Abstract
Photosynthetic properties of photoautotrophic suspensions cultured in a minimal growth medium have been evaluated to determine whether changes have occurred in ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity, phosphoenol-pyruvate (PEP) carboxylase activity, chlorophyll content, or culture growth. Five photoautotrophic lines Amaranthus powellii, Datura innoxia, Glycine max, Gossypium hirsutum, and a Nicotiana tabacum-Nicotiana glutinosa fusion hybrid were grown in a medium without organic carbon other than phytohormones, and without vitamins. These photoautotrophic lines had total Rubisco activities ranging from 85 to 266 micromoles CO(2) fixed per milligram chlorophyll hour(-1), with percent activation of Rubisco ranging from 16 to 53%. Inclusion of protease inhibitors in the homogenization buffer did not result in higher Rubisco activity. PEP carboxylase activity for cells cultured in minimal medium was found to range from 16 to 146 micromoles CO(2) per milligram chlorophyll hour(-1), with no higher activity in the C(4)Amaranthus cells compared with PEP carboxylase activity in the C(3) species assayed. Rubisco-to-PEP carboxylase ratios ranged from 2.2 to 1 up to 9.4 to 1. Chlorophyll contents increased in all but the Nicotiana cell line, and all of the photoautotrophic culture lines were capable of growth in vitamin-free medium with the exception of SB-P, which requires thiamine.
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Claims 8
Claim · model-written summary
Total Rubisco activity ranged from 85 to 266 micromoles CO(2) fixed per milligram chlorophyll hour(-1).
- Outcome
- total Rubisco activitiese0
- Value
- 85 to 266 micromoles CO(2) fixed per milligram chlorophyll hour(-1)e0
Not reportedTaxon
Verbatim
e0“These photoautotrophic lines had total Rubisco activities ranging from 85 to 266 micromoles CO(2) fixed per milligram chlorophyll hour(-1), with percent activation of Rubisco ranging from 16 to 53%.”
Claim · model-written summary
Rubisco activation ranged from 16 to 53%.
Not reportedTaxon
Verbatim
e0“percent activation of Rubisco ranging from 16 to 53%”
Claim · model-written summary
Protease inhibitors in homogenization buffer did not raise Rubisco activity.
Not reportedTaxonComparator
Verbatim
e0“Inclusion of protease inhibitors in the homogenization buffer did not result in higher Rubisco activity.”
Claim · model-written summary
PEP carboxylase activity ranged from 16 to 146 micromoles CO(2) per milligram chlorophyll hour(-1).
- Outcome
- PEP carboxylase activitye0
- Value
- 16 to 146 micromoles CO(2) per milligram chlorophyll hour(-1)e0
Not reportedTaxon
Verbatim
e0“PEP carboxylase activity for cells cultured in minimal medium was found to range from 16 to 146 micromoles CO(2) per milligram chlorophyll hour(-1)”
Claim · model-written summary
C4 Amaranthus cells did not have higher PEP carboxylase activity than the C3 species.
- Taxon
- Amaranthus
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Amaranthuse0 - Outcome
- PEP carboxylase activitye0
- Direction
- no highere0
- Comparator
- C(3) speciese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_with_green_foliage%2C_photographed_in_Tamil_Nadu%2C_India.jpg?width=500)
Verbatim
e0“with no higher activity in the C(4)Amaranthus cells compared with PEP carboxylase activity in the C(3) species assayed.”
Claim · model-written summary
Rubisco-to-PEP carboxylase ratios ranged from 2.2 to 1 to 9.4 to 1.
Not reportedTaxon
Verbatim
e0“Rubisco-to-PEP carboxylase ratios ranged from 2.2 to 1 up to 9.4 to 1.”
Claim · model-written summary
Chlorophyll content increased in all lines except Nicotiana.
Not reportedTaxon
Verbatim
e0“Chlorophyll contents increased in all but the Nicotiana cell line”
Claim · model-written summary
All photoautotrophic lines except SB-P grew in vitamin-free medium.
- Outcome
- growth in vitamin-free mediume0
- Qualifier
- with the exception of SB-P, which requires thiaminee0
Not reportedTaxon
Verbatim
e0“all of the photoautotrophic culture lines were capable of growth in vitamin-free medium with the exception of SB-P, which requires thiamine.”