubisco activity within leaves has significant effects on the patterns of carbon fixation across leaves”
Claim · model-written summary
CO2 diffusion does not appear to affect the carbon fixation pattern within spinach leaves.
- Taxon
- spinachSpinacia oleraceae0
- Outcome
- carbon fixation patterne7
- Qualifier
- does not appear to affecte7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Limitations of carbon fixation within spinach leaves due to light and CO2”
e7“CO2 diffusion does not appear to affect the carbon fixation pattern within spinach leaves”
The same questions in other papers
radiation · molecular: metabolites · Spinacia oleracea (spinach)Positive and negative results
1 paper in the same direction as this paper · 3 in the opposite direction
- negative
- negative
- no effect
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.