Abstract
Abstract— The activity of nitrate reductase from the curd of light‐grown cauliflower ( Brassica oleracea (L) var botrytis (DC) ‘St. Hilary’) is modulated by nitrate and by light. Using broad‐band sources of equal photosynthetically active radiation but with different proportions of red and far‐red light, a linear relationship between nitrate reductase activity and ψ(Estimated phytochrome photoequilibrium) was obtained. This relationship, apparent after 8 h incubation, was maintained and little altered after 48 h incubation. The linearity was apparent between ψE 0.26 and ψE 0.69; ψE 0.26 being no more effective than a dark control. Far‐red reversibility confirmed the involvement of phytochrome. Brief pulses of red light were also used to establish a range of phytochrome photoequilibria within the tissue. Again a linear relationship between ψ and nitrate reductase activity was obtained with a threshold for the response at ψ 0.3. With both monochromatic and broad‐band sources it was seen that neither photon fluence rate nor duration of exposure affected the final activity of the enzyme and that phytochrome was acting solely through ψ (or [Pfr] since phytochrome is stable in this tissue) to bring about these responses.
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Claims 8
Claim · model-written summary
Nitrate reductase activity in cauliflower curd was modulated by nitrate and light.
- Taxon
- cauliflower
Brassica oleracea var. botrytise0 - Material
- ‘St. Hilary’e0
- Organ / stage
- curde0
- Gene
- nitrate reductasee0
- Outcome
- activity of nitrate reductasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The activity of nitrate reductase from the curd of light‐grown cauliflower ( Brassica oleracea (L) var botrytis (DC) ‘St. Hilary’) is modulated by nitrate and by light”
Claim · model-written summary
Nitrate reductase activity had a linear relationship with estimated phytochrome photoequilibrium under broad-band light, apparent at 8 h and maintained at 48 h.
- Taxon
- CAULIFLOWERBrassica oleracea var. botrytist0
- Gene
- nitrate reductasee0
- Outcome
- nitrate reductase activitye0
- Qualifier
- after 8 h incubatione1
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a linear relationship between nitrate reductase activity and ψ(Estimated phytochrome photoequilibrium) was obtained”
e1“This relationship, apparent after 8 h incubation, was maintained and little altered after 48 h incubation”
t0“CAULIFLOWER”
Claim · model-written summary
The linear response occurred between ψE 0.26 and ψE 0.69, with ψE 0.26 no more effective than dark control.
- Taxon
- CAULIFLOWERBrassica oleracea var. botrytist0
- Outcome
- linearitye0
- Qualifier
- between ψE 0.26 and ψE 0.69e0
- Comparator
- dark controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The linearity was apparent between ψE 0.26 and ψE 0.69; ψE 0.26 being no more effective than a dark control”
t0“CAULIFLOWER”
Claim · model-written summary
Far-red reversibility confirmed phytochrome involvement in the response.
- Taxon
- CAULIFLOWERBrassica oleracea var. botrytist0
- Outcome
- involvement of phytochromee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Far‐red reversibility confirmed the involvement of phytochrome”
t0“CAULIFLOWER”
Claim · model-written summary
Under red-light pulses, photoequilibrium and nitrate reductase activity had a linear relationship with a threshold at ψ 0.3.
- Taxon
- CAULIFLOWERBrassica oleracea var. botrytist0
- Gene
- nitrate reductasee0
- Outcome
- nitrate reductase activitye0
- Qualifier
- threshold for the response at ψ 0.3e0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a linear relationship between ψ and nitrate reductase activity was obtained with a threshold for the response at ψ 0.3”
t0“CAULIFLOWER”
Claim · model-written summary
Photon fluence rate did not affect final nitrate reductase activity.
- Taxon
- CAULIFLOWERBrassica oleracea var. botrytist0
- Gene
- NITRATE REDUCTASEt1
- Outcome
- final activity of the enzymee0
- Direction
- neithere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“neither photon fluence rate nor duration of exposure affected the final activity of the enzyme”
t0“CAULIFLOWER”
t1“NITRATE REDUCTASE”
Claim · model-written summary
Exposure duration did not affect final nitrate reductase activity.
- Taxon
- CAULIFLOWERBrassica oleracea var. botrytist0
- Outcome
- final activity of the enzymee0
- Direction
- neithere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“neither photon fluence rate nor duration of exposure affected the final activity of the enzyme”
t0“CAULIFLOWER”
Claim · model-written summary
Phytochrome was interpreted as acting solely through ψ or Pfr to regulate nitrate reductase activity.
- Taxon
- CAULIFLOWERBrassica oleracea var. botrytist0
- Outcome
- these responsese0
- Qualifier
- solely through ψe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“phytochrome was acting solely through ψ (or [Pfr] since phytochrome is stable in this tissue) to bring about these responses”
t0“CAULIFLOWER”