Abstract
Sunflower leaf discs incubated in the light on carbohydrate substrates exhibit several-fold increases in amounts of extractable allagochrome and chlorogenic acid. These changes are linear with time, and oxygen is required. The light effect saturates at approximately 600 muW/cm(2) "white" light, roughly the compensation point for photosynthesis. Red light is as effective as white light. Incubation in the dark, or in far red light, produces negligible changes in allagochrome and chlorogenic acid content.Sucrose (0.2 m) has been used as the standard substrate. At this concentration, glucose and fructose are slightly more effective. The optimum temperature range for incubation is 20 to 30 degrees . Allagochrome and chlorogenic acid values of both light and dark incubated samples decrease between 30 and 50 degrees , approaching zero at 50 degrees . Net light effects decrease to zero between 40 and 50 degrees .Of the inhibitors tested, 2,4-dinitrophenol, hydroxylamine and salicylaldoxime have no effect on light enhanced allagochrome and chlorogenic acid values except at high concentrations (which are generally deleterious to leaf tissues and cause decreased values for both dark and light incubated samples). Net light effects are completely inhibited, without changes in values of dark incubated discs, by azide (0.1 to 1 mm) and dichlorophenyldimethylurea (1 to 10 mum).Leaf tissues from the xantha mutant of Helianthus annuus do not exhibit a light effect. The absence of light effects in nonphotosynthetic leaf tissue and the inhibiting effects of photosynthetic poisons suggest that the photosynthetic apparatus is somehow involved.An hypothesis for light regulated metabolism via phenolic synthesis is discussed.
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Claims 14
Claim · model-written summary
Light incubation on carbohydrate substrates increased extractable allagochrome and chlorogenic acid several fold in sunflower leaf discs.
- Taxon
- Sunflower
Helianthus annuuse0 - Treatment
- incubated in the light on carbohydrate substratese0
- Outcome
- amounts of extractable allagochrome and chlorogenic acide0
- Direction
- increasese0
- Value
- several-folde0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Sunflower leaf discs incubated in the light on carbohydrate substrates exhibit several-fold increases in amounts of extractable allagochrome and chlorogenic acid”
Claim · model-written summary
The increases in allagochrome and chlorogenic acid were linear over time and required oxygen.
- Taxon
- SunflowerHelianthus annuust0
- Outcome
- changese0
- Qualifier
- linear with time, and oxygen is requirede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Sunflower”
e0“These changes are linear with time, and oxygen is required”
Claim · model-written summary
The light response saturated near 600 muW/cm(2) white light.
- Taxon
- SunflowerHelianthus annuust0
- Outcome
- light effecte0
- Direction
- saturatese0
- Value
- approximately 600 muW/cm(2)e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Sunflower”
e0“The light effect saturates at approximately 600 muW/cm(2) "white" light”
Claim · model-written summary
Red light was as effective as white light.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- Red lighte0
- Outcome
- as effectivee0
- Direction
- as effectivee0
- Comparator
- white lighte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Sunflower”
e0“Red light is as effective as white light”
Claim · model-written summary
Dark or far red incubation produced negligible changes in allagochrome and chlorogenic acid content.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- Incubation in the dark, or in far red lighte0
- Outcome
- allagochrome and chlorogenic acid contente0
- Direction
- negligible changese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Sunflower”
e0“Incubation in the dark, or in far red light, produces negligible changes in allagochrome and chlorogenic acid content”
Claim · model-written summary
Glucose and fructose were slightly more effective than sucrose at 0.2 m.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- glucose and fructosee0
- Outcome
- slightly more effectivee0
- Direction
- slightly more effectivee0
- Qualifier
- 0.2 me0
- Comparator
- Sucrosee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Sunflower”
e0“Sucrose (0.2 m) has been used as the standard substrate. At this concentration, glucose and fructose are slightly more effective”
Claim · model-written summary
The optimum incubation temperature was 20 to 30 degrees.
- Taxon
- SunflowerHelianthus annuust0
- Outcome
- optimum temperature range for incubatione0
- Value
- 20 to 30 degreese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Sunflower”
e0“The optimum temperature range for incubation is 20 to 30 degrees”
Claim · model-written summary
Allagochrome and chlorogenic acid values declined between 30 and 50 degrees, approaching zero at 50 degrees.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- between 30 and 50 degreese0
- Outcome
- Allagochrome and chlorogenic acid valuese0
- Direction
- decreasee0
- Qualifier
- approaching zero at 50 degreese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Sunflower”
e0“Allagochrome and chlorogenic acid values of both light and dark incubated samples decrease between 30 and 50 degrees , approaching zero at 50 degrees”
Claim · model-written summary
Net light effects decreased to zero between 40 and 50 degrees.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- between 40 and 50 degreese0
- Outcome
- Net light effectse0
- Direction
- decreasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Sunflower”
e0“Net light effects decrease to zero between 40 and 50 degrees”
Claim · model-written summary
The three named inhibitors had no effect except at high concentrations, which decreased values in both light and dark samples.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- 2,4-dinitrophenol, hydroxylamine and salicylaldoximee0
- Outcome
- light enhanced allagochrome and chlorogenic acid valuese0
- Direction
- no effecte0
- Qualifier
- except at high concentrationse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Sunflower”
e0“2,4-dinitrophenol, hydroxylamine and salicylaldoxime have no effect on light enhanced allagochrome and chlorogenic acid values except at high concentrations (which are generally deleterious to leaf tissues and cause decreased values for both dark and light incubated samples)”
Claim · model-written summary
Azide completely inhibited net light effects without changing dark incubated disc values.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- azide (0.1 to 1 mm)e0
- Outcome
- Net light effectse0
- Direction
- completely inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Sunflower”
e0“Net light effects are completely inhibited, without changes in values of dark incubated discs, by azide (0.1 to 1 mm)”
Claim · model-written summary
Dichlorophenyldimethylurea completely inhibited net light effects without changing dark incubated disc values.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- dichlorophenyldimethylurea (1 to 10 mum)e0
- Outcome
- Net light effectse0
- Direction
- completely inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Sunflower”
e0“Net light effects are completely inhibited, without changes in values of dark incubated discs, by azide (0.1 to 1 mm) and dichlorophenyldimethylurea (1 to 10 mum)”
Claim · model-written summary
Xantha mutant leaf tissue did not show a light effect.
- Taxon
- Helianthus annuusHelianthus annuuse0
- Material
- xantha mutante0
- Outcome
- light effecte0
- Direction
- do not exhibite0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Leaf tissues from the xantha mutant of Helianthus annuus do not exhibit a light effect”
Claim · model-written summary
The authors suggest that photosynthetic apparatus is involved in the light response.
Not reportedTaxon
Verbatim
e0“The absence of light effects in nonphotosynthetic leaf tissue and the inhibiting effects of photosynthetic poisons suggest that the photosynthetic apparatus is somehow involved”
The same questions in other papers
growing medium · molecular: metabolites · Helianthus annuus (common sunflower)Positive and negative results
1 paper in the same direction as this paper · 1 in the opposite direction
- no effect
- positive
light · molecular: metabolites · Helianthus annuus (common sunflower)Positive and negative results
2 papers in the same direction as this paper · 8 in the opposite direction
- negative
- no effect
- negative
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.